View Filing Data

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2018	Mar. 01, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	ROCKET PHARMACEUTICALS, INC.
Entity Central Index Key	0001281895
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Public Float			$ 428.9
Entity Common Stock, Shares Outstanding		45,114,437
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 111,355	$ 18,142
Investments	94,375	0
Prepaid expenses and other assets	3,358	813
Total current assets	209,088	18,955
Property and equipment, net	2,027	985
Goodwill	30,815	0
Restricted cash	1,436	207
Deposits	545	0
Investments	7,402	0
Total assets	251,313	20,147
Current liabilities:
Accounts payable and accrued expenses	15,372	4,521
Total current liabilities	15,372	4,521
Convertible notes, net of unamortized discount	41,447	0
Deferred rent and lease obligations	457	107
Total liabilities	57,276	4,628
Commitments and contingencies (Note 13)
Shareholders' equity:
Common stock, $0.01 par value, 120,000,000 shares authorized; 45,194,736 and 6,795,627 shares issued and outstanding at December 31, 2018 and 2017, respectively	452	68
Treasury stock, at cost, 50,000 and 0 common shares at December 31, 2018 and 2017, respectively	(668)	0
Additional paid-in capital	300,253	5,340
Accumulated other comprehensive loss	(127)	0
Accumulated deficit	(105,873)	(31,355)
Total shareholders' equity	194,037	15,519
Total liabilities and shareholders' equity	251,313	20,147
Series A Convertible Preferred Shares [Member]
Shareholders' equity:
Preferred shares	0	16,060
Series B Convertible Preferred Shares [Member]
Shareholders' equity:
Preferred shares	$ 0	$ 25,406

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares issued (in shares)	45,194,736	6,795,627
Common stock, shares outstanding (in shares)	45,194,736	6,795,627
Treasury Stock, at cost (in shares)	50,000	0
Series A Convertible Preferred Shares [Member]
Shareholders' equity:
Preferred stock, shares authorized (in shares)	300,000	300,000
Preferred stock, shares issued (in shares)	0	128,738
Preferred stock, shares outstanding (in shares)	0	128,738
Series B Convertible Preferred Shares [Member]
Shareholders' equity:
Preferred stock, shares authorized (in shares)	300,000	300,000
Preferred stock, shares issued (in shares)	0	126,909
Preferred stock, shares outstanding (in shares)	0	126,909

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements of Operations [Abstract]
Revenue	$ 0	$ 0	$ 0
Operating expenses:
Research and development	53,270	14,917	5,994
General and administrative	17,886	4,855	1,580
Total operating expenses	71,156	19,772	7,574
Loss from operations	(71,156)	(19,772)	(7,574)
Research and development incentives	186	192	0
Interest expense	(6,039)	0	0
Interest and other income net	1,690	2	1
Accretion of discount on investments	801	0	0
Net loss	$ (74,518)	$ (19,578)	$ (7,573)
Net loss per share attributable to common shareholders - basic and diluted (in dollars per share)	$ (1.89)	$ (2.88)	$ (1.11)
Weighted-average common shares outstanding - basic and diluted (in shares)	39,377,666	6,795,627	6,833,718

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements of Comprehensive Loss [Abstract]
Net loss	$ (74,518)	$ (19,578)	$ (7,573)
Other comprehensive loss
Net unrealized loss on investments	(127)	0	0
Total comprehensive loss	$ (74,645)	$ (19,578)	$ (7,573)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Preferred Stock [Member] Series A Convertible Preferred Shares [Member]	Preferred Stock [Member] Series B Convertible Preferred Shares [Member]	Common Stock [Member]	Treasury Stock [Member]	Treasury Stock [Member] Series A Convertible Preferred Shares [Member]	Treasury Stock [Member] Series B Convertible Preferred Shares [Member]	Additional Paid in Capital [Member]	Additional Paid in Capital [Member] Series A Convertible Preferred Shares [Member]	Additional Paid in Capital [Member] Series B Convertible Preferred Shares [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Other Comprehensive Loss [Member] Series A Convertible Preferred Shares [Member]	Accumulated Other Comprehensive Loss [Member] Series B Convertible Preferred Shares [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] Series A Convertible Preferred Shares [Member]	Accumulated Deficit [Member] Series B Convertible Preferred Shares [Member]	Total	Series A Convertible Preferred Shares [Member]	Series B Convertible Preferred Shares [Member]
Beginning Balance at Dec. 31, 2015	$ 15,930	$ 0	$ 68	$ 0			$ 3,746			$ 0			$ (4,204)			$ 15,540
Beginning Balance (in shares) at Dec. 31, 2015	127,698	0	6,795,627
Issuance of stock	$ 130				$ 0			$ 0			$ 0			$ 0			$ 130
Issuance of shares (in shares)	1,040
Unrealized loss on investments																0
Share-based compensation	$ 0	$ 0	$ 0	0			274			0			0			274
Net loss	0	0	0	0			0			0			(7,573)			(7,573)
Ending Balance at Dec. 31, 2016	$ 16,060	$ 0	$ 68	0			4,020			0			(11,777)			8,371
Ending Balance (in shares) at Dec. 31, 2016	128,738	0	6,795,627
Issuance of stock		$ 25,406				$ 0			$ 0			$ 0			$ 0			$ 25,406
Issuance of shares (in shares)		126,909
Unrealized loss on investments																0
Share-based compensation	$ 0	$ 0	$ 0	0			1,320			0			0			1,320
Net loss	0	0	0	0			0			0			(19,578)			(19,578)
Ending Balance at Dec. 31, 2017	$ 16,060	$ 25,406	$ 68	0			5,340			0			(31,355)			15,519
Ending Balance (in shares) at Dec. 31, 2017	128,738	126,909	6,795,627
Conversion of convertible preferred shares into common shares	$ (16,060)	$ (25,406)	$ 194	0			41,272			0			0			0
Conversion of convertible preferred shares into common shares (in shares)	(128,738)	(126,909)	19,475,788
Exchange of common shares in connection with the Reverse Merger	$ 0	$ 0	$ 68	0			85,992			0			0			86,060
Exchange of common shares in connection with the Reverse Merger (in shares)	0	0	6,805,608
Issuance of stock	$ 0	$ 0	$ 115	0			153,907			0			0			154,022
Issuance of shares (in shares)	0	0	11,475,242
Issuance of common stock pursuant to settlement of restricted stock units	$ 0	$ 0	$ 3	0			(3)			0			0			0
Issuance of common stock pursuant to settlement of restricted stock units (in shares)	0	0	271,718
Issuance of common stock pursuant to exercise of stock options	$ 0	$ 0	$ 4	0			144			0			0			148
Issuance of common stock pursuant to exercise of stock options (in shares)	0	0	370,753
Shares repurchase	$ 0	$ 0	$ 0	(668)			0			0			0			(668)
Share repurchase (in shares)	0	0	0
Unrealized loss on investments	$ 0	$ 0	$ 0	0			0			(127)			0			(127)
Share-based compensation	0	0	0	0			13,601			0			0			13,601
Net loss	0	0	0	0			0			0			(74,518)			(74,518)
Ending Balance at Dec. 31, 2018	$ 0	$ 0	$ 452	$ (668)			$ 300,253			$ (127)			$ (105,873)			$ 194,037
Ending Balance (in shares) at Dec. 31, 2018	0	0	45,194,736

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Consolidated Statements of Changes in Stockholders' Equity [Abstract]
Issuance of common shares, issuance costs	$ 9.3

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities:
Net loss	$ (74,518)	$ (19,578)	$ (7,573)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of discount on convertible notes	3,059	0	0
Increase in lease liability	(161)	0	0
Series A preferred shares issued for services	0	0	100
Depreciation expense	330	204	67
Share-based compensation expense	13,601	1,320	274
Deferred rent	0	0	107
Loss on disposal of property and equipment	317	0	0
Accretion of discount on investments	(801)	0	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,505)	(720)	78
Accounts payable and accrued expenses	5,890	2,812	1,444
Net cash used in operating activities	(53,788)	(15,962)	(5,503)
Investing activities:
Cash acquired in connection with the Reverse Merger	76,348	0	0
Purchases of investments	(141,087)	0	0
Proceeds from maturities of investments	61,276	0	0
Proceeds from sale of property and equipment	20	0	0
Purchases of property and equipment	(1,453)	(760)	(335)
Payment of security deposit	(376)	0	0
Net cash used in investing activities	(5,272)	(760)	(335)
Financing activities:
Proceeds from exercise of options	148	0	0
Proceeds from issuance of common stock, net of issuance costs	154,022	0	0
Payments from related party payable	0	0	(14)
Payment to acquire treasury stock	(668)	0	0
Net cash provided by financing activities	153,502	25,406	16
Net change in cash, cash equivalents and restricted cash	94,442	8,684	(5,822)
Cash, cash equivalents and restricted cash at beginning of year	18,349	9,665	15,487
Cash, cash equivalents and restricted cash at end of year	112,791	18,349	9,665
Supplemental disclosure of non-cash financing and investing activities:
Conversion of convertible preferred stock into common stock	41,466	0	0
Unrealized loss on investments	127	0	0
Supplemental cash flow information:
Cash paid for interest	4,485	0	0
Cash paid for income taxes	2	0	0
Series A Convertible Preferred Shares [Member]
Financing activities:
Proceeds from issuance of convertible preferred stock, net	0	0	30
Series B Convertible Preferred Shares [Member]
Financing activities:
Proceeds from issuance of convertible preferred stock, net	$ 0	$ 25,406	$ 0

Nature of Business, Merger and Basis of Presentation	12 Months Ended
Nature of Business, Merger and Basis of Presentation	Dec. 31, 2018
Nature of Business, Merger and Basis of Presentation [Abstract]
Nature of Business, Merger and Basis of Presentation	1. Nature of Business, Merger and Basis of Presentation Rocket Pharmaceuticals, Inc., together with its subsidiaries (collectively, “Rocket” or the “Company”), is a clinical-stage, multi-platform biotechnology company focused on the development of first or best-in-class gene therapies, with direct on-target mechanism of action and clear clinical endpoints, for rare and devastating pediatric diseases. The Company has clinical-stage lentiviral vector (“LVV”) programs currently undergoing clinical testing for Fanconi Anemia (“FA”), a genetic defect in the bone marrow that reduces production of blood cells or promotes the production of faulty blood cells and Leukocyte Adhesion Deficiency-I (“LAD-I”), a genetic disorder that causes the immune system to malfunction. FA has been in clinical stage testing in the EU since 2016, and in the U.S., Rocket received investigational new drug (“IND”) clearance for both FA and LAD-I in late 2018. Two additional pre-clinical stage LVV programs include Pyruvate Kinase Deficiency (“PKD”), a rare red blood cell autosomal recessive disorder that results in chronic non-spherocytic hemolytic anemia; and Infantile Malignant Osteopetrosis (“IMO”), a genetic disorder characterized by increased bone density and bone mass secondary to impaired bone resorption. In addition, the Company has an adeno-associated virus (“AAV”), program for Danon disease, a multi-organ lysosomal-associated disorder leading to early death due to heart failure. An IND filing was cleared in Danon disease in early 2019, which will permit the commencement of human clinical studies following approval. The Company has global commercialization and development rights to all of its product candidates under royalty-bearing license agreements, with the exception of the CRISPR/Cas9 development program for which the Company currently only has development rights. Reverse Merger and Exchange Ratio On January 4, 2018, Rome Merger Sub (“Merger Sub”), a wholly owned subsidiary of Inotek Pharmaceuticals Corporation (“Inotek”), completed its merger with and into Rocket Pharmaceuticals, Ltd. (“Rocket Ltd”), with Rocket Ltd surviving as a wholly owned subsidiary of Inotek. This transaction is referred to as the “Reverse Merger.” The Reverse Merger was effected pursuant to an Agreement and Plan of Merger and Reorganization (the “Merger Agreement”), dated as of September 12, 2017, by and among Inotek, Rocket Ltd and Rome Merger Sub. As a result of the Reverse Merger, each outstanding share of Rocket Ltd share capital (including shares of Rocket Ltd share capital to be issued upon exercise of outstanding share options) automatically converted into the right to receive approximately 76.185 shares of Inotek’s common stock, par value $0.01 per share (the “Exchange Ratio”). Following the closing of the Reverse Merger, holders of Inotek’s common stock immediately prior to the Reverse Merger owned approximately 18.643% on a fully diluted basis, and holders of Rocket Ltd common stock immediately prior to the Reverse Merger owned approximately 81.357% on a fully diluted basis, of Inotek’s common stock. The Reverse Merger has been accounted for as a reverse acquisition under the acquisition method of accounting where Rocket Ltd is considered the accounting acquirer and Inotek is the acquired company for financial reporting purposes. Rocket Ltd was determined to be the accounting acquirer based on the terms of the Merger Agreement and other factors, such as relative voting rights and the composition of the combined company’s board of directors and senior management. The pre-acquisition financial statements of Rocket Ltd became the historical financial statements of Rocket following completion of the Reverse Merger. The historical financial statements, outstanding shares and all other historical share information have been adjusted by multiplying the respective share amount by the Exchange Ratio as if the Exchange Ratio had been in effect for all periods presented. Immediately following the Reverse Merger, the combined company changed its name from “Inotek Pharmaceuticals Corporation” to “Rocket Pharmaceuticals, Inc.” The combined company following the Reverse Merger may be referred to herein as “the combined company,” “Rocket,” or the “Company.” The Company’s common stock remained listed on the Nasdaq Stock Market, with trading having commenced on a post-split basis (giving effect to the Reverse Stock Split described below) and under the new name as of January 5, 2018. The trading symbol also changed on that date from “ITEK” to “RCKT.”

Risks and Liquidity	12 Months Ended
Risks and Liquidity	Dec. 31, 2018
Risks and Liquidity [Abstract]
Risks and Liquidity	2. Risks and Liquidity The Company has not generated any revenue and has incurred losses since inception. Operations of the Company are subject to certain risks and uncertainties, including, among others, uncertainty of drug candidate development, technological uncertainty, uncertainty regarding patents and proprietary rights, having no commercial manufacturing experience, marketing or sales capability or experience, dependency on key personnel, compliance with government regulations and the need to obtain additional financing. Drug candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance-reporting capabilities. The Company’s drug candidates are in the development and clinical stage. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. The Company’s consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business. The Company has experienced negative cash flows from operations and had an accumulated deficit of $105,873 as of December 31, 2018. As of December 31, 2018, the Company has $213,132 of cash, cash equivalents and investments. Rocket expects such resources would be sufficient to fund its operating expenses and capital expenditure requirements into the second half of 2020. In the longer term, the future viability of the Company is dependent on its ability to generate cash from operating activities or to raise additional capital to finance its operations. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

3. Summary of Significant Accounting Policies

Principles of Consolidation

The consolidated financial statements represent the consolidation of the accounts of the Company and its subsidiaries in conformity with accounting principles generally accepted in the United States (“US GAAP”). All intercompany accounts have been eliminated in consolidation.

Use of Estimates

The preparation of the consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include but are not limited to fair value under acquisition accounting, goodwill impairment, the accrual of research and development expenses, the valuation of equity transactions and share-based awards. Changes in estimates and assumptions are reflected in reported results in the period in which they become known. Actual results could differ from those estimates.

Cash, Cash Equivalents and Restricted Cash

Cash, cash equivalents and restricted cash consists of bank deposits, certificates of deposit and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts.

Restricted cash consists of deposits collateralizing letters of credit issued by a bank in connection with the Company’s operating leases (See Note 13) and a deposit collateralizing a letter of credit issued by a bank supporting the Company’s Corporate Credit Card. As of December 31, 2018, and 2017, restricted cash was $1,436 and $207, respectively. Cash, cash equivalents and restricted cash consist of the following:

	December 31, 2018		December 31, 2017

Cash and cash equivalents	$	111,355	$	18,142
Restricted cash		1,436		207
	$	112,791	$	18,349

Concentrations of credit risk and off-balance sheet risk

Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and available-for-sale securities. The Company maintains its cash and cash equivalent balances with high-quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s marketable securities primarily consist of U.S. Treasury securities, U.S. government agency securities and certificates of deposit, and potentially subject the Company to concentrations of credit risk. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to be at least AA+/Aa1 rated, thereby reducing credit risk exposure.

Investments

Investments consist of investments in United States Treasury securities. Management determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company classifies its investments as available-for-sale pursuant to Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) 320, Investments—Debt and Equity Securities. Investments are recorded at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive loss in shareholders’ equity and a component of total comprehensive loss in the consolidated statements of comprehensive loss, until realized. Realized gains and losses are included in investment income on a specific-identification basis. There were no realized gains or losses on investments for the years ended December 31, 2018, 2017 and 2016. There was $127 and $0 of net unrealized losses on investments for the years ended December 31, 2018 and 2017, respectively.

The Company reviews investments for other-than-temporary impairment whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. Other-than-temporary impairments of investments are recognized in the consolidated statements of operations if the Company has experienced a credit loss, has the intent to sell the investment, or if it is more likely than not that the Company will be required to sell the investment before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period. The weighted average maturity of the Company’s investment portfolio is 5.5 months and the average duration of the Company’s long-term investments is 14 months.

Investments at December 31, 2018 consist of the following:

	Cost Basis		Unrealized Losses			Fair Value

United States Treasury securities		101,904		(127	)		101,777
	$	101,904	$	(127	)	$	101,777

The Company evaluated its securities for other-than-temporary impairment and determined that no such impairment existed at December 31, 2018.

Goodwill

Business combinations are accounted for under the acquisition method (see Note 4). The total cost of an acquisition is allocated to the underlying identifiable net assets, based on their respective estimated fair values as of the acquisition date. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash inflows and outflows, discount rates, asset lives and market multiples, among other items. Assets acquired and liabilities assumed are recorded at their estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill.

Goodwill is tested for impairment annually as of December 31, or more frequently when events or changes in circumstances indicate that the asset might be impaired. Examples of such events or circumstances include, but are not limited to, a significant adverse change in legal or business climate, an adverse regulatory action or unanticipated competition. The Company has one segment and one reporting unit and as such reviews goodwill for impairment at the consolidated level.

When testing goodwill, the Company has the option to first assess qualitative factors for reporting units that carry goodwill. The qualitative assessment includes assessing the totality of relevant events and circumstances that affect the fair value or carrying value of the reporting unit. These events and circumstances include macroeconomic conditions, industry and competitive environment conditions, overall financial performance, reporting unit specific events and market considerations. The Company also considers recent valuations of the reporting unit, including the magnitude of the difference between the most recent fair value estimate and the carrying value, as well as both positive and adverse events and circumstances, and the extent to which each of the events and circumstances identified may affect the comparison of a reporting unit’s fair value with its carrying value. If the qualitative assessment results in a conclusion that it is more likely than not that the fair value of a reporting unit exceeds the carrying value, then no further testing is performed for that reporting unit.

In January 2017, the FASB issued ASU No. 2017-04, “Intangibles- Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment”, an amendment to simplify the subsequent quantitative measurement of goodwill by eliminating step two from the goodwill impairment test. As amended, an entity will recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value, not to exceed the total amount of goodwill allocated to the reporting unit. An entity still has the option to perform the qualitative test for a reporting unit to determine if the quantitative impairment test is necessary. Entities should apply for the amendment prospectively. The Company early adopted this guidance as of January 1, 2018. The Company performed the qualitative assessment of the its goodwill and determined that it is more likely than not that the fair value of a reporting unit exceeds the carrying value of the reporting unit. As a result, the Company has determined there was no goodwill impairment for the year ended December 31, 2018.

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the useful life of the asset. The estimated useful lives are three to five years. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in loss from operations.

Impairment of Long-Lived Assets

The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the asset’s carrying amount may not be recoverable. The Company conducts our long-lived asset impairment analyses in accordance with ASC 360-10-15, “Impairment or Disposal of Long-Lived Assets.” ASC 360-10-15 requires us to group assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities and evaluate the asset group against the sum of the undiscounted future cash flows. If the undiscounted cash flows do not indicate the carrying amount of the asset is recoverable, an impairment charge is measured as the amount by which the carrying amount of the asset group exceeds its fair value based on discounted cash flow analysis or appraisals. Following this review, no impairment of long-lived assets was noted as of December 31, 2018, 2017 and 2016.

Fair Value Measurements

The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. FASB ASC 820, Fair Value Measurements and Disclosures (“ASC 820”), establishes a hierarchy of inputs used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of the investments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below:

Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly.

Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable.

To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The fair value of the Company’s financial instruments, including cash and cash equivalents, prepaid expenses and other assets, accounts payable and accrued expenses approximate their respective carrying values due to the short-term nature of these instruments. The fair value of the 2021 Convertible Notes as of December 31, 2018 was $43,182. The Company’s assets and liabilities measured at fair value on a recurring basis include its short and long term investments.

Deferred Rent and Lease Liability

The Company recognizes rent expense on a straight-line basis, after considering the effect of rent escalation provisions resulting in a level rent expense recognized over the lease term. For the lease liability, the Company reduces the rent expense on a straight-line basis over the remaining life of the lease.

Research and Development

Research and development costs, which include salaries and staff costs, license costs, regulatory and scientific consulting fees, as well as contract research, and share-based compensation expense, are accounted for in accordance with ASC Topic 730, Research and Development (“ASC 730”).

The Company does not currently have any commercial biopharmaceutical products, and does not expect to have any for several years, if at all. Accordingly, research and development costs are expensed as incurred. While certain of the Company’s research and development costs may have future benefits, the policy of expensing all research and development expenditures is predicated on the fact that the Company has no history of successful commercialization of product candidates to base any estimate of the number of future periods that would be benefited.

Foreign Currency Transactions

Certain transactions during the years ended December 31, 2018, 2017 and 2016 are denominated in Euros. Gains and losses on foreign currency transactions are not significant for the years ended December 31, 2018, 2017 and 2016.

Treasury Stock

The Company records treasury stock at cost. Treasury stock consists of 50,000 shares that were settled in December 2018.

Share-Based Compensation

The Company measures the cost of employee and nonemployee services received in exchange for an award of equity instruments based on the fair value of the award on the grant date. That cost is recognized on a straight-line basis over the period during which the employee and nonemployee is required to provide service in exchange for the award. The fair value of options on the date of grant is calculated using the Black-Scholes option pricing model based on key assumptions such as stock price, expected volatility and expected term. The Company’s estimates of these assumptions are primarily based on the trading price of the Company’s stock, historical data, peer company data and judgment regarding future trends and factors.

The Company classifies share-based compensation expense in its statement of operations in the same manner in which the award recipient’s payroll costs and services are classified or in which the award recipient’s service payments are classified.

The Company recognizes compensation expense for at least the portion of awards that are vested. Forfeitures are accounted for as they occur.

The Company measures the compensation expense of share options and other share-based awards granted to employees, nonemployees and directors using the grant date fair value of the award and recognizes compensation expense as determined by the Black-Scholes Option pricing model on a straight-line basis over their requisite service period, which is generally the vesting period of the respective award.

Effective July 1, 2018, the Company adopted ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”), which expands the scope of Topic 718 to include share-based payment awards to nonemployees. As a result, stock-based awards granted to consultants and non-employees are accounted for in the same manner as awards granted to employees and directors as described above. Prior to the adoption of ASU 2018-07, for stock-based awards granted to consultants and non-employees, the Company recognized compensation expense over the period during which services are rendered by such consultants and non-employees until completed. At the end of each financial reporting period prior to completion of the service, the estimated fair value of these awards was re-measured using the then-current fair value of our common stock and updated assumption inputs in the Black-Scholes option-pricing model.

NYC Biotechnology Tax Credit Program

New York City allows investors and owners of emerging technology companies focused on biotechnology to claim a tax credit against the General Corporation Tax and Unincorporated Business Tax for amounts paid or incurred for certain facilities, operations, and employee training in New York City. The credit is recognized as research and development incentives when approved by New York City of the eligibility for the credit and the credit amount. During the years ended December 31, 2018, 2017 and 2016, the Company recorded research and development incentive income of $186, $192 and $0, respectively.

Income Taxes

The Company accounts for income taxes under the asset and liability method. The Company recognizes deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as for operating loss and tax credit carry-forwards. The Company measures deferred tax assets and liabilities using enacted tax rates expected to apply to taxable income in the years in which the Company expects to recover or settle those temporary differences. The Company recognizes the effect of a change in tax rates on deferred tax assets and liabilities in the results of operations in the period that includes the enactment date. The Company reduces the measurement of a deferred tax asset, if necessary, by a valuation allowance if it is more likely than not that the Company will not realize some or all of the deferred tax asset.

The Company’s deferred tax assets relate primarily to its net operating loss carryforwards and other balance sheet differences. In accordance with ASC 740 “Income Taxes”, the Company recorded a full valuation allowance to fully offset the gross deferred tax asset because it is not more likely than not that the Company will realize future benefits associated with these deferred tax assets at December 31, 2018 and 2017.

The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.

On December 22, 2017, the Tax Cut and Jobs Act (the “Act”), was signed into law by the President of the United States. The Act includes a number of provisions, including the lowering of the U.S. corporate tax rate from 34 percent to 21 percent, effective January 1, 2018 and the establishment of a territorial-style system for taxing foreign-source income of domestic multinational corporations.

Net Loss Per Share

The Company calculates net loss per share in accordance with FASB ASC 260, Earnings per Share. Basic net loss per share attributable to common shareholders is computed by dividing the net loss attributable to common shareholders by the weighted average number of common shares outstanding for the period. Diluted net loss attributable to common shareholders is computed by adjusting net loss attributable to common shareholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share attributable to common shareholders is computed by dividing the diluted net loss attributable to common shareholders by the weighted average number of common shares outstanding for the period, including potential dilutive common shares. For purposes of this calculation, outstanding options and convertible preferred shares are considered potential dilutive common shares. In connection with the Reverse Merger, all of the convertible preferred shares were converted into common stock. This conversion was in accordance with the original terms.

Segment Reporting

Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment.

Comprehensive Loss

Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions, and other events and circumstances from non-owner sources, and consists of net loss and changes in unrealized gains and losses on investments.

Recent Accounting Pronouncements

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), as amended, which supersedes the current leasing guidance and upon adoption, will require lessees to recognize right-of-use assets and lease liabilities on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. The new standard is effective for the Company for the annual period beginning after December 15, 2018, and can be early adopted. Upon the adoption of the guidance, operating leases are capitalized on the balance at the present value of lease payments. The balance sheet amount recorded for existing leases at the date of adoption of ASU 2016-02 must be calculated using the applicable incremental borrowing rate at the date of adoption. The Company completed its calculations of the assets and liabilities to be recorded and required additional disclosures upon the adoption of ASU 2016-02.

The FASB issued ASU 2018-11 in July 2018, which includes certain amendments to ASU 2016-02 intended to provide relief in implementing the new standard. Among these amendments is the option to not restate comparative periods presented in the financial statements. The Company intends to elect this new transition approach, using a cumulative-effect adjustment on the effective date of the standard, with comparative periods presented in accordance with the previous guidance in ASC 840.

The Company elected the available package of practical expedients which allows the Company to not reassess previous accounting conclusions around whether arrangements are or contain leases, the classification of leases, and the treatment of initial direct costs. The Company also expects it will make an accounting policy election to utilize the short-term lease exemption, whereby leases with a term of 12 months or less will not follow the recognition and measurement requirements of the new standard.

In preparation for adoption of the standard, the Company has implemented internal controls to enable the preparation of financial information including the assessment of the impact of the standard. The adoption of the new standard is expected to result in the recognition of additional lease liabilities ranging from $3.0 million to $3.7 million, and right-of-use assets ranging from $2.6 million to $3.2 million as of January 1, 2019 related to the Company’s operating leases.

In January 2017, the FASB issued ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business” (“ASU 2017-01”). ASU 2017-01 provides that when substantially all of the fair value of the assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the set is not a business. ASU 2017-01 is effective to annual periods beginning after December 31, 2018 and interim periods within annual periods beginning after December 31, 2019. Adoption of ASU 2017-01 may impact the Company’s accounting for future acquisitions.

Acquisition Accounting

12 Months Ended

Dec. 31, 2018

Acquisition Accounting [Abstract]

Acquisition Accounting

4. Acquisition Accounting

The identifiable assets and liabilities of Inotek are allocated in the Company’s consolidated financial statements at their fair values at the acquisition date, January 4, 2018. Goodwill is calculated as the excess value of consideration paid over the fair value of assets acquired and liabilities assumed.

The acquisition-date fair value of the consideration transferred is as follows:

Number of shares of the combined company owned by Inotek shareholders		6,805,608
Number of shares issuable in connection with fully vested RSUs of Inotek immediately prior to the Reverse Merger		271,718
Inotek common stock on the acquisition date		7,077,326
Price per share of Inotek common stock on acquisition date	$	12.16
Total purchase price	$	86,060

The following table summarizes the fair value purchase price allocation of the assets acquired and liabilities assumed at the date of acquisition which is subject to adjustment as the Company finalizes it valuation:

Cash and cash equivalents	$	76,348
Short term investments		21,292
Prepaid expense and other assets		1,041
Property and equipment		256
Deposits		168
Goodwill		30,815
Accounts payable and accrued expenses		(4,961	)
Convertible notes		(38,388	)
Unfavorable lease liability		(511	)
Net assets acquired	$	86,060

The goodwill of $30,815 represents the premium over the purchase price. Goodwill is mainly attributable to the value of cash and cash equivalents and short term investments acquired as of the acquisition date and access to capital markets. The allocation of the purchase price with the assistance of a third party valuation, is based on certain management assumptions (Level 3 inputs). The Company incurred and expensed acquisition costs of $147 for the year ended December 31, 2018.

The following supplemental unaudited pro forma information presents the Company’s financial results as if the acquisition of Inotek had occurred on January 1, 2017:

	Year Ended December 31,
	2018			2017
Revenue	$	-		$	-
Net loss		(78,248	)		(35,760	)

The above unaudited pro forma information was determined based on the historical US GAAP results of the Company and Inotek. The unaudited pro forma consolidated results are not necessarily indicative of what the Company’s consolidated results of operations actually would have been if the acquisition was completed on January 1, 2017. The unaudited pro forma consolidated net loss includes pro forma adjustments primarily relating to the following non-recurring items directly attributable to the business combination:

(1)	Elimination of $4,512 of transaction costs for both the Company and Inotek from the year ended December 31, 2018;

(2)	Elimination of $3,459 of stock-based compensation expense related to the acceleration of vesting and modification of certain previously unvested Inotek awards in connection with the Reverse Merger from the year ended December 31, 2018;

(3)	Elimination of $1,622 of expense related to severance and stay bonuses from the year ended December 31, 2018;

(4)	To adjust interest expense incurred in connection with the 2021 Convertible Notes assumed in connection with the Reverse Merger based on the fair value of the 2021 Convertible Notes on the date of the Reverse Merger, as if it occurred on January 1, 2017;

(5)	To adjust depreciation expense associated with property and equipment acquired in connection with the Reverse Merger based on the fair value of the property and equipment on the date of the Reverse Merger, as if it occurred on January 1, 2017; and

(6)	To adjust expense associated with operating lease obligations assumed in connection with the Merger based on the fair value of the leases on the date of the Merger, as if it occurred on January 1, 2017.

Fair Value of Financial Instruments

12 Months Ended

Dec. 31, 2018

Fair Value of Financial Instruments [Abstract]

Fair Value of Financial Instruments

5. Fair Value of Financial Instruments

Items measured at fair value on a recurring basis are the Company’s investments. The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy:

	Fair Value Measurements as of
	December 31, 2018 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Money market mutual funds (included in cash and cash equivalents)	$	30,552	$	-	$	-	$	30,552

United States Treasury securities		101,777		-		-		101,777
Investments		101,777		-		-		101,777

	$	132,329	$	-	$	-	$	132,329

The Company classifies its money market mutual funds and United States Treasury securities as Level 1 assets under the fair value hierarchy, as these assets have been valued using quoted market prices in active markets without any valuation adjustment.

Property and Equipment

12 Months Ended

Dec. 31, 2018

Property and Equipment [Abstract]

Property and Equipment

6. Property and Equipment

The Company’s property and equipment consisted of the following:

	December 31, 2018			December 31, 2017
Laboratory equipment	$	1,556		$	1,042
Computer equipment		179			98
Furniture and fixtures		273			115
Construction in progress		469			—
Leasehold improvements		29			—
		2,506			1,255
Less: accumulated depreciation		(479	)		(270	)
	$	2,027		$	985

During the years ended December 31, 2018, 2017 and 2016, the Company recognized $330, $204 and $67 of depreciation expense, respectively.

Accounts Payable and Accrued Expenses

12 Months Ended

Dec. 31, 2018

Accounts Payable and Accrued Expenses [Abstract]

Accounts Payable and Accrued Expenses

7. Accounts Payable and Accrued Expenses

At December 31, 2018 and 2017, the Company’s accounts payable and accrued expenses consisted of the following:

	December 31, 2018		December 31, 2017
Bonus	$	1,774	$	703
Research and development		10,414		3,273
Severance and benefits		7		138
Professional fees		690		382
Government grant payable		534		—
Accrued interest		1,241		—
Accrued vacation		123		—
Other		589		25
	$	15,372	$	4,521

Convertible Notes Payable

12 Months Ended

Dec. 31, 2018

Convertible Notes Payable [Abstract]

Convertible Notes Payable

8. Convertible Notes Payable

On January 4, 2018, in connection with the Reverse Merger, Inotek’s obligations under its outstanding convertible notes, with an aggregate principal value of $52,000, were assumed by the Company (the “2021 Convertible Notes”). The 2021 Convertible Notes were issued in 2016 and mature on August 1, 2021 (“Maturity Date”). The 2021 Convertible Notes are unsecured, accrue interest at a rate of 5.75% per annum and interest is payable semi-annually on February 1 and August 1 of each year. Each holder of a 2021 Convertible Note (the “Holder”) has the option until the close of business on the second business day immediately preceding the Maturity Date to convert all, or any portion, of the 2021 Convertible Notes held by it at a conversion rate of 31.1876 shares of the Company’s common stock per $1 principal amount of 2021 Convertible Notes (the “Conversion Rate”) which is $32.08 per share. The Conversion Rate is subject to adjustment from time to time upon the occurrence of certain events, including the issuance of stock dividends and payment of cash dividends.

In addition, in certain circumstances, the Conversion Rate will be increased in respect of a Holder’s conversion of 2021 Convertible Notes in connection with the occurrence of one or more corporate events specified in the indenture (as supplemented, the “Indenture”) governing the 2021 Convertible Notes (each such specified corporate event, a “Make-Whole Fundamental Change”) that occurs prior to the Maturity Date (a “Make-Whole Fundamental Change Conversion”) or in respect of a Holder’s voluntary conversion of 2021 Convertible Notes other than in connection with a Make-Whole Fundamental Change (a “Voluntary Conversion”). In connection with a Make-Whole Fundamental Change Conversion or a Voluntary Conversion, the Company will increase the Conversion Rate for the 2021 Convertible Notes surrendered for conversion by a number of additional shares of the Company’s common stock set forth in the Additional Shares Make-Whole Table in the Indenture, based on the applicable Stock Price (as defined in the Indenture) and Effective Date (as defined in the Indenture) for such conversion. The additional shares potentially issuable in connection with a Make-Whole Fundamental Change Conversion or a Voluntary Conversion range from 0 to 6.2375 per $1 principal amount of 2021 Convertible Notes, subject to adjustment. If the Stock Price applicable to any conversion is greater than $160.00 per share, the Conversion Rate will not be increased. If the Stock Price applicable to any conversion is less than $26.72 per share, the Conversion Rate in connection with a Make-Whole Fundamental Change Conversion will not be increased but it will be increased by 6.2375 shares in connection with a Voluntary Conversion. Upon conversion, Holders of the 2021 Convertible Notes will receive shares of the Company’s common stock and cash in lieu of fractional shares.

Upon the occurrence of a Fundamental Change, the occurrence of certain change of control transactions or delisting events (as defined in the Indenture), each Holder may require the Company to repurchase for cash all or any portion of the 2021 Convertible Notes held by such Holder at a repurchase price equal to 100% of the principal amount thereof, plus accrued and unpaid interest thereon.

The Company, at its option, may redeem for cash all or any portion of the 2021 Convertible Notes if the last reported sale price of a share of the Company’s common stock is equal to or greater than 200% of the conversion price for the 2021 Convertible Notes then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending within the five trading days immediately preceding the date on which the Company provides notice of redemption, at a redemption price equal to 100% of the principal amount of the 2021 Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date.

If an Event of Default (as defined in the Indenture), other than certain events of bankruptcy, insolvency or reorganization involving the Company, occurs and is continuing, the trustee under the Indenture or the Holders of at least 25% in principal amount of the outstanding 2021 Convertible Notes may declare 100% of the principal of and accrued and unpaid interest, if any, on all of the 2021 Convertible Notes to be due and payable immediately. Upon the occurrence of an Event of Default relating to bankruptcy, insolvency or reorganization involving the Company, 100% of the principal of and accrued and unpaid interest, if any, on all of the 2021 Convertible Notes would become due and payable automatically.

Notwithstanding the foregoing, the Indenture provides that, to the extent the Company elects, the sole remedy for an Event of Default relating to certain failures by the Company to comply with certain reporting covenants in the Indenture, will (i) for the first 90 days after the occurrence of such an Event of Default, consist exclusively of the right to receive additional interest on the 2021 Convertible Notes at a rate equal to 0.25% per annum of the principal amount of the 2021 Convertible Notes outstanding for each day during such 90-day period on which such an Event of Default is continuing and (ii) for the period from, and including, the 91st day after the occurrence of such an Event of Default to, and including, the 180th day after the occurrence of such an Event of Default, consist exclusively of the right to receive additional interest on the 2021 Convertible Notes at a rate equal to 0.50% per annum of the principal amount of the 2021 Convertible Notes outstanding for each day during such additional 90-day period on which such an Event of Default is continuing (such additional interest, “Additional Interest”). After 180 days, if such Event of Default is not cured or waived, the 2021 Convertible Notes would be subject to acceleration in accordance with the Indenture.

The 2021 Convertible Notes are considered a hybrid financial instrument consisting of a fixed interest rate “host” and various embedded features that required evaluation as potential embedded derivatives under FASB ASC 815, Derivatives and Hedging (“ASC 815”). Based on the nature of the host instrument and the embedded features, management concluded that none of the conversion, put and redemption features required bifurcation and separate accounting from the host instrument. The Company determined that the Additional Interest was an embedded derivative that contains non-credit related events of default. As a result, the Additional Interest feature required bifurcation and separate accounting under ASC 815. Based on the amount of Additional Interest that would be owed and the likelihood of occurrence, Rocket estimated the fair value of the Additional Interest feature to be insignificant upon issuance, at the time of the Reverse Merger, and as of December 31, 2018.

The Company recorded the 2021 Convertible Notes at their fair value of $38,388 on January 4, 2018, the date of the acquisition. The difference between the fair value of the 2021 Convertible Notes and the principal value represents a discount on the notes that is being amortized to interest expense over the remaining term using the effective interest method. As of December 31, 2018, the stated interest rate was 5.75%, and the effective interest rate was 15.3%.

The table below summarizes the carrying value of the 2021 Convertible Notes as of December 31, 2018:

Principal amount	$	52,000
Discount		(10,553	)
Carrying value as of December 31, 2018	$	41,447

Accretion of the 2021 Convertible Notes discount was $3,059 for the year ended December 31, 2018.

Shareholders' Equity	12 Months Ended
Shareholders' Equity	Dec. 31, 2018
Shareholders' Equity [Abstract]
Shareholders' Equity	9. Shareholders’ Equity Preferred Shares On January 4, 2018, immediately prior to and in connection with the closing of the Reverse Merger, and in accordance with the original terms of the convertible preferred shares, all of the outstanding convertible preferred shares of Rocket Ltd were converted into an aggregate of 19,475,788 shares of common stock. Exchange Ratio On January 4, 2018, in connection with the Reverse Merger, Rocket’s historical share and per share information has been adjusted in the consolidated financial statements presented to give effect to the Exchange Ratio. Common Shares At the time of the Reverse Merger, Rocket Ltd’s outstanding shares of common stock were 26,281,396 which includes 19,475,788 issued upon the conversion of Rocket Ltd’s convertible preferred stock. On January 24, 2018, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with Cowen and Company, LLC and Evercore Group L.L.C., as representatives (the “Representatives”) of the several underwriters (collectively with the Representatives, the “Underwriters”), pursuant to which the Company sold 6,325,000 shares of common stock (the “Shares”), which includes 825,000 shares that were sold pursuant to an option granted to the Underwriters (the “Offering”). The Shares were sold in the Offering at a public offering price of $13.25 per share in which the Company received gross proceeds of $83,806 net of $5,288 of offering costs, commission and legal and other expenses for net proceeds from the Offering of $78,518, after deducting the underwriting discounts and commissions and legal and accounting costs. On November 30, 2018, the Company announced the closing of its previously announced underwritten public offering of 4,082,500 shares of its common stock, which includes the full exercise of the underwriters’ option to purchase 532,500 additional shares of its common stock, at a public offering price of $15.50 per share. The gross proceeds to Rocket from the offering were approximately $63,339, net of $4,035 of offering costs, commissions, legal and other expenses for a net proceeds from the offering of $59,304. BofA Merrill Lynch, Cowen and Company, LLC and Evercore ISI acted as joint book-running managers for the offering. Oppenheimer & Co. acted as lead manager and Ladenburg Thalmann acted as co-manager. In addition to the shares sold in the public offering, on November 30, 2018 Rocket closed a concurrent sale of 967,742 shares of common stock at a price of $15.50 per share, for gross proceeds of $15,000, net of offering costs of $200 for net proceeds of $14,800, in a private placement to RTW Investments, LP, (“RTW”) an existing stockholder of the Company and an affiliate of Roderick Wong, the chairman of Rocket’s board of directors. The sale of these shares was not registered under the Securities Act of 1933, as amended, and such shares are subject to customary resale restrictions. Additionally, RTW signed a 90-day lock-up with respect to all shares of Rocket beneficially held by RTW. On December 27 and 28, 2018, the Company repurchased 100,000 shares of its common stock for aggregate consideration of approximately $1,400. The repurchases were made on the Nasdaq Stock Market at prevailing market prices in accordance with SEC Rule 10b-18. 50,000 of the shares repurchased by the Company settled on December 31, 2018 and the remaining 50,000 shares repurchased at an average price of $14.50 settled on January 2, 2019. As of December 31, 2018, at an average price of $13.36, the Company recorded a prepaid expense of $726 related to the 50,000 shares that settled on January 2, 2019 and recorded treasury stock of $668 relating to the 50,000 shares that settled as of December 31, 2018. These shares were subsequently retired in January 2019. Immediately following the stock repurchases (the “Repurchases”), the Company sold 100,000 shares of common stock (the “Shares”) for $1,396 to RTW Innovation Master Fund, Ltd. (“RTW Innovation”), which is an affiliate of the Company and is managed by RTW. RTW Innovation purchased the shares for a per-Share price of $13.93, plus an amount equal to the Company’s expenses incurred in connection with the Repurchases (including broker’s commissions) and the issuance of the Shares. The offering and sale of the Shares was completed as a private placement under Section 4(a)(2) of the Securities Act of 1933, as amended and included in the common shares outstanding as of December 31, 2018.

Share-Based Awards

12 Months Ended

Dec. 31, 2018

Share-Based Awards [Abstract]

Share-Based Awards

10. Share-Based Awards

2015 Share Option Plan

The Rocket Ltd 2015 Share Option Plan provides for the Company to grant incentive stock options or nonqualified stock options for the purchase of common shares to employees, members of the board of directors and consultants. The 2015 Share Option Plan is administered by an administrative committee appointed by the board of directors or, in the absence of such appointment, the entire board of directors. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, or their committee if so delegated, except that the exercise price per share of share options may not be less than 100% of the fair market value of the share of common shares on the date of grant (or 110% of the fair market value in the case of an employee who owns shares representing more than 10% of the voting power of all classes of shares for the Company) and the term of share options may not be greater than ten years (or five years in the case of an employee who owns shares representing more than 10% of the voting power of all classes of shares for the Company). The Company generally grants share-based awards with service conditions only (“service-based” awards).

As required by the 2015 Share Option Plan, the exercise price for share options granted was not to be less than the fair value of common shares as determined by the Company as of the date of grant. The Company valued its common shares by taking into consideration its most recently available valuation of common shares performed by management and the board of directors as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the date of grant.

The total number of shares that may be issued under the 2015 Share Option Plan was 9,904,050 shares; however, the 2,944,702 shares that remained available under the 2015 Share Option Plan were added to the share reserve of the 2014 Plan in connection with the Reverse Merger.

By virtue of the terms of the Merger Agreement, each stock option outstanding under the Rocket Ltd 2015 Share Option Plan immediately prior to the consummation of the Reverse Merger was automatically converted into a stock option exercisable for a number of shares of the Company’s common stock calculated based on the exchange ratio and the exercise price per share of such outstanding stock option.

Pursuant to the Merger Agreement, the Company sponsored Inotek’s equity compensation plans: the Amended and Restated 2014 Stock Option and Incentive Plan (the “2014 Plan”), the 2004 Stock Option and Incentive Plan (the “2004 Plan”), and the 2014 Employee Stock Purchase Plan (“ESPP”) and assumed all stock options and restricted stock units (“RSUs”) outstanding under each of the plans immediately prior to the effective time of the Reverse Merger.

Second Amended and Restated 2014 Stock Option and Incentive Plan

In March 2018, Rocket’s board of directors approved the Second Amended and Restated 2014 Stock Option and Incentive Plan (the “Revised 2014 Plan”) which was subsequently approved by the Company’s shareholders at the Annual Meeting held on June 25, 2018. The Revised 2014 Plan contains the following material features and changes from the 2014 Plan:

Provides for an aggregate maximum number of shares of common stock initially authorized for issuance of 4,294,830 shares. On January 1, 2019, and each January 1 thereafter for the term of the Revised 2014 Plan, the number of shares reserved and available under the Revised 2014 Plan will automatically increase by 4% of the number of shares of our common stock issued and outstanding on the immediately preceding December 31;

Increase the number of shares of stock underlying stock options or stock appreciation rights that may be granted to any one individual in any single calendar year to 1,000,000 shares of common stock, and an increase in the number of shares of stock that may be issued in the form of incentive stock options;

Eliminates certain provisions relating to awards of “performance-based compensation”; and

Expires on June 25, 2028.

2004 Stock Option and Incentive Plan

In July 2004, Inotek’s board of directors adopted the 2004 Plan for the issuance of incentive stock options, restricted stock, and other equity awards, all for common stock, as determined by the board of directors to employees, officers, directors, consultants, and advisors of Inotek and its subsidiaries. Only stock options were granted under the 2004 Plan. The 2004 Plan expired in February 2014 but remains effective for all outstanding options. All of the stock options granted under the 2004 Plan were fully vested at the time of the Reverse Merger.

Vesting of all unvested Inotek option awards issued and outstanding was accelerated at the effective time of the Reverse Merger, and all such option awards issued and outstanding at the time of the Reverse Merger, aggregating to 523,456, remained issued and outstanding. For accounting purposes, since the acceleration of vesting was negotiated in contemplation of the Reverse Merger, the remaining unrecognized compensation expense associated with the original grant date fair value of the options of $2,997 was recognized in the Company’s consolidated statement of operations for the year ended December 31, 2018. In addition, the exercise period for all Inotek options outstanding at the effective time of the Reverse Merger was extended beyond the respective periods provided in the original awards. The Company recorded $462 in connection with the extension of the exercise periods in the consolidated statement of operations for the year ended December 31, 2018, equal to the difference in the fair value of the options immediately prior to and immediately following the modification of the exercise period.

Share Option Valuation

The weighted average assumptions that the Company used in the Black-Scholes pricing model to determine the fair value of the share options granted to employees and directors were as follows:

	Years Ended December 31,
	2018			2017			2016

Risk-free interest rate		2.64	%		2.06	%		1.65	%
Expected term (in years)		5.85			6.00			6.00
Expected volatility		87.7	%		91.3	%		96.10	%
Expected dividend yield		0.00	%		0.00	%		0.00	%
Exercise price	$	17.82		$	2.97		$	1.21
Fair value of common stock	$	17.98		$	2.63		$	0.98

The weighted average assumptions that the Company used in the Black-Scholes pricing model to determine the fair value of the share options granted to non-employees were as follows:

	Years Ended December 31,
	2018			2017			2016

Risk-free interest rate		2.85	%		2.39	%		2.39	%
Expected term (in years)		9.75			6.70			5.87
Expected volatility		82.19	%		90.62	%		106.15	%
Expected dividend yield		0.00	%		0.00	%		0.00	%
Exercise price	$	18.75		$	1.21		$	1.21
Fair value of common stock	$	19.63		$	1.08		$	1.11

The Company recognizes stock-based compensation expense for at least the portion of awards that have vested.

The following table summarizes stock option activity for the years ended December 31, 2018 and 2017, under the Revised 2014 Plan:

		Number of Shares			Weighted Average Exercise Price		Weighted Average Contractual Term (Years)

Outstanding as of December 31, 2015	*		5,332,950		$	0.69		9.90
Granted			1,005,871			1.21		7.23
Forfeited			(146,656	)		1.21		9.13
Outstanding as of December 31, 2016	*		6,192,164		$	0.79		9.00
Granted			812,894			2.98		5.50
Forfeited			(45,711	)		1.21		8.88
Outstanding as of December 31, 2017	*		6,959,347		$	1.06		8.17
Assumed as part of merger with Inotek			523,456			2.01		6.78
Granted			1,650,878			17.82		9.26
Exercised			(370,753	)		1.27		-
Forfeited			(146,931	)		3.02
Outstanding as of December 31, 2018			8,615,997		$	4.48		7.51

Options vested and exercisable as of December 31, 2018			6,466,265		$	1.22		6.52

*	Affected by Exchange Ratio

Restricted Stock Units

All unvested Inotek RSU awards issued and outstanding were accelerated at the effective time of the Reverse Merger. For accounting purposes, since the acceleration of vesting upon change of control was included in the original terms of the award, the remaining unrecognized compensation expense associated with the original grant date fair value of the RSU awards was recognized as a pre-merger expense of Inotek.

The following table summarizes the RSU activity for the year ended December 31, 2018 under the Revised 2014 Plan:

	Number of Shares
Outstanding as of December 31, 2017		-
Assumed as part of merger with Inotek		271,719
Settled		(271,719	)
Outstanding as of December 31, 2018		-

As of December 31, 2018, none of the RSU’s remain unsettled.

The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The intrinsic value of options exercised and exercisable as of December 31, 2018 was $6 and $88.

The weighted average grant-date fair value per share of stock options granted during the years ended December 31, 2018, 2017 and 2016 was $13.21, $2.23, and $74.15, respectively.

The total fair value of options vested during the years ended December 31, 2018, 2017 and 2016 was $91,334, $502, and $845 respectively.

Employee Stock Purchase Plan

In November 2014, Inotek’s board of directors adopted and the stockholders approved the ESPP. The ESPP provides that the number of shares reserved and available for issuance under the ESPP shall be cumulatively increased each January 1, beginning on January 1, 2016, by the lesser of (i) 150,000 shares of common stock or (ii) the number of shares necessary to set the number of shares of common stock under the ESPP at 1% percent of the outstanding number of shares as of January 1 of the applicable year. However, the board of directors reserves the right to determine that there will be no increase for any year or that any increase will be for a lesser number of shares. On January 1, 2018, 6,562 shares were added to the ESPP. On September 11, 2018, the board of directors determined that there would be no increase in shares reserved and available for issuance under the ESPP on January 1, 2019. As of December 31, 2018, there were 68,256 shares available for issuance under the ESPP. During the year ended December 31, 2018, 0 shares of common stock were purchased and the Company recorded $0 of stock-based compensation expense pursuant to the ESPP.

Share-Based Compensation

	Year Ended December 31,
	2018		2017		2016

Research and development	$	7,375	$	523	$	159
General and administrative		6,226		797		115
Total share based compensation expense	$	13,601	$	1,320	$	274

As of December 31, 2018, the Company had an aggregate of $18,272 of unrecognized share-based compensation cost, which is expected to be recognized over the weighted average period of 2.05 years.

Net Loss Per Share

12 Months Ended

Dec. 31, 2018

Net Loss Per Share [Abstract]

Net Loss Per Share

11. Net Loss Per Share

Basic and diluted net loss per share attributable to common shareholders was calculated as follows:

	For the Years Ended December 31,
	2018			2017			2016

Numerator:
Net loss attributable to common shareholders	$	(74,518	)	$	(19,578	)	$	(7,573	)
Denominator:
Weighted-average common shares outstanding - basic and diluted		39,377,666			6,795,627			6,833,718
Net loss per share attributable to common shareholders - basic and diluted	$	(1.89	)	$	(2.88	)	$	(1.11	)

The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common shareholders for the periods indicated because including them would have had an anti-dilutive effect:

	For the Years Ended December 31,
	2018		2017		2016
Shares issuable upon conversion of the 2021 Convertible Notes		1,620,948		-		-
Warrants exercisable for common shares		14,102		-		-
Options to purchase common shares		8,615,997		6,756,695		6,192,164
Redeemable Series A convertible preferred shares (as converted to common shares)		-		9,807,564		9,807,905
Redeemable Series A convertible preferred shares (as converted to common shares)		-		9,668,224		-
		10,251,047		26,232,483		16,000,069

The Company has warrants of 14,102 outstanding as of December 31, 2018, convertible into 14,102 of common shares at an exercise price of $24.82 per share which expire on June 28, 2023.

Income Taxes

12 Months Ended

Dec. 31, 2018

Income Taxes [Abstract]

Income Taxes

12. Income Taxes

Net loss by jurisdiction consists of the following:

	For the years ended December 31,
	2018		2017		2016
Domestic	$	74,518	$	-	$	-
Foreign		-		19,578		7,573
Total	$	74,518	$	19,578	$	7,573

No provision for federal or state income taxes was recorded during the years ended December 31, 2018, 2017, and 2016, as the Company incurred operating losses and maintains a full valuation allowance against its net deferred tax assets.

A reconciliation of income tax benefit computed at the statutory federal income tax rate to income taxes as reflected in the financial statements is as follows:

	For the years ended December 31,
	2018			2017			2016
U.S. federal tax at statutory rate		21.0	%		34.0	%		34.0	%
Foreign source income not subject to tax		0.0	%		-34.0	%		-34.0	%
Stae income taxes		15.8	%		0.0	%		0.0	%
New York City tax		-			6.5	%		6.3	%
Other		-1.6	%		-			-
Section 382 limitation		-38.7	%		-			-
Valuation allowance		3.5	%		-6.5	%		-6.3	%
Effective tax rate		0	%		0	%		0	%

The significant components of the Company’s deferred income tax assets and liabilities after applying the enacted corporate tax rates are as follows:

	For the years ended December 31,
	2018			2017			2016
Deferred income tax assets (liabilities)
Net operating losses (“NOL”) and credit carryforwards	$	28,400		$	1,620		$	458
Capitalized research and development costs		17,098			-			-
Other		1,385			136			25
Stock compensation		4,563			-			-
Debt discount		(3,652	)		-			-
Valuation allowance		(47,794	)		(1,756	)		(483	)
Net deferred income tax asset	$	-		$	-		$	-

As of December 31, 2018, the Company had federal and state net operating loss carryforwards of approximately $96,400 and $124,500, respectively, which begin to expire in 2025. Additionally $62,300 of the Federal NOLs can be carried forward indefinitely.

As required by ASC 740, Income Taxes, management of Rocket has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, which are comprised principally of NOL carryforwards and capitalized research and development costs. As a result of the fact that Rocket has incurred tax losses from inception, management has determined that it is more likely than not that Rocket will not recognize the benefits of federal and state net deferred tax assets and, as a result, a full valuation allowance has been established against its net deferred tax assets as of December 31, 2018 and 2017. Rocket has offset certain deferred tax liabilities with deferred tax assets that are expected to generate offsetting deductions within the same period. During the years ended December 31, 2018, 2017 and 2016, the valuation allowance increased by $46,016 and $1,273 respectively. Realization of deferred tax assets is dependent upon the generation of future taxable income.

During 2018, the Company recorded tax charges for the impact of the Tax Act effects using the currently available information and technical guidance on the interpretations of the Tax Act. As permitted by SEC Staff Accounting Bulletin 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act, the Company recorded provisional estimates and have subsequently finalized our accounting analysis based on the guidance, interpretations, and data available as of December 31, 2018. Adjustments made in the fourth quarter of 2018 upon finalization of our accounting analysis were not material to our Consolidated Financial Statements.

Under Internal Revenue Code Section 382, if a corporation undergoes an “ownership change,” the corporation’s ability to use its pre-change NOL carryforwards and other pre-change tax attributes to offset its post-change income may be limited. The Company has completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since the Company became a “loss corporation” as defined in Section 382. The Company experienced multiple ownership changes occurring in 2005, 2007, 2015, and 2018. The ownership change has and will continue to subject our pre-ownership change net operating loss carryforwards to an annual limitation, which will significantly restrict our ability to use them to offset taxable income in periods following the ownership change. In general, the annual use limitation equals the aggregate value of our stock at the time of the ownership change multiplied by a specified tax-exempt interest rate. As a result of the ownership change, the Company is limited to an approximate $1,700 annual limitation on our ability to utilize our pre-merger NOL’s and R&D Credits. Due to this limitation, approximately $93,000 of the $127,100 pre-merger Federal NOL will expire unutilized as the cumulative limitation amount over a 20 year carryforward period is $34,100. Additionally, $4,900 of Federal R&D Credits will expire unutilized. As a result, the Company has reduced its deferred tax assets related to the Federal NOL and Federal R&D Credits which is offset by the corresponding valuation allowance. The calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations for both federal taxes and the many states in which Rocket operates or does business in. ASC 740 states that a tax benefit from an uncertain tax position may be recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, on the basis of the technical merits.

The Company recorded uncertain tax positions as liabilities in accordance with ASC 740 and adjust these liabilities when our judgment changes as a result of the evaluation of new information not previously available. Because of the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different from our current estimate of the unrecognized tax benefit liabilities. These differences will be reflected as increases or decreases to income tax expense in the period in which new information is available. As of December 31, 2018 the Company has not recorded any uncertain tax positions in our financial statements.

The Company recognizes interest and penalties related to unrecognized tax benefits on the income tax expense line in the accompanying consolidated statement of operations. As of December 31, 2018 and 2017, no accrued interest or penalties are included on the related tax liability line in the consolidated balance sheet.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies [Abstract]

Commitments and Contingencies

13. Commitments and Contingencies

Operating Leases

On March 31, 2016, the Company entered into a lease agreement for its office and laboratory space at the Alexandria Center for Life Sciences in New York, New York with a term ending on July 31, 2021 (the “NY Lease Agreement”). In connection with the NY Lease Agreement, the Company established an irrevocable standby letter of credit (“ARE LOC”) with a bank. The ARE LOC, in which the landlord is the beneficiary, serves as the Company’s security deposit on the lease. The Company has a certificate of deposit with a bank as collateral for the ARE LOC which is classified as restricted cash in the consolidated balance sheets. On June 28, 2018, the Company entered into Amendment No.1 to the NY Lease Agreement, whereby the landlord agreed to relieve the Company of its obligations under the lease for a portion of the leased space upon the takeover of the space by a replacement tenant. The Company agreed to extend the lease for the remaining laboratory space by one additional year. The Company recorded an additional rent expense of $94 related to the early exit from the lease during the year end December 31, 2018. A replacement tenant has executed a new lease for the office space and as of September 7, 2018, the Company was relieved of its obligations for rent and security deposit for the office space. In October 2018, the Company provided a new letter of credit for $89 (the “New ARE LOC”) relating to the remaining lab space and the existing ARE LOC of $209 was released back to the Company. The New ARE LOC expires and is automatically renewed April 8 of each succeeding calendar year until October 29, 2020, unless written notice is provided no later than 90 days before the then existing expiration date. The Company continues to maintain laboratory space at the Alexandria Center for Life Science facility as its hub for research and development activities.

On June 7, 2018, the Company entered into a three year lease agreement with ESRT Empire State Building, L.L.C. for office space in the Empire State Building (the “ESB Lease Agreement”). In connection with the ESB Lease Agreement, the Company established an irrevocable standby letter of credit (the “Empire LOC”) with a bank for $936 which expires on June 30, 2019 and is renewed automatically for a one year period until its expiration date of September 30, 2021. The Empire LOC serves as the Company’s security deposit on the lease in which the landlord is the beneficiary. The Company has a certificate of deposit of $936 with a bank as collateral for the Empire LOC which is classified as part of restricted cash in the consolidated balance sheet as of December 31, 2018.

On January 4, 2018, in connection with the Reverse Merger, the Company assumed an operating lease for Inotek’s former headquarters in Lexington, Massachusetts, with a term ending in February 2023. In May 2018, the Company separated from the last legacy employee of Inotek and abandoned use of the leased space at that time. In connection with the abandonment of the Massachusetts lease, the Company recorded a liability at the present value of the difference between the lease payments and projected sublease income at the cease use date of $435. The difference between the lease liability recorded at acquisition and the $435 lease abandonment is a deferred gain which is being recognized to other income over the remaining life of the lease. In addition, as of May 2018, the Company wrote off the remaining furniture and fixtures of $205. In July 2018, the Company signed an agreement to sublease a portion of the Lexington, Massachusetts space and in September 2018, the Company signed an agreement to sublease the remaining portion of the Lexington, Massachusetts space.

On August 14, 2018, Rocket entered into a lease for approximately 92,000 rentable square feet in Cranbury, New Jersey, for office space, process development, research activities and potentially manufacturing to support the Company’s pipeline (the “NJ Lease Agreement”). The term of the NJ Lease Agreement will commence for 72,000 rentable square feet upon substantial completion of leasehold improvements (the “Commencement Date”), and the remaining 20,000 square feet will commence upon the earlier of the Company’s election to commence the lease of such additional space or thirty months from the Commencement Date. The NJ Lease Agreement has a term of fifteen years from the Commencement Date, with an option to renew for two consecutive five-year renewal terms. Estimated rent payments are $1,200 per annum, payable in monthly installments, depending upon the nature of the leased space, and subject to annual base rent increases of 3%. The total commitment under the lease is estimated to be approximately $26,492 over the 15 year term of the lease. The Company delivered a cash security deposit of $287 to the landlord in connection with the NJ Lease Agreement which has been reflected in deposits in the consolidated balance sheets.

The total restricted cash balance for the Company’s operating leases at December 31, 2018 is $936. Rent expense was $807, $563 and $358 for the years ended December 31, 2018, 2017 and 2016.

As of December 31, 2018, the remaining aggregate annual commitments pursuant to the leases, as amended, are as follows:

2019	$	1,372
2020		1,953
2021		1,841
2022		1,739
2023		1,615
Thereafter		20,144
Total	$	28,664

Securities Litigation

On January 6, 2017, a purported stockholder of Inotek filed a putative class action in the U.S. District Court for the District of Massachusetts, captioned Whitehead v. Inotek Pharmaceuticals Corporation, et al., No. 1:17-cv-10025. An amended complaint was filed on July 10, 2017, and a second amended complaint was filed on September 5, 2017. The second amended complaint alleged violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and SEC Rule 10b-5 against Inotek, David Southwell, and Rudolf Baumgartner based on allegedly false and misleading statements and omissions regarding Inotek’s phase 2 and phase 3 clinical trials of trabodenoson. The lawsuit sought, among other things, unspecified compensatory damages for purchasers of Inotek’s common stock between July 23, 2015 and July 10, 2017, as well as interest and attorneys’ fees and costs. The second amended complaint was dismissed with prejudice on June 27, 2018. Plaintiffs filed a notice of appeal to the First Circuit Court of Appeals on July 27, 2018, voluntarily dismissed their appeal on August 31, 2018, and the First Circuit entered judgment dismissing the action on September 5, 2018.

From time to time, the Company may be subject to other various legal proceedings and claims that arise in the ordinary course of its business activities. Although the results of litigation and claims cannot be predicted with certainty, the Company does not believe it is party to any other claim or litigation the outcome of which, if determined adversely to the Company, would individually or in the aggregate be reasonably expected to have a material adverse effect on its business. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors.

Indemnification Arrangements

Pursuant to its bylaws and as permitted under Delaware law, the Company has indemnification obligations to directors, officers, employees or agents of the Company or anyone serving in these capacities. The maximum potential amount of future payments the Company could be required to pay is unlimited. The Company has insurance that reduces its monetary exposure and would enable it to recover a portion of any future amounts paid. As a result, the Company believes that the estimated fair value of these indemnification commitments is minimal.

Throughout the normal course of business, the Company has agreements with vendors that provide goods and services required by the Company to run its business. In some instances, vendor agreements include language that requires the Company to indemnify the vendor from certain damages caused by the Company’s use of the vendor’s goods and/or services. The Company has insurance that would allow it to recover a portion of any future amounts that could arise from these indemnifications. As a result, the Company believes that the estimated fair value of these indemnification commitments is minimal.

Agreements Related to Intellectual Property	12 Months Ended
Agreements Related to Intellectual Property	Dec. 31, 2018
Agreements Related to Intellectual Property [Abstract]
Agreements Related to Intellectual Property	14. Agreements Related to Intellectual Property The Company has various license and research and collaboration arrangements. The transactions principally resulted in the acquisition of rights to intellectual property which is in the preclinical phase and has not been tested for safety or feasibility. In all cases, the Company did not acquire tangible assets, processes, protocols or operating systems. The Company expenses the acquired intellectual property rights as of the acquisition date on the basis that the cost of intangible assets purchased from others for use in research and development activities, has no alternative future uses. License 161101 and SRA 161101 On April 20, 2018, the Company entered into Amendment No. 1 to the clinical trial agreement with the Fred Hutchinson Research Cancer Center (“Hutch”) for the clinical trial entitled: Gene Therapy for Patients with Fanconi Anemia Complementation Group A. The Company agreed to pay $108 for additional budgeted amounts for the period from March 2018 through August 2018. LAD-I (leukocyte adhesion deficiency-I) Master Research Agreement with CIEMAT On March 1, 2018, the Company entered into Amendment No. 1 to the LAD-1 Master Research Agreement whereby the Company and Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (“CIEMAT”) agreed to a modification of the original commitment from Rocket of €1,690 down by €361 (approximately $444). PKD (pyruvate kinase deficiency) Master Research Agreement with CIEMAT On September 17, 2018, the Company entered into Amendment No. 1 to the PKD Master Research Agreement whereby the Company and CIEMAT agreed to a modification of the original commitment from Rocket of €4,190 down by €1,007 (approximately $1,168). Contract Research and Collaboration Agreement with Lund University and J. Richter In August 2016, Rocket entered into a research and collaboration agreement with Lund University and Johan Richter, M.D., Ph.D. under which Dr. Richter grants to Rocket an exclusive, perpetual, sublicensable, worldwide license to certain intellectual property rights of Dr. Richter relating to lentiviral-mediated gene transfer to treat Osteopetrosis. In exchange for the license, Rocket is obligated to make an up-front payment, certain clinical and commercial milestone payments, royalty payments (on net sales of products covered by a valid claim within the licensed intellectual property) and sublicense revenue payments to Dr. Richter. Under the terms of the agreement, Lund University and Dr. Richter are obligated to perform contract research for Rocket regarding the use of lentiviral-mediated gene transfer to treat Osteopetrosis. Intellectual property resulting from the contract research created by Dr. Richter is included in the license described above and also subject to an option for Rocket to purchase ownership of such rights. Intellectual property created by Lund University in conducting such research is non-exclusively licensed to Rocket for non-commercial use and also subject to an option for Rocket to purchase or license such intellectual property under commercially reasonable terms. Rocket is obligated to pay for the contract research according to an agreed budget in quarterly installments in advance. As consideration for an option to acquire rights from Lund University on commercially reasonable terms and conditions, Rocket paid Lund University an upfront license fee of €0.02 million (approximately $0.02 million), which was expensed as research and development costs. Rocket is obligated to make aggregate milestone payments of up to €0.1 million (approximately $0.1 million) to Lund University and Dr. Richter upon the achievement of specified development and regulatory milestones. With respect to any commercialized products covered by the Lund University agreement, Rocket is obligated to pay a low single digit percentage royalty on net sales, subject to specified adjustments, by Rocket or its sublicensees or affiliates. In the event that Rocket enters into a sublicense agreement with a sublicensee, Rocket will be obligated to pay a portion of any consideration received from such sublicensees in specified circumstances. Rocket may terminate this agreement at any time by providing Lund University and Dr. Richter with 90 days’ advance notice. The research agreement has an initial term of 24 months. In August 2018, the research and collaboration agreement was renewed for an additional year expiring August 2019. License Agreement for Danon Disease In February 2017, the Company entered into a License Agreement with The Regents of the University of California, represented by its San Diego campus (“UCSD”), under which UCSD granted us an exclusive, sublicensable, worldwide license to certain intellectual property rights for the treatment of lysosomal storage diseases, including Danon disease. In exchange for the license, the Company became obligated to make an up-front payment, certain clinical and commercial milestone payments, royalty payments (on net sales of products covered by a valid claim within the licensed intellectual property), maintenance fees and sublicense revenue payments. The upfront license fee of $0.05 million was expensed as research and development costs. The Company is obligated to make aggregate milestone payments of up to $1.5 million to UCSD upon the achievement of specified development and regulatory milestones for the treatment of Danon disease. A reduced schedule of milestone payments applies to achieving the same milestones for additional indications. With respect to any commercialized products covered by the agreement, the Company will obligated to pay a low single digit percentage royalty on net sales, subject to specified adjustments. If the Company enters into a sublicense agreement with a sublicensee, we will be obligated to pay a portion of any consideration received from such sublicensees in specified circumstances. The Company is also subject to certain diligence milestones for development of a product using the intellectual property licensed from UCSD under this agreement. The term of the license agreement with UCSD is through the expiration of the licensed patents, some of which are still in the pending application phase. REGENXBIO, Inc. License On November 19, 2018, the Company through its wholly-owned subsidiary Rocket Pharmaceuticals, Ltd., entered into a License Agreement (the “License Agreement”) with REGENXBIO Inc. (“RGNX”), pursuant to which the Company obtained an exclusive license for all U.S. patents and patent applications related to RGNX’s NAV AAV-9 vector for the treatment of Danon disease in humans by in vivo gene therapy using AAV-9 to deliver any known LAMP2 transgene isoforms and all possible combinations of LAMP2 transgene isoforms (the “Field”), as well as an exclusive option to license (the “Option Right”) all U.S. patents and patent applications for two additional NAV AAVvectors in the Field (each, a “Licensed Patent” and collectively, the “Licensed Patents”). Under the terms of the License Agreement, the Company is obligated to use commercially reasonable efforts to develop, commercialize, market, promote and sell products incorporating the Licensed Patents (“Licensed Products”). Unless the License Agreement is terminated earlier as provided below, the license from RGNX expires on a country-by-country, Licensed Product-by-Licensed Product basis until the later of the expiration date of the last to expire of the last valid claim of the applicable Licensed Patent or ten years after the first commercial sale of a Licensed Product in such country. The License Agreement provides that RGNX may terminate the agreement upon a material breach by the Company if the Company does not cure such breach within a specified notice period, if the Company commences a challenge against RGNX or certain of its licensors to declare or render invalid or unenforceable the licensed patents or upon the Company’s bankruptcy or insolvency. The Company may terminate the agreement in its entirety or terminate one or more of the licensed vectors at any time upon six months’ notice. The Company’s Option Right expires 4 years from the date of the License Agreement. In consideration for the rights granted to the Company under the License Agreement, the Company made an upfront payment to RGNX of $7,000 included as research and development expenses. A fee of $2,000 per additional vector would be due if the Company exercises its Option Right to purchase additional vectors. The License Agreement provides for royalties payable to RGNX in the high-single digits to low-teens on net sales levels of Licensed Products during the royalty term. If successful, the Company will be required to make milestone payments to RGNX of up to $13,000 for each Licensed Product upon the achievement of specified clinical development and regulatory milestones in the U.S. and European Union. In addition, the Company shall pay RGNX 20% of the payment fees received from a priority review voucher issued in connection with or otherwise related to a Licensed Product. These royalty obligations are subject to specified reductions if additional licenses from third parties are required. The Company must also pay RGNX a portion of all non-royalty sublicense income (if any) received from sublicensees.

Strategic Research Collaboration	12 Months Ended
Strategic Research Collaboration	Dec. 31, 2018
Strategic Research Collaboration [Abstract]
Strategic Research Collaboration	15. Strategic Research Collaboration On May 16, 2018, Rocket and the Stanford University School of Medicine (“Stanford University”) entered into a strategic collaboration to support the advancement of FA and PKD gene therapy research. Under the terms of the collaboration agreement, Stanford University will serve as the lead clinical trial research center in the U.S. for the planned FA registrational trial and would also be the lead U.S. site for PKD clinical trials. The project will also separately evaluate the potential for non-myeloablative, non-genotoxic antibody-based conditioning regimens as a future development possibility that may be applied across bone marrow-derived disorders. In addition, Rocket agreed to support expansion of Stanford University’s Laboratory for Cell and Gene Therapy (“LCGM”) in efforts to further enhance the development of Rocket’s internal pipeline. Rocket agreed to fund up to $3,500 for the LCGM expansion upon which 40% or $1,400 was due upon execution of the agreement and the balance is due upon the achievement of certain milestones. $1,400 of the $3,500 milestone payments was paid during the year ended December 31, 2018. As of December 31, 2018, none of the remaining milestones were met with regard to the LCGM. In January 2019, the Company and Stanford signed a Clinical Trial Agreement for the treatment of FA. Upon the signing of the January 2019 Stanford Clinical Trial Agreement, the second milestone of $1,400 for the LGCM became due and was expensed in January 2019, when the milestone was met.

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	16. Related Party Transactions During January 2018, the Company sold certain furniture and fixtures from the Inotek former corporate headquarters to a director of the Company for $20. During March 2018, the Company entered into a consulting agreement with a member of the Board of Directors for strategic and finance consulting services to be provided to the Company. The Company incurred expenses of $210 in connection with this consulting agreement. During April 2018, the Company entered into a consulting agreement with a different member of the Board of Directors for business development consulting services. Payments for the services under the agreement are $28 per quarter, and the Company may terminate the agreement with 14 days’ notice. The Company incurred expenses of $110 in connection with this consulting agreement.

401(k) Savings Plan	12 Months Ended
401(k) Savings Plan	Dec. 31, 2018
401(k) Savings Plan [Abstract]
401(k) Savings Plan	17. 401(k) Savings Plan The Company has a defined contribution savings plan (the “Plan”) under Section 401(k) of the Internal Revenue Code of 1986. This Plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. Company contributions to the Plan may be made at the discretion of the Company’s board of directors. The Company has elected to match 4% of employee contributions to the Plan, subject to certain limitations. The Company’s matching contribution for the year ended December 31, 2018, 2017 and 2016, was $112, $39 and $28, respectively.

Selected Quarterly Financial Data (unaudited)

12 Months Ended

Dec. 31, 2018

Selected Quarterly Financial Data (unaudited) [Abstract]

Selected Quarterly Financial Data (unaudited)

18. Selected Quarterly Financial Data (unaudited)

The following table contains quarterly financial information for 2018 and 2017. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair presentation of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period.

	2018
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter

Total revenue	$	-		$	-		$	-		$	-
Total operating expenses		14,405			14,872			15,333			26,546
Loss from operations		(14,405	)		(14,872	)		(15,333	)		(26,546	)
Net loss		(15,343	)		(15,767	)		(16,089	)		(27,319	)
Net loss per common share—basic and diluted	$	(0.42	)	$	(0.40	)	$	(0.40	)	$	(0.66	)

	2017
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter

Total revenue	$	-		$	-		$	-		$	-
Total operating expenses		2,870			3,521			6,725			6,656
Loss from operations		(2,870	)		(3,521	)		(6,725	)		(6,656	)
Net loss		(2,679	)		(3,521	)		(6,723	)		(6,655	)
Net loss per common share—basic and diluted	$	(0.39	)	$	(0.49	)	$	(0.99	)	$	(0.98	)

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Summary of Significant Accounting Policies [Abstract]

Principles of Consolidation

Use of Estimates

Cash, Cash Equivalents and Restricted Cash

	December 31, 2018		December 31, 2017

Cash and cash equivalents	$	111,355	$	18,142
Restricted cash		1,436		207
	$	112,791	$	18,349

Concentrations of Credit Risk and Off-balance Sheet Risk

Concentrations of credit risk and off-balance sheet risk

Investments

Investments at December 31, 2018 consist of the following:

	Cost Basis		Unrealized Losses			Fair Value

United States Treasury securities		101,904		(127	)		101,777
	$	101,904	$	(127	)	$	101,777

The Company evaluated its securities for other-than-temporary impairment and determined that no such impairment existed at December 31, 2018.

Goodwill

Property and Equipment

Impairment of Long-Lived Assets

Fair Value Measurements

Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly.

Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable.

Deferred Rent and Lease Liability

Research and Development

Foreign Currency Transactions

Treasury Stock

The Company records treasury stock at cost. Treasury stock consists of 50,000 shares that were settled in December 2018.

Share-Based Compensation

The Company recognizes compensation expense for at least the portion of awards that are vested. Forfeitures are accounted for as they occur.

NYC Biotechnology Tax Credit Program

Net Loss Per Share

Recent Accounting Pronouncements

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Summary of Significant Accounting Policies [Abstract]

Cash, Cash Equivalents and Restricted Cash

Cash, cash equivalents and restricted cash consist of the following:

	December 31, 2018		December 31, 2017

Cash and cash equivalents	$	111,355	$	18,142
Restricted cash		1,436		207
	$	112,791	$	18,349

Investments

Investments at December 31, 2018 consist of the following:

	Cost Basis		Unrealized Losses			Fair Value

United States Treasury securities		101,904		(127	)		101,777
	$	101,904	$	(127	)	$	101,777

Acquisition Accounting (Tables)

12 Months Ended

Dec. 31, 2018

Acquisition Accounting [Abstract]

Acquisition-date Fair Value of Consideration

The acquisition-date fair value of the consideration transferred is as follows:

Number of shares of the combined company owned by Inotek shareholders		6,805,608
Number of shares issuable in connection with fully vested RSUs of Inotek immediately prior to the Reverse Merger		271,718
Inotek common stock on the acquisition date		7,077,326
Price per share of Inotek common stock on acquisition date	$	12.16
Total purchase price	$	86,060

Recognized Identified Assets Acquired and Liabilities Assumed

Cash and cash equivalents	$	76,348
Short term investments		21,292
Prepaid expense and other assets		1,041
Property and equipment		256
Deposits		168
Goodwill		30,815
Accounts payable and accrued expenses		(4,961	)
Convertible notes		(38,388	)
Unfavorable lease liability		(511	)
Net assets acquired	$	86,060

Pro Forma Information

The following supplemental unaudited pro forma information presents the Company’s financial results as if the acquisition of Inotek had occurred on January 1, 2017:

	Year Ended December 31,
	2018			2017
Revenue	$	-		$	-
Net loss		(78,248	)		(35,760	)

Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value of Financial Instruments [Abstract]

Fair Value of Financial Instruments Measured on Recurring Basis

The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy:

	Fair Value Measurements as of
	December 31, 2018 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Money market mutual funds (included in cash and cash equivalents)	$	30,552	$	-	$	-	$	30,552

United States Treasury securities		101,777		-		-		101,777
Investments		101,777		-		-		101,777

	$	132,329	$	-	$	-	$	132,329

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property and Equipment [Abstract]

Property and Equipment

The Company’s property and equipment consisted of the following:

	December 31, 2018			December 31, 2017
Laboratory equipment	$	1,556		$	1,042
Computer equipment		179			98
Furniture and fixtures		273			115
Construction in progress		469			—
Leasehold improvements		29			—
		2,506			1,255
Less: accumulated depreciation		(479	)		(270	)
	$	2,027		$	985

Accounts Payable and Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2018

Accounts Payable and Accrued Expenses [Abstract]

Accounts Payable and Accrued Expenses

At December 31, 2018 and 2017, the Company’s accounts payable and accrued expenses consisted of the following:

	December 31, 2018		December 31, 2017
Bonus	$	1,774	$	703
Research and development		10,414		3,273
Severance and benefits		7		138
Professional fees		690		382
Government grant payable		534		—
Accrued interest		1,241		—
Accrued vacation		123		—
Other		589		25
	$	15,372	$	4,521

Convertible Notes Payable (Tables)

12 Months Ended

Dec. 31, 2018

Convertible Notes Payable [Abstract]

Carrying Value of Convertible Notes

The table below summarizes the carrying value of the 2021 Convertible Notes as of December 31, 2018:

Principal amount	$	52,000
Discount		(10,553	)
Carrying value as of December 31, 2018	$	41,447

Share-Based Awards (Tables)

12 Months Ended

Dec. 31, 2018

Share-Based Awards [Abstract]

Weighted-Average Assumptions for Stock Options

The weighted average assumptions that the Company used in the Black-Scholes pricing model to determine the fair value of the share options granted to employees and directors were as follows:

	Years Ended December 31,
	2018			2017			2016

Risk-free interest rate		2.64	%		2.06	%		1.65	%
Expected term (in years)		5.85			6.00			6.00
Expected volatility		87.7	%		91.3	%		96.10	%
Expected dividend yield		0.00	%		0.00	%		0.00	%
Exercise price	$	17.82		$	2.97		$	1.21
Fair value of common stock	$	17.98		$	2.63		$	0.98

The weighted average assumptions that the Company used in the Black-Scholes pricing model to determine the fair value of the share options granted to non-employees were as follows:

	Years Ended December 31,
	2018			2017			2016

Risk-free interest rate		2.85	%		2.39	%		2.39	%
Expected term (in years)		9.75			6.70			5.87
Expected volatility		82.19	%		90.62	%		106.15	%
Expected dividend yield		0.00	%		0.00	%		0.00	%
Exercise price	$	18.75		$	1.21		$	1.21
Fair value of common stock	$	19.63		$	1.08		$	1.11

Stock Option Activity

The following table summarizes stock option activity for the years ended December 31, 2018 and 2017, under the Revised 2014 Plan:

		Number of Shares			Weighted Average Exercise Price		Weighted Average Contractual Term (Years)

Outstanding as of December 31, 2015	*		5,332,950		$	0.69		9.90
Granted			1,005,871			1.21		7.23
Forfeited			(146,656	)		1.21		9.13
Outstanding as of December 31, 2016	*		6,192,164		$	0.79		9.00
Granted			812,894			2.98		5.50
Forfeited			(45,711	)		1.21		8.88
Outstanding as of December 31, 2017	*		6,959,347		$	1.06		8.17
Assumed as part of merger with Inotek			523,456			2.01		6.78
Granted			1,650,878			17.82		9.26
Exercised			(370,753	)		1.27		-
Forfeited			(146,931	)		3.02
Outstanding as of December 31, 2018			8,615,997		$	4.48		7.51

Options vested and exercisable as of December 31, 2018			6,466,265		$	1.22		6.52

*	Affected by Exchange Ratio

RSU Activity

The following table summarizes the RSU activity for the year ended December 31, 2018 under the Revised 2014 Plan:

	Number of Shares
Outstanding as of December 31, 2017		-
Assumed as part of merger with Inotek		271,719
Settled		(271,719	)
Outstanding as of December 31, 2018		-

Stock-Based Compensation Expense

Share-Based Compensation

	Year Ended December 31,
	2018		2017		2016

Research and development	$	7,375	$	523	$	159
General and administrative		6,226		797		115
Total share based compensation expense	$	13,601	$	1,320	$	274

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2018

Net Loss Per Share [Abstract]

Basic and Diluted Net Loss Per Share

Basic and diluted net loss per share attributable to common shareholders was calculated as follows:

	For the Years Ended December 31,
	2018			2017			2016

Numerator:
Net loss attributable to common shareholders	$	(74,518	)	$	(19,578	)	$	(7,573	)
Denominator:
Weighted-average common shares outstanding - basic and diluted		39,377,666			6,795,627			6,833,718
Net loss per share attributable to common shareholders - basic and diluted	$	(1.89	)	$	(2.88	)	$	(1.11	)

Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share

	For the Years Ended December 31,
	2018		2017		2016
Shares issuable upon conversion of the 2021 Convertible Notes		1,620,948		-		-
Warrants exercisable for common shares		14,102		-		-
Options to purchase common shares		8,615,997		6,756,695		6,192,164
Redeemable Series A convertible preferred shares (as converted to common shares)		-		9,807,564		9,807,905
Redeemable Series A convertible preferred shares (as converted to common shares)		-		9,668,224		-
		10,251,047		26,232,483		16,000,069

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Taxes [Abstract]

Net Loss by Jurisdiction

Net loss by jurisdiction consists of the following:

	For the years ended December 31,
	2018		2017		2016
Domestic	$	74,518	$	-	$	-
Foreign		-		19,578		7,573
Total	$	74,518	$	19,578	$	7,573

Reconciliation of Income Tax Benefit Computed at Statutory Federal Income Tax Rate to Income Taxes

A reconciliation of income tax benefit computed at the statutory federal income tax rate to income taxes as reflected in the financial statements is as follows:

	For the years ended December 31,
	2018			2017			2016
U.S. federal tax at statutory rate		21.0	%		34.0	%		34.0	%
Foreign source income not subject to tax		0.0	%		-34.0	%		-34.0	%
Stae income taxes		15.8	%		0.0	%		0.0	%
New York City tax		-			6.5	%		6.3	%
Other		-1.6	%		-			-
Section 382 limitation		-38.7	%		-			-
Valuation allowance		3.5	%		-6.5	%		-6.3	%
Effective tax rate		0	%		0	%		0	%

Deferred Tax Assets and Liabilities

The significant components of the Company’s deferred income tax assets and liabilities after applying the enacted corporate tax rates are as follows:

	For the years ended December 31,
	2018			2017			2016
Deferred income tax assets (liabilities)
Net operating losses (“NOL”) and credit carryforwards	$	28,400		$	1,620		$	458
Capitalized research and development costs		17,098			-			-
Other		1,385			136			25
Stock compensation		4,563			-			-
Debt discount		(3,652	)		-			-
Valuation allowance		(47,794	)		(1,756	)		(483	)
Net deferred income tax asset	$	-		$	-		$	-

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies [Abstract]

Remaining Aggregate Annual Commitments

As of December 31, 2018, the remaining aggregate annual commitments pursuant to the leases, as amended, are as follows:

2019	$	1,372
2020		1,953
2021		1,841
2022		1,739
2023		1,615
Thereafter		20,144
Total	$	28,664

Selected Quarterly Financial Data (unaudited) (Tables)

12 Months Ended

Dec. 31, 2018

Selected Quarterly Financial Data (unaudited) [Abstract]

Quarterly Financial Information

	2018
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter

Total revenue	$	-		$	-		$	-		$	-
Total operating expenses		14,405			14,872			15,333			26,546
Loss from operations		(14,405	)		(14,872	)		(15,333	)		(26,546	)
Net loss		(15,343	)		(15,767	)		(16,089	)		(27,319	)
Net loss per common share—basic and diluted	$	(0.42	)	$	(0.40	)	$	(0.40	)	$	(0.66	)

	2017
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter

Total revenue	$	-		$	-		$	-		$	-
Total operating expenses		2,870			3,521			6,725			6,656
Loss from operations		(2,870	)		(3,521	)		(6,725	)		(6,656	)
Net loss		(2,679	)		(3,521	)		(6,723	)		(6,655	)
Net loss per common share—basic and diluted	$	(0.39	)	$	(0.49	)	$	(0.99	)	$	(0.98	)

Nature of Business, Merger and Basis of Presentation (Details)		12 Months Ended
	Jan. 04, 2018 $ / shares shares	Dec. 31, 2018 Program $ / shares	Dec. 31, 2017 $ / shares
Programs in Clinical Testing [Abstract]
Number of additional programs in preclinical stages targeting other rare genetic diseases \| Program		2
Reverse Merger and Exchange Ratio [Abstract]
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common Stock [Member]
Reverse Merger and Exchange Ratio [Abstract]
Ownership percentage on fully diluted basis	81.357%
Common Stock [Member] \| Inotek [Member]
Reverse Merger and Exchange Ratio [Abstract]
Ownership percentage on fully diluted basis	18.643%
Inotek [Member] \| Common Stock [Member]
Reverse Merger and Exchange Ratio [Abstract]
Number of shares received pursuant to merger agreement (in shares) \| shares	76.185
Common stock, par value (in dollars per share)	$ 0.01

Risks and Liquidity (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Risks and Liquidity [Abstract]
Accumulated deficit	$ (105,873)	$ (31,355)
Cash, cash equivalents and investments	$ 213,132

Summary of Significant Accounting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Segment shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($)	Jan. 04, 2018 USD ($)	Dec. 31, 2015 USD ($)
Cash, Cash Equivalents and Restricted Cash [Abstract]
Cash and cash equivalents	$ 111,355	$ 18,142
Restricted cash	1,436	207
Total	112,791	18,349	$ 9,665		$ 15,487
Investments [Abstract]
Realized gains (losses) on investment	0	0	0
Unrealized losses on investments	$ (127)	0	0
Weighted average maturity period of investment portfolio	5 months 15 days
Average duration of long-term investments	14 months
Investments [Abstract]
Cost basis	$ 101,904
Unrealized losses	(127)
Fair value	$ 101,777
Goodwill [Abstract]
Number of operating segments \| Segment	1
Number of reporting units \| Segment	1
Goodwill impairment	$ 0
Impairment of Long-Lived Assets [Abstract]
Impairment of long-lived assets	$ 0	$ 0	0
Treasury Stock [Abstract]
Treasury Stock (in shares) \| shares	50,000	0
NYC Biotechnology Tax Credit Program [Abstract]
Research and development incentive income	$ 186	$ 192	$ 0
Income Tax [Abstract]
Federal corporate tax rate	21.00%	34.00%	34.00%
Minimum [Member]
Property and Equipment [Abstract]
Estimated useful lives	3 years
Maximum [Member]
Property and Equipment [Abstract]
Estimated useful lives	5 years
2021 Convertible Notes [Member]
Fair Value Measurements [Abstract]
Fair value convertible note	$ 43,182			$ 38,388
United States Treasury Securities [Member]
Investments [Abstract]
Cost basis	101,904
Unrealized losses	(127)
Fair value	101,777
Accounting Standards Update 2016-02 [Member] \| Minimum [Member] \| Plan [Member]
Recent Accounting Pronouncements [Abstract]
Lease liabilities	3,000
Right-of-use asset	2,600
Accounting Standards Update 2016-02 [Member] \| Maximum [Member] \| Plan [Member]
Recent Accounting Pronouncements [Abstract]
Lease liabilities	3,700
Right-of-use asset	$ 3,200

Acquisition Accounting (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jan. 04, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Estimated Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Goodwill		$ 30,815	$ 0
Non-recurring Items Directly Attributable to Business Combination [Abstract]
Share-based compensation expense		13,601	1,320	$ 274
Inotek [Member]
Acquisition-date Fair Value of Consideration Transferred [Abstract]
Number of shares issuable - consideration transferred (in shares)	7,077,326
Price per share of Inotek common stock on acquisition date (in dollars per share)	$ 12.16
Total purchase price	$ 86,060
Estimated Fair Values of Assets Acquired and Liabilities Assumed [Abstract]
Cash and cash equivalents	76,348
Short-term investments	21,292
Prepaid expense and other assets	1,041
Property and equipment	256
Deposits	168
Goodwill	30,815
Accounts payable and accrued expenses	(4,961)
Convertible notes	(38,388)
Unfavorable lease liability	(511)
Net assets acquired	$ 86,060
Acquisition Cost Incurred [Abstract]
Transaction costs		147
Supplemental Unaudited Pro Forma Information [Abstract]
Revenue		0	0
Net loss		(78,248)	$ (35,760)
Inotek [Member] \| Restricted Stock Units [Member]
Acquisition-date Fair Value of Consideration Transferred [Abstract]
Number of shares issuable - consideration transferred (in shares)	271,718
Inotek [Member] \| Common Stock [Member]
Acquisition-date Fair Value of Consideration Transferred [Abstract]
Number of shares issuable - consideration transferred (in shares)	6,805,608
Inotek [Member] \| Acquisition-related Costs [Member]
Non-recurring Items Directly Attributable to Business Combination [Abstract]
Transaction costs		4,512
Share-based compensation expense		3,459
Severance and stay bonuses expenses		$ 1,622

Fair Value of Financial Instruments (Details) - Recurring [Member] $ in Thousands	Dec. 31, 2018 USD ($)
Assets [Abstract]
Fair value of financial instruments	$ 132,329
Money Market Mutual Funds [Member]
Assets [Abstract]
Cash and cash equivalents	30,552
United States Treasury Securities [Member]
Assets [Abstract]
Fair value of financial instruments	101,777
Investments [Member]
Assets [Abstract]
Fair value of financial instruments	101,777
Level 1 [Member]
Assets [Abstract]
Fair value of financial instruments	132,329
Level 1 [Member] \| Money Market Mutual Funds [Member]
Assets [Abstract]
Cash and cash equivalents	30,552
Level 1 [Member] \| United States Treasury Securities [Member]
Assets [Abstract]
Fair value of financial instruments	101,777
Level 1 [Member] \| Investments [Member]
Assets [Abstract]
Fair value of financial instruments	101,777
Level 2 [Member]
Assets [Abstract]
Fair value of financial instruments	0
Level 2 [Member] \| Money Market Mutual Funds [Member]
Assets [Abstract]
Cash and cash equivalents	0
Level 2 [Member] \| United States Treasury Securities [Member]
Assets [Abstract]
Fair value of financial instruments	0
Level 2 [Member] \| Investments [Member]
Assets [Abstract]
Fair value of financial instruments	0
Level 3 [Member]
Assets [Abstract]
Fair value of financial instruments	0
Level 3 [Member] \| Money Market Mutual Funds [Member]
Assets [Abstract]
Cash and cash equivalents	0
Level 3 [Member] \| United States Treasury Securities [Member]
Assets [Abstract]
Fair value of financial instruments	0
Level 3 [Member] \| Investments [Member]
Assets [Abstract]
Fair value of financial instruments	$ 0

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property and Equipment [Abstract]
Property and equipment, gross	$ 2,506	$ 1,255
Less: accumulated depreciation	(479)	(270)
Property and equipment, net	2,027	985
Depreciation expense	330	204	$ 67
Laboratory Equipment [Member]
Property and Equipment [Abstract]
Property and equipment, gross	1,556	1,042
Computer Equipment [Member]
Property and Equipment [Abstract]
Property and equipment, gross	179	98
Furniture and Fixtures [Member]
Property and Equipment [Abstract]
Property and equipment, gross	273	115
Construction in Progress [Member]
Property and Equipment [Abstract]
Property and equipment, gross	469	0
Leasehold Improvements [Member]
Property and Equipment [Abstract]
Property and equipment, gross	$ 29	$ 0

Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable and Accrued Expenses [Abstract]
Bonus	$ 1,774	$ 703
Research and development	10,414	3,273
Severance and benefits	7	138
Professional fees	690	382
Government grant payable	534	0
Accrued interest	1,241	0
Accrued vacation	123	0
Other	589	25
Total	$ 15,372	$ 4,521

Convertible Notes Payable (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 04, 2018
Debt [Abstract]
Accretion of debt discount	$ 3,059	$ 0	$ 0
Carrying value of convertible notes [Abstract]
Carrying value	$ 41,447	$ 0
2021 Convertible Notes [Member]
Debt [Abstract]
Debt instrument maturity date	Aug. 01, 2021
Convertible senior notes, interest rate, stated percentage	5.75%
Conversion ratio	31.1876
Conversion price (in dollars per share)	$ 32.08
Conversion per principal amount of debt	$ 1
Percentage of common stock conversion price	200.00%
Number of trading days immediately preceding notice of redemption	5 days
Redemption price percentage	100.00%
Percentage of convertible notes due and payable in event of default	100.00%
Debt instrument, additional interest in the event of default for first 90 Days	0.25%
Debt instrument, additional interest in the event of default between 91st Day to 180th Day	0.50%
Effective interest rate	15.30%
Fair value convertible note	$ 43,182			$ 38,388
Accretion of debt discount	3,059
Carrying value of convertible notes [Abstract]
Principal amount	52,000
Discount	(10,553)
Carrying value	$ 41,447
2021 Convertible Notes [Member] \| Minimum [Member]
Debt [Abstract]
Conversion ratio	0
Stock price considered for conversion rate (in dollars per share)	$ 26.72
Percentage holders of principal amount of debt	25.00%
2021 Convertible Notes [Member] \| Maximum [Member]
Debt [Abstract]
Conversion ratio	6.2375
Stock price considered for conversion rate (in dollars per share)	$ 160.00

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands							12 Months Ended
	Jan. 02, 2019	Dec. 31, 2018	Dec. 28, 2018	Nov. 30, 2018	Jan. 24, 2018	Jan. 04, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shareholders' Equity Disclosure [Abstract]
Common stock, shares outstanding (in shares)		45,194,736				26,281,396	45,194,736	6,795,627
Gross proceeds, offering amount							$ 154,022	$ 0	$ 0
Shares repurchase							(668)
Treasury stock		$ (668)					$ (668)	$ 0
Common Stock [Member]
Shareholders' Equity Disclosure [Abstract]
Conversion of convertible preferred shares into common shares (in shares)						19,475,788	19,475,788
Number of shares sold (in shares)							11,475,242
Shares repurchase (in shares)							0
Shares repurchase							$ 0
Number of shares settled (in shares)		50,000
Average price of shares (in dollars per share)		$ 14.50
Prepaid Expense		$ 726					$ 726
Common Stock [Member] \| Subsequent Event [Member]
Shareholders' Equity Disclosure [Abstract]
Number of shares settled (in shares)	50,000
Average price of shares (in dollars per share)	$ 13.36
Common Stock [Member] \| RTW Investments, LP [Member]
Shareholders' Equity Disclosure [Abstract]
Number of shares sold (in shares)							100,000
Public offering price (in dollars per share)		$ 13.93					$ 13.93
Gross proceeds, offering amount							$ 1,396
Treasury Stock [Member]
Shareholders' Equity Disclosure [Abstract]
Shares repurchase (in shares)			100,000
Shares repurchase			$ (1,400)				(668)
Treasury stock		$ (668)					$ (668)
IPO [Member] \| Common Stock [Member]
Shareholders' Equity Disclosure [Abstract]
Number of shares sold (in shares)					6,325,000
Public offering price (in dollars per share)				$ 15.50	$ 13.25
Number of shares in public offering (in shares)				4,082,500
Number of shares sold pursuant to options granted (in shares)				532,500	825,000
Gross proceeds, offering amount				$ 63,339	$ 83,806
Net proceeds, offering amount				59,304	78,518
Offering costs				$ 4,035	$ 5,288
Private Placement [Member] \| Common Stock [Member]
Shareholders' Equity Disclosure [Abstract]
Public offering price (in dollars per share)				$ 15.50
Number of shares sold pursuant to options granted (in shares)				967,742
Gross proceeds, offering amount				$ 15,000
Net proceeds, offering amount				14,800
Offering costs				$ 200

Share-Based Awards, Stock Option and Incentive Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Option and Incentive Plan [Abstract]
Stock-based compensation expense	$ 13,601	$ 1,320	$ 274
Stock Options [Member]
Stock Option and Incentive Plan [Abstract]
Assumed as part of merger (in shares)	523,456
2015 Share Option Plan [Member] \| Stock Options [Member]
Stock Option and Incentive Plan [Abstract]
Exercise price per share of share options to fair market value of ordinary shares on date of grant, employees with at least 10% voting power	110.00%
Term of share options for employees with at least 10% voting power.	5 years
Number of shares available for issuance (in shares)	9,904,050
2015 Share Option Plan [Member] \| Stock Options [Member] \| Minimum [Member]
Stock Option and Incentive Plan [Abstract]
Exercise price per share of share options to fair market value of ordinary shares on date of grant	100.00%
2015 Share Option Plan [Member] \| Stock Options [Member] \| Maximum [Member]
Stock Option and Incentive Plan [Abstract]
Term Period of share options	10 years
Amended and Restated 2014 Stock Option and Incentive Plan [Member]
Stock Option and Incentive Plan [Abstract]
Number of shares available for issuance (in shares)	2,944,702
Second Amended and Restated 2014 Stock Option and Incentive Plan [Member]
Stock Option and Incentive Plan [Abstract]
Number of shares authorized (in shares)	4,294,830
Percentage of shares outstanding used to calculate annual increase in number of shares that can be issued	4.00%
Second Amended and Restated 2014 Stock Option and Incentive Plan [Member] \| Single Individual [Member] \| Maximum [Member]
Stock Option and Incentive Plan [Abstract]
Number of shares authorized (in shares)	1,000,000
2004 Stock Option and Incentive Plan [Member]
Stock Option and Incentive Plan [Abstract]
Stock-based compensation expense	$ 2,997
Incremental compensation cost	$ 462
2004 Stock Option and Incentive Plan [Member] \| Inotek [Member]
Stock Option and Incentive Plan [Abstract]
Assumed as part of merger (in shares)	523,456

Share-Based Awards, Share Option Valuation (Details) - Stock Options [Member] - $ / shares

12 Months Ended

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

^[1]

Stock Option Activity [Roll Forward]

Outstanding at beginning of period (in shares)

^[1]

6,959,347

6,192,164

5,332,950

Assumed as part of merger (in shares)

523,456

Granted (in shares)

1,650,878

812,894

1,005,871

Expired (in shares)

(370,753)

Forfeited (in shares)

(146,931)

(45,711)

(146,656)

Outstanding at end of period (in shares)

8,615,997

6,959,347

^[1]

6,192,164

^[1]

5,332,950

Options vested and exercisable at end of period (in shares)

6,466,265

Weighted Average Exercise Price [Abstract]

Outstanding at beginning of period (in dollars per share)

^[1]

$ 1.06

$ 0.79

$ 0.69

Assumed as part of merger (in dollars per share)

2.01

Granted (in dollars per share)

17.82

2.98

1.21

Exercised (in dollars per share)

1.27

forfeited (in dollars per share)

3.02

1.21

Outstanding at end of period (in dollars per share)

4.48

$ 1.06

^[1]

$ 0.79

^[1]

$ 0.69

Options vested and exercisable at end of period (in dollars per share)

$ 1.22

Weighted-Average Remaining Contractual Term [Abstract]

Outstanding

7 years 6 months 4 days

8 years 2 months 1 day

^[1]

9 years

^[1]

9 years 10 months 24 days

Assumed as part of merger

6 years 9 months 11 days

Granted

9 years 3 months 4 days

5 years 6 months

7 years 2 months 23 days

Forfeited

8 years 10 months 17 days

9 years 1 month 17 days

Exercised

0 years

Options vested and exercisable

6 years 6 months 7 days

Employees and Directors [Member]

Weighted-Average Assumptions [Abstract]

Risk-free interest rate

2.64%

2.06%

1.65%

Expected term

5 years 10 months 6 days

6 years

Expected volatility

87.70%

91.30%

96.10%

Expected dividend yield

0.00%

Exercise price (in dollars per share)

$ 17.82

$ 2.97

$ 1.21

Fair value of common stock (in dollars per share)

$ 17.98

$ 2.63

$ 0.98

Non-Employees [Member]

Weighted-Average Assumptions [Abstract]

Risk-free interest rate

2.85%

2.39%

Expected term

9 years 9 months

6 years 8 months 12 days

5 years 10 months 13 days

Expected volatility

82.19%

90.62%

106.15%

Expected dividend yield

0.00%

Exercise price (in dollars per share)

$ 18.75

$ 1.21

Fair value of common stock (in dollars per share)

$ 19.63

$ 1.08

$ 1.11

[1]	Affected by Exchange Ratio

Share-Based Awards, Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Options [Member]
Additional Disclosures [Abstract]
Intrinsic value of options exercised	$ 6
Intrinsic value of options exercisable	$ 88
Weighted average grant date fair value of shares granted (in dollars per share)	$ 13.21	$ 2.23	$ 74.15
Total fair value of options vested	$ 91,334	$ 502	$ 845
2014 Share Option Plan [Member] \| Restricted Stock Units [Member]
RSU Activity [Roll Forward]
Outstanding at beginning of period (in shares)	0
Assumed as part of reverse merger (in shares)	271,719
Settled (in shares)	(271,719)
Outstanding at end of period (in shares)	0	0

Share-Based Awards, Employee Stock Purchase Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 11, 2018
Share-based Compensation [Abstract]
Stock-based compensation expense	$ 13,601	$ 1,320	$ 274
Employee Stock Purchase Plan [Member]
Share-based Compensation [Abstract]
Annual maximum increase in number of shares that can be issued under ESPP (in shares)				150,000
Percentage of shares outstanding used to calculate annual increase in number of shares that can be issued				1.00%
Number of shares added to ESPP (in shares)	6,562
Number of shares available for issuance (in shares)	68,256				0
Stock purchased under ESPP (in shares)	0
Stock-based compensation expense	$ 0

Share-Based Awards, Stock-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock-Based Compensation [Abstract]
Stock-based compensation expense	$ 13,601	$ 1,320	$ 274
Unrecognized share-based compensation cost	$ 18,272
Weighted average period expected to recognize unrecognized share-based compensation cost	2 years 18 days
Research and Development [Member]
Stock-Based Compensation [Abstract]
Stock-based compensation expense	$ 7,375	523	159
General and Administrative [Member]
Stock-Based Compensation [Abstract]
Stock-based compensation expense	$ 6,226	$ 797	$ 115

Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator [Abstract]
Net loss attributable to common shareholders									$ (74,518)	$ (19,578)	$ (7,573)
Denominator [Abstract]
Weighted-average common shares outstanding - basic and diluted (in shares)									39,377,666	6,795,627	6,833,718
Net loss per share attributable to common shareholders - basic and diluted (in dollars per share)	$ (0.66)	$ (0.40)	$ (0.40)	$ (0.42)	$ (0.98)	$ (0.99)	$ (0.49)	$ (0.39)	$ (1.89)	$ (2.88)	$ (1.11)
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Securities excluded from computation of diluted net loss per share (in shares)									10,251,047	26,232,483	16,000,069
Shares Issuable upon Conversion of the 2021 Convertible Notes [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Securities excluded from computation of diluted net loss per share (in shares)									1,620,948	0	0
Warrants Exercisable for Common Shares [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Securities excluded from computation of diluted net loss per share (in shares)									14,102	0	0
Exercise price of warrants (in dollars per share)	$ 24.82								$ 24.82
Class of warrant or right, number of securities called by warrants or rights (in shares)	14,102								14,102
Warrants expiry date	Jun. 28, 2023								Jun. 28, 2023
Options to Purchase Common Shares [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Securities excluded from computation of diluted net loss per share (in shares)									8,615,997	6,756,695	6,192,164
Redeemable Series A Convertible Preferred Shares [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Securities excluded from computation of diluted net loss per share (in shares)									0	9,807,564	9,807,905
Redeemable Series A Convertible Preferred Shares [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Securities excluded from computation of diluted net loss per share (in shares)									0	9,668,224	0

Income Taxes, Net Loss by Jurisdiction (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Loss by Jurisdiction [Abstract]
Net loss	$ 27,319	$ 16,089	$ 15,767	$ 15,343	$ 6,655	$ 6,723	$ 3,521	$ 2,679	$ 74,518	$ 19,578	$ 7,573
Domestic [Member]
Net Loss by Jurisdiction [Abstract]
Net loss									74,518	0	0
Details of Income Taxes [Abstract]
Provision for income taxes									0	0	0
Foreign [Member]
Net Loss by Jurisdiction [Abstract]
Net loss									0	19,578	7,573
State [Member]
Details of Income Taxes [Abstract]
Provision for income taxes									$ 0	$ 0	$ 0

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Income Taxes, Reconciliation Between Effective Tax Rates and Statutory Rates (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Income Tax Benefit Computed at Statutory Federal Income Tax Rate to Income Taxes [Abstract]
U.S. federal tax at statutory rate	21.00%	34.00%	34.00%
Foreign source income not subject to tax	0.00%	(34.00%)	(34.00%)
State income taxes	15.80%	0.00%	0.00%
New York City tax	0.00%	6.50%	6.30%
Other	(1.60%)	0.00%	0.00%
Section 382 limitation	(38.70%)	0.00%	0.00%
Valuation allowance	3.50%	(6.50%)	(6.30%)
Effective tax rate	0.00%	0.00%	0.00%

Income Taxes, Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets (liabilities) [Abstract]
Net operating losses ("NOL") and credit carryforwards	$ 28,400	$ 1,620	$ 458
Capitalized research and development costs	17,098	0	0
Other	1,385	136	25
Stock compensation	4,563	0	0
Debt discount	(3,652)	0	0
Valuation allowance	(47,794)	(1,756)	(483)
Net deferred income tax asset	$ 0	$ 0	$ 0

Income Taxes, NOL Carryforwards and Tax Credits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Abstract]
Increase in valuation allowance	$ 46,016	$ 46,016	$ 1,273
Annual limitations under section 382 of IRC	1,700
Uncertain Tax Positions [Abstract]
Uncertain tax positions	0
Income Tax Penalties and Interest Accrued [Abstract]
Accrued interest or penalties	0	0
Federal [Member]
Operating Loss Carryforwards [Abstract]
NOL carryforwards	$ 96,400	127,100
NOL carryforwards, expiration date	Dec. 31, 2025
Net operating loss, subject to expiration	$ 34,100	$ 93,000
Cumulative limitation period	20 years
Net operating loss not subject to expiration	$ 62,300
Federal [Member] \| Research and Development [Member]
Tax Credit Carryforward [Abstract]
Tax credit carryforwards, subject to expiration	4,900
State [Member]
Operating Loss Carryforwards [Abstract]
NOL carryforwards	$ 124,500
NOL carryforwards, expiration date	Dec. 31, 2025

Commitments and Contingencies (Details) $ in Thousands	12 Months Ended
Commitments and Contingencies (Details) $ in Thousands	Dec. 31, 2018 USD ($) ft² LeaseAgreement	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Oct. 31, 2018 USD ($)	Jun. 07, 2018 USD ($)
Operating Leases [Abstract]
Write off of furniture and fixtures	$ 0	$ 0	$ 0
Restricted cash	1,436	207
Rent expense	807	$ 563	$ 358
Remaining Aggregate Annual Commitments [Abstract]
2019	1,372
2020	1,953
2021	1,841
2022	1,739
2023	1,615
Thereafter	20,144
Total	28,664
Property Subject to Operating Lease [Member]
Operating Leases [Abstract]
Restricted cash	$ 936
NY Lease Agreement [Member]
Operating Leases [Abstract]
Letter of credit expiration date	Oct. 29, 2020
Number of days written notice	90 days
Term of lease agreement	1 year
Early exit from lease	$ 94
Letter of credit	$ 209			$ 89
Lease expiration date	Feb. 28, 2023
Empire State Building, L.L.C [Member]
Operating Leases [Abstract]
Letter of credit expiration date	Jun. 30, 2019
Term of lease agreement	3 years
Term of renewal lease agreement	1 year
Renewal lease agreement expiration date	Sep. 30, 2021
Letter of credit					$ 936
Certificate of deposit					$ 936
MA Lease Agreement [Member]
Operating Leases [Abstract]
Accrued rent liability	$ 435
MA Lease Agreement [Member] \| Furniture and Fixtures [Member]
Operating Leases [Abstract]
Write off of furniture and fixtures	$ 205
NJ Lease Agreement [Member]
Operating Leases [Abstract]
Term of lease agreement	15 years
Term of renewal lease agreement	5 years
Area of lease \| ft²	92,000
Area handed to commence term of lease \| ft²	72,000
Area handed over upon earlier of election to commence lease of additional space \| ft²	20,000
Number of options to renew lease agreement \| LeaseAgreement	2
Estimated rent payments	$ 1,200
Percentage of annual increase in base rent	3.00%
Estimated total lease commitment amount	$ 26,492
Cash security deposit	$ 287
NJ Lease Agreement [Member] \| Maximum [Member]
Operating Leases [Abstract]
Period of time to commence lease of additional space	30 months

Agreements Related to Intellectual Property (Details) € in Thousands, $ in Thousands					1 Months Ended			6 Months Ended	12 Months Ended
	Sep. 17, 2018 USD ($)	Sep. 17, 2018 EUR (€)	Mar. 01, 2018 USD ($)	Mar. 01, 2018 EUR (€)	Feb. 28, 2017 USD ($)	Aug. 31, 2016 USD ($)	Aug. 31, 2016 EUR (€)	Aug. 31, 2018 USD ($)	Dec. 31, 2018 EUR (€) Patent	Dec. 31, 2018 USD ($) $ / Vector	Aug. 31, 2016 EUR (€)
License 161101 and SRA 161101 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development costs								$ 108
LAD-I [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development costs \| €				€ 1,690
Research and development costs, change in amount			$ (444)	€ (361)
PKD [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development costs \| €		€ 4,190
Research and development costs, change in amount	$ (1,168)	€ (1,007)
Contract Research and Collaboration Agreement with Lund University and J. Richter [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development costs						$ 20	€ 20
Term of agreement									24 months
Termination notice period									90 days
Agreement expiration date									Aug. 31, 2019
Contract Research and Collaboration Agreement with Lund University and J. Richter [Member] \| Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential future obligation						$ 100					€ 100
License Agreement for Danon Disease [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development costs					$ 50
License Agreement for Danon Disease [Member] \| Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential future obligation					$ 1,500
REGENXBIO, Inc. License [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development costs \| €									€ 7,000
Potential future obligation										$ 13,000
Term of agreement									10 years
Termination notice period									6 months
Number of patents \| Patent									2
Options right expiry term									4 years
Fee payable (per additional vector) \| $ / Vector										2,000
Royalties payable on fees received									20.00%

Strategic Research Collaboration (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2019	Dec. 31, 2018
Collaboration Agreement [Abstract]
Funding in strategic research collaboration		$ 3,500
Percentage of funding due upon execution of the agreement		40.00%
Initial funding due upon the execution of the agreement		$ 1,400
Milestone payment made during period		$ (1,400)
Subsequent Events [Member]
Collaboration Agreement [Abstract]
Milestone payment made during period	$ (1,400)

Related Party Transactions (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Abstract]
Proceeds from sale of property and equipment		$ 20	$ 0	$ 0
Member of the Board of Directors [Member]
Related Party Transaction [Abstract]
Accrued consulting services		210
Member of the Board of Directors Two [Member]
Related Party Transaction [Abstract]
Accrued consulting services		110
Business development consulting services expense (per quarter)		$ 28
Termination notice period for business development consulting services agreement		14 days
Director [Member]
Related Party Transaction [Abstract]
Proceeds from sale of property and equipment	$ 20

401(k) Savings Plan (Details) - USD ($) $ in Thousands	12 Months Ended
401(k) Savings Plan (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
401(k) Savings Plan [Abstract]
Percentage of matching employee contributions	4.00%
Matching employee contributions	$ 112	$ 39	$ 28

Selected Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Selected Quarterly Financial Data (unaudited) [Abstract]
Total revenue	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Total operating expenses	26,546	15,333	14,872	14,405	6,656	6,725	3,521	2,870	71,156	19,772	7,574
Loss from operations	(26,546)	(15,333)	(14,872)	(14,405)	(6,656)	(6,725)	(3,521)	(2,870)	(71,156)	(19,772)	(7,574)
Net loss	$ (27,319)	$ (16,089)	$ (15,767)	$ (15,343)	$ (6,655)	$ (6,723)	$ (3,521)	$ (2,679)	$ (74,518)	$ (19,578)	$ (7,573)
Net loss per common share-basic and diluted (in dollars per share)	$ (0.66)	$ (0.40)	$ (0.40)	$ (0.42)	$ (0.98)	$ (0.99)	$ (0.49)	$ (0.39)	$ (1.89)	$ (2.88)	$ (1.11)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details