MeiraGTx (MGTX) 10-Q 8 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	MGTX
Entity Registrant Name	MeiraGTx Holdings plc
Entity Central Index Key	1,735,438
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		27,386,632
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Sep. 30, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 88,560,634	$ 8,548,638
Prepaid expenses	2,029,327	1,961,243
Other current assets	716,737	965,233
Total Current Assets	91,306,698	11,475,114
Property and equipment, net	13,624,968	14,255,729
Security deposits	180,870
Restricted cash	123,376	123,376
TOTAL ASSETS	105,235,912	25,854,219
CURRENT LIABILITIES:
Accounts payable	2,415,667	7,055,380
Accrued expenses	6,042,290	9,332,944
Note payable		1,442,009
Warrant liability		2,679,633
Capitalized lease obligation - current portion	29,284	30,850
Due to Kadmon	0	861,030
Total Current Liabilities	8,487,241	21,401,846
Capitalized lease obligation	12,092	34,298
Deferred rent	210,993	266,290
Other liabilities	181,515	178,419
TOTAL LIABILITIES	8,891,841	21,880,853
COMMITMENTS
Convertible Preferred C Shares 0 and 5,005,935 outstanding at September 30, 2018 and December 31, 2017, respectively (liquidation preference of $52,455,700 at December 31, 2017)		51,338,631
SHAREHOLDERS' EQUITY (DEFICIT):
Ordinary Shares, $0.00003881 nominal value 27,184,132 issued and outstanding at September 30, 2018 8,826,190 issued and 8,714,563 issued and outstanding at December 31, 2017	1,055	342
Capital in excess of nominal value	223,868,465	20,080,713
Accumulated other comprehensive loss	(292,477)	(2,022,477)
Accumulated deficit	(127,232,972)	(65,423,843)
Total Shareholders' Equity (Deficit)	96,344,071	(47,365,265)
TOTAL LIABILITIES, CONVERTIBLE PREFERRED C SHARES AND SHAREHOLDERS' EQUITY (DEFICIT)	$ 105,235,912	$ 25,854,219

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred Stock, Shares Outstanding	0	5,005,935
Preferred Stock, Liquidation Preference, Value		$ 52,455,700
Common stock, par value	$ 0.00003881	$ 0.00003881
Common stock, shares authorized	1,288,327,750	1,288,327,750
Common stock, shares issued	27,184,132	8,826,190
Common stock, shares outstanding	27,184,132	8,714,563

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating expenses:
General and administrative	$ 6,629,052	$ 2,374,527	$ 35,129,120	$ 6,744,963
Research and development	8,109,160	6,388,227	22,827,176	16,575,129
Total operating expenses	14,738,212	8,762,754	57,956,296	23,320,092
Loss from operations	(14,738,212)	(8,762,754)	(57,956,296)	(23,320,092)
Other non-operating income (expense):
Other income			83,075
Foreign currency (loss) gain	(677,488)	391,521	(2,425,488)	990,395
Change in fair value of warrant liability			(1,514,775)
Interest income	264	2,915	50,926	21,295
Interest expense	(9,508)	(72,736)	(46,571)	(131,756)
Net loss	(15,424,944)	(8,441,054)	(61,809,129)	(22,440,158)
Other comprehensive income (loss)	508,758	(348,338)	1,730,000	(824,252)
Comprehensive loss	(14,916,186)	(8,789,392)	(60,079,129)	(23,264,410)
Net loss	(15,424,944)	(8,441,054)	(61,809,129)	(22,440,158)
Accretion on convertible preferred C shares and warrants		(191,758)	(1,806,512)	(244,920)
Adjusted net loss	$ (15,424,944)	$ (8,632,812)	$ (63,615,641)	$ (22,685,078)
Basic and diluted net loss per ordinary share	$ (0.59)	$ (1)	$ (3.89)	$ (2.66)
Weighted-average number of ordinary shares outstanding	26,340,450	8,607,832	16,355,849	8,536,447

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED C SHARES AND SHAREHOLDERS' EQUITY (DEFICIT) - 9 months ended Sep. 30, 2018 - USD ($)	Total	IPO [Member]	Ordinary shares [Member]	Ordinary shares [Member]IPO [Member]	Capital in Excess of Nominal Value [Member]	Capital in Excess of Nominal Value [Member]IPO [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Convertible Preferred C Shares [Member]	Convertible Preferred C Shares [Member]Accounts Payable [Member]	Convertible Preferred C Shares [Member]License Agreement [Member]	Convertible Preferred C Shares [Member]Sales Agreement [Member]
Beginning Balance at Dec. 31, 2017	$ (47,365,265)		$ 342		$ 20,080,713		$ (2,022,477)	$ (65,423,843)
Temporary equity, beginning Balance at Dec. 31, 2017									$ 51,338,631
Sale of A ordinary shares in initial public offering, net of issuance costs		$ 65,324,265		$ 194		$ 65,324,071
Beginning Balance, Shares at Dec. 31, 2017			8,826,190
Temporary equity, beginning Balance, Shares at Dec. 31, 2017	5,005,935								5,005,935
Accretion of issuance costs on convertible preferred C shares	$ (761,012)				(761,012)
Issuance of convertible preferred C shares, net of issuance costs										$ 1,356,129	$ 140,000	$ 56,159,119
Accretion of warrants issued in connection with convertible preferred C shares	(1,045,500)				(1,045,500)
Issuance of shares, net of issuance costs, Shares				5,000,000						129,419	13,360	5,425,124
Accretion of issuance costs on convertible preferred C shares									$ 761,012
Accretion of warrants issued in connection with convertible preferred C shares									1,045,500
Exercise of warrants	4,194,408				4,194,408				$ 9,720,000
Exercise of warrants, Share									927,594
Conversion convertible preferred C shares into A ordinary shares	120,520,391		$ 446		120,519,945				$ (120,520,391)
Conversion of convertible preferred C shares into A ordinary shares, Shares			11,501,432						(11,501,432)
Share-based compensation	$ 15,555,913		$ 73		15,555,840
Share-based compensation, Shares			1,856,510
Temporary equity, ending Balance, Shares at Sep. 30, 2018	0
Foreign currency translation	$ 1,730,000						1,730,000
Net loss	(61,809,129)							(61,809,129)
Ending Balance at Sep. 30, 2018	$ 96,344,071		$ 1,055		$ 223,868,465		$ (292,477)	$ (127,232,972)
Ending Balance, Shares at Sep. 30, 2018			27,184,132

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED C SHARES AND SHAREHOLDERS' EQUITY (DEFICIT) (Parenthetical)	9 Months Ended
	Sep. 30, 2018USD ($)
IPO [Member]
Sale of A ordinary shares in initial public offering, issuance costs	$ 9,675,735

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Cash flows from operating activities:
Net loss			$ (61,809,129)	$ (22,440,158)
Adjustments to reconcile net loss to net cash used in operating activities:
Preferred C shares issued in connection with a license agreement			137,658
Issuance of shares for services				16,875
Share-based compensation expense			15,555,913	2,019,652
Foreign currency loss (gain)	$ 677,488	$ (391,521)	2,425,488	(990,395)
Depreciation			1,549,686	579,696
Amortization of interest on asset retirement obligation			10,918	14,202	$ 19,313
Change in fair value of warrant liability			1,514,775
Decrease (increase) in operating assets:
Prepaid expenses and other current assets			(112,440)	(259,757)
Security deposits			(180,980)
Other current assets			239,627	(959,566)
Increase (decrease) in operating liabilities:
Deferred rent			(55,460)	1,184,269
Due to Kadmon			(861,030)	171,620
Accounts payable			(2,337,302)	3,850,544
Interest payable			0	0
Accrued expenses			(3,496,882)	2,467,083
Net cash used in operating activities			(47,419,158)	(14,345,935)
Cash flows from investing activities:
Purchase of property and equipment			(2,372,622)	(8,389,156)
Net cash used in investing activities			(2,372,622)	(8,389,156)
Cash flows from financing activities:
Payments on capitalized lease obligation			(23,772)	(16,753)
Exercise of warrants			9,720,000
Proceeds from the sale of ordinary shares			69,750,000
Proceeds from the sale of convertible preferred C shares			56,849,592	7,739,574
Issuance (payment) of note payable			(1,442,009)	(2,500,000)
Proceeds from excercised stock options				9,950
Net cash provided by financing activities			130,047,495	10,214,271
Net increase (decrease) in cash, cash equivalents and restricted cash			80,255,715	(12,520,820)
Effect of exchange rate changes on cash			(243,719)	12,125
Cash, cash equivalents and restricted cash at beginning of period			8,672,014	17,930,421	17,930,421
Cash, cash equivalents and restricted cash at end of period	$ 88,684,010	$ 5,421,726	88,684,010	5,421,726	$ 8,672,014
Supplemental disclosure of non-cash transactions:
Fixed asset acquisition included in accounts payable and accrued expenses at end of period				1,641,145
Issuance of convertible preferred C shares in connection with payables			1,356,129
Conversion of convertible preferred C shares into ordinary shares			120,520,391
Reclassification of warrant liability upon exercise of warrants			4,194,408
Capitalized lease obligation for equipment purchase				78,063
Issuance of ordinary shares in connection with a research agreement				17,001
Supplemental disclosure of cash flow information:
Cash paid for interest			31,531	2,728
Ordinary shares [Member]
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense			6,456,215
Cash flows from financing activities:
Issuance costs in connection with shares			(4,115,843)
Supplemental disclosure of non-cash transactions:
Issuance costs in connection with sale of ordinary shares in accrued expenses at end of period			309,892
Convertible Preferred C Shares [Member]
Cash flows from financing activities:
Issuance costs in connection with shares			$ (690,473)	$ (18,500)

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation: The Company MeiraGTx Holdings plc (the “Company” or “Meira Holdings”), a limited company under the laws of the Cayman Islands, is a clinical-stage biotech company developing novel gene therapy treatments for a wide range of inherited and acquired disorders for which there are no effective treatments available. The Company is focused on developing therapies for ocular diseases, including rare inherited blindness as well as Xerostomia following radiation treatment for head and neck cancers and neurodegenerative diseases such as amyothrophic lateral sclerosis (“ALS”) and Parkinson’s disease (“PD”). Reorganization and Initial Public Offering We commenced operations as MeiraGTx Limited, a private limited company incorporated under the laws of England and Wales in 2015. On May 28, 2018, the Board of Directors of MeiraGTx Limited approved the Reorganization Transactions, effective June 7, 2018, pursuant to which the Board of Directors approved the transfer of the shares held by each of the MeiraGTx Limited’s shareholders for the equivalent class and number of shares issued by Meira Holdings. On June 7, 2018, the Company completed its IPO, selling 5,000,000 ordinary shares (“Ordinary Shares”) at a public offering price of $15.00 per share, and receiving $65.3 million in net proceeds, after deducting underwriting discounts and commissions and offering expenses payable by us. Reverse Share Split On June 7, 2018 MeiraGTx Limited’s Board of Directors and shareholders approved a 1:3.881 reverse share split. All share information presented in these financial statements and accompanying footnotes have been retroactively adjusted to reflect the decreased number of shares resulting from this action. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). Interim Financial Statements The accompanying condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q S-X. S-1 No. 333-224914), Liquidity The Company has not generated any revenues and has not yet achieved profitable operations. There is no assurance that profitable operations, if ever achieved, could be sustained on a continuing basis. In addition, development activities, clinical and preclinical testing, and commercialization of the Company’s product candidates will require significant additional financing. Management expects to incur substantial and increasing losses in future periods. The success of the Company is subject to certain risks and uncertainties, including among others, uncertainty of product development; competition in the Company’s field of use; uncertainty of capital availability; uncertainty in the Company’s ability to enter into agreements with collaborative partners; dependence on third parties; and dependence on key personnel. The Company has not generated positive cash flows from operations, and there are no assurances that the Company will be successful in obtaining an adequate level of financing for the development and commercialization of its product candidates. As of September 30, 2018, the Company had cash and cash equivalents in the amount of $88,560,634, which consisted of depository accounts. The Company estimates that its cash and cash equivalents on hand at September 30, 2018 will cover its expenses into the second quarter of 2020. Risks and Uncertainties The Company operates in an industry that is subject to intense competition, government regulation and rapid technological change. The Company’s operations are subject to significant risk and uncertainties including financial, operational, technological, regulatory and other risks, including the potential risk of business failure. The Company’s limited capital resources and operations to date have been funded primarily with the proceeds from private equity offerings and the IPO. In the future, the Company may seek to raise additional capital through equity offerings, debt financings, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements or other sources to enable it to complete the development and potential commercialization of its product candidates.

Summary of Significant Accounti

Summary of Significant Accounting Policies and Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Recent Accounting Pronouncements	2. Summary of Significant Accounting Policies and Recent Accounting Pronouncements: Certain of the Company’s significant accounting policies are described below. All of the Company’s significant accounting policies are disclosed in the notes to the audited consolidated financial statements as of and for the year ended December 31, 2017 included in the Company’s Prospectus. Since the date of such financial statements, the Company has adopted the new accounting pronouncements which are disclosed further in this note. Consolidation The accompanying condensed consolidated financial statements include the accounts of Meira Holdings and its wholly owned subsidiaries: MeiraGTx Limited, a limited company under the laws of England and Wales (“Meira Limited); MeiraGTx, LLC, a Delaware corporation (“Meira LLC”); BRI-Alzan, (“BRI-Alzan”); MeiraGTx B.V., a Netherlands corporation (“Meira BV”); MeiraGTx UK II Limited, (“Meira UK II”), a limited company under the laws of England and Wales; and MeiraGTx UK Limited (“Meira UK”), a limited company under the laws of England and Wales. All intercompany balances and transactions between the consolidated companies have been eliminated in consolidation. Use of Estimates Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these condensed consolidated financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the condensed consolidated financial statements if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. In preparing these condensed consolidated financial statements, management used significant estimates in the following areas, among others: valuation of A ordinary shares (“ A Ordinary Shares”) issued prior to the Company’s initial public offering, for the acquisition of assets, the accounting for research and development costs, warrants, share-based compensation, asset retirement obligations and accrued expenses. Fair Value Measurements Fair value is defined as the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. The fair value should be calculated based on assumptions that market participants would use in pricing the asset or liability, not on assumptions specific to the entity. In addition, the fair value of liabilities should include consideration of non-performance The Company follows ASC Topic 820, Fair Value Measurements and Disclosures • Level 1: Observable inputs such as quoted prices in active markets for identical assets the reporting entity has the ability to access as of the measurement date; • Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and • Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The table below represents the values of the Company’s financial assets and liabilities that are required to be measured at fair value on a recurring basis: Fair Value Measurement Using: Description September 30, Significant Significant Other Significant Restricted cash $ 123,376 $ 123,376 $ — $ — Fair Value Measurement Using: Description December 31, Significant Significant Other Significant Restricted cash $ 123,376 $ 123,376 $ — $ — Warrants $ 2,679,633 $ — $ — $ 2,679,633 The table below represents a rollforward of the assets and liabilities that are required to be measured at fair value on a recurring basis from December 31, 2017 to September 30, 2018: Significant Balance as of December 31, 2017 $ 2,679,633 Change in fair value of warrants 1,514,775 Exercise of warrants (4,194,408 ) Balance as of September 30, 2018 $ — The warrants were classified as liabilities because the underlying Convertible Preferred C Shares (the “Preferred Shares”) had a redemption feature in the event of a change of control of the Company. On June 5, 2018, the warrants were exercised at which time the warrant liability was determined to be $4,194,408, which represented the difference in the market value of the Preferred Shares and the exercise price of the warrants. This resulted in an increase of the warrant liability in the amount of $1,514,775 for the nine- month period ended September 30, 2018. The related warrant liability of $4,194,408 was reclassified as Capital in Excess of Nominal Value at such time. The fair values of the warrants at June 4, 2018, March 31, 2018 and December 31, 2017 were estimated using the Black-Scholes valuation model with the following assumptions: June 4, 2018 March 31, 2018 December 31, 2017 Risk-free interest rate 1.77 % 1.86 % 1.72 % Expected volatility 80 % 80 % 80 % Expected dividend yield 0 0 0 Expected life 1 day 5.5 months 9 months For the unobservable inputs for the warrants, the expected volatility was determined at each measurement date by taking an average of the volatility of other publicly-traded peer biotechnology companies. The expected life was determined at each measurement date based upon the Company’s estimate of the time until the Company has a conversion event. The fair value of the Preferred Shares was based upon recent issuances of the Company’s Preferred Shares on or about December 31, 2017, March 31, 2018 and June 5, 2018. Net Loss per Ordinary Share Basic net loss per Ordinary Share is computed by dividing net loss by the weighted average number of shares of the Company’s Ordinary Shares assumed to be outstanding during the period of computation. Diluted net loss per ordinary share is computed similar to basic net loss per share except that the denominator is increased to include the number of additional Ordinary Shares that would have been outstanding if the potential Ordinary Shares had been issued at the beginning of the year and if the additional Ordinary Shares were dilutive (treasury stock method) or the two-class Asset Retirement Obligation Accounting for Asset Retirement Obligations requires legal obligations associated with the retirement of long-lived assets to be recognized at fair value when incurred and capitalized as part of the related long-lived asset. In the absence of quoted market prices, the Company estimates the fair value of its asset retirement obligations using Level 3 present value techniques, in which estimates of future cash flows associated with retirement activities are discounted using a credit-adjusted risk-free rate. Asset retirement obligations currently reported as other liabilities on the Condensed Consolidated Balance Sheet were measured during a period of historically low interest rates. The impact on measurements of new asset retirement obligations using different rates in the future may be significant. The Company uses estimates to determine the amount of the asset retirement obligations at the end of the lease term and discounts such asset retirement obligations using an estimated discount rate. Interest on the discounted asset retirement obligation is amortized over the term of the lease using the effective interest method and is recorded as interest expense in the condensed consolidated statements of operations and comprehensive loss. The change in asset retirement obligations is as follows: September 30, 2018 December 31, 2017 Balance at beginning of period $ 178,419 $ 221,254 Amortization of interest 10,918 19,313 Change in estimate — (75,011 ) Effects of exchange rate (7,822 ) 12,863 Balance at end of period $ 181,515 $ 178,419 Research and Development Research and development costs are charged to expense as incurred. These costs include, but are not limited to, employee-related expenses, including salaries, benefits and travel of the Company’s research and development personnel; expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical and preclinical studies and manufacture the drug product for the clinical studies and preclinical activities; acquisition of in-process Costs for certain development activities, such as Company funded outside research programs, are recognized based on an evaluation of the progress to completion of specific tasks with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the condensed financial statements as prepaid expenses or accrued expenses, as the case may be. Segment Information Management has concluded it has a single reporting segment for purposes of reporting financial condition and results of operations. The following table summarizes non-current September 30, 2018 December 31, 2017 United States $ 468,922 $ 436,463 United Kingdom 13,460,292 13,942,642 $ 13,929,214 $ 14,379,105 Recent Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, 505-50 all 2018-07 No. 2018-07 In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business, ASU 2017-01 , ASU 2017-01 ASU 2017-01 also ASU 2017-01 should 2017-01 In December 2016, the FASB issued ASU No. 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, or ASU 2016-20, that allows met. ASU 2016-20 also requires ASU 2014-09. ASU 2014-09. ASU 2016-20 In November 2016, the Financial Accounting Standards Board, or FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash ASU 2016-18, which the beginning-of-period and end-of-period amounts ASU 2016-18 also ASU 2016-18 will ASU 2016-18 In October 2016, the FASB issued ASU 2016-16, Income Intra-Entity Transfers of Assets Other than Inventory ASU 2016-16 which ASU 2016-16 to In May 2016, the FASB issued ASU No. 2016-12 , Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients ASU 2016-12, which ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) ASU 2014-09, on ASU 2016-12 are ASU 2014-09, as ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date ASU 2015-14 . ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606), Identifying Performance Obligations and Licensing ASU 2016-10 , ASU 2016-10 requires 2016-10 categorizes ASU 2016-10 has ASU 2014-09, as ASU 2015-14. In ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606), Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ASU 2016-08, which ASU 2014-09 by ASU 2016-08 has ASU 2014-09, as ASU 2015-14. The In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers 2014-09, 2014-09 2014-09 2014-09 non-public 2014-09 2014-09 2014-09

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Accrued Expenses	3. Accrued Expenses Accrued expenses for the periods presented are comprised of the following: September 30, 2018 December 31, 2017 Clinical Trial Costs $ 2,900,351 $ 4,859,410 Professional Fees 983,677 231,923 Compensation and Benefits 872,406 2,386,903 Consulting 820,828 1,220,477 Rent 144,449 387,267 Other 320,579 246,964 $ 6,042,290 $ 9,332,944

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	4. Share-Based Compensation 2018 and 2016 Equity Incentive Plans The Company maintains the 2018 Incentive Award Plan and 2016 Equity Incentive Plan (together, the “Plans”), under which, the Company has granted share options to selected officers, employees and non-employee A summary of the Company’s share option activity related to employees, non-employee non-employee Number of Options Weighted- Aggregate Outstanding at December 31, 2017 938,637 $ 5.12 $ 1,420,650 Granted 695,685 5.79 Exercised — — Expired — — Forfeited (4,635 ) (4.98 ) Outstanding at September 30, 2018 1,629,687 $ 5.42 $ 13,336,764 Weighted average remaining contractual life of options outstanding as of December 31, 2017 (yrs) 9.09 Weighted average remaining contractual life of options outstanding as of September 30, 2018 (yrs) 8.74 Options exercisable at December 31, 2017 186,395 $ 7.72 $ — Options exercisable at September 30, 2018 411,140 $ 6.43 $ 2,948,369 Weighted average remaining contractual life of options exercisable as of December 31, 2017 (yrs) 8.21 Weighted average remaining contractual life of options exercisable as of September 30, 2018 (yrs) 7.95 The total fair value of options vested during the three-month periods ended September 30, 2018 and 2017 was $503,828 and $41,309, respectively. The total fair value of options vested during the nine-month periods ended September 30, 2018 and 2017 was $1,060,177 and $800,599, respectively. During the nine-month periods ended September 30, 2018 and 2017, the Company granted 695,685 and 610,645 share options. The grant date fair values of the share options granted were estimated using the Black-Scholes option valuation model with the following ranges of assumptions: 2018 2017 Risk-free interest rate 2.32% - 2.93% 2.28% - 2.51% Expected volatility 90% 80% Expected dividend yield 0% 0% Expected life (in years) 5.5 - 10.0 5.5 - 10.0 As of September 30, 2018, the total compensation expense relating to unvested options granted that had not yet been recognized was $6,407,369, which is expected to be realized over a period of 3.96 years. The Company will issue shares upon exercise of options from Ordinary Shares reserved. The weighted average grant date fair value of options granted during the nine-month periods ended September 30, 2018 and 2017 was $4.46 and $2.79, respectively. Restricted Ordinary Shares In 2015, in connection with certain service and consulting agreements, certain employees and a consultant were awarded an aggregate of 867,935 restricted Ordinary Shares of the Company. Such shares were subject to forfeiture over a three-year service period. The shares granted to the consultant and employees were valued at $7.72 and $7.76 per share, respectively, and were included in loss from operations over the requisite service period. As of September 30, 2018, all such shares are no longer subject to forfeiture as the three-year service period has been completed. On June 7, 2018, 1,306,348 restricted Ordinary Shares, which represented 5% of the fully-diluted outstanding shares of the Company as of such date, were issued to certain members of senior management in accordance with their employment agreements. One-third S-1 A summary of the restricted Ordinary Shares is as follows: Ordinary Shares $ Value Non-vested 105,913 $ 865,861 Issued during the nine-month period ended September 30, 2018 1,306,348 19,595,220 Vesting during the nine-month period ended September 30, 2018 (650,225 ) (9,030,541 ) Non-vested 762,036 $ 11,430,540 Ordinary Shares On March 1, 2018, a funding milestone was met under the employment agreements for certain members of senior management. Accordingly, the employees were issued an aggregate of 550,162 fully vested Ordinary Shares, which represented 3% of the fully-diluted outstanding shares of the Company as of such date. The shares were recorded as share-based compensation in the amount of $3,096,104. Additionally, under the terms of the employment agreements, the Company was required to pay the income taxes incurred by the grantees in connection with the grant of those shares. Total compensation expense in connection with the issuance of those Ordinary Shares, in the amount of $6,456,215, of which $3,096,104 was share-based, was recorded as general and administrative expense during the nine-month period ended September 30, 2018. During the three-month and nine-month periods ended September 30, 2018 and 2017 the Company recognized total share-based compensation expense in the accompanying condensed consolidated statements of operations and comprehensive loss as follows: Three-month periods ended September 30, 2018 2017 Research and development $ 1,040,499 $ 373,570 General and administrative 1,881,858 135,263 Total share based compensation $ 2,922,357 $ 508,833 Nine-month periods ended September 30, 2018 2017 Research and development $ 2,931,010 $ 1,613,493 General and administrative 12,624,903 430,430 Total share based compensation $ 15,555,913 $ 2,043,923 The Company does not expect to realize any tax benefits from its share option activity or the recognition of share-based compensation expense because the Company currently has net operating losses and has a full valuation allowance against its deferred tax assets. Accordingly, no amounts related to excess tax benefits have been reported in cash flows from operations or cash flows from financing activities for the three-month and nine-month periods ended September 30, 2018 and 2017.

Ordinary Shares and Convertible

Ordinary Shares and Convertible Preferred C Shares	9 Months Ended
	Sep. 30, 2018
Federal Home Loan Banks [Abstract]
Ordinary Shares and Convertible Preferred C Shares	5. Ordinary Shares and Convertible Preferred C Shares: Ordinary Shares As discussed in Note 4, on March 1, 2018, a funding milestone was met under the employment agreements for certain members of senior management. Accordingly, the employees were issued an aggregate of 550,162 fully vested Ordinary Shares. In connection with the Company’s initial public offering, on June 7, 2018, the Company issued 5,000,000 Ordinary Shares at an offering price of $15.00 per share for gross proceeds of $75,000,000, excluding offering costs of $9,675,735. Also, as discussed in Note 4, on June 7, 2018, upon the effectiveness of the Company’s Registration Statement, 1,306,348 restricted Ordinary Shares, which represented 5% of the fully-diluted outstanding shares of the Company as of such date, were issued to certain members of senior management in accordance with their employment agreements. One-third Warrants On June 5, 2018, all of the outstanding warrants to purchase 927,594 Preferred Shares at an exercise price of approximately $10.48 per share were exercised for aggregate cash proceeds of $9,720,000. Convertible Preferred C Shares During the nine-month period ended September 30, 2018, the Company issued 5,425,124 Preferred Shares at an offering price of approximately $10.48 per share for gross proceeds of $56,849,592, excluding offering costs of $690,473. Also, during the nine-month period ended September 30, 2018, the Company issued 129,419 Preferred Shares in lieu of payment of accounts payable in the aggregate amount $1,356,129 to certain vendors. On March 15, 2018, the Company issued 13,360 Preferred Shares in connection with a license agreement. On June 7, 2018, upon effectiveness of the Company’s Registration Statement on Form S-1,

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Net Loss per Share	6. Net Loss per Share The Company computes net loss per share in accordance with ASC 260-10, Earnings per Share Basic and diluted net loss per ordinary share is computed as follows: Three-month periods ended September 30, 2018 2017 Net loss—basic and diluted $ (15,424,944 ) $ (8,441,054 ) Accretion of Preferred Shares financing costs — (130,258 ) Accretion of warrants — (61,500 ) Adjusted net loss—basic and diluted $ (15,424,944 ) $ (8,632,812 ) Weighted-average ordinary shares outstanding: Basic and Diluted 26,340,450 8,607,832 Net loss per share: Basic and Diluted $ (0.59 ) $ (1.00 ) Nine-month periods ended September 30, 2018 2017 Net loss—basic and diluted $ (61,809,129 ) $ (22,440,158 ) Accretion of Preferred Shares financing costs (761,012 ) (183,420 ) Accretion of warrants (1,045,500 ) (61,500 ) Adjusted net loss—basic and diluted $ (63,615,641 ) $ (22,685,078 ) Weighted-average ordinary shares outstanding: Basic and Diluted 16,355,849 8,536,447 Net loss per share: Basic and Diluted $ (3.89 ) $ (2.66 ) The following securities are considered to be Ordinary Share equivalents, but were not included in the computation of diluted net loss per Ordinary Share because to do so would have been anti-dilutive: September 30, 2018 September 30, 2017 Preferred Shares — 2,339,578 A restricted ordinary shares subject to forfeiture 762,036 175,913 Stock options 1,629,687 938,637 2,391,723 3,454,128

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	7. Income Taxes The Company did not record a provision for income taxes for the three-months and nine-months ended September 30, 2018 and 2017, as the Company has generated losses for all periods. The Company periodically evaluates the realizability of its net deferred tax assets based on all available evidence, both positive and negative. The realization of net deferred tax assets is dependent on the Company’s ability to generate sufficient future taxable income during periods prior to the expiration of tax attributes to fully utilize these assets. The Company weighed both positive and negative evidence and determined that there is a continued need for a full valuation allowance on its deferred tax assets in the United States and United Kingdom as of September 30, 2018. Should the Company determine that it would be able to realize its remaining deferred tax assets in the foreseeable future, an adjustment to its remaining deferred tax assets would cause a material increase to income in the period such determination is made.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	8. Related Party Transactions: Transition Services Agreement Effective April 24, 2015, the Company entered into a three-year transition services agreement (the “TSA”) with Kadmon, which is a minority shareholder of the Company, whereby Kadmon would provide office and laboratory facilities as well as certain other personnel support activities to the Company. Under the agreement, the Company was charged for (i) rent based upon the square footage of the office and laboratory facilities used by the Company (ii) other personnel support activities based upon the hours of the personnel providing the support activities, and (iii) and other direct costs incurred by Kadmon on behalf of the Company, plus a 7% administrative fee. The TSA terminated on April 24, 2018 and the Company is currently leasing office space on a month to month basis from Kadmon. During the three-month periods ended September 30, 2018 and 2017, the Company incurred the following charges from Kadmon, which are included in loss from operations: 2018 2017 Rent $ 140,805 $ 136,353 Personnel — 5,202 Other — 41 Total charges incurred $ 140,805 $ 141,596 During the nine-month periods ended September 30, 2018 and 2017, the Company incurred the following charges from Kadmon, which are included in loss from operations: 2018 2017 Rent $ 416,479 $ 411,877 Personnel 6,493 30,480 Other — 5,247 Total charges incurred $ 422,972 $ 447,604 During the three-month periods ended September 30, 2018 and 2017, the Company made cash payments totaling $140,954 and $0, respectively, to Kadmon. During the nine-month periods ended September 30, 2018 and 2017, the Company made cash payments totaling $1,284,258 and $275,941, respectively, to Kadmon. The amount due to Kadmon at September 30, 2018 and December 31, 2017 is $0 and $861,030, respectively and is disclosed as Due to Kadmon on the Company’s condensed consolidated balance sheets. Research Agreement Effective October 23, 2016, the Company entered into a four-year master services agreement with UCL Consultants Limited, an entity affiliated with University College of London (“UCL”), which is a shareholder of the Company. Pursuant to the agreement, UCL Consultants Limited provides pre-clinical Total research and development expenses under this agreement for the three-month periods ended September 30, 2018 and 2017 were approximately $137,000 and $112,000, respectively. Total research and development expenses under this agreement for the nine-month periods ended September 30, 2018 and 2017 was approximately $509,000 and $334,000, respectively. Future obligations, under the agreement equal £695,321, or approximately $905,934, through October 2020. The amount due to UCL under the master services agreement at September 30, 2018 and December 31, 2017 is $484,408 and $775,315, respectively, and is included in accounts payable and accrued expenses on the condensed consolidated balance sheets. Manufacturing Agreement Effective September 1, 2016, the Company entered into a manufacturing and drug supply agreement with UCL. Pursuant to the agreement, UCL manufactured materials for the Company’s clinical trials under the direction of the Company. Either party could terminate the agreement by giving 30 days written notice. The agreement was terminated in January 2018. Total research and development expenses under this agreement for the three-month periods ended September 30, 2018 and 2017 was approximately $0 and $567,150, respectively. Total research and development expenses under this agreement for the nine-month periods ended September 30, 2018 and 2017 was approximately $0 and $1,609,668, respectively. The amount due to UCL under the manufacturing and drug supply agreement at September 30, 2018 and December 31, 2017 is $0 and $2,466,142, respectively, and is included in accrued expenses in the condensed consolidated balance sheet. License Agreement Effective March 15, 2018, the Company entered into an exclusive worldwide license agreement with UCL Business, PLC (“UCL Business”), to develop up to eight programs using certain ocular gene therapy technology. Under the terms of the agreement, the Company has agreed to pay UCL Business certain sales milestone payments, if achieved, in the aggregate amount of £39.8 million, or approximately $51.9 million using the exchange rate at September 30, 2018, and royalties on net sales, as defined upon commercialization. Additionally, the Company is responsible for all patent prosecution and maintenance costs incurred and has also agreed to pay UCL Business an annual maintenance fee of £50,000, or approximately $66,000, until the first commercial sale of a product. The agreement will terminate upon the later of (i) the last valid claim in a relevant product, (ii) the expiration of regulatory exclusivity to all licensed products, or (iii) the 10 th The Company did not incur any research and development expenses under the agreement during the three-month and nine-month periods ended September 30, 2018 and 2017. Leases December 2016 Lease Effective December 15, 2016, the Company entered into a non-cancellable Total rent expense under this operating lease was $0 and $390,903 for the three-month periods ended September 30, 2018 and 2017, respectively. Total rent expense under this operating lease was $0 and $1,172,709 for the nine-month periods ended September 30, 2018 and 2017, respectively. On October 26, 2017, in connection with the amendment to the lease, the Company issued a promissory note in the amount of $1,442,009 to ARE. The note accrued interest at the rate of 5% per annum and was due on December 31, 2018. However, if the Company had sufficient liquidity, as defined in the note, then the note, including accrued interest, would become due and payable at that time. In accordance with the sufficient liquidity provision, the Company repaid the note, plus accrued interest, in the aggregate amount of $1,472,433 during the three-month period ended March 31, 2018. The Company recorded interest expense of $0 and $30,424 for the three-month and nine-month periods ended September 30, 2018. July 2016 Lease Effective July 1, 2016, the Company entered into a non-cancellable Total rent expense under this operating lease was $121,888 and $121,889 for the three-month periods ended September 30, 2018 and 2017, respectively. Total rent expense under this operating lease was $365,668 and $365,669 for the nine-month periods ended September 30, 2018 and 2017, respectively. As of September 30, 2018, the aggregate future minimum rental payments under this lease are $1,795,570. In connection with the signing of this lease, the Company entered into a standby letter of credit agreement for $122,866, which serves as a security deposit for the premises. The standby letter of credit expires on July 7, 2017 and is automatically renewed annually through July 7, 2021. This standby letter of credit is secured with restricted cash in a money market account. The aggregate future minimum rental payments under this lease are as follow: 2018 $ 131,618 2019 535,683 2020 554,432 2021 573,837 Total future rent payments $ 1,795,570

Commitments

Commitments	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments	9. Commitments: On September 7, 2018, the Company entered into an exclusive licensing agreement with the National Institutes of Health (“NIH”) for worldwide rights to expanded indications for use of AAV-AQP1 AAV-AQP1 AAV-AQP1 On July 27, 2018 two leases for office and laboratory facilities in London, UK expired. Effective July 27, 2018, the Company entered into two new non-cancellable The aggregate future minimum rental payments under these leases are as follow: 2018 $ 89,565 2019 358,258 2020 358,258 2021 358,258 2022 358,258 Thereafter 1,582,308 Total future rent payments $ 3,104,905

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	10. Subsequent Events: Management has evaluated subsequent events through the date of this filing. Based on our evaluation, the following disclosures have been made: On October 5, 2018, the Company entered into an agreement to acquire Vector Neurosciences Inc. (“Vector”) pursuant to an Agreement and Plan of Merger (the “Merger Agreement”) by and among the Company, Vector, VN Acquisition, Inc., a wholly-owned subsidiary of the Company (“Merger Sub 1”), VN Acquisition 2, Inc., a wholly-owned subsidiary of the Company (“Merger Sub 2”), the Vector stockholders named therein and the Vector stockholder representative, pursuant to which Merger Sub 1 was merged with and into Vector, with Vector being the surviving corporation (“Merger 1”) and, immediately following Merger 1, Vector was merged with and into Merger Sub 2, with Merger Sub 2 being the surviving corporation (together with Merger 1, the “Merger”). As a result of the Merger, Vector is a wholly-owned subsidiary of the Company. The Company’s board of directors, Vector’s board of directors and Vector’s stockholders have, in each case, unanimously approved the Merger, the Merger Agreement and the transactions contemplated by the Merger Agreement. The merger consideration to Vector’s stockholders consists of 225,000 shares of the Company’s Ordinary Shares as initial merger consideration, consisting of 202,500 shares which were issued at the closing of the Merger and an additional 22,500 shares to be issued 18 months following the closing, subject to any indemnification claims under the Merger Agreement. Based on the closing price of the Company’s Ordinary Shares on October 5, 2018, the value of the initial merger consideration is approximately $3.0 million. In addition, pursuant to the terms of the Merger Agreement, the Company will issue to Vector’s stockholders additional Ordinary Shares equal to a maximum value of $21 million if specified regulatory milestones are met and will make royalty payment to Vector’s stockholders in an amount equal to a percentage of the value of sales of certain products developed based on the Vector assets, which royalty payments are also payable in Ordinary Shares. The number of Ordinary Shares to be issued in connection with such milestones and royalties will be based on the three-day (AAV-GAD), AAV-GAD On October 9, 2018, the Company entered into a research collaboration agreement with Janssen Pharmaceuticals, Inc. (“Janssen”), one of the Janssen Pharmaceutical Companies of Johnson & Johnson, to develop regulatable gene therapy treatment using the Company’s proprietary riboswitch technology. As part of the agreement, the Company will use its proprietary riboswitch technology to engineer regulatable gene therapy constructs encoding proprietary gene sequences from Janssen.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
The Company	The Company MeiraGTx Holdings plc (the “Company” or “Meira Holdings”), a limited company under the laws of the Cayman Islands, is a clinical-stage biotech company developing novel gene therapy treatments for a wide range of inherited and acquired disorders for which there are no effective treatments available. The Company is focused on developing therapies for ocular diseases, including rare inherited blindness as well as Xerostomia following radiation treatment for head and neck cancers and neurodegenerative diseases such as amyothrophic lateral sclerosis (“ALS”) and Parkinson’s disease (“PD”).
Reorganization and Initial Public Offering	Reorganization and Initial Public Offering We commenced operations as MeiraGTx Limited, a private limited company incorporated under the laws of England and Wales in 2015. On May 28, 2018, the Board of Directors of MeiraGTx Limited approved the Reorganization Transactions, effective June 7, 2018, pursuant to which the Board of Directors approved the transfer of the shares held by each of the MeiraGTx Limited’s shareholders for the equivalent class and number of shares issued by Meira Holdings. On June 7, 2018, the Company completed its IPO, selling 5,000,000 ordinary shares (“Ordinary Shares”) at a public offering price of $15.00 per share, and receiving $65.3 million in net proceeds, after deducting underwriting discounts and commissions and offering expenses payable by us.
Liquidity	Liquidity The Company has not generated any revenues and has not yet achieved profitable operations. There is no assurance that profitable operations, if ever achieved, could be sustained on a continuing basis. In addition, development activities, clinical and preclinical testing, and commercialization of the Company’s product candidates will require significant additional financing. Management expects to incur substantial and increasing losses in future periods. The success of the Company is subject to certain risks and uncertainties, including among others, uncertainty of product development; competition in the Company’s field of use; uncertainty of capital availability; uncertainty in the Company’s ability to enter into agreements with collaborative partners; dependence on third parties; and dependence on key personnel. The Company has not generated positive cash flows from operations, and there are no assurances that the Company will be successful in obtaining an adequate level of financing for the development and commercialization of its product candidates. As of September 30, 2018, the Company had cash and cash equivalents in the amount of $88,560,634, which consisted of depository accounts. The Company estimates that its cash and cash equivalents on hand at September 30, 2018 will cover its expenses into the second quarter of 2020.
Risks and Uncertainties	Risks and Uncertainties The Company operates in an industry that is subject to intense competition, government regulation and rapid technological change. The Company’s operations are subject to significant risk and uncertainties including financial, operational, technological, regulatory and other risks, including the potential risk of business failure. The Company’s limited capital resources and operations to date have been funded primarily with the proceeds from private equity offerings and the IPO. In the future, the Company may seek to raise additional capital through equity offerings, debt financings, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements or other sources to enable it to complete the development and potential commercialization of its product candidates.
Interim Financial Statements	Interim Financial Statements The accompanying condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q S-X. S-1 No. 333-224914),
Reverse Share Split	Reverse Share Split On June 7, 2018 MeiraGTx Limited’s Board of Directors and shareholders approved a 1:3.881 reverse share split. All share information presented in these financial statements and accompanying footnotes have been retroactively adjusted to reflect the decreased number of shares resulting from this action.
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Consolidation	Consolidation The accompanying condensed consolidated financial statements include the accounts of Meira Holdings and its wholly owned subsidiaries: MeiraGTx Limited, a limited company under the laws of England and Wales (“Meira Limited); MeiraGTx, LLC, a Delaware corporation (“Meira LLC”); BRI-Alzan, (“BRI-Alzan”); MeiraGTx B.V., a Netherlands corporation (“Meira BV”); MeiraGTx UK II Limited, (“Meira UK II”), a limited company under the laws of England and Wales; and MeiraGTx UK Limited (“Meira UK”), a limited company under the laws of England and Wales. All intercompany balances and transactions between the consolidated companies have been eliminated in consolidation.
Use of Estimates	Use of Estimates Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these condensed consolidated financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the condensed consolidated financial statements if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. In preparing these condensed consolidated financial statements, management used significant estimates in the following areas, among others: valuation of A ordinary shares (“ A Ordinary Shares”) issued prior to the Company’s initial public offering, for the acquisition of assets, the accounting for research and development costs, warrants, share-based compensation, asset retirement obligations and accrued expenses.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. The fair value should be calculated based on assumptions that market participants would use in pricing the asset or liability, not on assumptions specific to the entity. In addition, the fair value of liabilities should include consideration of non-performance The Company follows ASC Topic 820, Fair Value Measurements and Disclosures • Level 1: Observable inputs such as quoted prices in active markets for identical assets the reporting entity has the ability to access as of the measurement date; • Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and • Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The table below represents the values of the Company’s financial assets and liabilities that are required to be measured at fair value on a recurring basis: Fair Value Measurement Using: Description September 30, Significant Significant Other Significant Restricted cash $ 123,376 $ 123,376 $ — $ — Fair Value Measurement Using: Description December 31, Significant Significant Other Significant Restricted cash $ 123,376 $ 123,376 $ — $ — Warrants $ 2,679,633 $ — $ — $ 2,679,633 The table below represents a rollforward of the assets and liabilities that are required to be measured at fair value on a recurring basis from December 31, 2017 to September 30, 2018: Significant Balance as of December 31, 2017 $ 2,679,633 Change in fair value of warrants 1,514,775 Exercise of warrants (4,194,408 ) Balance as of September 30, 2018 $ — The warrants were classified as liabilities because the underlying Convertible Preferred C Shares (the “Preferred Shares”) had a redemption feature in the event of a change of control of the Company. On June 5, 2018, the warrants were exercised at which time the warrant liability was determined to be $4,194,408, which represented the difference in the market value of the Preferred Shares and the exercise price of the warrants. This resulted in an increase of the warrant liability in the amount of $1,514,775 for the nine- month period ended September 30, 2018. The related warrant liability of $4,194,408 was reclassified as Capital in Excess of Nominal Value at such time. The fair values of the warrants at June 4, 2018, March 31, 2018 and December 31, 2017 were estimated using the Black-Scholes valuation model with the following assumptions: June 4, 2018 March 31, 2018 December 31, 2017 Risk-free interest rate 1.77 % 1.86 % 1.72 % Expected volatility 80 % 80 % 80 % Expected dividend yield 0 0 0 Expected life 1 day 5.5 months 9 months For the unobservable inputs for the warrants, the expected volatility was determined at each measurement date by taking an average of the volatility of other publicly-traded peer biotechnology companies. The expected life was determined at each measurement date based upon the Company’s estimate of the time until the Company has a conversion event. The fair value of the Preferred Shares was based upon recent issuances of the Company’s Preferred Shares on or about December 31, 2017, March 31, 2018 and June 5, 2018.
Net Loss per Ordinary Share	Net Loss per Ordinary Share Basic net loss per Ordinary Share is computed by dividing net loss by the weighted average number of shares of the Company’s Ordinary Shares assumed to be outstanding during the period of computation. Diluted net loss per ordinary share is computed similar to basic net loss per share except that the denominator is increased to include the number of additional Ordinary Shares that would have been outstanding if the potential Ordinary Shares had been issued at the beginning of the year and if the additional Ordinary Shares were dilutive (treasury stock method) or the two-class
Asset Retirement Obligation	Asset Retirement Obligation Accounting for Asset Retirement Obligations requires legal obligations associated with the retirement of long-lived assets to be recognized at fair value when incurred and capitalized as part of the related long-lived asset. In the absence of quoted market prices, the Company estimates the fair value of its asset retirement obligations using Level 3 present value techniques, in which estimates of future cash flows associated with retirement activities are discounted using a credit-adjusted risk-free rate. Asset retirement obligations currently reported as other liabilities on the Condensed Consolidated Balance Sheet were measured during a period of historically low interest rates. The impact on measurements of new asset retirement obligations using different rates in the future may be significant. The Company uses estimates to determine the amount of the asset retirement obligations at the end of the lease term and discounts such asset retirement obligations using an estimated discount rate. Interest on the discounted asset retirement obligation is amortized over the term of the lease using the effective interest method and is recorded as interest expense in the condensed consolidated statements of operations and comprehensive loss. The change in asset retirement obligations is as follows: September 30, 2018 December 31, 2017 Balance at beginning of period $ 178,419 $ 221,254 Amortization of interest 10,918 19,313 Change in estimate — (75,011 ) Effects of exchange rate (7,822 ) 12,863 Balance at end of period $ 181,515 $ 178,419
Research and Development	Research and Development Research and development costs are charged to expense as incurred. These costs include, but are not limited to, employee-related expenses, including salaries, benefits and travel of the Company’s research and development personnel; expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical and preclinical studies and manufacture the drug product for the clinical studies and preclinical activities; acquisition of in-process Costs for certain development activities, such as Company funded outside research programs, are recognized based on an evaluation of the progress to completion of specific tasks with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the condensed financial statements as prepaid expenses or accrued expenses, as the case may be.
Segment Information	Segment Information Management has concluded it has a single reporting segment for purposes of reporting financial condition and results of operations. The following table summarizes non-current September 30, 2018 December 31, 2017 United States $ 468,922 $ 436,463 United Kingdom 13,460,292 13,942,642 $ 13,929,214 $ 14,379,105
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, 505-50 all 2018-07 No. 2018-07 In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business, ASU 2017-01 , ASU 2017-01 ASU 2017-01 also ASU 2017-01 should 2017-01 In December 2016, the FASB issued ASU No. 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, or ASU 2016-20, that allows met. ASU 2016-20 also requires ASU 2014-09. ASU 2014-09. ASU 2016-20 In November 2016, the Financial Accounting Standards Board, or FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash ASU 2016-18, which the beginning-of-period and end-of-period amounts ASU 2016-18 also ASU 2016-18 will ASU 2016-18 In October 2016, the FASB issued ASU 2016-16, Income Intra-Entity Transfers of Assets Other than Inventory ASU 2016-16 which ASU 2016-16 to In May 2016, the FASB issued ASU No. 2016-12 , Revenue from Contracts with Customers (Topic 606), Narrow-Scope Improvements and Practical Expedients ASU 2016-12, which ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) ASU 2014-09, on ASU 2016-12 are ASU 2014-09, as ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date ASU 2015-14 . ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606), Identifying Performance Obligations and Licensing ASU 2016-10 , ASU 2016-10 requires 2016-10 categorizes ASU 2016-10 has ASU 2014-09, as ASU 2015-14. In ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606), Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ASU 2016-08, which ASU 2014-09 by ASU 2016-08 has ASU 2014-09, as ASU 2015-14. The In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers 2014-09, 2014-09 2014-09 2014-09 non-public 2014-09 2014-09 2014-09

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Compnay's Financial Assets and Liabilities Measured at Fair Value	The table below represents the values of the Company’s financial assets and liabilities that are required to be measured at fair value on a recurring basis: Fair Value Measurement Using: Description September 30, Significant Significant Other Significant Restricted cash $ 123,376 $ 123,376 $ — $ — Fair Value Measurement Using: Description December 31, Significant Significant Other Significant Restricted cash $ 123,376 $ 123,376 $ — $ — Warrants $ 2,679,633 $ — $ — $ 2,679,633
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below represents a rollforward of the assets and liabilities that are required to be measured at fair value on a recurring basis from December 31, 2017 to September 30, 2018: Significant Balance as of December 31, 2017 $ 2,679,633 Change in fair value of warrants 1,514,775 Exercise of warrants (4,194,408 ) Balance as of September 30, 2018 $ —
Fair Values of Warrants Estimated by Using Black-Scholes Valuation Model	The fair values of the warrants at June 4, 2018, March 31, 2018 and December 31, 2017 were estimated using the Black-Scholes valuation model with the following assumptions: June 4, 2018 March 31, 2018 December 31, 2017 Risk-free interest rate 1.77 % 1.86 % 1.72 % Expected volatility 80 % 80 % 80 % Expected dividend yield 0 0 0 Expected life 1 day 5.5 months 9 months
Schedule of change in asset retirement obligations	The change in asset retirement obligations is as follows: September 30, 2018 December 31, 2017 Balance at beginning of period $ 178,419 $ 221,254 Amortization of interest 10,918 19,313 Change in estimate — (75,011 ) Effects of exchange rate (7,822 ) 12,863 Balance at end of period $ 181,515 $ 178,419
Summary of Non-Current Assets by Geographical Area	The following table summarizes non-current September 30, 2018 December 31, 2017 United States $ 468,922 $ 436,463 United Kingdom 13,460,292 13,942,642 $ 13,929,214 $ 14,379,105

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses for the periods presented are comprised of the following: September 30, 2018 December 31, 2017 Clinical Trial Costs $ 2,900,351 $ 4,859,410 Professional Fees 983,677 231,923 Compensation and Benefits 872,406 2,386,903 Consulting 820,828 1,220,477 Rent 144,449 387,267 Other 320,579 246,964 $ 6,042,290 $ 9,332,944

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Company's Share Option Activity Related to Employees, Non-Employee Members of the Board of Directors and Non-Employee Consultants	A summary of the Company’s share option activity related to employees, non-employee non-employee Number of Options Weighted- Aggregate Outstanding at December 31, 2017 938,637 $ 5.12 $ 1,420,650 Granted 695,685 5.79 Exercised — — Expired — — Forfeited (4,635 ) (4.98 ) Outstanding at September 30, 2018 1,629,687 $ 5.42 $ 13,336,764 Weighted average remaining contractual life of options outstanding as of December 31, 2017 (yrs) 9.09 Weighted average remaining contractual life of options outstanding as of September 30, 2018 (yrs) 8.74 Options exercisable at December 31, 2017 186,395 $ 7.72 $ — Options exercisable at September 30, 2018 411,140 $ 6.43 $ 2,948,369 Weighted average remaining contractual life of options exercisable as of December 31, 2017 (yrs) 8.21 Weighted average remaining contractual life of options exercisable as of September 30, 2018 (yrs) 7.95
Schedule of Grant Date Fair Values of the Stock Option Granted	The grant date fair values of the share options granted were estimated using the Black-Scholes option valuation model with the following ranges of assumptions: 2018 2017 Risk-free interest rate 2.32% - 2.93% 2.28% - 2.51% Expected volatility 90% 80% Expected dividend yield 0% 0% Expected life (in years) 5.5 - 10.0 5.5 - 10.0
Summary of Restricted Ordinary Shares	A summary of the restricted Ordinary Shares is as follows: Ordinary Shares $ Value Non-vested 105,913 $ 865,861 Issued during the nine-month period ended September 30, 2018 1,306,348 19,595,220 Vesting during the nine-month period ended September 30, 2018 (650,225 ) (9,030,541 ) Non-vested 762,036 $ 11,430,540
Schedule of Share Based Compensation Expense	During the three-month and nine-month periods ended September 30, 2018 and 2017 the Company recognized total share-based compensation expense in the accompanying condensed consolidated statements of operations and comprehensive loss as follows: Three-month periods ended September 30, 2018 2017 Research and development $ 1,040,499 $ 373,570 General and administrative 1,881,858 135,263 Total share based compensation $ 2,922,357 $ 508,833 Nine-month periods ended September 30, 2018 2017 Research and development $ 2,931,010 $ 1,613,493 General and administrative 12,624,903 430,430 Total share based compensation $ 15,555,913 $ 2,043,923

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss per Share	Basic and diluted net loss per ordinary share is computed as follows: Three-month periods ended September 30, 2018 2017 Net loss—basic and diluted $ (15,424,944 ) $ (8,441,054 ) Accretion of Preferred Shares financing costs — (130,258 ) Accretion of warrants — (61,500 ) Adjusted net loss—basic and diluted $ (15,424,944 ) $ (8,632,812 ) Weighted-average ordinary shares outstanding: Basic and Diluted 26,340,450 8,607,832 Net loss per share: Basic and Diluted $ (0.59 ) $ (1.00 ) Nine-month periods ended September 30, 2018 2017 Net loss—basic and diluted $ (61,809,129 ) $ (22,440,158 ) Accretion of Preferred Shares financing costs (761,012 ) (183,420 ) Accretion of warrants (1,045,500 ) (61,500 ) Adjusted net loss—basic and diluted $ (63,615,641 ) $ (22,685,078 ) Weighted-average ordinary shares outstanding: Basic and Diluted 16,355,849 8,536,447 Net loss per share: Basic and Diluted $ (3.89 ) $ (2.66 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share	The following securities are considered to be Ordinary Share equivalents, but were not included in the computation of diluted net loss per Ordinary Share because to do so would have been anti-dilutive: September 30, 2018 September 30, 2017 Preferred Shares — 2,339,578 A restricted ordinary shares subject to forfeiture 762,036 175,913 Stock options 1,629,687 938,637 2,391,723 3,454,128

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Incurred Charges Included in Loss from Operations	During the three-month periods ended September 30, 2018 and 2017, the Company incurred the following charges from Kadmon, which are included in loss from operations: 2018 2017 Rent $ 140,805 $ 136,353 Personnel — 5,202 Other — 41 Total charges incurred $ 140,805 $ 141,596 During the nine-month periods ended September 30, 2018 and 2017, the Company incurred the following charges from Kadmon, which are included in loss from operations: 2018 2017 Rent $ 416,479 $ 411,877 Personnel 6,493 30,480 Other — 5,247 Total charges incurred $ 422,972 $ 447,604

Commitments (Tables)

Commitments (Tables)	9 Months Ended
	Sep. 30, 2018
July 2016 Lease [Member]
Schedule of Future Minimum Rental Payments	The aggregate future minimum rental payments under this lease are as follow: 2018 $ 131,618 2019 535,683 2020 554,432 2021 573,837 Total future rent payments $ 1,795,570
July 27, 2018 Lease [Member]
Schedule of Future Minimum Rental Payments	The aggregate future minimum rental payments under these leases are as follow: 2018 $ 89,565 2019 358,258 2020 358,258 2021 358,258 2022 358,258 Thereafter 1,582,308 Total future rent payments $ 3,104,905

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Detail)	Jun. 07, 2018USD ($)$ / sharesshares	Mar. 01, 2018shares	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Schedule Of Description Of Business [Line Items]
Reverse share split ratio	0.257
Cash and cash equivalents			$ 88,560,634	$ 8,548,638
Ordinary shares [Member]
Schedule Of Description Of Business [Line Items]
Ordinary shares, issued | shares	5,000,000	550,162
Ordinary shares, offering price | $ / shares	$ 15
Proceeds from issuance initial public offering net	$ 65,300,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Company's Financial Instruments Carried at Fair Value Measurements (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Restricted Cash [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, net asset (liability)	$ 123,376	$ 123,376
Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, net asset (liability)		2,679,633
Fair Value, Inputs, Level 1 [Member] | Restricted Cash [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, net asset (liability)	$ 123,376	123,376
Fair Value, Inputs, Level 3 [Member] | Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, net asset (liability)		$ 2,679,633

Summary of Significant Accoun_5

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)	9 Months Ended
	Sep. 30, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of warrants	$ 1,514,775
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	2,679,633
Change in fair value of warrants	1,514,775
Exercise of warrants	(4,194,408)
Ending balance	$ 0

Summary of Significant Accoun_6

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2018	Jun. 05, 2018	Dec. 31, 2017
Warrant liability		$ 4,194,408	$ 2,679,633
Change in fair value of warrants	$ 1,514,775
Exercise of warrants liability	4,194,408
Capital in Excess of Nominal Value [Member]
Exercise of warrants liability	$ 4,194,408

Summary of Significant Accoun_7

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Fair Values of Warrants Estimated by Using Black-Scholes Valuation Model (Detail) - Warrants [Member]	Jun. 04, 2018	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Risk-free interest rate	1.72%	1.86%	1.77%
Expected volatility	80.00%	80.00%	80.00%
Expected dividend yield	0.00%	0.00%	0.00%
Expected life	1 day	5 months 15 days	9 months

Summary of Significant Accoun_8

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Schedule of Change in Asset Retirement Obligations (Detail) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Asset Retirement Obligation [Abstract]
Balance at beginning of period	$ 178,419	$ 221,254	$ 221,254
Amortization of interest	10,918	$ 14,202	19,313
Change in estimate			(75,011)
Effects of exchange rate	(7,822)		12,863
Balance at end of period	$ 181,515		$ 178,419

Summary of Significant Accoun_9

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Summary of Non-Current Assets by Geographical Area (Detail) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Operation By Geographical [Line Items]
Non current assets	$ 13,929,214	$ 14,379,105
United States
Operation By Geographical [Line Items]
Non current assets	468,922	436,463
United Kingdom
Operation By Geographical [Line Items]
Non current assets	$ 13,460,292	$ 13,942,642

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Clinical Trial Costs	$ 2,900,351	$ 4,859,410
Professional Fees	983,677	231,923
Compensation and Benefits	872,406	2,386,903
Consulting	820,828	1,220,477
Rent	144,449	387,267
Other	320,579	246,964
Accrued expenses	$ 6,042,290	$ 9,332,944

Share based Compensation - Addi

Share based Compensation - Additional Information (Detail) - USD ($)	Jun. 07, 2018	Mar. 01, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual life of options outstanding					8 years 8 months 26 days		9 years 1 month 2 days
Fair value of options Vested			$ 503,828	$ 41,309	$ 1,060,177	$ 800,599
Share options granted during the period					695,685
Fully-diluted outstanding shares	5.00%
Share based compensation					$ 15,555,913	2,019,652
Excess Tax Benefit from Share-based Compensation, Operating Activities			0	0	0	0
Excess Tax Benefit from Share-based Compensation, Financing Activities			0	$ 0	$ 0	$ 0
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual life of options outstanding					10 years
Ordinary shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares awarded, per share	$ 15
Fully-diluted outstanding shares		3.00%
Share based compensation		$ 3,096,104			$ 6,456,215
Ordinary shares, issued	5,000,000	550,162
Ordinary shares [Member] | General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation					$ 3,096,104
Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares	1,306,348				1,306,348
Ordinary shares forfeiture period								3 years
Ordinary shares awarded, per share	$ 15
Fully-diluted outstanding shares	5.00%
Share based compensation			3,405,274		$ 17,026,140
Restricted Shares [Member] | General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation			1,992,182		$ 8,523,932
Restricted Shares [Member] | Ordinary shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares								867,935
Employee and Non Employee Board of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share options granted during the period					695,685	610,645
Total unvested options compensation expense			$ 6,407,369		$ 6,407,369
Unvested options expected to be realized					3 years 11 months 15 days
Weighted average grant date fair value of options granted					$ 4.46	$ 2.79
Consultant [Member] | Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares awarded, per share			$ 7.72		7.72
Employee [Member] | Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares awarded, per share			$ 7.76		$ 7.76
First Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Over Three Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					36 months

Share Based Compensation - Summ

Share Based Compensation - Summary of Company's Share Option Activity Related to Employees, Non-Employee Members of the Board of Directors and Non-Employee Consultants (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of options, Beginning balance	938,637
Number of options, Granted	695,685
Number of options, Exercised	0
Number of options, Expired	0
Number of options, Forfeited	(4,635)
Number of options, Ending balance	1,629,687	938,637
Weighted average remaining contractual life of options outstanding	8 years 8 months 26 days	9 years 1 month 2 days
Number of options, Options exercisable	411,140	186,395
Weighted average remaining contractual life of options exercisable	7 years 11 months 12 days	8 years 2 months 16 days
Weighted- average exercise price, beginning balance	$ 5.12
Weighted- average exercise price, granted	5.79
Weighted- average exercise price, exercised	0
Weighted- average exercise price, expired	0
Weighted- average exercise price, forfeited	(4.98)
Weighted- average exercise price, ending balance	5.42	$ 5.12
Weighted- average exercise price, option exercisable	$ 6.43	$ 7.72
Aggregate Intrinsic Value	$ 13,336,764	$ 1,420,650
Aggregate Intrinsic Value, Options exercisable	$ 2,948,369

Share Based Compensation - Sche

Share Based Compensation - Schedule of Grant Date Fair Values of the Stock Option Granted Black Scholes Valuation Model (Detail) - Employee and Non Employee Board of Directors [Member]	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	2.32%	2.28%
Risk-free interest rate	2.93%	2.51%
Expected volatility	90.00%	80.00%
Expected dividend yield	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of non-employee options (in years)	5 years 6 months	5 years 6 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of non-employee options (in years)	10 years	10 years

Share Based Compensation - Su_2

Share Based Compensation - Summary of Restricted Ordinary Shares (Detail) - Restricted Shares [Member] - USD ($)	Jun. 07, 2018	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested Ordinary Shares, Beginning Balance		105,913
Issued, Ordinary Shares	1,306,348	1,306,348
Vesting, Ordinary Shares		(650,225)
Non-vested Ordinary Shares, Ending Balance		762,036
Non-vested Value, Beginning Balance		$ 865,861
Issued, Value		19,595,220
Vesting, Value		(9,030,541)
Non-vested Value, Ending Balance		$ 11,430,540

Share Based Compensation - Sc_2

Share Based Compensation - Schedule of Share Based Compensation Expense (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share Based Compensation Expense [Line Items]
Total share based compensation	$ 2,922,357	$ 508,833	$ 15,555,913	$ 2,043,923
Research and Development Expense [Member]
Share Based Compensation Expense [Line Items]
Total share based compensation	1,040,499	373,570	2,931,010	1,613,493
General and Administrative Expense [Member]
Share Based Compensation Expense [Line Items]
Total share based compensation	$ 1,881,858	$ 135,263	$ 12,624,903	$ 430,430

Ordinary Shares and Convertib_2

Ordinary Shares and Convertible Preferred C Shares - Additional Information (Detail) - USD ($)	Jun. 07, 2018	Jun. 05, 2018	Mar. 15, 2018	Mar. 01, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2015
Percentage of fully diluted shares	5.00%
Preferred shares, purchase		927,594
Preferred shares, exercise price		$ 10.48
Preferred shares, value		$ 9,720,000				$ 9,720,000
Gross proceeds from preferred shares						56,849,592	$ 7,739,574
Preferred share conversion value	$ 664,718				$ 130,258	$ 761,012	183,420
Restricted Shares [Member]
Ordinary shares, offering price	$ 15
Ordinary shares	1,306,348					1,306,348
Percentage of fully diluted shares	5.00%
Ordinary shares [Member]
Ordinary shares, issued	5,000,000			550,162
Ordinary shares, offering price	$ 15
Proceeds from issuance initial public offering	$ 75,000,000
Offering costs	$ 9,675,735					$ 4,115,843
Percentage of fully diluted shares				3.00%
Preferred shares conversion into ordinary shares	11,501,432					11,501,432
Ordinary shares [Member] | Restricted Shares [Member]
Ordinary shares								867,935
Preferred C Shares [Member]
Ordinary shares, issued						5,425,124
Ordinary shares, offering price						$ 10.48
Offering costs						$ 690,473
Gross proceeds from preferred shares						56,849,592
Convertible Preferred C Shares [Member]
Offering costs						$ 690,473	$ 18,500
Preferred shares, purchase						927,594
Preferred shares conversion into ordinary shares						(11,501,432)
Convertible Preferred C Shares [Member] | License Agreement [Member]
Ordinary shares, issued			13,360			13,360
Convertible Preferred C Shares [Member] | Payments In Lieu [Member]
Ordinary shares, issued						129,419
Shares issued, value						$ 1,356,129

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Basic and Diluted Net Loss per Share (Detail) - USD ($)	Jun. 07, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net loss - basic and diluted		$ (15,424,944)	$ (8,441,054)	$ (61,809,129)	$ (22,440,158)
Accretion of Preferred Shares financing costs	$ (664,718)		(130,258)	(761,012)	(183,420)
Accretion of warrants			(61,500)	(1,045,500)	(61,500)
Adjusted net loss - basic and diluted		$ (15,424,944)	$ (8,632,812)	$ (63,615,641)	$ (22,685,078)
Weighted-average ordinary shares outstanding:
Basic and Diluted		26,340,450	8,607,832	16,355,849	8,536,447
Net loss per share:
Basic and Diluted		$ (0.59)	$ (1)	$ (3.89)	$ (2.66)

Net Loss per Share - Schedule_2

Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share (Detail) - shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earning per share, amount	2,391,723	3,454,128
Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earning per share, amount		2,339,578
Restricted Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earning per share, amount	762,036	175,913
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earning per share, amount	1,629,687	938,637

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Provision for Income Taxes	$ 0	$ 0	$ 0	$ 0

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail)	Apr. 24, 2015	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2018USD ($)Program	Sep. 30, 2017USD ($)	Dec. 31, 2017GBP (£)	Dec. 31, 2017USD ($)	Oct. 31, 2020GBP (£)	Oct. 31, 2020USD ($)	Sep. 30, 2018GBP (£)	Sep. 30, 2018USD ($)	Oct. 26, 2017USD ($)
Related Party Transaction [Line Items]
Amount due under services agreement									$ 861,030				$ 0
Related party transaction amounts of work orders issued		$ 140,805		$ 141,596		$ 422,972	$ 447,604
Research and development expenses		8,109,160		6,388,227		22,827,176	16,575,129
Interest expense		9,508		72,736		$ 46,571	131,756
July 2016 Lease [Member]
Related Party Transaction [Line Items]
Operating lease expiration date						Dec. 31, 2021
Operating leases rent expense payment description						The Company records monthly rent expense on a straight-line basis from July 1, 2016 through December 31, 2021.
Deferred rent									231,276				210,993
Operating lease rent expenses		121,888		121,889		$ 365,668	365,669
Aggregate future minimum rental payments under operating lease													1,795,570
Letter of credit outstanding amount													122,866
December 2016 [Member]
Related Party Transaction [Line Items]
Operating lease expiration date						Oct. 31, 2032
Operating leases rent expense payment description						The Company recorded monthly rent expense on a straight-line basis from December 15, 2016 through October 31, 2032
Operating lease termination date						Mar. 31, 2018
Base rent and management fees					$ 563,507
Promissory note issued														$ 1,442,009
Deferred rent									0				0
Operating lease rent expenses		0		390,903		$ 0	1,172,709
Promissory note rate of interest						5.00%
Promissory note expiration due date						Dec. 31, 2018
Repayment of promissory note			$ 1,472,433
Interest expense		0				$ 30,424
UCL Consultants Limited [Member] | Research Agreement [Member]
Related Party Transaction [Line Items]
Amount due under services agreement									775,315				484,408
Related party transaction amounts of work orders issued								£ 241,053	311,000
Agreement termination notice period						30 days
Research and development expenses		137,000		112,000		$ 509,000	334,000
UCL Consultants Limited [Member] | Manufacturing Agreement [Member]
Related Party Transaction [Line Items]
Amount due under services agreement									$ 2,466,142				0
Agreement termination notice period						30 days
Research and development expenses		0		567,150		$ 0	1,609,668
Agreement termination date						2018-01
UCL Consultants Limited [Member] | License Agreement [Member]
Related Party Transaction [Line Items]
Research and development expenses		0		0		$ 0	0
Number of programs | Program						8
Potential milestone payment upon achievement of milestone												£ 39,800,000	51,900,000
Annual maintenance fee												£ 50,000	$ 66,000
UCL Consultants Limited [Member] | Scenario, Forecast [Member] | Research Agreement [Member]
Related Party Transaction [Line Items]
Future obligations under agreement										£ 695,321	$ 905,934
Kadmon [Member] | Transition Services Agreement with Related Party [Member]
Related Party Transaction [Line Items]
Percentage of administrative fees	7.00%
Services agreement period	3 years
Services termination date	Apr. 24, 2018
Cash payment		$ 140,954		$ 0		$ 1,284,258	$ 275,941

Related Party Transactions - In

Related Party Transactions - Incurred Charges included in Loss from Operations (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction [Line Items]
Total charges incurred	$ 140,805	$ 141,596	$ 422,972	$ 447,604
Rent [Member]
Related Party Transaction [Line Items]
Total charges incurred	$ 140,805	136,353	416,479	411,877
Personnel [Member]
Related Party Transaction [Line Items]
Total charges incurred		5,202	$ 6,493	30,480
Other [Member]
Related Party Transaction [Line Items]
Total charges incurred		$ 41		$ 5,247

Related Party Transaction - Sch

Related Party Transaction - Schedule of Future Minimum Rental Payments (Detail) - July 2016 Lease [Member]	Sep. 30, 2018USD ($)
Related Party Transaction [Line Items]
2,018	$ 131,618
2,019	535,683
2,020	554,432
2,021	573,837
Total future rent payments	$ 1,795,570

Commitments - Additional Inform

Commitments - Additional Information (Detail) - July 27, 2018 Lease [Member]	Jul. 27, 2018USD ($)Lease
Other Commitments [Line Items]
Deferred rent | $	$ 363,000
Operating lease termination date	May 24, 2027
Number of leases expired	2
Number of new leases	2

Commitments - Schedule of Futur

Commitments - Schedule of Future Minimum Rental Payments (Detail) - July 27, 2018 Lease [Member]	Jul. 27, 2018USD ($)
Operating Leased Assets [Line Items]
2,018	$ 89,565
2,019	358,258
2,020	358,258
2,021	358,258
2,022	358,258
Thereafter	1,582,308
Total future rent payments	$ 3,104,905

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Vector Neurosciences Inc [Member] - Subsequent Event [Member]	Oct. 05, 2018USD ($)shares
Subsequent Event [Line Items]
Agreement date	Oct. 5, 2018
Number of shares issued as initial merger consideration	225,000
Period of shares issued as initial merger consideration	18 months
Initial merger consideration value | $	$ 3,000,000
Maximum [Member]
Subsequent Event [Line Items]
Value of stockholders additional ordinary shares | $	$ 21,000,000
Issued at Closing of Merger [Member]
Subsequent Event [Line Items]
Number of shares issued as initial merger consideration	202,500
Issued Following Closing of Merger [Member]
Subsequent Event [Line Items]
Number of shares issued as initial merger consideration	22,500