Immunic (IMUX) 10-K 26 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 19, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36201
Entity Registrant Name	Immunic, Inc.
Entity Central Index Key	0001280776
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	56-2358443
Entity Address, Address Line One	1200 Avenue of the Americas,
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10036
City Area Code	332
Local Phone Number	255-9818
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	IMUX
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 181.4
Entity Common Stock, Shares Outstanding		21,168,240
Documents Incorporated by Reference	Certain portions of the registrant’s definitive Proxy Statement for its 2021 Annual Meeting of Stockholders are incorporated by reference into Items 10, 11, 12, 13 and 14 of Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 127,452	$ 29,369
Other current assets and prepaid expenses	6,293	2,861
Total current assets	133,745	32,230
Property and equipment, net	203	80
Goodwill	32,970	32,970
Right of use asset, net	901	633
Other long-term assets	42	42
Total assets	167,861	65,955
Current liabilities:
Accounts payable	3,700	2,423
Accrued expenses	4,318	3,298
Other current liabilities	379	1,351
Total current liabilities	8,397	7,072
Long-term liabilities:
Operating lease liabilities	679	520
Total long-term liabilities	679	520
Total liabilities	9,076	7,592
Commitments and contingencies (note 6)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 20,000,000 authorized and no shares issued or outstanding at December 31, 2020 and 2019	0	0
Preferred stock, $0.0001 par value; 20,000,000 authorized and no shares issued or outstanding at December 31, 2020 and 2019	2	1
Additional paid-in capital	266,823	119,646
Accumulated other comprehensive loss	(4,112)	(1,373)
Accumulated deficit	(103,928)	(59,911)
Total stockholders’ equity	158,785	58,363
Total liabilities and stockholders’ equity	$ 167,861	$ 65,955

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2020$ / sharesshares	Dec. 31, 2019$ / sharesshares	Apr. 12, 2019shares	Mar. 27, 2019€ / sharesshares	Dec. 31, 2018€ / sharesshares
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share) | $ / shares	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share) | (per share)	$ 0.0001	$ 0.0001		€ 1	€ 1
Common stock, shares authorized (in shares)	130,000,000	130,000,000			846,953
Common stock, shares issued (in shares)	21,168,240	10,744,806	120,070	156,920
Common stock, shares outstanding (in shares)	21,168,240	10,744,806

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 38,637	$ 22,512
General and administrative	10,334	14,520
Total operating expenses	48,971	37,032
Loss from operations	(48,971)	(37,032)
Other income:
Interest income	58	107
Other income, net	4,896	1,992
Total other income	4,954	2,099
Net loss	$ (44,017)	$ (34,933)
Net loss per share, basic and diluted (usd per share)	$ (2.81)	$ (4.52)
Weighted-average common shares outstanding, basic and diluted (in shares)	15,663,826	7,722,269

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (44,017)	$ (34,933)
Other comprehensive loss:
Foreign currency translation, net of tax	(2,739)	(554)
Total comprehensive loss	$ (46,756)	$ (35,487)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Series A-2 Convertible Preferred StockPreferred Stock	Series A-1 Convertible Preferred StockPreferred Stock	Pre-Closing Financing	Pre-Closing FinancingCommon Stock	Pre-Closing FinancingAdditional Paid-In Capital	4SC Settlement Agreement	4SC Settlement AgreementCommon Stock	4SC Settlement AgreementAdditional Paid-In Capital	Public Offering	Public OfferingCommon Stock	Public OfferingAdditional Paid-In Capital	April 2020 Equity Issuances	April 2020 Equity IssuancesCommon Stock	April 2020 Equity IssuancesAdditional Paid-In Capital	June 2020 Equity Issuances	June 2020 Equity IssuancesCommon Stock	June 2020 Equity IssuancesAdditional Paid-In Capital	August 2020 Equity Issuances	August 2020 Equity IssuancesCommon Stock	August 2020 Equity IssuancesAdditional Paid-In Capital	Executive Bonus Agreement	Executive Bonus AgreementCommon Stock	Executive Bonus AgreementAdditional Paid-In Capital
Beginning balance (in shares) at Dec. 31, 2018		846,953				299,456	13,541
Beginning balance at Dec. 31, 2018	$ (25,741)	$ 0	$ 56	$ (819)	$ (24,978)	$ 34,313	$ 2,879
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(34,933)				(34,933)
Foreign exchange translation adjustment	(554)			(554)
Stock-based compensation	529		529
Conversion of Series A Preferred Stock to common stock		(5,302,029)				(299,456)	(13,541)
Conversion of Series A Preferred Stock to common stock	37,193	$ 1	37,192			$ (34,313)	$ (2,879)
Issuance of stock (in shares)		127,500							2,197,742			120,070			630,907												460,336
Issuance of stock	0							$ 29,935		$ 29,935	$ 1,540		$ 1,540	$ 4,980		$ 4,980										$ 6,014		$ 6,014
Exchange of common stock in connection with Transaction (in shares)		1,059,269
Exchange of common stock in connection with Transaction	39,400		39,400
Ending balance (in shares) at Dec. 31, 2019		10,744,806				0	0
Ending balance at Dec. 31, 2019	58,363	$ 1	119,646	(1,373)	(59,911)	$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(44,017)				(44,017)
Foreign exchange translation adjustment	(2,739)			(2,739)
Stock-based compensation	2,747		2,747
Issuance of stock (in shares)															733,728			1,764,706			2,175,000			5,750,000
Issuance of stock														$ 10,925		$ 10,925	$ 13,918		$ 13,918	$ 23,048		$ 23,048	$ 96,540	$ 1	$ 96,539
Ending balance (in shares) at Dec. 31, 2020		21,168,240				0	0
Ending balance at Dec. 31, 2020	$ 158,785	$ 2	$ 266,823	$ (4,112)	$ (103,928)	$ 0	$ 0

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Pre-Closing Financing
Issuance costs		$ 61
Public Offering
Issuance costs	$ 339	$ 377
April 2020 Equity Issuances
Issuance costs	1,082
June 2020 Equity Issuances
Issuance costs	1,752
August 2020 Equity Issuances
Issuance costs	$ 6,960

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (44,017)	$ (34,933)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	39	50
Gain on sale of ELAD Assets	0	(329)
Gain on disposal of equipment	0	(26)
Stock-based compensation	2,747	6,512
Unrealized foreign currency gain	(2,528)	0
Contingent payment settled in common stock	0	1,540
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(2,779)	(2,224)
Accounts payable	1,000	(462)
Other current liabilities	(1,255)	1,102
Accrued expenses and other liabilities	669	225
Net cash used in operating activities	(46,124)	(28,545)
Cash flows from investing activities:
Purchases of property and equipment	(146)	(55)
Cash distribution in connection with ELAD Assets sale	0	(75)
Proceeds from sale of ELAD assets	0	2,475
Cash acquired in connection with the Transaction	0	8,151
Proceeds from sale of equipment	0	40
Net cash (used in) provided by investing activities	(146)	10,536
Cash flows from financing activities:
Proceeds from issuance of preferred stock	0
Deferred financing costs	0	(270)
Net cash provided by financing activities	144,431	34,895
Effect of exchange rate changes on cash and cash equivalents	(78)	(589)
Net change in cash and cash equivalents	98,083	16,297
Cash and cash equivalents, beginning of period	29,369	13,072
Cash and cash equivalents, end of period	127,452	29,369
Supplemental disclosure of noncash investing and financing activities:
Stock issuance and deferred financing costs included in accounts payable and accrued expenses	0	20
Conversion of convertible preferred stock to common stock	0	37,193
Fair value of net assets acquired in the Transaction	0	39,400
Offering costs in accrued expenses	114	0
Purchases of property and equipment included in accounts payable	0	19
Pre-Closing Financing
Cash flows from financing activities:
Proceeds from issuance of common stock	0	29,965
Public Offering
Cash flows from financing activities:
Proceeds from issuance of common stock	10,925	5,200
April 2020 Equity Issuances
Cash flows from financing activities:
Proceeds from issuance of common stock	13,918	0
June 2020 Equity Issuances
Cash flows from financing activities:
Proceeds from issuance of common stock	23,048	0
August 2020 Equity Issuances
Cash flows from financing activities:
Proceeds from issuance of common stock	$ 96,540	$ 0

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Pre-Closing Financing
Issuance costs	$ 61
Public Offering
Issuance costs	339	$ 161
April 2020 Equity Issuances
Issuance costs	1,082
June 2020 Equity Issuances
Issuance costs	1,752
August 2020 Equity Issuances
Issuance costs	$ 6,960

Description of Business and Bas

Description of Business and Basis of Financial Statements	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Description of Business and Basis of Financial Statements	Description of Business and Basis of Financial Statements Description of Business Immunic, Inc. ("Immunic" or the "Company") a clinical-stage biopharmaceutical company developing a pipeline of selective oral immunology therapies aimed at treating chronic inflammatory and autoimmune diseases, including relapsing-remitting multiple sclerosis ("RRMS"), ulcerative colitis ("UC"), Crohn’s disease ("CD") and psoriasis. Immunic is headquartered in New York with its main operations in Gräfelfing, Germany. Immunic currently has 28 employees. Immunic is currently pursuing three development programs, all orally available small molecule inhibitors in the clinical development phase. These include the IMU-838 program, which is focused on the development of oral formulations of small molecule inhibitors of the enzyme dihydroorotate dehydrogenase (“DHODH”); the IMU-935 program, which is focused on an inverse agonist of RORγt, an immune cell-specific isoform of retinoic acid receptor-related orphan nuclear receptor gamma (“RORγ”), and the IMU-856 program, which involves the development of a drug targeting the restoration of intestinal barrier function. These product candidates are being developed to address diseases such as RRMS, UC, CD, and psoriasis. In addition to these large markets, these products are also being developed to address certain rare diseases with high unmet medical needs, such as primary sclerosing cholangitis (“PSC”), and Guillain-Barré syndrome (“GBS”). Immunic is also investigating IMU-838 as a potential treatment option for coronavirus disease 2019 (“COVID-19”). The Company’s business, operating results, financial condition and growth prospects are subject to significant risks and uncertainties, including the failure of its clinical trials to meet their endpoints, failure to obtain regulatory approval and needing additional funding to complete the development and commercialization of the Company's three development programs. Liquidity and Financial Condition Immunic has no products approved for commercial sale and has not generated any revenue from product sales. Immunic has never been profitable and has incurred operating losses in each year since inception (2016). Immunic has an accumulated deficit of approximately $103.9 million as of December 31, 2020 and approximately $59.9 million as of December 31, 2019. Substantially all of Immunic’s operating losses resulted from expenses incurred in connection with its research and development programs and from general and administrative costs associated with its operations. Immunic expects to incur significant expenses and increasing operating losses for the foreseeable future as it initiates and continues the preclinical and clinical development of its product candidates and adds personnel necessary to advance its clinical pipeline of product candidates. Immunic expects that its operating losses will fluctuate significantly from quarter-to-quarter and year-to-year due to timing of clinical development programs. From inception through December 31, 2020, Immunic has raised net cash of approximately $216.8 million from private and public offerings of preferred and common stock. As of December 31, 2020, Immunic had cash and cash equivalents of approximately $127.5 million. With these funds, Immunic expects to be able to fund its operations beyond twelve months from the date of the issuance of the accompanying audited consolidated financial statements. Reverse Acquisition On April 12, 2019, pursuant to the terms of the Agreement, dated as of January 6, 2019, between Vital Therapies, Inc., a Delaware corporation (“Vital”), Immunic AG, and the shareholders of Immunic AG party thereto (the “Agreement”), the holders of Immunic AG ordinary shares exchanged all of their outstanding shares for shares of Vital common stock, resulting in Immunic AG becoming a wholly-owned subsidiary of Vital (the “Transaction”). Immediately following the Transaction, Vital Therapies, Inc. changed its name to “Immunic, Inc.” and its ticker symbol to “IMUX”. Immediately prior to the closing of the Transaction, (i) each Immunic AG preferred share was converted into one Immunic AG ordinary share, and (ii) each Immunic AG ordinary share was converted into the right to receive 17.17 shares of Vital’s common stock, after giving effect to the Reverse Stock Split (as defined below). The exchange ratio was determined through arm’s-length negotiations between Vital and Immunic AG. The aggregate consideration issuable in the Transaction, after giving effect to the Reverse Stock Split, was 8,927,130 shares of Vital’s common stock. Following the Transaction and after giving effect to the Reverse Stock Split, the former shareholders of Immunic AG owned approximately 88.25% of the fully diluted common stock of the Company, and the shareholders of Vital immediately prior to the Transaction owned 1,059,269 shares (plus 127,500 restricted stock units (“RSUs”) all of which have been issued to date to former Vital officers) of the common stock of the Company or approximately 11.75%. The issuance of shares of Vital’s common stock in the Transaction was registered with the Securities and Exchange Commission (“SEC”) on a Registration Statement on Form S-4 (Registration No. 333-229510). Immediately prior to the closing of the Transaction, Immunic AG issued, in a private placement transaction (the “Financing”), an aggregate of 2,197,742 ordinary shares to certain of its shareholders for aggregate consideration of €26.7 million (approximately $29.9 million), pursuant to the terms of the Investment and Subscription Agreement, dated as of January 6, 2019, between Immunic and the shareholders and investors party thereto (the “Subscription Agreement”). The Transaction has been accounted for as a reverse acquisition under the acquisition method of accounting. Because Immunic AG’s pre-Transaction owners held an 88.25% economic and voting interest in the combined company immediately following the closing of the Transaction, Immunic AG is considered to be the acquirer of Vital for accounting purposes. Additionally, Immunic AG is considered to be the predecessor for reporting purposes and the financial results of Immunic AG are reported in the historical comparable periods. Reverse Stock Split On April 12, 2019, immediately following the closing of the Transaction, the Company effected a 40-for-1 reverse stock split of its common stock (the “Reverse Stock Split”). Accordingly, all references to share and per share amounts in the accompanying audited consolidated financial statements and notes have been retroactively adjusted to reflect the Reverse Stock Split for all periods presented. No fractional shares were issued in connection with the Reverse Stock Split. Unless otherwise noted, all references to common stock share and per share amounts have also been adjusted to reflect the exchange ratio of 17.17. Basis of Presentation and Consolidation The accompanying consolidated financial statements have been prepared in conformity with United States generally accepted accounting principles, ("U.S. GAAP") and include the accounts of Immunic and its wholly-owned subsidiaries, Immunic AG and Immunic Research GmbH (which both began operations in 2016), Immunic Australia Pty Ltd. (which began operations in 2018) and Vital Therapies (Beijing) Company Limited (“VTL China”), acquired through the Transaction (which began operations in 2005). VTL China was sold in September 2019 in connection with the sale of certain of Vital's clinical development-related intellectual property rights (the "ELAD Assets"). All intercompany accounts and transactions have been eliminated in consolidation. Immunic manages its operations as a single reportable segment for the purposes of assessing performance and making operating decisions. Certain prior period amounts have been reclassified to conform to the current basis of presentation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires the Company to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements. The most significant estimates in the Company’s financial statements and accompanying notes relate to the application of the acquisition method of accounting related to the Transaction, clinical trial expenses, share-based compensation. Management believes its estimates to be reasonable under the circumstances. Actual results could differ materially from those estimates and assumptions. Foreign Currency Translation and Presentation The Company’s reporting currency is United States (“U.S.”) dollars. During the twelve months ended December 31, 2020 and 2019, Immunic AG and Immunic Research GmbH’s operations were located in Germany with the euro being its functional currency. Immunic Australia Pty Ltd.’s functional currency is the Australian dollar. All amounts in the financial statements where the functional currency is not the U.S. dollar are translated into U.S. dollar equivalents at exchange rates as follows: • assets and liabilities at reporting period-end rates; • income statement accounts at average exchange rates for the reporting period; and • components of equity at historical rates. Gains and losses from translation of the financial statements into U.S. dollars are recorded in stockholders’ equity as a component of accumulated other comprehensive income (loss). Realized and unrealized gains and losses resulting from foreign currency transactions denominated in currencies other than the functional currency are reflected as general and administrative expenses in the Consolidated Statements of Operations. Foreign currency transaction gains and losses related to long-term intercompany loans that are payable in the foreseeable future are recorded in Other Income. The Consolidated Statements of Cash Flows were prepared by using the average exchange rate in effect during the reporting period which reasonably approximates the timing of the cash flows. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents. Cash and cash equivalents consist of cash on hand and deposits in banks located in the U.S., Germany and Australia. The Company maintains cash and cash equivalent balances denominated in Euro and U.S. dollars with major financial institutions in the U.S. and Germany in excess of the deposit limits insured by the government. Management periodically reviews the credit standing of these financial institutions and believes that the Company is not exposed to any significant credit risk. The Company currently deposits its cash and cash equivalents with two large financial institutions. Fair Value Measurement Fair value is defined as the price that would be received to sell an asset or be paid to transfer a liability in an orderly transaction between market participants on the measurement date. Accounting guidance establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 1 assets consisted of money market funds for the periods presented. The Company had no Level 1 liabilities for the periods presented. Level 2— Inputs other than observable quoted prices for the asset or liability, either directly or indirectly; these include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. The Company had no Level 2 assets or liabilities for the periods presented. Level 3—Unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of assets or liabilities. The Company had no Level 3 assets or liabilities for the periods presented. The carrying value of cash and cash equivalents, other current assets and prepaid expenses, accounts payable, accrued expenses, and other current liabilities approximates fair value due to the short period of time to maturity. Property and Equipment Property and equipment is stated at cost. Depreciation is computed using the straight-line method based on the estimated service lives of the assets which range from three years to thirteen years. Depreciation and amortization expense was $39,000 and $50,000 for the years ended December 31, 2020 and 2019, respectively. Impairment of Long-Lived Assets The Company records impairment losses on long-lived assets used in operations when indicators of impairment are present and the undiscounted cash flows estimated to be generated by those assets are less than the assets’ carrying amount. Impaired assets are then recorded at their estimated fair value. There were no impairment losses during the years ended December 31, 2020 and 2019. Goodwill Business combinations are accounted for under the acquisition method. The total purchase price of an acquisition is allocated to the underlying identifiable net assets, based on their respective estimated fair values as of the acquisition date. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash inflows and outflows, probabilities of success, discount rates, and asset lives, among other items. Assets acquired and liabilities assumed are recorded at their estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Goodwill is tested for impairment at the reporting unit level annually in the fourth quarter, or more frequently when events or changes in circumstances indicate that the asset might be impaired. Examples of such events or circumstances include, but are not limited to, a significant adverse change in legal or business climate, an adverse regulatory action or unanticipated competition. The Company assesses qualitative factors to determine whether the existence of events or circumstances would indicate that it is more likely than not that the fair value of the reporting unit is less than its carrying amount. If after assessing the totality of events or circumstances, the Company were to determine that it is more likely than not that the fair value of the reporting unit is less than its carrying amount, then the Company would perform a quantitative test that compares the fair value to its carrying value to determine the amount of any impairment. Impairment testing for goodwill is done at the reporting unit level. The Company has determined that it operates in a single operating segment and has a single reporting unit. The Company has determined there was no goodwill impairment as of December 31, 2020. Research and Development Expenses These costs primarily include external development expenses and internal personnel expenses for the three development programs, IMU-838, IMU-935 and IMU-856. Immunic has spent the majority of its research and development resources on IMU-838, the Company's lead development program for clinical trials in RRMS, UC, COVID-19, and PSC. IMU-935 is currently being tested in a Phase 1 clinical trial in healthy volunteers, which was initiated in September 2019. IMU-856 is currently being tested in a Phase 1 clinical trial in healthy volunteers, which was initiated in August 2020. Research and development expenses consist of expenses incurred in research and development activities, which include clinical trials, contract research services, certain milestone payments, salaries and related employee benefits, allocated facility costs and other outsourced services. Research and development expenses are charged to operations as incurred. The Company enters into agreements with contract research organizations (“CROs”) to provide clinical trial services for individual studies and projects by executing individual work orders governed by a Master Service Arrangement (“MSA”). The MSAs and associated work orders provide for regular recurrent payments and payments upon the completion of certain milestones. The Company regularly assesses the timing of payments against actual costs incurred to ensure a proper accrual of related expenses in the appropriate accounting period. Collaboration Arrangements Certain collaboration and license agreements may include payments to or from the Company of one or more of the following: non-refundable or partially refundable upfront or license fees; development, regulatory and commercial milestone payments; payment for manufacturing supply services; partial or complete reimbursement of research and development costs; and royalties on net sales of licensed products. The Company assesses whether such contracts are within the scope of Financial Accounting Standards Board (FASB) Accounting Standards Update (“ASU”) 2014-09 “ Revenue from Contracts with Customers ” and ASU No. 2018-18, “ Collaborative Arrangements”, ("ASU 2018-18"). ASU 2018-18, clarifies that certain elements of collaborative arrangements could qualify as transactions with customers in the scope of ASC 606. In October 2018, the Company entered into an option and license agreement (the "Daiichi Sankyo Agreement") with Daiichi Sankyo Co., Ltd. ("Daiichi Sankyo") which granted the Company the right to license a group of compounds, designated by the Company as IMU-856, as a potential new oral treatment option for diseases such as inflammatory bowel disease, irritable bowel syndrome with diarrhea, immune checkpoint inhibitor induced colitis and other barrier function associated diseases. During the option period, the Company performed agreed upon research and development activities for which it was reimbursed by Daiichi Sankyo up to a maximum agreed-upon limit. Such reimbursement was recorded as other income. There are no more research and development reimbursements expected under this agreement. General and Administrative Expenses General and administrative expenses consist primarily of salaries and related costs for personnel in executive, finance, business development and other support functions. Other general and administrative expenses include, but are not limited to, stock-based compensation, insurance costs, professional fees for legal, accounting and tax services, consulting, related facility costs and travel. Stock-Based Compensation The Company measures the cost of employee and non-employee services received in exchange for equity awards based on the grant-date fair value of the award recognized generally as an expense (i) on a straight-line basis over the requisite service period for those awards whose vesting is based upon a service condition, and (ii) on an accelerated method for awards whose vesting is based upon a performance condition, but only to the extent it is probable that the performance condition will be met. Stock-based compensation is (i) estimated at the date of grant based on the award’s fair value for equity classified awards and (ii) final measurement date for liability classified awards. Forfeitures are recorded in the period in which they occur. The Company estimates the fair value of stock options using the Black-Scholes-Merton option-pricing model ("BSM"), which requires the use of estimates and subjective assumptions, including the risk-free interest rate, the fair value of the underlying common stock, the expected dividend yield of the Company’s common stock, the expected volatility of the price of the Company’s common stock, and the expected term of the option. These estimates involve inherent uncertainties and the application of management’s judgment. If factors change and different assumptions are used, the Company’s stock-based compensation expense could be materially different in the future. Leases The Company leases office space and office equipment. The underlying lease agreements have lease terms of less than 12 months and up to 60 months. The short-term leases are deemed immaterial and have not been included in the operating lease right of use asset and operating lease liability. The Company has two existing leases for office space. At inception of a lease agreement, the Company determines whether an agreement represents a lease and at commencement each lease agreement is assessed as to classification as an operating or financing lease. The Company's two leases have been classified as operating leases and an operating lease right-of-use asset and an operating lease liability have been recorded on the Company’s balance sheet. A right-of-use lease asset represents the Company’s right to use the underlying asset for the lease term and the lease obligation represents its commitment to make the lease payments arising from the lease. Right-of-use lease assets and obligations are recognized at the commencement date based on the present value of remaining lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company has used an estimated incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The right-of-use lease asset includes any lease payments made prior to commencement and excludes any lease incentives. The lease term used in estimating future lease payments may include options to extend when it is reasonably certain that the Company will exercise that option. Operating lease expense is recognized on a straight-line basis over the lease term, subject to any changes in the lease or changes in expectations regarding the lease term. Variable lease costs such as common area costs and property taxes are expensed as incurred. Leases with an initial term of twelve months or less are not recorded on the balance sheet. Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Accumulated other comprehensive income (loss) has been reflected as a separate component of stockholders’ equity in the accompanying Consolidated Balance Sheets and consists of foreign currency translation adjustments (net of tax). Income Taxes The Company is subject to corporate income tax laws and regulations in the U.S., Germany and Australia. Tax regulations within each jurisdiction are subject to the interpretation of the related tax laws and regulations and require significant judgment in their application. The Company utilizes the asset and liability method of accounting for income taxes which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the audited consolidated financial statements. Deferred income tax assets and liabilities are determined based on the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of changes in tax rates on deferred tax assets and liabilities is recognized in operations in the period that includes the enactment date. Deferred taxes are reduced by a valuation allowance when, in the opinion of management, it is more likely than not some portion or the entire deferred tax asset will not be realized. As of December 31, 2020, and December 31, 2019, the Company maintained a full valuation allowance against the balance of deferred tax assets. It is the Company’s policy to provide for uncertain tax positions and the related interest and penalties based upon management’s assessment of whether a tax benefit is more likely than not to be sustained upon examination by tax authorities. The Company recognizes interest and penalties accrued on any unrecognized tax benefits as a component of income tax expense. Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of common shares and, if dilutive, common stock equivalents outstanding for the period determined using the treasury-stock method. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position. Potentially dilutive securities, not included in the calculation of diluted net loss per share attributable to common stockholders because to do so would be anti-dilutive, are as follows: As of December 31, 2020 2019 Options to purchase common stock 1,117,160 471,048 Recently Adopted Accounting Standards In January 2017, the FASB issued ASU 2017-04, " Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ." This guidance eliminates Step 2 from the goodwill impairment test, instead requiring an entity to recognize a goodwill impairment charge for the amount by which the goodwill carrying amount exceeds the reporting unit’s fair value. The Company adopted this ASU, as required, in the quarter ended March 31, 2020 on a prospective basis. The adoption of this ASU did not have a significant impact on the Company's consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, “ Fair Value Measurement - Disclosure Framework” ("ASU 2018-13.") ASU 2018-13 modifies the disclosure requirements for fair value measurements. The amendments relate to disclosures regarding unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements and the narrative description of measurement uncertainty, and are to be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments must be applied retrospectively to all periods presented upon their effective date. The Company adopted this ASU, as required, in the quarter ended March 31, 2020. The adoption of this ASU did not have a significant impact on the Company's consolidated financial statements. In November 2018, the FASB issued ASU 2018-18, “ Collaborative Arrangements” ("ASU 2018-18"). ASU 2018-18, clarifies that elements of collaborative arrangements could qualify as transactions with customers in the scope of ASC 606. The Company adopted this ASU, as required, in the quarter ended March 31, 2020. The Company does not have any agreements that meet the definition of a collaboration arrangement at this time.

Accounting for the Transaction

Accounting for the Transaction	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Accounting for the Transaction	Accounting for the Transaction Based on the exchange ratio of 17.17 shares of Vital common stock for each share of Immunic AG, immediately following the Transaction, former Vital stockholders owned approximately 11.75% of the capital stock of the combined organization on a fully diluted basis, and former Immunic AG stockholders owned approximately 88.25% of the capital stock of the combined organization on a fully diluted basis. At the closing of the Transaction, all shares of Immunic AG common stock then outstanding were exchanged for Vital common stock. In addition, pursuant to the terms of the Agreement, the Company, for accounting purposes, assumed all outstanding stock options to purchase 16,987 shares of Vital common stock and 127,500 RSUs at the closing of the Transaction, after giving effect to the Reverse Stock Split. Since the exercise prices of the outstanding options to purchase common stock were less than the trading price on the day of the consummation of the Transaction, they were not included in the formula below in calculating the purchase price. The tangible and intangible assets and liabilities of Vital acquired in the Transaction are recorded based on their fair values as of the completion of the Transaction, with the excess of the purchase consideration over the fair value of net assets assigned to and recorded as goodwill. The following summarizes the purchase price paid in the Transaction (amounts in thousands except share and per share amounts): Number of shares owned by Vital stockholders (1) 1,059,269 RSUs (2) 127,500 Total fully-diluted shares 1,186,769 Multiplied by the fair value per share of Vital common stock (3) $ 33.20 Estimated purchase price $ 39,400 (1) The number of shares of 1,059,269 represents the historical 42,369,694 shares of Vital common stock outstanding immediately prior to the closing of the Transaction, adjusted for the Reverse Stock Split. (2) The number of RSUs of 127,500 represents the historical 5,100,000 Vital RSUs of which all have been issued to date to Vital former officers in 2019. (3) Based on the last reported sale price of Vital common stock on the Nasdaq Global Market on April 12, 2019, the closing of the Transaction, adjusted for the Reverse Stock Split. The following summarizes the allocation of the purchase price to the net tangible and intangible assets acquired: (in thousands) Cash and cash equivalents $ 8,151 Prepaid expenses and other assets 307 Supplies and working cell banks 1,000 Clinical development equipment 306 Other property and equipment 30 In-process research and development (“IPR&D ” ) 764 Accounts payable, accrued expenses and other liabilities (4,128) Goodwill 32,970 Purchase price $ 39,400

ELAD Sales Agreement

ELAD Sales Agreement	12 Months Ended
	Dec. 31, 2020
Discontinued Operations and Disposal Groups [Abstract]
ELAD Sales Agreement	ELAD Sales Agreement In March 2019, Vital entered into an asset purchase agreement (the “Vital APA ” ) to sell certain of Vital’s clinical development-related assets and related intellectual property rights to RH Cell Therapeutics (the “Purchaser”) for approximately $2.5 million. The assets sold were clinical development equipment, supplies, intellectual property and working cell banks in addition to the equity interest in VTL China (collectively the “ELAD Assets ” ). The Purchaser deposited $1.1 million into escrow and paid the Company $50,000 prior to the Transaction. The Vital APA was amended and restated on May 28, 2019, to allow for two closings. In the first closing which occurred on May 28, 2019, the $1.1 million was released from escrow to the Company. In addition, the Purchaser executed a promissory note with a face amount of $1.325 million, which accrues simple interest of 10% per annum. The fair value of the promissory note was estimated to be $920,000. Therefore, the fair value of the ELAD Assets was based on the cash in escrow, the $50,000 deposit and the fair value of the promissory note. The estimated fair value of the ELAD Assets was included in the purchase accounting allocation as follows (in thousands): Clinical development equipment 306 Supplies and working cell banks 1,000 In process research & development (“IPR&D”) 764 Total $ 2,070 In the first closing, the Company transferred title of the clinical development equipment and supplies to the Purchaser. Also, the fair value of the promissory note was recorded as a note receivable and the fair value of the IPR&D and working cell banks assets were removed from the Company’s audited consolidated balance sheet. The promissory note was paid in full upon the second closing on September 4, 2019, at which time the Company transferred title to the intellectual property and working cell banks as well as its equity interest in VTL China. The difference of $405,000 between the $1.325 million face value of the promissory note collected and the fair value of $920,000 was recorded as other income in the accompanying consolidated statements of operations for the year ended December 31, 2019. The Purchaser is not a related party.

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Details	Balance Sheet Details Prepaid Expenses and Other Current Assets Prepaid Expense and Other Current Assets consist of (in thousands): December 31, 2020 2019 Prepaid clinical and related costs $ 3,416 $ 1,307 VAT receivable 295 408 Australian research and development tax incentive 1,348 350 Other 1,234 796 Total $ 6,293 $ 2,861 Accounts Payable Accounts Payable consist of (in thousands): December 31, 2020 2019 Clinical costs $ 3,408 $ 1,981 Legal and audit costs 139 226 Other 153 216 Total $ 3,700 $ 2,423 Accrued Expenses Accrued expenses consist of (in thousands): December 31, 2020 2019 Accrued clinical and related costs $ 3,301 $ 2,863 Accrued legal and audit costs 114 211 Accrued compensation 658 — Accrued other 245 224 Total $ 4,318 $ 3,298 Other Current Liabilities Other Current Liabilities consist of (in thousands): December 31, 2020 2019 Deferred income $ — $ 1,008 Other 379 343 Total $ 379 $ 1,351

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Lease The Company leases certain office space under non-cancelable operating leases. The leases terminate on April 30, 2023 for the New York City office and June 30, 2025 for the Gräfelfing, Germany office. The Company formerly leased office space in Martinsried, Germany pursuant to a modified lease that terminated on August 31, 2020. These leases include both lease (e.g., fixed rent) and non-lease components (e.g., common-area and other maintenance costs). The non-lease components are deemed to be executory costs and are therefore excluded from the minimum lease payments used to determine the present value of the operating lease obligation and related right-of-use asset. The New York City lease has renewal options but they were not included in calculating the right of use asset and liabilities. On April 7, 2020, the Company signed a five The leases do not provide an implicit rate and, due to the lack of a commercially salable product, the Company is generally considered unable to obtain commercial credit. Therefore, the Company estimated its incremental interest rate to be 6%, considering the quoted rates for the lowest investment-grade debt and the interest rates implicit in recent financing leases. Immunic used its estimated incremental borrowing rate and other information available at the lease commencement date in determining the present value of the lease payments. Immunic’s operating lease costs and variable lease costs were $354,000 and $135,000 for the years ended December 31, 2020 and 2019, respectively. Variable lease costs consist primarily of common area maintenance costs, insurance and taxes which are paid based upon actual costs incurred by the lessor. Maturities of the operating lease obligation are as follows as of December 31, 2020 (in thousands): 2021 $ 348 2022 $ 348 2023 $ 198 2024 $ 124 2025 $ 62 Thereafter $ — Total lease payments $ 1,080 Less: interest portion $ 107 Present value of lease obligation $ 973 Contractual Obligations As of December 31, 2020, the Company has non-cancelable contractual obligations under certain agreements related to its development programs IMU-838, IMU-935 and IMU-856 totaling approximately $1.2 million, all of which is expected to be paid in 2021. Other Commitments and Obligations In May 2016 the Company entered into a purchase agreement (the “Agreement”) with 4SC AG whereby the Company acquired certain assets, including the rights to patents and patent applications, trademarks and know-how. This transaction has been accounted for as an asset acquisition under Accounting Standards Update 2017-01 - Business Combinations (Topic 805): Clarifying the Definition of a Business. The Agreement included payments (Tranches III and IV) that were contingent upon the occurrence of certain events and required the Company to pay royalties equal to 4.4% of the aggregated net sales for a certain period as defined in the Agreement (Tranche III) upon commercialization of the acquired assets. Effective April 12, 2019, the parties agreed to settle Tranche IV by issuing 120,070 shares of the Company’s common stock, immediately following the Transaction, to 4SC AG while keeping Tranche III in effect. Approximately $1.5 million of expense was recorded as a result of the issuance of these shares on April 12, 2019. No royalties are payable as of December 31, 2020 or 2019 as sales have not commenced. Daiichi Sankyo Agreement On January 5, 2020, the Company exercised its option to obtain the exclusive worldwide right to commercialization of IMU-856. Among other things, the option exercise grants Immunic AG the rights to Daiichi Sankyo’s patent application related to IMU-856. In connection with the option exercise, the Company paid a one-time upfront licensing fee to Daiichi Sankyo. Under the Daiichi Sankyo Agreement, Daiichi Sankyo is also eligible to receive future development, regulatory and sales milestone payments, as well as royalties related to IMU-856. Legal Proceedings The Company is not currently a party to any litigation, nor is it aware of any pending or threatened litigation, that it believes would materially affect its business, operating results, financial condition or cash flows. However, its industry is characterized by frequent claims and litigation including securities litigation, claims regarding patent and other intellectual property rights and claims for product liability. As a result, in the future, the Company may be involved in various legal proceedings from time to time.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value	Fair Value The following fair value hierarchy table present information about each major category of the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands): Fair Value Measurement at December 31, 2020 Fair Value Level 1 Level 2 Level 3 Assets Money market funds $ 39,615 $ 39,615 $ — $ — Fair Value Measurement at December 31, 2019 Fair Value Level 1 Level 2 Level 3 Assets Money market funds $ 4,491 $ 4,491 $ — $ — There were no transfers between Level 1, Level 2 or Level 3 assets during the periods presented. For the Company’s money market funds, which are included as a component of cash and cash equivalents on the consolidated balance sheet, realized gains and losses are included in interest income (expense) on the consolidated statements of operations.

Common Stock and Preferred Stoc

Common Stock and Preferred Stock (Converted into Common Stock)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Common Stock and Preferred Stock (Converted into Common Stock)	Common Stock and Preferred Stock (Converted into Common Stock) Shelf Registration Statements In May 2018, Vital filed a shelf registration statement on Form S-3, (the “2018 Shelf Registration Statement”), which became effective in June 2018. The 2018 Shelf Registration Statement permits the offering, issuance and sale of up to $200.0 million of common stock, preferred stock, warrants, debt securities, and/or units in one or more offerings and in any combination. In November 2020, Immunic filed a shelf registration statement on Form S-3. The 2020 Shelf Registration Statement permits the offering, issuance and sale of up to $250.0 million of common stock, preferred stock, warrants, debt securities, and/or units in one or more offerings and in any combination of the foregoing. In July 2019, the Company filed a Prospectus Supplement for the offering, issuance and sale of up to a maximum aggregate offering price of $40.0 million of common stock that may be issued and sold under an at-the-market sales agreement ("July 2019 ATM") with SVB Leerink LLC (“SVB Leerink”) as agent. The Company intends to use the net proceeds from the offering to continue to fund the ongoing clinical development of its product candidates and for other general corporate purposes, including funding existing and potential new clinical programs and product candidates. The July 2019 ATM will terminate upon the earlier of (i) the issuance and sale of all of the shares through SVB Leerink on the terms and subject to the conditions set forth in the July 2019 ATM or (ii) termination of the July 2019 ATM as otherwise permitted thereby. The July 2019 ATM may be terminated at any time by either party upon ten days’ prior notice, or by SVB Leerink at any time in certain circumstances, including the occurrence of a material adverse effect on the Company. As of December 31, 2020, $23.3 million in capacity remains under the July 2019 ATM. In December 2020, the Company filed another Prospectus Supplement for the offering, issuance and sale of up to a maximum aggregate offering price of $50.0 million of common stock that may be issued and sold under another at-the-market sales agreement ("December 2020 ATM") with SVB Leerink as agent. The Company intends to use the net proceeds from the offering to continue to fund the ongoing clinical development of its product candidates and for other general corporate purposes, including funding existing and potential new clinical programs and product candidates. The December 2020 ATM will terminate upon the earlier of (i) the issuance and sale of all of the shares through SVB Leerink on the terms and subject to the conditions set forth in the December 2020 ATM or (ii) termination of the December 2020 ATM as otherwise permitted thereby. The December 2020 ATM may be terminated at any time by either party upon ten days’ prior notice, or by SVB Leerink at any time in certain circumstances, including the occurrence of a material adverse effect on the Company. As of December 31, 2020, $50.0 million in capacity remains under the December 2020 ATM. The Company has agreed to pay SVB Leerink a commission equal to 3.0% of the gross proceeds from the sales of common shares pursuant to both ATM's and has agreed to provide SVB Leerink with customary indemnification and contribution rights. For the year ended December 31, 2020, the Company raised gross proceeds of $11.3 million pursuant to the July 2019 ATM through the sale of 733,728 shares of common stock at a weighted average price of $15.42 per share. The net proceeds from the July 2019 ATM were $11.0 million after deducting underwriter commissions of $339,356. For the year ended December 31, 2019, the Company raised gross proceeds of $5.4 million pursuant to the July 2019 ATM through the sale of 630,907 shares of common stock at a weighted average price of $8.49 per share. The net proceeds from the July 2019 ATM were $4.9 million after deducting underwriter commissions of $161,000 and estimated offering expenses of $305,000. As of December 31, 2019, there was $34.6 million available under the July 2019 ATM. Public Equity Offerings April 2020 Registered Direct Offering On April 23, 2020, the Company entered into an engagement letter with ROTH Capital Partners, LLC ("RCP") relating to the Company’s registered direct offering of common stock to select institutional investors. Pursuant to this agreement, the Company agreed to pay RCP a cash fee of 6.5% of the gross proceeds from the offering raised from investors and to reimburse RCP for certain costs incurred in connection therewith. In addition, on April 23, 2020, the Company and the investors entered into a securities purchase agreement relating to the issuance and sale of an aggregate of 1,764,706 shares of common stock. The purchase price per share was $8.50 for aggregate gross proceeds to the Company of approximately $15.0 million. The net proceeds to the Company from this offering, after deducting the Company’s offering expenses, were approximately $13.9 million. June 2020 Offering On June 10, 2020, the Company entered into a placement agency agreement with RCP and Ladenburg Thalmann & Co. Inc. relating to the Company’s public offering of 2,175,000 shares of common stock. Pursuant to this agreement, the Company agreed to pay the placement agents a cash fee of 6.5% of the gross proceeds from the offering raised from investors and to reimburse the placement agents for certain costs incurred in connection therewith. In addition, on June 10, 2020, the Company and certain institutional investors entered into securities purchase agreements relating to the issuance and sale of an aggregate of 2,175,000 shares of the Company’s common stock. The purchase price per share in the Offering was $11.40 for aggregate gross proceeds to the Company of approximately $25.0 million. The net proceeds to the Company from this offering, after deducting the Company’s offering expenses, were approximately $23.0 million. August 2020 Offering On August 4, 2020, the Company entered into an underwriting agreement with SVB Leerink LLC, as representative of the several underwriters in connection with the Company’s public offering of 5,000,000 shares of common stock, at a public offering price of $18.00 per share. Under the terms of the Underwriting Agreement, the Company granted the Underwriters an option, exercisable for 30 days, to purchase up to an additional 750,000 shares of Common Stock at the public offering price, less underwriting discounts and commissions, which was exercised in full on August 6, 2020. On August 7, 2020, the Company closed the Offering. The net proceeds to the Company from the Offering, after giving effect to the exercise in full by the Underwriters of their option to purchase the Option Shares, was approximately $96.5 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. Stock Subscription Not Yet Issued On March 27, 2019, stockholders of the Company resolved to increase the Company’s share capital by an additional 156,920 ordinary shares, par value €1.00 per share, of which 27,176 shares related to bonuses for executive officers of the Company. Under German law a capital increase is valid as soon as the consummation of the capital increase has been officially registered with the commercial register, which occurred on April 3, 2019. Therefore, the capital increase became effective subsequent to March 31, 2019. Common Stock Immunic AG, a non-public company as of December 31, 2018, had authorized 846,953 shares of common stock, par value €1.00 per share, which were issued in March 2016 for approximately $56,000. As of December 31, 2020, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue 130,000,000 shares of common stock, par value of $0.0001. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any. Through December 31, 2020, no cash dividends had been declared or paid. Preferred Stock From inception (2016) through 2018, Immunic AG issued 13,541 Series A-1 Convertible and 299,456 Series A-2 Convertible preferred shares, par value €1.00 per share, to investors as part of its growth financing plan in the total amount of €31.7 million (approximately $37.2 million). Series A-1 Convertible and Series A-2 Convertible preferred shares were converted into Immunic AG’s ordinary shares immediately prior to the Transaction and were then exchanged for Immunic (former Vital) common shares at the consummation of the Transaction. The Company’s certificate of incorporation, as amended and restated, authorizes the Company to issue 20,000,000 shares of $0.0001 par value preferred stock, rights and preferences to be set by the board of directors. No preferred shares were outstanding as of December 31, 2020. Stock Warrants The Company issued warrants to purchase common stock in connection with financing activities and for consulting services in 2011. Warrants for 6,015 shares of common stock at an exercise price of $3,719.60 expired on September 25, 2019. Stock Reserved for Future Issuance Shares reserved for future issuance as of December 31, 2020 are as follows: Number of Common stock reserved for issuance for: Outstanding stock options 1,117,160 Common stock options available for future grant: 2014 Equity Incentive Plan 43,311 2017 Inducement Equity Incentive Plan 46,250 2019 Omnibus Equity Incentive Plan 831,474 Total common shares reserved for future issuance 2,038,195

Stock Compensation Plans

Stock Compensation Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Compensation Plans	Stock Compensation Plans Stock Option Programs Under German law, (i) a company’s management board consists of employee members and is responsible for overseeing its daily business, and (ii) a company’s supervisory board supervises the management board and serves a role equivalent to the board of directors of an American corporation. Under two stock option programs, the Company granted stock options to the members of the Immunic AG supervisory board (the “Supervisory Board”) and to key employees in 2018 and in 2019 prior to the Transaction. The programs were intended to incentivize the beneficiaries to dedicate their working capabilities in the best manner possible to the benefit of the Company. The stock options vest if and when an exit event occurs. An exit event is defined as a direct initial public offering has taken place, or an indirect initial public offering has taken place, or a trade sale has been consummated, or a disposal of the Company’s assets has been consummated, or another financially equivalent realization event has occurred. Under the stock option program for the members of the Supervisory Board (the “VSOP SB”), the Company granted stock options of the Company to members of the Company’s Supervisory Board for the time period of their service as members of the Supervisory Board. The shareholders’ approved the VSOP SB with a total of 31,593 stock options, corresponding to approximately 0.5% of the Company’s issued share capital at the time of the decision. Under the stock option program for key employees (the “VSOP”), the Company granted stock options of the Company to certain key employees. With the approval of the Supervisory Board, Immunic AG’s management board determined how many stock options were granted and how they were allocated to the respective beneficiaries up to a total of 31,593. Further terms and conditions of both programs, the VSOP SB and the VSOP, were substantially similar. The following information is therefore shown aggregated for both programs. The Company accounts for both programs as cash-settled options and classifies their fair value as a liability upon vesting. Vesting of options granted under the VSOP SB and VSOP was contingent upon an exit event. Upon consummation of the Transaction, which occurred on April 12, 2019, all of the awards vested and were settled for cash of $508,000 based on their fair value. As a result, the Company recorded $508,000 in compensation expense related to these stock options in the twelve months ended December 31, 2019. In July 2019, the Company’s stockholders approved the 2019 Omnibus Equity Incentive Plan (the “2019 Plan”) which was adopted by the Board with an effective date of June 14, 2019. The 2019 Plan allows for the grant of equity awards to employees, consultants and non-employee directors. An initial maximum of 1,500,000 shares of the Company’s common stock are available for grant under the 2019 Plan. The 2019 Plan includes an evergreen provision that allows for the annual addition of up to 4% of the Company’s fully-diluted outstanding stock, with a maximum allowable increase of 4,900,000 shares over the term of the 2019 Plan. In accordance with this provision, the shares available for grant were increased by 448,634 shares effective April 1, 2020. The 2019 Plan is currently administered by the Board, or, at the discretion of the Board, by a committee of the Board, which determines the exercise prices, vesting schedules and other restrictions of awards under the 2019 Plan at its discretion. Options to purchase stock may not have an exercise price that is less than the fair market value of underlying shares on the date of grant, and may not have a term greater than ten years. Incentive stock options granted to employees typically vest over four years. Non-statutory options granted to employees, officers, members of the Board, advisors, and consultants of the Company typically vest over three Shares that are expired, terminated, surrendered or canceled under the 2019 Plan without having been fully exercised will be available for future awards. Movements during the year The following table illustrates the number and weighted average exercise prices of, and movements in, stock options for the VSOP SB and VSOP during the year ended December 31, 2019. There were no awards granted or outstanding after the awards settled in 2019: 2019 Unvested Awards Weighted-Average Fair Value Outstanding as of January 1 6,937 $ 12.87 Granted during the period 32,177 $ 12.87 Forfeited during the period — $ — Settled in cash during the period (39,114) $ 12.87 Expired during the period — $ — Outstanding at December 31 — $ — Exercisable at December 31 — $ — No expense was recognized during the year ended December 31, 2020. There was $508,000 of expense recognized in 2019 upon the vesting of the awards as a result of closing the Transaction. There were no cancellations or modifications to the awards in 2019. The following table summarizes stock option activity since January 1, 2019 under the 2019 Plan: Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2019 — $ — Granted 456,645 $ 12.57 Exercised — $ — Forfeited or expired — $ — Outstanding as of December 31, 2019 456,645 $ 12.57 9.63 $ 114,399 Options vested and expected to vest as of December 31, 2019 456,645 $ 12.57 9.63 $ 114,399 Options exercisable as of December 31, 2019 31,956 $ 13.00 9.59 $ 3,382 Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2020 456,645 $ 12.57 Granted 744,406 $ 13.24 Exercised — $ — Forfeited or expired (83,891) $ 13.32 Outstanding as of December 31, 2020 1,117,160 $ 12.96 9.24 $ 2,894,754 Options vested and expected to vest as of December 31, 2020 1,117,160 $ 12.96 9.24 $ 2,894,754 Options exercisable as of December 31, 2020 263,507 $ 13.04 8.92 $ 661,952 Measurement The fair value of the Company’s stock for purposes of determining the exercise price of options granted under the VSOP for the year ended December 31, 2019 was $12.87, which was determined based on prices negotiated with investors participating in the Financing as noted above. The fair value of the zero-cost VSOP SB and the VSOP options was equal to the fair value of the underlying stock. The weighted-average assumptions used in the BSM option pricing model to determine the fair value of the employee and non-employee stock option grants relating to the 2019 Plan were as follows: Risk-Free Interest Rate The risk-free rate assumption is based on the U.S. Treasury instruments with maturities similar to the expected term of the stock options. Expected Dividend Yield The Company has not issued any dividends and does not expect to issue dividends over the life of the options. As a result, the Company has estimated the dividend yield to be zero. Expected Volatility Due to the Company’s limited operating history and a lack of company specific historical and implied volatility data, the Company estimates expected volatility based on the historical volatility of a group of comparable companies that are publicly traded. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. Expected Term The expected term of options is estimated considering the vesting period at the grant date, the life of the option and the average length of time similar grants have remained outstanding in the past. The weighted-average grant date fair value of stock options granted under the 2019 Plan during the years ended December 31, 2020 and 2019 was $9.50 and $8.28, respectively. The following are the underlying assumptions used in the Black-Scholes-Merton option pricing model to determine the fair value of stock options granted to employees and to non-employees under this stock plan: 2020 2019 Risk-free interest rate 0.42% 1.71% Expected dividend yield 0% 0% Expected volatility 88.5% 75.3% Expected term of options (years) 5.8 5.9 Early Exit Bonus Share Agreement (Anti-Dilution Adjustment) In accordance with an Early Exit Bonus Share Agreement (Anti-Dilution Adjustment) between the shareholders of Immunic AG dated August 2017, each of the four members of the Management Board of Immunic AG, through a limited liability company controlled by the respective board member, received new shares in Immunic AG as a form of anti-dilution protection. The AG shares were subscribed by the Management Board members at a price corresponding to their nominal value in the course of the Additional Financing of Immunic AG, which was carried out in March 2019. As part of the closing of the share exchange with Vital, Therapies, Inc., now Immunic, Inc., in April 2019, the AG shares were exchanged for 460,336 restricted shares in with Vital, Therapies, Inc., now Immunic, Inc., which were issued to the members of the management Board. Upon consummation of the Transaction, compensation cost of €5.3 million (approximately $6.0 million) was recognized. Stock-Based Compensation Expense Total stock-based compensation expense for all stock awards recognized in the accompanying audited consolidated statements of operations is as follows (in thousands): Year 2020 2019 Research and development $ 731 $ 1,824 General and administrative 2,016 6,736 Total $ 2,747 $ 8,560 As of December 31, 2020 there was $7.0 million in total unrecognized compensation expense relating to the 2019 Plan to be recognized over a weighted average period of 2.72 years. General and administrative expenses for the year ended December 31, 2019 include $6.0 million of stock compensation expense related to the Early Exit Bonus Share Agreement disclosed above. Research and development expense for the year ended December 31, 2019 includes $1.5 million of stock compensation expense as a result of the settlement of Tranche IV with 4SC AG as explained in Note 6. Summary of Equity Incentive Plans Assumed from Vital Upon completion of the Transaction with Vital on April 12, 2019, Vital’s 2012 Stock Option Plan (the “2012 Plan”), Vital’s 2014 Equity Incentive Plan (the “2014 Plan”) and Vital’s 2017 Inducement Equity Incentive Plan (the “Inducement Plan”), were assumed by the Company. All awards granted under these plans have either been forfeited or expired. There remain 43,311 shares available for grant under the 2014 Plan as of December 31, 2020. In September 2017, Vital’s board of directors approved the Inducement Plan, which was amended and restated in November 2017. Under the Inducement Plan 46,250 shares of Vital’s common stock were reserved to be used exclusively for non-qualified grants to individuals who were not previously employees or directors as an inducement material to a grantee's entry into employment within the meaning of Rule 5635(c)(4) of the Nasdaq Listing Rules. No expense was recorded for the plans assumed from Vital during the years ended December 31, 2020 and 2019. The following table summarizes stock option activity since January 1, 2019 under the plans assumed from Vital: Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2019 — $ — Assumed in the Transaction with Vital 17,117 $ 306.99 Granted — $ — Exercised — $ — Forfeited or expired (2,714) $ 312.18 Outstanding as of December 31, 2019 14,403 $ 306.01 2.58 $ — Options vested and expected to vest as of December 31, 2019 14,403 $ 306.01 2.58 $ — Options exercisable as of December 31, 2019 14,403 $ 306.01 2.58 $ — Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2020 14,403 $ 306.01 Granted — $ — Exercised — $ — Forfeited or expired (14,403) $ 306.01 Outstanding as of December 31, 2020 — $ — Options vested and expected to vest as of December 31, 2020 — $ — 0.00 $ — Options exercisable as of December 31, 2020 — $ — 0.00 $ — — $ — 0.00 $ — In an effort to maximize the cash on Vital’s balance sheet for the Transaction, Vital restructured existing change of control and severance agreements with certain of its executive officers in January 2019. At the same time, Vital canceled options granted to such officers and granted them a total of 127,500 RSUs. The primary effect of the amendments and the RSU grants was to substitute stock awards for cash payments owed upon a change of control.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Net loss before income tax was subject to tax in the following jurisdictions for the following periods (in thousands): Years Ended December 31, 2020 2019 United States $ (8,681) $ (20,258) Germany (33,617) (23,674) Foreign (1,719) (827) $ (44,017) $ (44,759) The rate reconciliation consists of the following: Years Ended December 31, 2020 2019 Federal statutory rate 21.0 % 21.0 % State tax (net of federal benefit) 0.0 % 0.0 % Foreign rate differential 3.0 % 3.3 % Stock options (0.9) % (1.1) % Tax effect of rate change (1.9) % 0.0 % Other (0.9) % (3.0) % Change in valuation allowance (20.3) % (20.2) % Effective tax rate 0.0 % 0.0 % Deferred income taxes result from temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements that will result in taxable or deductible amounts in future years. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in years in which those temporary differences are expected to be recovered or settled. As tax laws and rates change, deferred tax assets and liabilities are adjusted through income tax expense. There is no current or deferred income tax expense in the years ended December 31, 2020 and 2019, respectively. Significant components of the Company's net deferred tax assets are shown below. A valuation allowance has been established as realization of such net deferred tax assets has not met the more likely-than-not threshold requirement. If the Company's judgment changes and it is determined that the Company will be able to realize these net deferred tax assets, the tax benefits relating to any reversal of the valuation allowance on the net deferred tax assets will be accounted for as a reduction to income tax expense. December 31, 2020 2019 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 17,369 $ 16,357 Federal and state tax credits — — Stock-based compensation 125 — Foreign net operating loss carryforwards 18,998 12,237 Other, net 30 72 Total deferred tax assets 36,522 28,666 Deferred tax liabilities: Property, plant and equipment (5) (311) Total deferred tax liability (5) (311) Net deferred tax assets 36,517 28,355 Less valuation allowance (36,517) (28,355) $ — $ — The Company has incurred net operating losses each year since inception due to its history as a development stage company with no realized revenues from its planned principal operations. These cumulative operating losses provide significant negative evidence in the determination of whether or not the Company will be able to realize deferred tax assets such as net operating losses and other favorable temporary differences. There can be no assurance that it will ever generate taxable income. As a result, the Company has maintained a full valuation allowance against the entire balance of its net deferred tax assets since the date of inception. The valuation allowance has increased by $6.8 million and $23.7 million for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, Immunic had available NOLs of approximately $75.7 million in Germany and Australia. These NOLs do not expire. The U.S. federal NOL carryforwards of $15.6 million were generated prior to 2018 and expire over 20 years beginning in 2023. The $67.1 million of post 2017 federal NOL carryforwards do not expire. Section 382 of the Internal Revenue Code of 1986, as amended, subject the future utilization of net operating losses, to an annual limitation in the event of certain ownership changes, as defined thereunder. The Company may have undergone such an ownership change and therefore may be limited in the amount of net operating losses available for utilization in the future. The Company did not have any uncertain tax positions for the years ended December 31, 2020 and 2019, respectively. Due to the full valuation allowance that the Company has on its net deferred tax asset balance, there are no uncertain tax positions that would impact the effective tax rate if recognized. The Company is subject to U.S. federal, New York, California, Texas, German and Australian income taxes. The Company is subject to U.S. federal or state income tax examination by tax authorities for tax returns filed for the years 2003 and forward due to the carryforward of NOLs. Tax years 2016 through 2019 are subject to audit by German and Australian tax authorities. The Company is not currently under examination by any tax jurisdictions.

EIB Loan

EIB Loan	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
EIB Loan	EIB LoanOn October 19, 2020, Immunic, Inc. (the “Company”) and Immunic AG, its wholly-owned subsidiary, entered into a Finance Contract (the “Loan Agreement”) with the European Investment Bank (“EIB”), pursuant to which EIB agreed to provide Immunic AG with a term loan in an aggregate amount of up to €24.5 million to support the development of Immunic’s lead asset, IMU-838, in moderate coronavirus disease 2019 (“COVID-19”), to be made available to be drawn in three tranches, with the second and third tranches subject to the completion of certain pre-defined milestones. The Company has the right to defer payment of principal and interest on the first and second tranches until five years after the respective borrowing dates, at which point such tranches must be repaid in full. The third tranche is repayable in annual installments commencing one year after its respective borrowing date and must be repaid in full no later than five years after such date. Any outstanding borrowings under the Loan Agreement will accrue interest as provided in the Loan Agreement. From January 1, 2021 until December 31, 2030, the Company and Immunic AG are also obligated to pay EIB a very low single digit percentage of their revenue, as set forth in the Loan Agreement, subject to certain conditions and limitations tied to the total amount drawn under the Loan Agreement and subject to a cap of €8.6 million if only the first tranche is drawn and subject to a cap of €30 million if the full loan amount is drawn. The Loan Agreement also includes certain prepayment penalties that may be triggered by certain prepayments prior to the maturity date. As of December 31, 2020, nothing was drawn down under this loan agreement. The Company will guarantee Immunic AG’s obligations to EIB pursuant to a Guarantee Agreement to be executed by the Company, Immunic AG and EIB (the “Guarantee Agreement”, and together with the Loan Agreement, the “Agreements”).

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions As previously disclosed, on April 15, 2020, the compensation committee of the Company’s Board independently reviewed and approved entering into an employment agreement with the Company’s current Chairman of the Board, Duane Nash, MD, JD, MBA (the “Executive Chairman Agreement”) and pursuant to such approval, on April 17, 2020, the Company and Mr. Nash entered into the Executive Chairman Agreement. Pursuant to the Executive Chairman Agreement, Mr. Nash serves as the Executive Chairman of the Board as long as he is a member of the Board, or until termination of the Executive Chairman Agreement (as described below) or upon his earlier death, incapacity, removal, or resignation. Pursuant to the Executive Chairman Agreement, Mr. Nash is entitled to receive: (i) a monthly base salary of $25,417 (it being agreed that such fee is inclusive of any fees associated with Mr. Nash’s services as both a director of the Company and in the capacity of Executive Chairman), (ii) employee benefits including, health insurance, dental insurance, basic life and accidental death and dismemberment insurance, long and short term disability insurance and participation in the Company’s 401(k) Plan, and (iii) reimbursements for pre-approved reasonable business-related expenses incurred in good faith in the performance of the Mr. Nash’s duties for the Company. The Executive Chairman Agreement establishes an “at will” employment relationship pursuant to which Mr. Nash serves as Executive Chairman. The Executive Chairman Agreement contemplated a term that ended on October 15, 2020 and was subsequently extend. On October 15, 2020, the Company and Mr. Nash entered into an addendum to the Executive Chairman Agreement, pursuant to which the term of the agreement was extended to April 15, 2021. The Company made a one-time award to Mr. Nash of 120,000 stock options, which vest monthly starting on November 15, 2020. All other terms of the employment agreement remained the same.

Selected Quarterly Data (unaudi

Selected Quarterly Data (unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Data (unaudited)	Selected Quarterly Data (unaudited) The following financial information reflects all normal recurring adjustments, which are, in the opinion of management, necessary for a fair statement of the results of the interim periods. Summarized quarterly data for 2020 and 2019 are as follows (in thousands, except per share data): For the Quarters Ended March 31 June 30 September 30 December 31 Total Year 2020 Operating expenses $ 9,014 $ 12,222 $ 13,545 $ 14,190 $ 48,971 Net loss $ (8,487) $ (11,458) $ (12,913) $ (11,159) $ (44,017) Basic and diluted net loss per share (1) $ (0.79) $ (0.90) $ (0.70) $ (0.53) $ (2.81) 2019 Operating expenses $ 4,662 $ 15,007 $ 9,177 $ 8,186 $ 37,032 Net loss $ (4,313) $ (14,714) $ (8,215) $ (7,691) $ (34,933) Basic and diluted net loss per share (1) $ (5.09) $ (1.52) $ (0.82) $ (0.75) $ (4.52) (1) Net loss per share is computed independently for each of the quarters presented. Therefore, the sum of the quarterly per share calculations will not necessarily equal the annual per share calculation.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires the Company to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements. The most significant estimates in the Company’s financial statements and accompanying notes relate to the application of the acquisition method of accounting related to the Transaction, clinical trial expenses, share-based compensation. Management believes its estimates to be reasonable under the circumstances. Actual results could differ materially from those estimates and assumptions.
Foreign Currency Translation and Presentation	Foreign Currency Translation and Presentation The Company’s reporting currency is United States (“U.S.”) dollars. During the twelve months ended December 31, 2020 and 2019, Immunic AG and Immunic Research GmbH’s operations were located in Germany with the euro being its functional currency. Immunic Australia Pty Ltd.’s functional currency is the Australian dollar. All amounts in the financial statements where the functional currency is not the U.S. dollar are translated into U.S. dollar equivalents at exchange rates as follows: • assets and liabilities at reporting period-end rates; • income statement accounts at average exchange rates for the reporting period; and • components of equity at historical rates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents.
Fair Value Measurement	Fair Value Measurement Fair value is defined as the price that would be received to sell an asset or be paid to transfer a liability in an orderly transaction between market participants on the measurement date. Accounting guidance establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 1 assets consisted of money market funds for the periods presented. The Company had no Level 1 liabilities for the periods presented. Level 2— Inputs other than observable quoted prices for the asset or liability, either directly or indirectly; these include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. The Company had no Level 2 assets or liabilities for the periods presented. Level 3—Unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of assets or liabilities. The Company had no Level 3 assets or liabilities for the periods presented. The carrying value of cash and cash equivalents, other current assets and prepaid expenses, accounts payable, accrued expenses, and other current liabilities approximates fair value due to the short period of time to maturity.
Property and Equipment	Property and EquipmentProperty and equipment is stated at cost. Depreciation is computed using the straight-line method based on the estimated service lives of the assets which range from three years to thirteen years.
Impairment of Long-lived Assets	Impairment of Long-Lived AssetsThe Company records impairment losses on long-lived assets used in operations when indicators of impairment are present and the undiscounted cash flows estimated to be generated by those assets are less than the assets’ carrying amount. Impaired assets are then recorded at their estimated fair value.
Goodwill	Goodwill Business combinations are accounted for under the acquisition method. The total purchase price of an acquisition is allocated to the underlying identifiable net assets, based on their respective estimated fair values as of the acquisition date. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash inflows and outflows, probabilities of success, discount rates, and asset lives, among other items. Assets acquired and liabilities assumed are recorded at their estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Goodwill is tested for impairment at the reporting unit level annually in the fourth quarter, or more frequently when events or changes in circumstances indicate that the asset might be impaired. Examples of such events or circumstances include, but are not limited to, a significant adverse change in legal or business climate, an adverse regulatory action or unanticipated competition.
Research and Development Expenses	Research and Development Expenses These costs primarily include external development expenses and internal personnel expenses for the three development programs, IMU-838, IMU-935 and IMU-856. Immunic has spent the majority of its research and development resources on IMU-838, the Company's lead development program for clinical trials in RRMS, UC, COVID-19, and PSC. IMU-935 is currently being tested in a Phase 1 clinical trial in healthy volunteers, which was initiated in September 2019. IMU-856 is currently being tested in a Phase 1 clinical trial in healthy volunteers, which was initiated in August 2020. Research and development expenses consist of expenses incurred in research and development activities, which include clinical trials, contract research services, certain milestone payments, salaries and related employee benefits, allocated facility costs and other outsourced services. Research and development expenses are charged to operations as incurred. The Company enters into agreements with contract research organizations (“CROs”) to provide clinical trial services for individual studies and projects by executing individual work orders governed by a Master Service Arrangement (“MSA”). The MSAs and associated work orders provide for regular recurrent payments and payments upon the completion of certain milestones. The Company regularly assesses the timing of payments against actual costs incurred to ensure a proper accrual of related expenses in the appropriate accounting period.
Collaborative Arrangements	Collaboration Arrangements Certain collaboration and license agreements may include payments to or from the Company of one or more of the following: non-refundable or partially refundable upfront or license fees; development, regulatory and commercial milestone payments; payment for manufacturing supply services; partial or complete reimbursement of research and development costs; and royalties on net sales of licensed products. The Company assesses whether such contracts are within the scope of Financial Accounting Standards Board (FASB) Accounting Standards Update (“ASU”) 2014-09 “ Revenue from Contracts with Customers ” and ASU No. 2018-18, “ Collaborative Arrangements”, ("ASU 2018-18"). ASU 2018-18, clarifies that certain elements of collaborative arrangements could qualify as transactions with customers in the scope of ASC 606. In October 2018, the Company entered into an option and license agreement (the "Daiichi Sankyo Agreement") with Daiichi Sankyo Co., Ltd. ("Daiichi Sankyo") which granted the Company the right to license a group of compounds, designated by the Company as IMU-856, as a potential new oral treatment option for diseases such as inflammatory bowel disease, irritable bowel syndrome with diarrhea, immune checkpoint inhibitor induced colitis and other barrier function associated diseases. During the option period, the Company performed agreed upon research and development activities for which it was reimbursed by Daiichi Sankyo up to a maximum agreed-upon limit. Such reimbursement was recorded as other income. There are no more research and development reimbursements expected under this agreement.
General and Administrative Expenses	General and Administrative ExpensesGeneral and administrative expenses consist primarily of salaries and related costs for personnel in executive, finance, business development and other support functions. Other general and administrative expenses include, but are not limited to, stock-based compensation, insurance costs, professional fees for legal, accounting and tax services, consulting, related facility costs and travel.
Stock-based Compensation	Stock-Based Compensation The Company measures the cost of employee and non-employee services received in exchange for equity awards based on the grant-date fair value of the award recognized generally as an expense (i) on a straight-line basis over the requisite service period for those awards whose vesting is based upon a service condition, and (ii) on an accelerated method for awards whose vesting is based upon a performance condition, but only to the extent it is probable that the performance condition will be met. Stock-based compensation is (i) estimated at the date of grant based on the award’s fair value for equity classified awards and (ii) final measurement date for liability classified awards. Forfeitures are recorded in the period in which they occur. The Company estimates the fair value of stock options using the Black-Scholes-Merton option-pricing model ("BSM"), which requires the use of estimates and subjective assumptions, including the risk-free interest rate, the fair value of the underlying common stock, the expected dividend yield of the Company’s common stock, the expected volatility of the price of the Company’s common stock, and the expected term of the option. These estimates involve inherent uncertainties and the application of management’s judgment. If factors change and different assumptions are used, the Company’s stock-based compensation expense could be materially different in the future.
Leases	Leases The Company leases office space and office equipment. The underlying lease agreements have lease terms of less than 12 months and up to 60 months. The short-term leases are deemed immaterial and have not been included in the operating lease right of use asset and operating lease liability. The Company has two existing leases for office space. At inception of a lease agreement, the Company determines whether an agreement represents a lease and at commencement each lease agreement is assessed as to classification as an operating or financing lease. The Company's two leases have been classified as operating leases and an operating lease right-of-use asset and an operating lease liability have been recorded on the Company’s balance sheet. A right-of-use lease asset represents the Company’s right to use the underlying asset for the lease term and the lease obligation represents its commitment to make the lease payments arising from the lease. Right-of-use lease assets and obligations are recognized at the commencement date based on the present value of remaining lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company has used an estimated incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The right-of-use lease asset includes any lease payments made prior to commencement and excludes any lease incentives. The lease term used in estimating future lease payments may include options to extend when it is reasonably certain that the Company will exercise that option. Operating lease expense is recognized on a straight-line basis over the lease term, subject to any changes in the lease or changes in expectations regarding the lease term. Variable lease costs such as common area costs and property taxes are expensed as incurred. Leases with an initial term of twelve months or less are not recorded on the balance sheet.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Accumulated other comprehensive income (loss) has been reflected as a separate component of stockholders’ equity in the accompanying Consolidated Balance Sheets and consists of foreign currency translation adjustments (net of tax).
Income Taxes	Income Taxes The Company is subject to corporate income tax laws and regulations in the U.S., Germany and Australia. Tax regulations within each jurisdiction are subject to the interpretation of the related tax laws and regulations and require significant judgment in their application. The Company utilizes the asset and liability method of accounting for income taxes which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the audited consolidated financial statements. Deferred income tax assets and liabilities are determined based on the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the
Net Loss Per Share	Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of common shares and, if dilutive, common stock equivalents outstanding for the period determined using the treasury-stock method. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In January 2017, the FASB issued ASU 2017-04, " Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ." This guidance eliminates Step 2 from the goodwill impairment test, instead requiring an entity to recognize a goodwill impairment charge for the amount by which the goodwill carrying amount exceeds the reporting unit’s fair value. The Company adopted this ASU, as required, in the quarter ended March 31, 2020 on a prospective basis. The adoption of this ASU did not have a significant impact on the Company's consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, “ Fair Value Measurement - Disclosure Framework” ("ASU 2018-13.") ASU 2018-13 modifies the disclosure requirements for fair value measurements. The amendments relate to disclosures regarding unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements and the narrative description of measurement uncertainty, and are to be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments must be applied retrospectively to all periods presented upon their effective date. The Company adopted this ASU, as required, in the quarter ended March 31, 2020. The adoption of this ASU did not have a significant impact on the Company's consolidated financial statements. In November 2018, the FASB issued ASU 2018-18, “ Collaborative Arrangements” ("ASU 2018-18"). ASU 2018-18, clarifies that elements of collaborative arrangements could qualify as transactions with customers in the scope of ASC 606. The Company adopted this ASU, as required, in the quarter ended March 31, 2020. The Company does not have any agreements that meet the definition of a collaboration arrangement at this time.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss per Share	Potentially dilutive securities, not included in the calculation of diluted net loss per share attributable to common stockholders because to do so would be anti-dilutive, are as follows: As of December 31, 2020 2019 Options to purchase common stock 1,117,160 471,048

Accounting for the Transaction

Accounting for the Transaction (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Assets Acquired and Liabilities Assumed	The following summarizes the purchase price paid in the Transaction (amounts in thousands except share and per share amounts): Number of shares owned by Vital stockholders (1) 1,059,269 RSUs (2) 127,500 Total fully-diluted shares 1,186,769 Multiplied by the fair value per share of Vital common stock (3) $ 33.20 Estimated purchase price $ 39,400 (1) The number of shares of 1,059,269 represents the historical 42,369,694 shares of Vital common stock outstanding immediately prior to the closing of the Transaction, adjusted for the Reverse Stock Split. (2) The number of RSUs of 127,500 represents the historical 5,100,000 Vital RSUs of which all have been issued to date to Vital former officers in 2019. (3) Based on the last reported sale price of Vital common stock on the Nasdaq Global Market on April 12, 2019, the closing of the Transaction, adjusted for the Reverse Stock Split. The following summarizes the allocation of the purchase price to the net tangible and intangible assets acquired: (in thousands) Cash and cash equivalents $ 8,151 Prepaid expenses and other assets 307 Supplies and working cell banks 1,000 Clinical development equipment 306 Other property and equipment 30 In-process research and development (“IPR&D ” ) 764 Accounts payable, accrued expenses and other liabilities (4,128) Goodwill 32,970 Purchase price $ 39,400

ELAD Sales Agreement (Tables)

ELAD Sales Agreement (Tables)	12 Months Ended
	Dec. 31, 2020
Discontinued Operations and Disposal Groups [Abstract]
Estimated Fair Value of ELAD Assets	The estimated fair value of the ELAD Assets was included in the purchase accounting allocation as follows (in thousands): Clinical development equipment 306 Supplies and working cell banks 1,000 In process research & development (“IPR&D”) 764 Total $ 2,070

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid Expense and Other Current Assets consist of (in thousands): December 31, 2020 2019 Prepaid clinical and related costs $ 3,416 $ 1,307 VAT receivable 295 408 Australian research and development tax incentive 1,348 350 Other 1,234 796 Total $ 6,293 $ 2,861
Schedule of Accounts Payable and Accrued Expenses	Accounts Payable consist of (in thousands): December 31, 2020 2019 Clinical costs $ 3,408 $ 1,981 Legal and audit costs 139 226 Other 153 216 Total $ 3,700 $ 2,423 Accrued Expenses Accrued expenses consist of (in thousands): December 31, 2020 2019 Accrued clinical and related costs $ 3,301 $ 2,863 Accrued legal and audit costs 114 211 Accrued compensation 658 — Accrued other 245 224 Total $ 4,318 $ 3,298
Schedule of Other Current Liabilities	Other Current Liabilities consist of (in thousands): December 31, 2020 2019 Deferred income $ — $ 1,008 Other 379 343 Total $ 379 $ 1,351

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Maturities of Operating Lease Obligations	Maturities of the operating lease obligation are as follows as of December 31, 2020 (in thousands): 2021 $ 348 2022 $ 348 2023 $ 198 2024 $ 124 2025 $ 62 Thereafter $ — Total lease payments $ 1,080 Less: interest portion $ 107 Present value of lease obligation $ 973

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following fair value hierarchy table present information about each major category of the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands): Fair Value Measurement at December 31, 2020 Fair Value Level 1 Level 2 Level 3 Assets Money market funds $ 39,615 $ 39,615 $ — $ — Fair Value Measurement at December 31, 2019 Fair Value Level 1 Level 2 Level 3 Assets Money market funds $ 4,491 $ 4,491 $ — $ —

Common Stock and Preferred St_2

Common Stock and Preferred Stock (Converted into Common Stock) (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Shares Reserved for Future Issuance	Shares reserved for future issuance as of December 31, 2020 are as follows: Number of Common stock reserved for issuance for: Outstanding stock options 1,117,160 Common stock options available for future grant: 2014 Equity Incentive Plan 43,311 2017 Inducement Equity Incentive Plan 46,250 2019 Omnibus Equity Incentive Plan 831,474 Total common shares reserved for future issuance 2,038,195

Stock Compensation Plans (Table

Stock Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Stock Option Activity	The following table illustrates the number and weighted average exercise prices of, and movements in, stock options for the VSOP SB and VSOP during the year ended December 31, 2019. There were no awards granted or outstanding after the awards settled in 2019: 2019 Unvested Awards Weighted-Average Fair Value Outstanding as of January 1 6,937 $ 12.87 Granted during the period 32,177 $ 12.87 Forfeited during the period — $ — Settled in cash during the period (39,114) $ 12.87 Expired during the period — $ — Outstanding at December 31 — $ — Exercisable at December 31 — $ — No expense was recognized during the year ended December 31, 2020. There was $508,000 of expense recognized in 2019 upon the vesting of the awards as a result of closing the Transaction. There were no cancellations or modifications to the awards in 2019. The following table summarizes stock option activity since January 1, 2019 under the 2019 Plan: Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2019 — $ — Granted 456,645 $ 12.57 Exercised — $ — Forfeited or expired — $ — Outstanding as of December 31, 2019 456,645 $ 12.57 9.63 $ 114,399 Options vested and expected to vest as of December 31, 2019 456,645 $ 12.57 9.63 $ 114,399 Options exercisable as of December 31, 2019 31,956 $ 13.00 9.59 $ 3,382 Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2020 456,645 $ 12.57 Granted 744,406 $ 13.24 Exercised — $ — Forfeited or expired (83,891) $ 13.32 Outstanding as of December 31, 2020 1,117,160 $ 12.96 9.24 $ 2,894,754 Options vested and expected to vest as of December 31, 2020 1,117,160 $ 12.96 9.24 $ 2,894,754 Options exercisable as of December 31, 2020 263,507 $ 13.04 8.92 $ 661,952
Schedule of Valuation Assumptions Used	The following are the underlying assumptions used in the Black-Scholes-Merton option pricing model to determine the fair value of stock options granted to employees and to non-employees under this stock plan: 2020 2019 Risk-free interest rate 0.42% 1.71% Expected dividend yield 0% 0% Expected volatility 88.5% 75.3% Expected term of options (years) 5.8 5.9
Schedule of Stock-based Compensation Expense for Stock Awards Recognized	Total stock-based compensation expense for all stock awards recognized in the accompanying audited consolidated statements of operations is as follows (in thousands): Year 2020 2019 Research and development $ 731 $ 1,824 General and administrative 2,016 6,736 Total $ 2,747 $ 8,560
Employee Stock Options, Vital Therapies Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Stock Option Activity	The following table summarizes stock option activity since January 1, 2019 under the plans assumed from Vital: Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2019 — $ — Assumed in the Transaction with Vital 17,117 $ 306.99 Granted — $ — Exercised — $ — Forfeited or expired (2,714) $ 312.18 Outstanding as of December 31, 2019 14,403 $ 306.01 2.58 $ — Options vested and expected to vest as of December 31, 2019 14,403 $ 306.01 2.58 $ — Options exercisable as of December 31, 2019 14,403 $ 306.01 2.58 $ — Options Weighted- Weighted- Aggregate Outstanding as of January 1, 2020 14,403 $ 306.01 Granted — $ — Exercised — $ — Forfeited or expired (14,403) $ 306.01 Outstanding as of December 31, 2020 — $ — Options vested and expected to vest as of December 31, 2020 — $ — 0.00 $ — Options exercisable as of December 31, 2020 — $ — 0.00 $ — — $ — 0.00 $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Net Loss before Income Tax Based on Jurisdictions	Net loss before income tax was subject to tax in the following jurisdictions for the following periods (in thousands): Years Ended December 31, 2020 2019 United States $ (8,681) $ (20,258) Germany (33,617) (23,674) Foreign (1,719) (827) $ (44,017) $ (44,759)
Income Tax Rate Reconciliation	The rate reconciliation consists of the following: Years Ended December 31, 2020 2019 Federal statutory rate 21.0 % 21.0 % State tax (net of federal benefit) 0.0 % 0.0 % Foreign rate differential 3.0 % 3.3 % Stock options (0.9) % (1.1) % Tax effect of rate change (1.9) % 0.0 % Other (0.9) % (3.0) % Change in valuation allowance (20.3) % (20.2) % Effective tax rate 0.0 % 0.0 %
Deferred Tax Assets and Liabilities	December 31, 2020 2019 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 17,369 $ 16,357 Federal and state tax credits — — Stock-based compensation 125 — Foreign net operating loss carryforwards 18,998 12,237 Other, net 30 72 Total deferred tax assets 36,522 28,666 Deferred tax liabilities: Property, plant and equipment (5) (311) Total deferred tax liability (5) (311) Net deferred tax assets 36,517 28,355 Less valuation allowance (36,517) (28,355) $ — $ —

Selected Quarterly Data (unau_2

Selected Quarterly Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Summarized Quarterly Information	Summarized quarterly data for 2020 and 2019 are as follows (in thousands, except per share data): For the Quarters Ended March 31 June 30 September 30 December 31 Total Year 2020 Operating expenses $ 9,014 $ 12,222 $ 13,545 $ 14,190 $ 48,971 Net loss $ (8,487) $ (11,458) $ (12,913) $ (11,159) $ (44,017) Basic and diluted net loss per share (1) $ (0.79) $ (0.90) $ (0.70) $ (0.53) $ (2.81) 2019 Operating expenses $ 4,662 $ 15,007 $ 9,177 $ 8,186 $ 37,032 Net loss $ (4,313) $ (14,714) $ (8,215) $ (7,691) $ (34,933) Basic and diluted net loss per share (1) $ (5.09) $ (1.52) $ (0.82) $ (0.75) $ (4.52) (1) Net loss per share is computed independently for each of the quarters presented. Therefore, the sum of the quarterly per share calculations will not necessarily equal the annual per share calculation.

Description of Business and B_2

Description of Business and Basis of Financial Statements - Additional Details (Detail) $ in Thousands, € in Millions	Apr. 12, 2019shares	Apr. 11, 2019USD ($)shares	Apr. 11, 2019EUR (€)shares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Business Acquisition [Line Items]
Accumulated deficit | $				$ 103,928	$ 59,911
Proceeds from issuance of private placement | $				216,800
Cash and cash equivalents | $				$ 127,452	$ 29,369	$ 13,072
Conversion ratio	0.025
Immunic AG
Business Acquisition [Line Items]
Percentage of shares owned	88.25%
Vital Therapies, Inc.
Business Acquisition [Line Items]
Percentage of shares owned	11.75%
Vital Therapies, Inc. | Immunic AG
Business Acquisition [Line Items]
Exchange ratio		17.17	17.17
Immunic AG | Vital Therapies, Inc.
Business Acquisition [Line Items]
Aggregate consideration issuable (in shares)	8,927,130
Shares owned prior to transaction (in shares)	1,059,269
Immunic AG | Restricted stock units | Vital Therapies, Inc.
Business Acquisition [Line Items]
RSUs owned prior to transaction (in shares)	127,500	5,100,000	5,100,000
Private Placement | Immunic AG
Business Acquisition [Line Items]
Shares issues in private placement transaction (in shares)		2,197,742	2,197,742
Aggregate consideration from private placement		$ 29,900	€ 26.7

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)lease	Dec. 31, 2019USD ($)
Property, Plant and Equipment [Line Items]
Cash equivalents, highly-liquid investments maturity (or less)	3 months
Depreciation and amortization expense	$ 39,000	$ 50,000
Impairment losses	0	$ 0
Goodwill impairment	$ 0
Lease term	5 years
Number of existing operating leases | lease	2
Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Lease term	12 months
Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	13 years
Lease term	60 months

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the calculation of diluted net loss per share (in shares)	1,117,160	471,048

Accounting for the Transactio_2

Accounting for the Transaction - Additional Information (Detail) $ in Thousands	Apr. 12, 2019USD ($)shares	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Apr. 11, 2019
Business Acquisition [Line Items]
Goodwill			$ 32,970	$ 32,970
Immunic, Inc.
Business Acquisition [Line Items]
Incurred costs			$ 10,000
Incurred costs, non-cash charges		$ 7,500
Immunic AG
Business Acquisition [Line Items]
Percentage of shares owned	88.25%
Immunic AG | Vital Therapies, Inc.
Business Acquisition [Line Items]
Exchange ratio					17.17
Vital Therapies, Inc.
Business Acquisition [Line Items]
Percentage of shares owned	11.75%
Vital Therapies, Inc. | Immunic, Inc.
Business Acquisition [Line Items]
Goodwill	$ 32,970
Outstanding stock options
Business Acquisition [Line Items]
Outstanding shares to purchase (in shares) | shares	16,987
Restricted stock units | Vital Therapies, Inc. | Immunic, Inc.
Business Acquisition [Line Items]
Outstanding shares to purchase (in shares) | shares	127,500

Accounting for the Transactio_3

Accounting for the Transaction - Preliminary Estimate of Purchase Price (Detail) - USD ($) $ / shares in Units, $ in Thousands	Apr. 12, 2019	Dec. 31, 2020	Dec. 31, 2019	Apr. 11, 2019
Business Acquisition [Line Items]
Number of shares owned by Vital stockholders (in shares)		21,168,240	10,744,806
Vital Therapies, Inc.
Business Acquisition [Line Items]
Number of shares owned by Vital stockholders (in shares)				42,369,694
Vital Therapies, Inc. | Immunic AG
Business Acquisition [Line Items]
Number of shares owned by Vital stockholders (in shares)	1,059,269
Total fully-diluted shares (in shares)	1,186,769
Multiplied by the fair value per share of Vital common stock (in USD per share)	$ 33.20
Estimated purchase price	$ 39,400
Restricted stock units | Vital Therapies, Inc. | Immunic AG
Business Acquisition [Line Items]
RSUs owned prior to transaction (in shares)	127,500			5,100,000
Outstanding shares to purchase (in shares)	127,500

Accounting for the Transactio_4

Accounting for the Transaction - Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Apr. 12, 2019
Business Acquisition [Line Items]
Goodwill	$ 32,970	$ 32,970
Vital Therapies, Inc. | Immunic, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents			$ 8,151
Prepaid expenses and other assets			307
Supplies and working cell banks			1,000
Clinical development equipment			306
Other property and equipment			30
In-process research and development (“IPR&D”)			764
Accounts payable, accrued expenses and other liabilities			(4,128)
Goodwill			32,970
Purchase price			$ 39,400

ELAD Sales Agreement - Addition

ELAD Sales Agreement - Additional Information (Detail) - ELAD-Related Assets - Disposal Group, Disposed of by Sale, Not Discontinued Operations - USD ($) $ in Thousands	May 28, 2019	Mar. 31, 2019	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration transferred		$ 2,500
Amount released from escrow	$ 1,100
Fair value of promissory note	920
Notes Receivable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Face amount of receivable	$ 1,325
Effective interest rate	10.00%
Fair value adjustment			$ 405
Vital Therapies, Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow deposit		1,100
Cash consideration	$ 50	$ 50

ELAD Sales Agreement - Estimate

ELAD Sales Agreement - Estimated Fair Value of ELAD Assets (Detail) - ELAD-Related Assets - Disposal Group, Disposed of by Sale, Not Discontinued Operations $ in Thousands	Dec. 31, 2020USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimated fair value of ELAD Assets	$ 2,070
Clinical development equipment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimated fair value of ELAD Assets	306
Supplies and working cell banks
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimated fair value of ELAD Assets	1,000
In process research & development (“IPR&D”)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimated fair value of ELAD Assets	$ 764

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Prepaid clinical and related costs	$ 3,416	$ 1,307
VAT receivable	295	408
Australian research and development tax incentive	1,348	350
Other	1,234	796
Total	$ 6,293	$ 2,861

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Accounts Payable (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Clinical costs	$ 3,408	$ 1,981
Legal and audit costs	139	226
Other	153	216
Total	$ 3,700	$ 2,423

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued clinical and related costs	$ 3,301	$ 2,863
Accrued legal and audit costs	114	211
Accrued compensation	658	0
Accrued other	245	224
Total	$ 4,318	$ 3,298

Balance Sheet Details - Sched_4

Balance Sheet Details - Schedule of Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred income	$ 0	$ 1,008
Other	379	343
Total	$ 379	$ 1,351

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2016	Dec. 31, 2020	Dec. 31, 2019	Apr. 12, 2019	Mar. 27, 2019	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Lease term		5 years
Increase in operating lease, right-of-use asset		$ 427
Operating and variable lease cost		354	$ 135
Contractual obligation		$ 1,200
Asset purchase agreement, royalties as percent of aggregated net sales	4.40%
Common stock, shares issued (in shares)		21,168,240	10,744,806	120,070	156,920
Common stock issued		$ 2	$ 1	$ 1,500		$ 56

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Annual Obligations Under All Non-Cancellable Operating Lease Commitments (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 348
2022	348
2023	198
2024	124
2025	62
Thereafter	0
Total lease payments	1,080
Less: interest portion	107
Present value of lease obligation	$ 973

Fair Value - Schedule of Financ

Fair Value - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - Money Market Funds - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets
Assets	$ 39,615	$ 4,491
Level 1
Assets
Assets	39,615	4,491
Level 2
Assets
Assets	0	0
Level 3
Assets
Assets	$ 0	$ 0

Common Stock and Preferred St_3

Common Stock and Preferred Stock (Converted into Common Stock) - Shelf Registration Statement (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Nov. 30, 2020	Jul. 31, 2019	May 31, 2018
Class of Stock [Line Items]
Maximum aggregate offering price of common stock, preferred stock, warrants, debt securities, and/or units					$ 200,000,000
Maximum common stock shares authorized (in shares)			250,000,000
Maximum aggregate offering price under ATM agreement		$ 34,600,000
Commission, percent of gross proceeds from sale of common stock	3.00%
Issuance of stock		0
July 2019 Equity Issuances
Class of Stock [Line Items]
Maximum aggregate offering price of common stock, preferred stock, warrants, debt securities, and/or units				$ 40,000,000
Maximum aggregate offering price under ATM agreement	$ 23,300,000
December 2020 Equity Issuances
Class of Stock [Line Items]
Maximum aggregate offering price of common stock, preferred stock, warrants, debt securities, and/or units	50,000,000
Maximum aggregate offering price under ATM agreement	50,000,000
At-The-Market Sales Agreement
Class of Stock [Line Items]
Issuance of stock	$ 11,300,000	$ 5,400,000
Issuance of stock (in shares)	733,728	630,907
Issuance of stock (in USD per share)	$ 15.42	$ 8.49
Proceeds from issuance of common stock	$ 11,000,000	$ 4,900,000
Underwriter commissions	$ 339,356	161,000
Estimated offering expenses		$ 305,000

Common Stock and Preferred St_4

Common Stock and Preferred Stock (Converted into Common Stock) - Registered Direct Offering (Details) - April 2020 Equity Issuances - USD ($) $ / shares in Units, $ in Thousands	Apr. 23, 2020	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Cash fee, percent of gross proceeds	6.50%
Shares issues in private placement transaction (in shares)	1,764,706
Sale of stock, price per share (in USD per share)	$ 8.50
Proceeds from issuance of common stock, gross	$ 15,000
Proceeds from issuance of common stock	$ 13,900	$ 13,918	$ 0

Common Stock and Preferred St_5

Common Stock and Preferred Stock (Converted into Common Stock) - Public Equity Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 07, 2020	Aug. 04, 2020	Jun. 10, 2020	Dec. 31, 2020	Dec. 31, 2019
June 2020 Equity Issuances
Class of Stock [Line Items]
Shares issues in private placement transaction (in shares)			2,175,000
Cash fee, percent of gross proceeds			6.50%
Sale of stock, price per share (in USD per share)			$ 11.40
Proceeds from issuance of common stock, gross			$ 25,000
Proceeds from issuance of common stock			$ 23,000	$ 23,048	$ 0
August 2020 Equity Issuances
Class of Stock [Line Items]
Shares issues in private placement transaction (in shares)		5,000,000
Sale of stock, price per share (in USD per share)		$ 18
Proceeds from issuance of common stock	$ 96,500			$ 96,540	$ 0
Exercisable period on additional issuance of common stock		30 days
Number of additional shares authorized (in shares)		750,000

Common Stock and Preferred St_6

Common Stock and Preferred Stock (Converted into Common Stock) - Stock Subscription Not Yet Issued (Details)	Dec. 31, 2020$ / sharesshares	Dec. 31, 2019$ / sharesshares	Apr. 12, 2019shares	Mar. 27, 2019€ / sharesshares	Dec. 31, 2018€ / shares
Class of Stock [Line Items]
Common stock, shares issued (in shares)	21,168,240	10,744,806	120,070	156,920
Common stock, par value (in USD per share) | (per share)	$ 0.0001	$ 0.0001		€ 1	€ 1
Executive Officers
Class of Stock [Line Items]
Common stock, shares issued (in shares)				27,176

Common Stock and Preferred St_7

Common Stock and Preferred Stock (Converted into Common Stock) - Common Stock (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Apr. 12, 2019USD ($)	Mar. 27, 2019€ / shares	Dec. 31, 2018€ / sharesshares	Mar. 31, 2016USD ($)
Equity [Abstract]
Common stock, shares authorized (in shares) | shares	130,000,000	130,000,000			846,953
Common stock, par value (in USD per share) | (per share)	$ 0.0001	$ 0.0001		€ 1	€ 1
Common stock issued | $	$ 2	$ 1	$ 1,500			$ 56
Common stock, cash dividends declared (in USD per share)	$ 0
Common stock cash dividends paid (in USD per share)	$ 0

Common Stock and Preferred St_8

Common Stock and Preferred Stock (Converted into Common Stock) - Preferred Stock (Detail) € / shares in Units, $ / shares in Units, $ in Thousands, € in Millions	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)shares	Dec. 31, 2018EUR (€)€ / sharesshares
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	0	0
Preferred stock, par value (in USD per share) | $ / shares	$ 0.0001	$ 0.0001
Preferred stock issued (in shares) | $	$ 0	$ 0
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares outstanding (in shares)	0	0
Immunic AG
Class of Stock [Line Items]
Preferred stock issued (in shares)			$ 37,200	€ 31.7
Immunic AG | Series A-1 Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)			13,541	13,541
Preferred stock, par value (in USD per share) | € / shares				€ 1
Immunic AG | Series A-2 Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)			299,456	299,456

Common Stock and Preferred St_9

Common Stock and Preferred Stock (Converted into Common Stock) - Stock Warrants (Detail)	Sep. 25, 2019$ / sharesshares
Class of Stock [Line Items]
Exercise price (usd per share) | $ / shares	$ 3,719.60
Warrant
Class of Stock [Line Items]
Number of warrants outstanding and exercisable (in shares) | shares	6,015

Common Stock and Preferred S_10

Common Stock and Preferred Stock (Converted into Common Stock) - Shares Reserved for Future Issuance (Detail)	Dec. 31, 2020shares
Class of Stock [Line Items]
Total common shares reserved for future issuance (in shares)	2,038,195
Outstanding stock options
Class of Stock [Line Items]
Total common shares reserved for future issuance (in shares)	1,117,160
2014 Equity Incentive Plan | Common stock options available for future grant:
Class of Stock [Line Items]
Total common shares reserved for future issuance (in shares)	43,311
2017 Inducement Equity Incentive Plan | Common stock options available for future grant:
Class of Stock [Line Items]
Total common shares reserved for future issuance (in shares)	46,250
2019 Omnibus Equity Incentive Plan | Common stock options available for future grant:
Class of Stock [Line Items]
Total common shares reserved for future issuance (in shares)	831,474

Stock Compensation Plans - Addi

Stock Compensation Plans - Additional Information (Detail) $ / shares in Units, $ in Thousands, € in Millions	1 Months Ended			6 Months Ended	12 Months Ended
	Jul. 31, 2019shares	Apr. 30, 2019USD ($)shares	Apr. 30, 2019EUR (€)shares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / shares	Sep. 30, 2017shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense | $				$ 7,000	$ 7,000
Period over which compensation cost will be recognized (in years)					2 years 8 months 19 days
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense | $						$ 6,000
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense | $						$ 1,500
VSOP SB
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for grant under stock option programs (in shares)					31,593
Percent of Company's total issued shared capital available for grant under stock option programs					0.50%
2019 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (in shares)	1,500,000
Expected term of options (years)					5 years 9 months 18 days	5 years 10 months 24 days
Weighted-average grant date fair value (in USD per share) | $ / shares					$ 9.50	$ 8.28
VSOP And VSOP SB
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense | $					$ 0	$ 508
Share price (in USD per share) | $ / shares				$ 12.87	$ 12.87	$ 12.87
2019 Omnibus Equity Incentive Plan, Evergreen Provision
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized, percent	4.00%
Additional shares authorized (in shares)	4,900,000			448,634
Executive Bonus Agreement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 6,000	€ 5.3
Issuance of stock (in shares)		460,336	460,336
2014 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (in shares)				43,311	43,311
2017 Inducement Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (in shares)							46,250
Maximum | 2019 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of options (years)					10 years
Incentive Employee Stock Option | 2019 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					4 years
Non-Statutory Employee Stock Option | Minimum | 2019 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					3 years
Non-Statutory Employee Stock Option | Maximum | 2019 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					4 years
Restricted stock units | Vital Therapies, Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs to be granted (in shares)					127,500

Stock Compensation Plans - Summ

Stock Compensation Plans - Summary of Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee Stock Options, Vital Therapies Inc.
Options
Outstanding, Beginning balance (in shares)	14,403	0
Assumed in the Transaction with Vital (in shares)		17,117
Granted (in shares)	0	0
Exercised (in shares)	0	0
Forfeited and expired (shares)	(14,403)	(2,714)
Outstanding, Ending balance (in shares)	0	14,403
Options vested and expected to vest (shares)	0	14,403
Options exercisable, (shares)	0	14,403
Weighted- Average Exercise Price
Outstanding, Beginning balance (in USD per share)	$ 306.01	$ 0
Assumed in the Transaction with Vital (in USD per share)		306.99
Granted (in USD per share)	0	0
Exercised (in USD per share)	0	0
Forfeited or expired (in USD per share)	306.01	312.18
Outstanding, Ending balance (in USD per share)	0	306.01
Options vested and expected to vest, Weighted-Average Exercise Price (usd per share)	0	306.01
Options exercisable, Weighted-Average Exercise Price (usd per share)	$ 0	$ 306.01
Other Disclosures
Outstanding, weighted-average remaining contractual term (in years)	0 years	2 years 6 months 29 days
Options vested and expected to vest , weighted-average remaining contractual term (in years)	0 years	2 years 6 months 29 days
Options exercisable, weighted-average remaining contractual term (in years)	0 years	2 years 6 months 29 days
Outstanding, aggregate intrinsic value	$ 0	$ 0
Options vested and expected to vest , aggregate intrinsic value	0	0
Options exercisable, aggregate intrinsic value	$ 0	$ 0
2019 Omnibus Equity Incentive Plan | Outstanding stock options
Options
Outstanding, Beginning balance (in shares)	456,645	0
Granted (in shares)	744,406	456,645
Exercised (in shares)	0	0
Forfeited and expired (shares)	(83,891)	0
Outstanding, Ending balance (in shares)	1,117,160	456,645
Options vested and expected to vest (shares)	1,117,160	456,645
Options exercisable, (shares)	263,507	31,956
Weighted- Average Exercise Price
Outstanding, Beginning balance (in USD per share)	$ 12.57	$ 0
Granted (in USD per share)	13.24	12.57
Exercised (in USD per share)	0	0
Forfeited or expired (in USD per share)	13.32	0
Outstanding, Ending balance (in USD per share)	12.96	12.57
Options vested and expected to vest, Weighted-Average Exercise Price (usd per share)	12.96	12.57
Options exercisable, Weighted-Average Exercise Price (usd per share)	$ 13.04	$ 13
Other Disclosures
Outstanding, weighted-average remaining contractual term (in years)	9 years 2 months 26 days	9 years 7 months 17 days
Options vested and expected to vest , weighted-average remaining contractual term (in years)	9 years 2 months 26 days	9 years 7 months 17 days
Options exercisable, weighted-average remaining contractual term (in years)	8 years 11 months 1 day	9 years 7 months 2 days
Outstanding, aggregate intrinsic value	$ 2,894,754	$ 114,399
Options vested and expected to vest , aggregate intrinsic value	2,894,754	114,399
Options exercisable, aggregate intrinsic value	$ 661,952	$ 3,382
VSOP And VSOP SB | Employee Stock Options, Immunic AG
Options
Outstanding, Beginning balance (in shares)	0	6,937
Granted (in shares)		32,177
Forfeited (in shares)		0
Settled in cash (in shares)		(39,114)
Expired (in shares)		0
Outstanding, Ending balance (in shares)		0
Options exercisable, (shares)		0
Weighted- Average Exercise Price
Outstanding, Beginning balance (in USD per share)	$ 0	$ 12.87
Granted (in USD per share)		12.87
Forfeited or expired (in USD per share)		0
Settled in cash in period (in USD per share)		12.87
Outstanding, Ending balance (in USD per share)		$ 0

Stock Compensation Plans - Rang

Stock Compensation Plans - Ranges of Underlying Assumptions Used in BSM Option Pricing Model to Determine Fair Value of Stock Options Granted to Employees and Nonemployees (Detail) - 2019 Omnibus Equity Incentive Plan	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.42%	1.71%
Expected dividend yield	0.00%	0.00%
Expected volatility	88.50%	75.30%
Expected term of options (years)	5 years 9 months 18 days	5 years 10 months 24 days

Stock Compensation Plans - Sche

Stock Compensation Plans - Schedule of Stock-based Compensation Expense for Stock Awards Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 2,747	$ 6,512
Employee
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	2,747	8,560
Employee | Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	731	1,824
Employee | General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$ 2,016	$ 6,736

Income Taxes - Net Loss before

Income Taxes - Net Loss before Income Tax Based on Jurisdictions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Contingency [Line Items]
Net loss before income tax	$ (44,017)	$ (44,759)
Federal | United States
Income Tax Contingency [Line Items]
Net loss before income tax	(8,681)	(20,258)
Foreign | Germany
Income Tax Contingency [Line Items]
Net loss before income tax	(33,617)	(23,674)
Foreign | Foreign
Income Tax Contingency [Line Items]
Net loss before income tax	$ (1,719)	$ (827)

Income Taxes - Income Tax Rate

Income Taxes - Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%
State tax (net of federal benefit)	0.00%	0.00%
Foreign rate differential	3.00%	3.30%
Stock options	(0.90%)	(1.10%)
Tax effect of rate change	(1.90%)	0.00%
Other	(0.90%)	(3.00%)
Change in valuation allowance	(20.30%)	(20.20%)
Effective tax rate	(0.00%)	0.00%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 17,369	$ 16,357
Federal and state tax credits	0	0
Stock-based compensation	125	0
Foreign net operating loss carryforwards	18,998	12,237
Other, net	30	72
Total deferred tax assets	36,522	28,666
Deferred tax liabilities:
Property, plant and equipment	(5)	(311)
Total deferred tax liability	(5)	(311)
Net deferred tax assets	36,517	28,355
Less valuation allowance	(36,517)	(28,355)
Net deferred tax assets, valuation allowance total	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Valuation allowance increase	$ 6.8	$ 23.7
Foreign
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	75.7
Prior to 2018 | Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	15.6
Post 2017 | Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 67.1

EIB Loan (Details)

EIB Loan (Details)	Oct. 19, 2020EUR (€)tranche
Debt Instrument [Line Items]
Number of tranches | tranche	3
Tranche payment deferral term	5 years
Line of Credit | EIB Loan
Debt Instrument [Line Items]
Term loan, maximum borrowing capacity	€ 24,500,000
Term loan, revenue share cap, first tranche	8,600,000
Term loan, revenue share cap, full loan amount drawn	€ 30,000,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - Board of Directors Chairman - USD ($)	Oct. 15, 2020	Apr. 17, 2020
Related Party Transaction [Line Items]
Monthly base salary		$ 25,417
Granted (in shares)	120,000

Selected Quarterly Data (unau_3

Selected Quarterly Data (unaudited) - Summarized Quarterly Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Operating expenses	$ 14,190	$ 13,545	$ 12,222	$ 9,014	$ 8,186	$ 9,177	$ 15,007	$ 4,662	$ 48,971	$ 37,032
Net loss	$ (11,159)	$ (12,913)	$ (11,458)	$ (8,487)	$ (7,691)	$ (8,215)	$ (14,714)	$ (4,313)	$ (44,017)	$ (34,933)
Basic and diluted net loss per share (usd per share)	$ (0.53)	$ (0.70)	$ (0.90)	$ (0.79)	$ (0.75)	$ (0.82)	$ (1.52)	$ (5.09)	$ (2.81)	$ (4.52)