Vaccinex (VCNX) 10-K 31 Mar 21 2020 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 26, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	VCNX
Entity Registrant Name	Vaccinex, Inc.
Entity Central Index Key	0001205922
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Seasoned Well Known Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Public Float			$ 23,670,590
Entity Common Stock, Shares Outstanding		28,441,112
Entity File Number	001-38624
Entity Tax Identification Number	16-1603202
Entity Address, Address Line One	1895 Mount Hope Avenue
Entity Address, City or Town	Rochester
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14620
City Area Code	585
Local Phone Number	271-2700
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 10,596	$ 2,776
Accounts receivable	157	898
Prepaid expenses and other current assets	533	336
Total current assets	11,286	4,010
Property and equipment, net	416	594
TOTAL ASSETS	11,702	4,604
Current liabilities:
Accounts payable	3,169	3,208
Accrued expenses	1,937	3,670
Senior secured convertible debt, net	8,074
Total current liabilities	13,180	6,878
Long-term debt	1,134
TOTAL LIABILITIES	14,314	6,878
Commitments and contingencies (Note 7)
Stockholders’ equity (deficit):
Common stock, par value of $0.0001 per share; 100,000,000 shares authorized as of December 31, 2020, and December 31, 2019; 22,388,027 and 14,887,999 shares issued as of December 31, 2020 and December 31, 2019, respectively; 22,387,175 and 14,887,147 shares outstanding as of December 31, 2020 and December 31, 2019, respectively	3	1
Additional paid-in capital	250,914	222,403
Treasury stock, at cost; 852 shares of common stock as of December 31, 2020 and December 31, 2019, respectively	(11)	(11)
Accumulated deficit	(277,481)	(248,630)
Total Vaccinex, Inc. stockholders’ deficit	(26,575)	(26,237)
Noncontrolling interests	23,963	23,963
TOTAL STOCKHOLDERS’ DEFICIT	(2,612)	(2,274)
TOTAL LIABILITIES AND STOCKHOLDERS’ DEFICIT	$ 11,702	$ 4,604

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	22,388,027	14,887,999
Common stock, shares outstanding	22,387,175	14,887,147
Treasury stock, common shares	852	852

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 50,000	$ 523,000
Grant revenue	575,000
Costs and expenses:
Cost of revenue	2,000	199,000
Research and development	21,549,000	25,670,000
General and administrative	7,405,000	6,669,000
Total costs and expenses	28,956,000	32,538,000
Loss from operations	(28,331,000)	(32,015,000)
Interest expense	(489,000)
Other income (expense), net	(31,000)	152,000
Loss before provision for income taxes	(28,851,000)	(31,863,000)
Provision for income taxes	0	0
Net loss	(28,851,000)	(31,863,000)
Net loss attributable to noncontrolling interests	0	0
Net loss attributable to Vaccinex, Inc. common stockholders	(28,851,000)	(31,863,000)
Comprehensive loss	$ (28,851,000)	$ (31,863,000)
Net loss per share attributable to Vaccinex, Inc. common stockholders, basic and diluted	$ (1.54)	$ (2.47)
Weighted-average shares used in computing net loss per share attributable to Vaccinex, Inc. common stockholders, basic and diluted	18,786,768	12,880,746

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Deficit	Total Vaccinex,Inc. Stockholders' Deficit	Noncontrolling Interests
Balance at Dec. 31, 2018	$ 15,342	$ 1	$ 208,156	$ (11)	$ (216,767)	$ (8,621)	$ 23,963
Balance, Shares at Dec. 31, 2018		11,476,601		852
Issuance of common shares	13,800		13,800			13,800
Issuance of common shares, Shares		3,382,332
Exchange of Vaccinex Products LP Units for common shares, Shares		29,066
Stock-based compensation	447		447			447
Net loss	(31,863)				(31,863)	(31,863)
Balance at Dec. 31, 2019	(2,274)	$ 1	222,403	$ (11)	(248,630)	(26,237)	23,963
Balance, Shares at Dec. 31, 2019		14,887,999		852
Issuance of common shares	28,475	$ 2	28,473			28,475
Issuance of common shares, Shares		7,450,004
Common shares issuance costs	(713)		(713)			(713)
Exchange of Vaccinex Products LP Units for common shares, Shares		26,241
Stock-based compensation	732		732			732
Stock-based compensation, Shares		20,000
Exercise of stock options	$ 19		19			19
Exercise of stock options, Shares	3,783	3,783
Net loss	$ (28,851)				(28,851)	(28,851)
Balance at Dec. 31, 2020	$ (2,612)	$ 3	$ 250,914	$ (11)	$ (277,481)	$ (26,575)	$ 23,963
Balance, Shares at Dec. 31, 2020		22,388,027		852

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (28,851,000)	$ (31,863,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	307,000	249,000
Debt related charges included in interest expense	297,000
Net amortization of premiums and discounts on marketable securities		(44,000)
Stock-based compensation	732,000	447,000
Change in fair value of derivative liability	(65,000)
Changes in operating assets and liabilities:
Accounts receivable	741,000	(260,000)
Prepaid expenses and other current assets	(197,000)	725,000
Accounts payable	122,000	725,000
Accrued expenses	(1,733,000)	(694,000)
Net cash used in operating activities	(28,647,000)	(30,715,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Sales of marketable securities		14,151,000
Purchase of property and equipment	(290,000)	(78,000)
Net cash (used in) provided by investing activities	(290,000)	14,073,000
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from private offering of common stock	11,475,000	13,800,000
Proceeds from issuance of common stock	17,000,000
Proceeds from issuance of convertible debt, net of discount	8,000,000
Redemption of convertible debt	(108,000)
Payments of convertible debt issuance costs	(50,000)
Proceeds from long-term debt	1,134,000
Payments of common stock issuance costs	(713,000)
Proceeds from exercise of stock options	19,000
Net cash provided by financing activities	36,757,000	13,800,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	7,820,000	(2,842,000)
CASH AND CASH EQUIVALENTS–Beginning of period	2,776,000	5,618,000
CASH AND CASH EQUIVALENTS–End of period	$ 10,596,000	2,776,000
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Purchase of property and equipment in accounts payable		$ (161,000)

Company and Nature of Business

Company and Nature of Business	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Company and Nature of Business	1. COMPANY AND NATURE OF BUSINESS Vaccinex, Inc. (together with its subsidiaries, the Company) was incorporated in Delaware in April 2001 and is headquartered in Rochester, New York. The Company is a clinical-stage biotechnology company engaged in the discovery and development of targeted biotherapeutics to treat serious diseases and conditions with unmet medical needs, including cancer, neurodegenerative diseases, and autoimmune disorders. Since its inception, the Company has devoted substantially all of its efforts toward product research and development, marketing development and raising capital. The Company is subject to a number of risks common to other early-stage biotechnology companies including, but not limited to, the successful development and commercialization of its product candidates, rapid technological change and competition, dependence on key personnel and collaborative partners, uncertainty of protection of proprietary technology and patents, clinical trial uncertainty, fluctuation in operating results and financial performance, the need to obtain additional funding, potential product liability, compliance with governmental regulations, technological and medical risks, customer demand, management of growth and effectiveness of marketing by the Company. If the Company does not successfully commercialize or partner any of its product candidates, it will be unable to generate product revenue or achieve profitability. Going Concern These consolidated financial statements have been prepared in accordance with generally accepted accounting principles applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred significant losses and negative cash flows from operations since inception and expects to incur additional losses until such time that it can generate significant revenue from the commercialization of its product candidates. The Company had losses from operations of $28.9 million and $31.9 million and negative cash flows from operating activities of $28.6 million and $30.7 million for the years ended December 31, 2020 and 2019, respectively, and an accumulated deficit of $277.5 million and $248.6 million as of December 31, 2020 and 2019, respectively. Given the Company’s projected operating requirements and its existing cash and cash equivalents, the Company is projecting insufficient liquidity to sustain its operations through one year following the date that the financial statements are issued. These conditions and events raise substantial doubt about the Company’s ability to continue as a going concern. In response to these conditions, management is currently evaluating different strategies to obtain the required funding of future operations. Financing strategies may include, but are not limited to, the public or private sale of equity, debt financings or funds from other capital sources, such as government funding, collaborations, strategic alliances, or licensing arrangements with third parties. There can be no assurances that the Company will be able to secure additional financing, or if available, that it will be sufficient to meet its needs or on favorable terms. Because management’s plans have not yet been finalized and are not within the Company’s control, the implementation of such plans cannot be considered probable. As a result, the Company has concluded that management’s plans do not alleviate substantial doubt about the Company’s ability to continue as a going concern. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. COVID-19 Pandemic In order to mitigate the spread of COVID-19, governments have at times imposed unprecedented restrictions on business operations, travel, and gatherings, resulting in a global economic downturn and other adverse economic and societal impacts. The Company has complied with state reopening guidance and has allowed research and development staff to begin working in the laboratory when necessary and using recommended health and safety precautions. The COVID-19 pandemic has impacted the expected timing of the Company’s clinical trials, the economy, the biotechnology industry, and the Company’s business. For example, the Company previously anticipated initiating a trial of pepinemab in Alzheimer’s disease in mid-2020, but the initial enrollment date has been delayed until the first half of 2021. In addition, to mitigate the impacts of the COVID-19 pandemic, including impacts on the Company’s ability to raise capital and to maintain its personnel, the Company applied for and received the PPP Loan. The Company may experience further disruptions as a result of the COVID-19 pandemic that could adversely impact its business, including disruption of research and clinical development activities, plans for release of data, manufacturing, supply, and interactions with regulators and other third parties, and difficulties in raising additional capital. The extent to which the COVID-19 pandemic may impact the Company’s business will depend on future developments, which are highly uncertain and cannot be predicted with confidence.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. The accompanying consolidated financial statements reflect the consolidated application of certain significant accounting policies, as described below and elsewhere in the accompanying notes to the consolidated financial statements. Basis of Presentation and Consolidation These consolidated financial statements reflect the accounts and operations of the Company and those of its subsidiaries in which the Company has a controlling financial interest. As of December 31, 2020, and 2019, the Company’s accounts include Vaccinex Products and VX3 (DE) LP, a Delaware limited partnership (VX3). VX3 was established in October 2017 by a group of Canadian investors and was determined to be a variable interest entity (“VIE”) in which the Company is the primary beneficiary. The Company consolidates any VIE of which it is the primary beneficiary. The Company presents its noncontrolling interests as a separate component of stockholders’ equity (deficit). The company presents the net loss of VX3 equal to the percentage ownership interest retained in such entity by the respective noncontrolling party (VX3), and as a separate component within its consolidated statements of operations and comprehensive loss. The financial position of Vaccinex Products and VX3 were not material as of December 31, 2020 and 2019, and there were no gains or losses for Vaccinex Products or VX3 for the years ended December 31, 2020 and 2019. Intercompany transactions and balances have been eliminated. Use of Estimates These consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amount of expenses during the reporting period. Such management estimates include those relating to assumptions used in the valuation of stock option awards, the valuation of derivative instruments, and valuation allowances against deferred income tax assets. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. The Company deposits its cash primarily in checking and money market accounts. Concentration of Credit Risk, Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents. Cash equivalents are deposited in interest-bearing money market accounts. Although the Company deposits its cash with multiple financial institutions, cash balances may occasionally be in excess of the amounts insured by the Federal Deposit Insurance Corporation. Management believes the financial risk associated with these balances is minimal and has not experienced any losses to date. The Company depends on third-party manufacturers for the manufacture of drug substance and drug product for clinical trials. The Company also relies on certain third parties for its supply chain. Disputes with these third - party manufacturers or shortages in goods or services from third-party suppliers could delay the manufacturing of the Company’s product candidates and adversely impact its results of operations. Fair Value of Financial Instruments Financial instruments consist of cash and cash equivalents, marketable securities, prepaid expenses and other current assets, accounts payable, accrued expenses, convertible promissory notes, and derivative liabilities. Cash equivalents and marketable securities are stated at fair value. Prepaid expenses and other current assets, accounts payable and accrued expenses are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment date. The Company’s derivative instrument related to certain features embedded within the Debenture is discussed in Note 9. The derivative is accounted for as a derivative liability and remeasured to fair value as of each balance sheet date and the related remeasurement adjustments are recorded as interest expense in the Company’s consolidated statement of operations and comprehensive loss. Financing Activities and Offering Costs During the year ended December 31, 2020, we raised total proceeds of approximately $37.6 million, net of commissions and discounts before expenses, from the following activities: During the year ended December 31, 2020, the Company completed private placements of our common stock to various investors in January 2020 and July 2020, for gross proceeds of $7.5 million and $4.0 million, respectively. During the year ended December 31, 2019, we received gross proceeds of $13.8 million. Additionally, in September 2020 we received gross proceeds of $2.0 million through an award from the Alzheimer’s Drug Discovery Foundation (“ADDF”), in the form of an investment in our common stock. On March 27, 2020, we announced that we had (i) entered into an open market sale agreement (the “Open Market Sale Agreement” or “ATM”) with Jefferies, LLC (“Jefferies”) and filed a prospectus supplement pursuant to which we were able to issue and sell up to $11.5 million of shares of our common stock from time and (ii) entered into a purchase agreement (the “Purchase Agreement”) with Keystone Capital Partners, LLC (“Keystone”) pursuant to which Keystone agreed to purchase up to an aggregate of $5.0 million of shares of our common stock from time to time. During the second quarter of 2020, 317,688 shares were sold through the Open Market Sale Agreement for proceeds of $1.2 million, net of commission, and 324,424 shares were sold through the Purchase Agreement with Keystone for proceeds of $1.2 million, net of discount. The Company has incurred certain costs in connection with its securities offerings with Jefferies and Keystone that occurred in 2020. The Company capitalizes such deferred offering costs, which consist of direct, incremental legal, professional, accounting, and other third-party fees. The deferred offering costs will be offset against offering proceeds upon the completion of an offering. Should the offering be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the Company’s condensed consolidated statement of operations and comprehensive loss. Accordingly, $713,000 of offering costs associated with the ATM Facility and Keystone were charged against paid in capital during the year ended December 31, 2020. There were no deferred offering costs on the consolidated balance sheet at December 31, 2020 or 2019. In August 2020, we entered into a Securities Purchase Agreement (the “SPA”), with 3i, LP, (“3i”) as collateral agent and purchaser (the “Convertible Debt Financing”). Pursuant to the SPA, on August 3, 2020, we issued a 7% Original Issue Discount Senior Secured Convertible Debenture (“Senior Secured Convertible Debenture” or “the Debenture”), in the principal amount of $8.64 million for a purchase price of $8.0 million, which reflects an original issue discount of approximately 8%. The Debenture will mature on August 3, 2021. The Debenture accrues interest at 7% per year and is convertible into shares of our common stock at a conversion price of $9.4125 per share, subject to certain customary adjustments. In addition, on May 8, 2020, the Company received a loan of $1.1 million from Five Star Bank (the “PPP Loan”) under the Paycheck Protection Program established as a part of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). Property and Equipment, Net Property and equipment are recorded at cost. Depreciation is computed over estimated useful lives of the related assets using the straight-line method. Leasehold improvements are amortized on a straight-line basis over the shorter of the useful life or term of the lease. Upon retirement or disposal, the cost and related accumulated depreciation are removed from the consolidated balance sheets and the resulting gain or loss is recorded to general and administrative expense in the consolidated statements of operations. Routine expenditures for maintenance and repairs are expensed as incurred. Estimated useful lives for property and equipment are as follows: Property and Equipment Estimated Useful Life Research equipment 5 years Furniture and fixtures 5 years Computer equipment 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term Impairment of Long-Lived Assets The Company reviews the recoverability of its long-lived assets when events or changes in circumstances occur that indicate that the carrying value of the asset may not be recoverable. The assessment of possible impairment is based on the ability to recover the carrying value of the assets from the expected future cash flows (undiscounted and without interest expense) of the related operations. If these cash flows are less than the carrying value of such assets, an impairment loss for the difference between the estimated fair value and carrying value is recorded. There was no impairment loss recognized during the years ended December 31, 2020 and 2019. Convertible Instruments The Company applies the accounting standards for derivatives and hedging and for distinguishing liabilities from equity when accounting for hybrid contracts that contain conversion options and other embedded features. The accounting standards require companies to bifurcate embedded features from their host instruments and account for them as free-standing derivative financial instruments according to certain criteria. The criteria include circumstances in which (i) the economic characteristics and risks of the embedded derivative instrument are not clearly and closely related to the economic characteristics and risks of the host contract, (ii) the hybrid instrument that embodies both the embedded derivative instrument and the host contract is not re-measured at fair value under otherwise applicable generally accepted accounting principles with changes in fair value reported in earnings as they occur and (iii) a separate instrument with the same terms as the embedded derivative instrument would be considered a derivative instrument. The Company’s derivative instrument related to certain features embedded within the Debenture is discussed in Note 9. The derivative is accounted for as a derivative liability and remeasured to fair value as of each balance sheet date and the related remeasurement adjustments are recognized in the Company’s consolidated statement of operations and comprehensive loss. Treasury Stock The Company records treasury stock activities under the cost method whereby the cost of the acquired stock is recorded as treasury stock. The Company’s accounting policy upon the formal retirement of treasury stock is to deduct the par value from common stock and to reflect any excess of cost over par value as a reduction to additional paid-in capital (to the extent created by previous issuances of the shares) and then retained earnings. There was no treasury stock repurchased for the years ended December 31, 2020 and 2019. Revenue Recognition The Company’s revenues are generated primarily through collaborative research, license, development and commercialization agreements. We recognize revenue when our customers obtain control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. We assess if these options provide a material right to the customer and if so, they are considered performance obligations. The exercise of a material right is accounted for as a contract modification for accounting purposes. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied at a point in time or over time, and if over time this is based on the use of an output or input method. Amounts received prior to revenue recognition are recorded as deferred revenue. Amounts expected to be recognized as revenue within the 12 months following the balance sheet date are classified as current portion of deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized as revenue within the 12 months following the balance sheet date are classified as deferred revenue, net of current portion. Amounts recognized as revenue, but not yet received or invoiced are generally recognized as contract assets in the Other Assets line item in the Consolidated Balance Sheets. Collaborative Arrangements – The Company has entered into collaboration agreements, which are within the scope of ASC 606, to discover, develop, manufacture and commercialize product candidates. The terms of these agreements typically contain multiple promises or obligations, which may include: (1) licenses, or options to obtain licenses, to use the Company’s research program materials, and (2) research and development activities to be performed on behalf of the collaboration partner. Payments the Company receives under these arrangements typically include one or more of the following: non-refundable, upfront license fees; option exercise fees; funding of research and/or development efforts; clinical and development, regulatory, and sales milestone payments; and royalties on future product sales. The Company also analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements For a complete discussion of accounting for collaboration revenues, see Note 6, “Collaboration Agreements”. Grant Revenue From time to time, the Company receives certain grant award funding to support its continuing research and development efforts. The Company considers these grants to be operating revenue as they support the Company’s primary operating activities. We recognize revenue from these contracts as we perform services under these arrangements when the funding is received. Revenues and related expenses are presented gross in the consolidated statements of operations and comprehensive loss as we have determined we control the arrangement as the primary obligor under the arrangements relative to the research and development services we perform. During the year ended December 31, 2020 the Company recorded grant revenue related to funds received from the Alzheimer’s Association of $575,000. No grant revenue was recorded for the year ended December 31, 2019. Research and Development Costs Expenditures, including payroll, contractor expenses and supplies, for research and development of products are expensed as incurred. Clinical trial and other development costs incurred by third parties are expensed as the contracted work is performed. Where contingent milestone payments are due to third parties under research and development arrangements, the milestone payment obligations are expensed when the milestone results are probable of being achieved. Stock-Based Compensation The Company utilizes the Black-Scholes stock option-pricing model as the method for estimating the grant date fair value of its stock option awards. The Black-Scholes stock option-pricing model requires the use of highly subjective and complex assumptions, including the stock options’ expected term and the price volatility of the underlying stock. The grant date fair value of the portion of the stock option award that is ultimately expected to vest is recognized as compensation expense over the stock option awards’ requisite service periods. The Company recognizes stock-based compensation to expense using the straight-line method over the requisite service period. If there are any modifications or cancelations of stock option awards, the Company may be required to accelerate, increase or decrease any remaining unrecognized stock-based compensation expense. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities, which relate primarily to the carrying amount of the Company’s property and equipment and its net operating loss carryforward, are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities. Valuation allowances are established when necessary to reduce deferred tax assets where, based upon the available evidence, management concludes that it is more likely than not that the deferred tax assets will not be realized. In evaluating its ability to recover deferred tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. Because of the uncertainty of the realization of the deferred tax assets, the Company has recorded a full valuation allowance against its deferred tax assets. Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more likely than not to be sustained on examination by a taxing authority, assuming they possess full knowledge of the position and facts. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes; however, the Company currently has no interest or penalties related to income taxes. Segment and Geographic Information The Company’s chief operating decision maker, its Chief Executive Officer, reviews its operating results on an aggregate basis for purposes of allocating resources and evaluating financial performance. The Company has one business activity, the discovery and development of targeted biotherapeutics to treat serious diseases and conditions with unmet medical needs, and there are no segment managers who are held accountable for operations or operating results. Accordingly, the Company operates in one segment. As of December 31, 2020, and 2019, all long-lived assets are located in the United States. Net Loss Per Share Attributable to Vaccinex, Inc. Common Stockholders The Company calculates its basic and diluted net loss per share attributable to Vaccinex, Inc. common stockholders by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of common shares plus common equivalent shares for the period, including any dilutive effect from such shares. Since the Company was in a net loss position for all periods presented, net loss per share attributable to common stockholders was the same on a basic and diluted basis, as the inclusion of all potential common equivalent shares outstanding would have been anti-dilutive. For purposes of this calculation, stock options to purchase common stock are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to Vaccinex, Inc. common stockholders as their effect is anti-dilutive. Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Leases, Targeted Improvements to ASC 842, Leases , Leases The Company has substantially completed its evaluation of the potential impact ASU 2016-02 may have on its financial position, results of operations, and related footnotes. The Company expects it will elect to utilize the available package of practical expedients permitted under the transition guidance within the new standard, which does not require the reassessment of the following: i) whether existing or expired arrangements are or contain a lease, ii) the lease classification of existing or expired leases, and iii) whether previous initial direct costs would qualify for capitalization under the new lease standard. Additionally, the Company expects it will make an accounting policy election to keep leases with an initial term of 12 months or less off of its balance sheet. The Company believes the largest impact will be the recognition of right-of-use assets and lease liabilities on the consolidated balance sheets, as the Company’s lease portfolio primarily consists of an operating lease for its corporate headquarters in Rochester, New York. The Company expects to recognize right-of-use assets and corresponding lease liabilities of approximately $.3 million at the date of adoption. The results of operations are not expected to change significantly as a result of adopting the new standard. During the first quarter of fiscal 2021, the Company will finalize its accounting assessment and quantification of the impact of adoption on the Company’s financial statements and corresponding disclosures. Recently Adopted Accounting Pronouncements In May 2014, FASB issued ASU No. 2014-09, Revenue (ASC 606): Revenue from Contracts with Customers Revenue Recognition In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808)—Clarifying the Interaction between Topic 808 and ASC 606

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	3. Property and Equipment Property and equipment consist of the following (in thousands): As of December 31, 2020 As of December 31, 2019 Leasehold improvements $ 3,174 $ 3,161 Research equipment 3,499 3,442 Furniture and fixtures 350 350 Computer equipment 273 214 Property and equipment, gross 7,296 7,167 Less: accumulated depreciation and amortization (6,880 ) (6,573 ) Property and equipment, net $ 416 $ 594 Depreciation expense related to property and equipment was $307,000 and $249,000 for the years ended December 31, 2020 and 2019, respectively. Accrued Expenses Accrued expenses consist of the following (in thousands): As of December 31, 2020 As of December 31, 2019 Accrued clinical trial cost $ 987 $ 3,252 Accrued payroll and related benefits 428 262 Accrued consulting and legal 225 79 Accrued interest 250 - Accrued other 47 77 Accrued expenses $ 1,937 $ 3,670

Fair Value of Financial Measure

Fair Value of Financial Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Measurements	4. Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Assets and liabilities recorded at fair value on a nonrecurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Financial instruments consist of cash, accounts receivable, accounts payable, accrued liabilities, and long-term debt. Cash, accounts receivable, accounts payable, accrued liabilities, and debt, are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment date of such amounts. Assets and Liabilities Measured at Fair Value on a Recurring Basis Fair value measurement standards also apply to certain financial assets and liabilities that are measured at fair value on a recurring basis (each reporting period). For the Company, these financial assets and liabilities include its cash equivalents deposited in money market funds and derivative instruments. The Company does not have any nonfinancial assets or liabilities that are measured at fair value on a recurring basis. The assets’ or liabilities’ fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The following table sets forth the fair value of the Company’s financial assets by level within the fair value hierarchy (in thousands): As of December 31, 2020 Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash equivalents: Money market fund $ 1,026 $ 1,026 $ - $ - Total Financial Assets $ 1,026 $ 1,026 $ - $ - As of December 31, 2019 Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash equivalents: Money market fund $ 1,464 $ 1,464 $ - $ - Total Financial Assets $ 1,464 $ 1,464 $ - $ - The Company did not transfer any assets measured at fair value on a recurring basis to or from Level 1 and Level 2 during the years ended December 31, 2020 and 2019. The Debenture, as discussed in Note 9, contains embedded derivative features that are required to be bifurcated and remeasured each reporting period. Each quarter, the change in the fair value of the embedded derivative features, if any, is recorded in the Consolidated Statement of Operations and Comprehensive Loss. The Company uses a binomial lattice

License and Services Agreement

License and Services Agreement	12 Months Ended
	Dec. 31, 2020
Research And Development [Abstract]
License and Services Agreement	5 . LICENSE AND SERVICES AGREEMENT VX3 (DE) LP, a Delaware limited partnership (VX3), was established in October 2017 by a group of Canadian investors including our majority stockholder FCMI Parent Co. (“FMCI Parent”), with capital contributions recorded as non-controlling interests of $23.9 million. VX3 was created for the purpose of funding the Company’s research and development activities for pepinemab, our most advanced product candidate. In November 2017, the Company entered into a license agreement (the “VX3 License Agreement”) with VX3. Under the VX3 License Agreement, the Company granted VX3 the license to use, make, have made, sell, offer and import pepinemab for the treatment of Huntington’s disease in the U.S. and Canada and, in return, VX3 agreed to fund research and development activities with up to an aggregate of $32.0 million in milestone payments to the Company and to share any pepinemab profits and sublicensing revenue under the agreement in an amount based on a calculation set forth in the agreement. No amounts were received under the VX3 license agreement for the years ended December 31, 2020 and 2019, respectively. The Company also entered into a services agreement with VX3 (the “Services Agreement”), pursuant to which the Company will carry out development activities for pepinemab for the treatment of Huntington’s disease in the U.S. and Canada in exchange for services payments from VX3. The VX3 License Agreement expires upon the last to expire licensed patent and may be terminated by either party upon uncured material breach, the occurrence of certain transactions or financings including the consummation of an initial public offering by the Company, uncured failure of VX3 to make any payment due under the Services Agreement, or upon written notice after November 6, 2020. The Services Agreement may be terminated by either party upon an uncured material breach and is automatically terminated upon termination of the VX3 License Agreement. The VX3 License Agreement provides that upon termination, the Company will issue to VX3 or its designees the number of shares of the Company’s common stock equal to the lesser of (1) the aggregate of all payments made to VX3 by its partners divided by $18.20 and (2) the then fair market value of VX3 divided by the then fair market value of one share of the Company’s common stock. The Company has a variable interest in VX3 through FCMI Parent, which is majority owned and controlled by the Company’s chairman, and it controlled 90% of VX3’s voting interest as of December 31, 2020 and 2019. VX3 does not have any business operations or generate any income or expenses and is primarily a funding mechanism specifically for the benefit of the Company, as its only activities consist of the receipt of funding and the contribution of such funding to the Company. Therefore, the Company determined that it is the primary beneficiary of VX3 and that the operating results of VX3 should be incorporated into the Company’s consolidated financial statements accordingly. The Company entered into an exchange agreement on August 13, 2018 with VX3 and its partners, including FCMI Parent, that provides each VX3 partner with the right to exchange all, but not less than all, of its partnership interests in VX3 for shares of the Company’s common stock. The exchange agreement also provides that FCMI Parent’s exercise of its option to exchange its VX3 partnership interests for shares of Company common stock, would trigger the exchange of all VX3 partnership interests for shares of Company common stock. Further, under the exchange agreement, the Company will have a right to require the exchange of all partnership interests in VX3 for shares of Company common stock in any of the following circumstances: • The Company enters into a transaction such as a sale, merger or consolidation such that shares of Company common stock are or will be sold or exchanged for cash and/or marketable securities; • On or after August 13, 2023; or • either the Company or VX3 enters into a licensing, partnering or similar transaction with respect to one or more products and indications licensed to VX3 by the Company, and all amounts then due and owing to VX3 in connection with such transaction have been paid to VX3. No amounts were received under the VX3 license or services agreement for the years ended December 31, 2020 and 2019, respectively. Noncontrolling equity interests do not participate in a proportionate share of the Company’s net losses for the year ended December 31, 2020 or December 31, 2019, respectively, pursuant to the aforementioned partnership, license, services and exchange agreements.

Collaboration Agreements

Collaboration Agreements	12 Months Ended
	Dec. 31, 2020
Collaboration Agreements [Abstract]
Collaboration Agreements	6 . COLLABORATION AGREEMENTS Surface Oncology, Inc. In November 2017, the Company entered into a research collaboration and license option agreement with Surface Oncology, Inc. (“Surface”) to identify and select antibodies against two target antigens, using the Company’s proprietary technology as described in the agreement. Under the agreement, Surface may purchase exclusive options, exercisable by providing a written notice to the Company, to obtain (i) an exclusive product license to make, use, sell and import products incorporating antibodies targeting the first antigen and (ii) an exclusive research tool license to use antibodies targeting the second antigen to perform research. Surface purchased the first option and exercised the second option and entered into an exclusive research tool license agreement with Surface in the third quarter of 2019. Under the research collaboration and license option agreement, Surface paid an upfront technology access fee of $250,000 and makes milestone payments upon completion of each of four designated milestones for the first target antigen specified in the agreement. For the second target antigen, Surface is obligated to make payments to the Company based on time incurred by the Company in the conduct of the work plan described in the agreement. Surface is required to reimburse the Company for expenses incurred (i) in the conduct of the work plan as detailed in the research funding budget and (ii) for patent filings and prosecution of the Company’s program intellectual property as described in the agreement. The exercise of each option would also entail a license fee and annual maintenance fees, and in the case of the product license, royalties and additional milestone payments. We have invoiced for service fee payments of $0 and $123,276 for work conducted under the agreement for the years ended December 31, 2020 and 2019, respectively. This agreement will expire upon the latest of the expiration of both research programs and all evaluation and testing periods. During the year ended December 31, 2020, the Company recorded $50,000 of revenue for an annual maintenance fee for the exclusive product license. During the year ended December 31, 2019, the Company recorded $400,000 of revenue related to its agreement with Surface, of which $300,000 was due to the purchase by Surface of its exclusive product license option and $100,000 was for the exclusive research tool license.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7 . COMMITMENTS AND CONTINGENCIES Sublicense Termination Payments In 2006, the Company licensed certain technology to EUSA Pharma SAS (“EUSA”) and in 2008, this technology was sublicensed by EUSA to Glaxo Group Limited (“GSK”) for development. GSK terminated its sub-license with EUSA in March 2010 and ownership of the technology reverted back to the Company. The Company may be required to pay EUSA up to $25.5 million plus ongoing royalty payments of 1% of net sales upon the occurrence of certain events involving the previously licensed technology, including Phase 3 clinical trial, FDA acceptance and approval and product sales. The Company is not planning any further commercialization efforts related to the previously licensed technology, and therefore does not anticipate any of the above-described amounts will be paid. Operating Lease The Company leases its facilities from 1895 Management, Ltd., a New York corporation controlled by an entity affiliated with a director of the Company, under non-cancellable operating leases. Following entry into a lease extension agreement in August 2020, the lease agreement requires monthly rental payments of $14,511 through October 31, 2022. The Company is responsible for all maintenance, utilities, insurance and taxes related to the facility. As of December 31, 2020, the future minimum payments for the operating leases total $174,132 in 2021 and $145,110 for 2022. Rent expense incurred under the operating lease for each of the years ended December 31, 2020 and 2019 was $169,000 and $168,000 respectively and is a component of general and administrative expense. Contingencies The Company is subject to claims and assessments from time to time in the ordinary course of business. The Company records a provision for a liability when it believes that it is both probable that a liability has been incurred and the amount can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount. In the normal course of business, the Company may become involved in legal proceedings. The Company will accrue a liability for such matters when it is probable that a liability has been incurred and the amount can be reasonably estimated. When only a range of possible loss can be established, the most probable amount in the range is accrued. If no amount within this range is a better estimate than any other amount within the range, the minimum amount in the range is accrued. The accrual for a litigation loss contingency might include, for example, estimates of potential damages, outside legal fees and other directly related costs expected to be incurred. As of December 31, 2020, and 2019, the Company was not involved in any material legal proceedings.

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2020
Debt Instruments [Abstract]
Long-term Debt	8. LONG-TERM DEBT On May 8, 2020, the Company received the PPP Loan in the amount of $1,133,600. The PPP Loan matures on May 8, 2022, with no principal payments required prior to the maturity date, and bears interest at an annual rate of 1.0%, with interest payments commencing on November 8, 2020, less the amount of any potential forgiveness. The PPP Loan may be repaid at any time prior to maturity without incurring prepayment penalties. Pursuant to the CARES Act, all or a portion of the PPP Loan may be forgiven if the PPP Loan is used for qualifying expenses as described in the CARES Act, subject to certain conditions. The Company has sought forgiveness for this loan, but until such forgiveness is granted the loan has been recorded as long-term debt and related interest has been accrued accordingly. As of December 31, 2020, the Company has reflected accrued interest and interest expense of $7,400 within its consolidated balance sheet and statement of operations and comprehensive loss, respectively.

Convertible Debenture

Convertible Debenture	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Convertible Debenture	9. CONVERTIBLE DEBENTURE The senior secured convertible debt comprises the following (in thousands): As of December 31, 2020 As of December 31, 2019 Senior secured convertible debenture $ 8,531 $ - Unamortized original issuance discount and debt issuance costs (458 ) - Total convertible debt $ 8,074 $ - On July 30, 2020, the Company consummated the Convertible Debt Financing pursuant to which the Company issued the Debenture in the principal amount of $8,640,000 for a purchase price of $8,000,000, which reflects an original issue discount of approximately 8%. The closing of the sale of the Debenture occurred on August 3, 2020. The Debenture will mature on the August 3, 2021. The Debenture accrues interest at 7% per year and is convertible into shares of common stock at the holder’s option, at a conversion price of $9.4125 per share, subject to certain customary adjustments (“Optional Conversion”). Should a holder elect to convert prior to maturity, the holder is entitled to a cash payment for interest that would have been earned by the holder through the original maturity of the Debenture (the “Interest Make-Whole”). Subject to the satisfaction of certain conditions, at any time, the Company may elect to redeem all or any portion of the Debenture for an amount equal to 115% of the outstanding principal balance being redeemed plus all accrued unpaid interest on the amount being redeemed and an amount due under the Interest Make-Whole (the “Optional Redemption”). The Debenture also provides that in connection with future capital raising transactions (subject to certain exceptions), the Company must offer to use 20% of the funds raised to redeem amounts outstanding under the Debenture (“Mandatory Redemption”). Any redemption in this circumstance will be at the election of the holder. Consistent with the Optional Conversion or Optional Redemption provisions, the Mandatory Redemption is subject to the Interest Make-Whole. During the year ended December 31, 2020, the Company made payments under the Mandatory Redemption provision totaling $116,329 consisting of $108,719 for principal repayments and $7,610 for accrued and make-whole interest. The Debenture contains customary representations and warranties and affirmative and restrictive covenants, including limitations on indebtedness, liens, dispositions of assets, organizational document amendments, change of control transactions, stock repurchases, indebtedness repayments, dividends, affiliate transactions and certain other matters. The Company’s obligations under the Debenture can be accelerated upon the occurrence of certain customary events of default and are secured under a security agreement by a lien on substantially all of the Company’s assets, subject to certain exceptions. In the event of default and acceleration of the Company’s obligations, the Company would be required to pay the outstanding principal balance of the Debenture plus all accrued unpaid interest and amounts due under the Interest Make-Whole, subject to alternate payment in the event that the event of default prevents the holder from converting the Debenture or disposing of the shares issuable thereunder, and all other amounts due in respect of the Debenture. If the Company, at any time while this Debenture is outstanding: (i) pays a stock dividend or otherwise makes a distribution or distributions payable in shares of common stock on shares of common stock or any common stock equivalents, (ii) subdivides outstanding shares of common stock into a larger number of shares, (iii) combines (including by way of a reverse stock split) outstanding shares of common stock into a smaller number of shares or (iv) issues, in the event of a reclassification of shares of the common stock, any shares of capital stock of the Company, then the conversion price will be multiplied by a fraction, the numerator of which will be the number of shares of common stock outstanding immediately before such event, and the denominator of which will be the number of shares of common stock outstanding immediately after such event. In addition to the adjustments above, if the Company grants, issues, or sells any common stock equivalents or rights to purchase stock, warrants, securities, or other property pro rata to the holders of any class of shares of common stock (the “Purchase Rights”), then upon subsequent conversion of the Debenture, the holder will be entitled to acquire the aggregate Purchase Rights which the holder could have acquired if the holder had held the number of shares of common stock acquirable upon complete conversion of the Debenture immediately before such grant, issuance or sale of Purchase Rights. The Company evaluated the Debenture and determined that the Interest Make-Whole feature and Optional Redemption meet the definition of an embedded derivative liability measured at fair value. On the issuance date, August 3, 2020, the fair value of the bifurcated embedded derivative liability was $65,000. The Company incurred $50,000 in fees paid to 3i in connection with the issuance of the Debenture. These costs were primarily allocated to the debt component and recognized as additional debt discount. The Company amortizes the debt discount, including the initial value of the derivative liability of $65,000, allocated fees of $50,000 and the original issuance discount of $640,000, over the term of the Debenture using the effective interest method. The annual effective interest rate is 16.54%. Total interest expense under the Senior Secured Convertible Debenture for the year ended December 31, 2020 was $554,303, prior to impact of change in fair value of derivative liability. The fair value of the derivative liability as of December 31, 2020 was $0. The Company recorded the change in the fair value of $65,000 as a reduction to interest expense in its consolidated statement of operations and comprehensive loss.

Common Stock Reserved For Issua

Common Stock Reserved For Issuance	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Common Stock Reserved For Issuance	1 0 . COMMON STOCK RESERVED FOR ISSUANCE Common stock has been reserved for the following potential future issuances: As of December 31, 2020 As of December 31, 2019 Shares underlying outstanding stock options 832,868 579,731 Shares available for future stock option grants 267,275 230,952 Exchange of Vaccinex Products, LP units 1,147,259 1,173,500 Conversion of VX3 units 1,318,797 1,318,797 Total shares of common stock reserved 3,566,199 3,302,980 During the years ended December 31, 2020 and 2019, 26,241 and 29,066 units, respectively, of Vaccinex Products, LP were exchanged for shares of the Company’s common stock at par value of $0.0001 per share.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	1 1 . STOCK-BASED COMPENSATION 2011 Employee Equity Plan The Company’s 2011 Employee Equity Plan (the “2011 Plan”) was terminated in connection with the adoption of the Company’s 2018 Omnibus Incentive Plan (the “2018 Plan”) in August 2018, and the Company will not grant any additional stock options under the 2011 Plan. However, the 2011 Plan will continue to govern the terms and conditions of the outstanding stock options previously granted thereunder. Stock options granted under the 2011 Plan expire in five or ten years from the date of grant. 2018 Omnibus Incentive Plan In August 2018, the Company’s Board of Directors adopted, and its stockholders approved, the 2018 Plan, which allows for the granting of stock, stock option, and stock appreciation rights awards to employees, advisors and consultants. Stock options granted under the 2018 Plan may be either incentive stock options or non-statutory stock options. Incentive stock options may be granted to employees, advisors and consultants at exercise prices of no less than the fair value of the common stock on the grant date. If at the time of grant, the optionee owns stock representing more than 10% of the voting power of all classes of stock of the Company, the exercise price must be at least 110% of the fair value of the common stock on the grant date as determined by the board of directors. Non-statutory stock options may be granted to employees, advisors and consultants at exercise prices of less than the fair market value of a share of common stock on the date the non-statutory stock option is granted but shall under no circumstances be less than adequate consideration as determined by the board of directors for such a share. The vesting period of stock option grants is determined by the board of directors, ranging from zero to eight years. Stock options granted under the 2018 Plan expire in five or ten years from the date of grant. The Company reserved 425,000 shares of common stock for issuance, subject to certain adjustments, pursuant to awards under the 2018 Plan. Any shares of common stock related to awards outstanding under the 2011 Plan as of the effective date of the 2018 Plan, which thereafter terminate by expiration, forfeiture, cancellation or otherwise without the issuance of such shares, will be added to, and included in, the number of shares of common stock available for grant under the 2018 Plan. In addition, effective January 1, 2020 and continuing until the expiration of the 2018 Plan, the number of shares of common stock available for issuance under the 2018 Plan will automatically increase annually by 2% of the total number of issued and outstanding shares of the Company’s common stock as of December 31 st A summary of the Company’s stock option activity and related information is as follows: Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 1, 2019 405,683 $ 9.69 6.5 $ - Granted 203,936 5.02 Exercised - - $ - Canceled (29,888 ) 9.86 Balance as of December 31, 2019 579,731 8.04 7.0 $ 120 Granted 330,845 4.45 Exercised (3,783 ) 5.11 $ 3 Canceled (73,925 ) 5.82 Balance as of December 31, 2020 832,868 $ 6.83 6.9 $ 2 Exercisable as of December 31, 2020 577,006 $ 7.68 6.3 $ 2 The weighted-average grant date fair value of stock options granted to employees and directors for the years ended December 31, 2020 and 2019 was $2.70 and $3.35 per share, respectively. The aggregate grant date fair value of stock options that vested during the years ended December 31, 2020 and 2019 was $732,408 and $161,613, respectively. The intrinsic value of stock options vested and expected to vest and exercisable is calculated based on the difference between the exercise price and the fair value of the Company’s common stock as of December 31, 2020 and 2019. The intrinsic value of exercised stock options is the difference between the fair value of the underlying common stock and the exercise price as of the exercise date. The intrinsic value of exercisable awards at December 31, 2020 was $2,212. As of December 31, 2020, and 2019, total unrecognized compensation cost related to stock options granted to employees was $628,036 and $627,129, respectively, which is expected to be recognized over a weighted-average period of 2.5 and 2.4 years, respectively. Determination of Fair Value The determination of the fair value of stock options on the date of grant using the Black-Scholes option-pricing model is affected by the estimated fair value of the Company’s common stock, as well as assumptions regarding a number of variables that are complex, subjective and generally require significant judgment to determine. The assumptions used to calculate the fair value of stock options were: Fair Value of Common Stock Prior to the IPO, the fair value of the common stock underlying the stock options was determined by the Company’s board of directors, with input from management and third-party valuations. Subsequent to the IPO, the fair value of the Company’s common stock was based on its publicly traded price per share. Expected Term The expected term represents the period that the Company’s stock option awards are expected to be outstanding. Stock options granted have a maximum contractual life of 10 years. The Company estimates the expected term of the stock option to be 6.3 years based on historical data on employee exercises and post-vesting employment termination behavior. Expected Volatility As the Company does not have a trading history for its common stock, the expected stock price volatility for the Company’s common stock was estimated by taking the average historic price volatility for industry peers based on daily price observations over a period equivalent to the expected term of the stock option grants. Industry peers consist of several public companies in the Company’s industry which are of similar size, complexity and stage of development. The Company intends to continue to consistently apply this process using the same or similar public companies until a sufficient amount of historical information regarding the volatility of its own share price becomes available, or unless circumstances change such that the identified companies are no longer similar to the Company, in which case, more suitable companies whose share prices are publicly available would be used in the calculation. Risk-Free Interest Rate The risk-free interest rate is based on the U.S. Treasury rate, with maturities similar to the expected term of the stock options. Expected Dividend Yield The Company does not anticipate paying any dividends in the foreseeable future and, therefore, uses an expected dividend yield of zero. The grant date fair value of employee stock options was estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2020 2019 Expected term (in years) 6.3 6.0 Expected volatility 75 % 75 % Risk-free interest rate 0.9 % 2.5 % Expected dividend yield - % - % Total stock-based compensation expense recognized in the consolidated statements of operations and comprehensive loss is as follows (in thousands): Year Ended December 31, 2020 2019 Research and development $ 129 $ 100 General and administrative 603 347 Total stock-based compensation expense $ 732 $ 447

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	1 2 . INCOME TAXES No provision for income taxes was recorded in the years ended December 31, 2020 and 2019. The Company remains in a cumulative loss position with a full valuation allowance recorded against its net deferred income tax assets as of December 31, 2020. The reconciliation of federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2020 2019 Expected income tax benefit at the federal statutory rate 21.0 % 21.0 % State taxes, net of federal benefit 5.1 5.1 Research and development credit, net 8.2 10.9 Non-deductible items and others (0.2 ) 0.1 Change in valuation allowance (34.1 ) (37.1 ) Total 0.0 % 0.0 % Deferred income taxes reflect the net effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The principal components of the Company’s deferred tax assets consisted of the following as of December 31, 2020 and 2019 (in thousands): As of December 31, 2020 2019 Deferred tax assets: Federal and state net operating loss carryforwards $ 67,737 $ 60,467 Research and development tax credits 20,513 18,161 Depreciation and amortization 424 439 Reserves and accruals 229 168 Other 381 274 Total deferred tax assets 89,284 79,509 Less: valuation allowance (89,284 ) (79,509 ) Net deferred tax assets - - Deferred tax liability: Net deferred tax assets and liability $ - $ - The Company’s valuation allowance increased by $9.8 million and by $11.8 million for the years ended December 31, 2020 and 2019, respectively, in order to maintain a full valuation allowance against its deferred tax assets. Based on the Company’s history of losses, the Company recorded a full valuation allowance against its deferred tax assets as of December 31, 2019 and 2018. The Company intends to maintain a valuation allowance until sufficient positive evidence exists to support a reversal of the valuation allowance and the realization of the Company’s deferred tax assets. As of December 31, 2020, the Company had federal and state operating loss carryforwards of $257.0 million and $268.1 million, which begin to expire in the years ending December 31, 2024 and 2034, respectively. The Company had federal research and development tax credit carryforwards of $20.5 million as of December 31, 2020. This credit begins to expire in the year ending December 31, 2021. Under the provisions of Sections 382 and 383 of the Internal Revenue Code (the IRC), net operating loss and credit carryforwards and other tax attributes may be subject to limitation if there has been a significant change in ownership of the Company, as defined by the IRC. Future owner or equity shifts could result in limitations on net operating loss and credit carryforwards. The Company files income tax returns in the U.S. federal jurisdiction as well as many U.S. state jurisdictions. The tax years from January 1, 2017 to December 31, 2020 remain open to examination by the major jurisdictions in which the Company is subject to tax. Fiscal years outside the normal statute of limitations remain open to audit by tax authorities due to tax attributes generated in those early years, which have been carried forward and may be audited in subsequent years when utilized. The Company evaluates tax positions for recognition using a more-likely-than-not recognition threshold, and those tax positions eligible for recognition are measured as the largest amount of tax benefit that is greater than 50% likely of being realized upon the effective settlement with a taxing authority that has full knowledge of all relevant information. As of December 31, 2020, and 2019, the Company had no unrecognized income tax benefits that would affect the Company’s effective tax rate if recognized.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	1 3 . NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented as they had an anti-dilutive effect: Year Ended December 31, 2020 2019 Options to purchase common stock 766,638 555,611 Contingently issuable common stock upon exchange of Vaccinex Products, LP units 1,164,791 1,197,479 Contingently issuable common stock upon exchange of VX3 units 1,318,797 1,318,797

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	1 4 . EMPLOYEE BENEFIT PLAN The Company sponsors a 401(k) plan that stipulates that eligible employees can elect to contribute to the 401(k) plan, subject to certain limitations, up to the lesser of the statutory maximum or 100% of eligible compensation on a pre-tax basis. Through December 31, 2020 and 2019, the Company has not elected to match employee contributions as permitted by the plan. The Company pays the administrative costs for the plan.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	1 5 . RELATED PARTY TRANSACTIONS As discussed in Note 7, the Company also leases its facility from 1895 Management, Ltd., a New York corporation controlled by an entity affiliated with the Company’s chairman and major stockholder of the Company. Rent expense incurred under this operating lease was $169,000 and $168,000, respectively, for each of the years ended December 31, 2020 and 2019. As discussed in Note 6, in November 2017, the Company entered into a research collaboration and license option agreement with Surface to identify and select antibodies against two target antigens, using the Company’s proprietary technology as described in the agreement. J. Jeffrey Goater, a member of the Company’s board of directors, served as the Chief Business Officer of Surface at that time, and currently serves as the Chief Executive Officer and a director of Surface. On January 21, 2020, the Company entered into a stock purchase agreement pursuant to which the Company issued and sold to certain investors 1,468,563 shares of its common stock at a purchase price of $5.09 per share for aggregate gross proceeds of $7.5 million (“the January 2020 Private Placement”). FCMI Parent Co., the Company’s majority stockholder, which is controlled by Albert D. Friedberg, the chairman of the Company’s board of directors, Vaccinex (Rochester) L.L.C., which is majority owned and controlled by Dr. Maurice Zauderer, the Company’s President, Chief Executive Officer, and a member of its board of directors, and Jacob Frieberg, a member of the Company’s board of directors, purchased 982,318, 98,231, and 39,292 shares of our common stock for aggregate purchase prices of $4,999,999, $499,996, and $199,996, respectively, in the January 2020 Private Placement. In connection with the January 2020 Private Placement, on January 23, 2020, the Company entered into a registration rights agreement with the investors pursuant to which the Company filed a registration statement on Form S-3 (File No. 333-236417), declared effective on March 11, 2020, to register the resale of the shares acquired by the investors in the January 2020 Private Placement. On July 9, 2020, the Company entered into a stock purchase agreement (the “July 2020 Stock Purchase Agreement”) with Friedberg Global-Macro Hedge Fund, Ltd. (the “Investor”), pursuant to which the Company issued and sold to the Investor 1,126,760 shares (the “Shares”) of the Company’s common stock, at a purchase price of $3.55 per Share (the “Private Placement”), for gross proceeds of $4.0 million. Albert D. Friedberg, the Company’s chairman and beneficial owner of a majority of the Company’s outstanding common stock, controls Friedberg Mercantile Group, the investment manager of the Investor, which exercises voting and dispositive power over shares held directly by the Investor. The closing of the Private Placement occurred on July 10, 2020. The Company intends to use the net proceeds from the Private Placement to fund the ongoing development of pepinemab, the Company’s lead product candidate, and for working capital and general corporate purposes. Also, on July 10, 2020, the Company entered into a registration rights agreement with the Investor, pursuant to which the Company filed a registration statement on Form S-3 (File No. 333-246326), declared effective on August 25, 2020, to register the resale of the Shares. On July 26, 2019, the Company entered into a stock purchase agreement (the “Stock Purchase Agreement”) with certain investors including FCMI Parent, the Company’s majority stockholder, and Vaccinex (Rochester), L.L.C. FCMI Parent is majority owned and controlled by the Company’s chairman of the board and the Company’s president and chief executive officer, Dr. Maurice Zauderer, who is also the president and majority owner of Vaccinex, (Rochester), L.L.C. Pursuant to the Stock Purchase Agreement, the Company issued and sold to the investors 3,382,332 shares of its common stock at a purchase price of $4.08 per Share. The aggregate gross proceeds for the sale of the shares were $13.8 million. In connection with the Stock Purchase Agreement, on July 30, 2019, the Company entered into a registration rights agreement (the “Registration Rights Agreement”) with the investors that were party to the Stock Purchase Agreement, including FCMI Parent and Vaccinex (Rochester), L.L.C. that affords the investors certain registration rights with respect to the shares of the Company’s common stock purchased pursuant to the Stock Purchase Agreement. Pursuant to the Registration Rights Agreement, the Company filed a registration statement on Form S-3 (File No. 333-233607), declared effective on October 8, 2019, registering the shares acquired by the investors in the private placement.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	1 6 . SUBSEQUENT EVENT In January 2021, the Company sold 522,272 shares of the Company’s common stock at a weighted average price of $2.58 through the Open Market Sale Agreement, for net proceeds of $1.3 million. In February 2021, the Company sold 5,415,628 shares of the Company’s common stock at a weighted average price of $5.82 through the Open Market Sale Agreement, for net proceeds of $30.6 million. In January and February 2021, the Company made payments under the Mandatory Redemption provision of the Debenture totaling $6,372,575, consisting of $5,955,678 for principal repayments and $416,897 for accrued and make-whole interest. In March 2021, one VX3 partner exchanged its partnership interests in VX3, for 109,900 shares of the Company’s common stock.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation These consolidated financial statements reflect the accounts and operations of the Company and those of its subsidiaries in which the Company has a controlling financial interest. As of December 31, 2020, and 2019, the Company’s accounts include Vaccinex Products and VX3 (DE) LP, a Delaware limited partnership (VX3). VX3 was established in October 2017 by a group of Canadian investors and was determined to be a variable interest entity (“VIE”) in which the Company is the primary beneficiary. The Company consolidates any VIE of which it is the primary beneficiary. The Company presents its noncontrolling interests as a separate component of stockholders’ equity (deficit). The company presents the net loss of VX3 equal to the percentage ownership interest retained in such entity by the respective noncontrolling party (VX3), and as a separate component within its consolidated statements of operations and comprehensive loss. The financial position of Vaccinex Products and VX3 were not material as of December 31, 2020 and 2019, and there were no gains or losses for Vaccinex Products or VX3 for the years ended December 31, 2020 and 2019. Intercompany transactions and balances have been eliminated.
Use of Estimates	Use of Estimates These consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amount of expenses during the reporting period. Such management estimates include those relating to assumptions used in the valuation of stock option awards, the valuation of derivative instruments, and valuation allowances against deferred income tax assets. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. The Company deposits its cash primarily in checking and money market accounts.
Concentration of Credit Risk, Other Risks and Uncertainties	Concentration of Credit Risk, Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents. Cash equivalents are deposited in interest-bearing money market accounts. Although the Company deposits its cash with multiple financial institutions, cash balances may occasionally be in excess of the amounts insured by the Federal Deposit Insurance Corporation. Management believes the financial risk associated with these balances is minimal and has not experienced any losses to date. The Company depends on third-party manufacturers for the manufacture of drug substance and drug product for clinical trials. The Company also relies on certain third parties for its supply chain. Disputes with these third - party manufacturers or shortages in goods or services from third-party suppliers could delay the manufacturing of the Company’s product candidates and adversely impact its results of operations.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial instruments consist of cash and cash equivalents, marketable securities, prepaid expenses and other current assets, accounts payable, accrued expenses, convertible promissory notes, and derivative liabilities. Cash equivalents and marketable securities are stated at fair value. Prepaid expenses and other current assets, accounts payable and accrued expenses are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment date. The Company’s derivative instrument related to certain features embedded within the Debenture is discussed in Note 9. The derivative is accounted for as a derivative liability and remeasured to fair value as of each balance sheet date and the related remeasurement adjustments are recorded as interest expense in the Company’s consolidated statement of operations and comprehensive loss.
Financing Activities and Offering Costs	Financing Activities and Offering Costs During the year ended December 31, 2020, we raised total proceeds of approximately $37.6 million, net of commissions and discounts before expenses, from the following activities: During the year ended December 31, 2020, the Company completed private placements of our common stock to various investors in January 2020 and July 2020, for gross proceeds of $7.5 million and $4.0 million, respectively. During the year ended December 31, 2019, we received gross proceeds of $13.8 million. Additionally, in September 2020 we received gross proceeds of $2.0 million through an award from the Alzheimer’s Drug Discovery Foundation (“ADDF”), in the form of an investment in our common stock. On March 27, 2020, we announced that we had (i) entered into an open market sale agreement (the “Open Market Sale Agreement” or “ATM”) with Jefferies, LLC (“Jefferies”) and filed a prospectus supplement pursuant to which we were able to issue and sell up to $11.5 million of shares of our common stock from time and (ii) entered into a purchase agreement (the “Purchase Agreement”) with Keystone Capital Partners, LLC (“Keystone”) pursuant to which Keystone agreed to purchase up to an aggregate of $5.0 million of shares of our common stock from time to time. During the second quarter of 2020, 317,688 shares were sold through the Open Market Sale Agreement for proceeds of $1.2 million, net of commission, and 324,424 shares were sold through the Purchase Agreement with Keystone for proceeds of $1.2 million, net of discount. The Company has incurred certain costs in connection with its securities offerings with Jefferies and Keystone that occurred in 2020. The Company capitalizes such deferred offering costs, which consist of direct, incremental legal, professional, accounting, and other third-party fees. The deferred offering costs will be offset against offering proceeds upon the completion of an offering. Should the offering be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the Company’s condensed consolidated statement of operations and comprehensive loss. Accordingly, $713,000 of offering costs associated with the ATM Facility and Keystone were charged against paid in capital during the year ended December 31, 2020. There were no deferred offering costs on the consolidated balance sheet at December 31, 2020 or 2019. In August 2020, we entered into a Securities Purchase Agreement (the “SPA”), with 3i, LP, (“3i”) as collateral agent and purchaser (the “Convertible Debt Financing”). Pursuant to the SPA, on August 3, 2020, we issued a 7% Original Issue Discount Senior Secured Convertible Debenture (“Senior Secured Convertible Debenture” or “the Debenture”), in the principal amount of $8.64 million for a purchase price of $8.0 million, which reflects an original issue discount of approximately 8%. The Debenture will mature on August 3, 2021. The Debenture accrues interest at 7% per year and is convertible into shares of our common stock at a conversion price of $9.4125 per share, subject to certain customary adjustments. In addition, on May 8, 2020, the Company received a loan of $1.1 million from Five Star Bank (the “PPP Loan”) under the Paycheck Protection Program established as a part of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”).
Property and Equipment, Net	Property and Equipment, Net Property and equipment are recorded at cost. Depreciation is computed over estimated useful lives of the related assets using the straight-line method. Leasehold improvements are amortized on a straight-line basis over the shorter of the useful life or term of the lease. Upon retirement or disposal, the cost and related accumulated depreciation are removed from the consolidated balance sheets and the resulting gain or loss is recorded to general and administrative expense in the consolidated statements of operations. Routine expenditures for maintenance and repairs are expensed as incurred. Estimated useful lives for property and equipment are as follows: Property and Equipment Estimated Useful Life Research equipment 5 years Furniture and fixtures 5 years Computer equipment 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews the recoverability of its long-lived assets when events or changes in circumstances occur that indicate that the carrying value of the asset may not be recoverable. The assessment of possible impairment is based on the ability to recover the carrying value of the assets from the expected future cash flows (undiscounted and without interest expense) of the related operations. If these cash flows are less than the carrying value of such assets, an impairment loss for the difference between the estimated fair value and carrying value is recorded. There was no impairment loss recognized during the years ended December 31, 2020 and 2019.
Convertible Instruments	Convertible Instruments The Company applies the accounting standards for derivatives and hedging and for distinguishing liabilities from equity when accounting for hybrid contracts that contain conversion options and other embedded features. The accounting standards require companies to bifurcate embedded features from their host instruments and account for them as free-standing derivative financial instruments according to certain criteria. The criteria include circumstances in which (i) the economic characteristics and risks of the embedded derivative instrument are not clearly and closely related to the economic characteristics and risks of the host contract, (ii) the hybrid instrument that embodies both the embedded derivative instrument and the host contract is not re-measured at fair value under otherwise applicable generally accepted accounting principles with changes in fair value reported in earnings as they occur and (iii) a separate instrument with the same terms as the embedded derivative instrument would be considered a derivative instrument. The Company’s derivative instrument related to certain features embedded within the Debenture is discussed in Note 9. The derivative is accounted for as a derivative liability and remeasured to fair value as of each balance sheet date and the related remeasurement adjustments are recognized in the Company’s consolidated statement of operations and comprehensive loss.
Treasury Stock	Treasury Stock The Company records treasury stock activities under the cost method whereby the cost of the acquired stock is recorded as treasury stock. The Company’s accounting policy upon the formal retirement of treasury stock is to deduct the par value from common stock and to reflect any excess of cost over par value as a reduction to additional paid-in capital (to the extent created by previous issuances of the shares) and then retained earnings. There was no treasury stock repurchased for the years ended December 31, 2020 and 2019.
Revenue Recognition	Revenue Recognition The Company’s revenues are generated primarily through collaborative research, license, development and commercialization agreements. We recognize revenue when our customers obtain control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. We assess if these options provide a material right to the customer and if so, they are considered performance obligations. The exercise of a material right is accounted for as a contract modification for accounting purposes. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied at a point in time or over time, and if over time this is based on the use of an output or input method. Amounts received prior to revenue recognition are recorded as deferred revenue. Amounts expected to be recognized as revenue within the 12 months following the balance sheet date are classified as current portion of deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized as revenue within the 12 months following the balance sheet date are classified as deferred revenue, net of current portion. Amounts recognized as revenue, but not yet received or invoiced are generally recognized as contract assets in the Other Assets line item in the Consolidated Balance Sheets. Collaborative Arrangements – The Company has entered into collaboration agreements, which are within the scope of ASC 606, to discover, develop, manufacture and commercialize product candidates. The terms of these agreements typically contain multiple promises or obligations, which may include: (1) licenses, or options to obtain licenses, to use the Company’s research program materials, and (2) research and development activities to be performed on behalf of the collaboration partner. Payments the Company receives under these arrangements typically include one or more of the following: non-refundable, upfront license fees; option exercise fees; funding of research and/or development efforts; clinical and development, regulatory, and sales milestone payments; and royalties on future product sales. The Company also analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements For a complete discussion of accounting for collaboration revenues, see Note 6, “Collaboration Agreements”.
Grant Revenue	Grant Revenue From time to time, the Company receives certain grant award funding to support its continuing research and development efforts. The Company considers these grants to be operating revenue as they support the Company’s primary operating activities. We recognize revenue from these contracts as we perform services under these arrangements when the funding is received. Revenues and related expenses are presented gross in the consolidated statements of operations and comprehensive loss as we have determined we control the arrangement as the primary obligor under the arrangements relative to the research and development services we perform. During the year ended December 31, 2020 the Company recorded grant revenue related to funds received from the Alzheimer’s Association of $575,000. No grant revenue was recorded for the year ended December 31, 2019.
Research and Development Costs	Research and Development Costs Expenditures, including payroll, contractor expenses and supplies, for research and development of products are expensed as incurred. Clinical trial and other development costs incurred by third parties are expensed as the contracted work is performed. Where contingent milestone payments are due to third parties under research and development arrangements, the milestone payment obligations are expensed when the milestone results are probable of being achieved.
Stock-Based Compensation	Stock-Based Compensation The Company utilizes the Black-Scholes stock option-pricing model as the method for estimating the grant date fair value of its stock option awards. The Black-Scholes stock option-pricing model requires the use of highly subjective and complex assumptions, including the stock options’ expected term and the price volatility of the underlying stock. The grant date fair value of the portion of the stock option award that is ultimately expected to vest is recognized as compensation expense over the stock option awards’ requisite service periods. The Company recognizes stock-based compensation to expense using the straight-line method over the requisite service period. If there are any modifications or cancelations of stock option awards, the Company may be required to accelerate, increase or decrease any remaining unrecognized stock-based compensation expense.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities, which relate primarily to the carrying amount of the Company’s property and equipment and its net operating loss carryforward, are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities. Valuation allowances are established when necessary to reduce deferred tax assets where, based upon the available evidence, management concludes that it is more likely than not that the deferred tax assets will not be realized. In evaluating its ability to recover deferred tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. Because of the uncertainty of the realization of the deferred tax assets, the Company has recorded a full valuation allowance against its deferred tax assets. Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more likely than not to be sustained on examination by a taxing authority, assuming they possess full knowledge of the position and facts. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes; however, the Company currently has no interest or penalties related to income taxes.
Segment and Geographic Information	Segment and Geographic Information The Company’s chief operating decision maker, its Chief Executive Officer, reviews its operating results on an aggregate basis for purposes of allocating resources and evaluating financial performance. The Company has one business activity, the discovery and development of targeted biotherapeutics to treat serious diseases and conditions with unmet medical needs, and there are no segment managers who are held accountable for operations or operating results. Accordingly, the Company operates in one segment. As of December 31, 2020, and 2019, all long-lived assets are located in the United States.
Net Loss Per Share Attributable to Vaccinex, Inc. Common Stockholders	Net Loss Per Share Attributable to Vaccinex, Inc. Common Stockholders The Company calculates its basic and diluted net loss per share attributable to Vaccinex, Inc. common stockholders by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of common shares plus common equivalent shares for the period, including any dilutive effect from such shares. Since the Company was in a net loss position for all periods presented, net loss per share attributable to common stockholders was the same on a basic and diluted basis, as the inclusion of all potential common equivalent shares outstanding would have been anti-dilutive. For purposes of this calculation, stock options to purchase common stock are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to Vaccinex, Inc. common stockholders as their effect is anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Leases, Targeted Improvements to ASC 842, Leases , Leases The Company has substantially completed its evaluation of the potential impact ASU 2016-02 may have on its financial position, results of operations, and related footnotes. The Company expects it will elect to utilize the available package of practical expedients permitted under the transition guidance within the new standard, which does not require the reassessment of the following: i) whether existing or expired arrangements are or contain a lease, ii) the lease classification of existing or expired leases, and iii) whether previous initial direct costs would qualify for capitalization under the new lease standard. Additionally, the Company expects it will make an accounting policy election to keep leases with an initial term of 12 months or less off of its balance sheet. The Company believes the largest impact will be the recognition of right-of-use assets and lease liabilities on the consolidated balance sheets, as the Company’s lease portfolio primarily consists of an operating lease for its corporate headquarters in Rochester, New York. The Company expects to recognize right-of-use assets and corresponding lease liabilities of approximately $.3 million at the date of adoption. The results of operations are not expected to change significantly as a result of adopting the new standard. During the first quarter of fiscal 2021, the Company will finalize its accounting assessment and quantification of the impact of adoption on the Company’s financial statements and corresponding disclosures. Recently Adopted Accounting Pronouncements In May 2014, FASB issued ASU No. 2014-09, Revenue (ASC 606): Revenue from Contracts with Customers Revenue Recognition In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808)—Clarifying the Interaction between Topic 808 and ASC 606

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Estimated Useful Lives for Property and Equipment	Estimated useful lives for property and equipment are as follows: Property and Equipment Estimated Useful Life Research equipment 5 years Furniture and fixtures 5 years Computer equipment 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Property and Equipment	Property and equipment consist of the following (in thousands): As of December 31, 2020 As of December 31, 2019 Leasehold improvements $ 3,174 $ 3,161 Research equipment 3,499 3,442 Furniture and fixtures 350 350 Computer equipment 273 214 Property and equipment, gross 7,296 7,167 Less: accumulated depreciation and amortization (6,880 ) (6,573 ) Property and equipment, net $ 416 $ 594
Accrued Expenses	Accrued expenses consist of the following (in thousands): As of December 31, 2020 As of December 31, 2019 Accrued clinical trial cost $ 987 $ 3,252 Accrued payroll and related benefits 428 262 Accrued consulting and legal 225 79 Accrued interest 250 - Accrued other 47 77 Accrued expenses $ 1,937 $ 3,670

Fair Value of Financial Measu_2

Fair Value of Financial Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of Fair Value of Financial Assets by Level within Fair Value Hierarchy	The following table sets forth the fair value of the Company’s financial assets by level within the fair value hierarchy (in thousands): As of December 31, 2020 Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash equivalents: Money market fund $ 1,026 $ 1,026 $ - $ - Total Financial Assets $ 1,026 $ 1,026 $ - $ - As of December 31, 2019 Fair Value Level 1 Level 2 Level 3 Financial Assets: Cash equivalents: Money market fund $ 1,464 $ 1,464 $ - $ - Total Financial Assets $ 1,464 $ 1,464 $ - $ -

Convertible Debenture (Tables)

Convertible Debenture (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Senior Secured Convertible Debt	The senior secured convertible debt comprises the following (in thousands): As of December 31, 2020 As of December 31, 2019 Senior secured convertible debenture $ 8,531 $ - Unamortized original issuance discount and debt issuance costs (458 ) - Total convertible debt $ 8,074 $ -

Common Stock Reserved For Iss_2

Common Stock Reserved For Issuance (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Common Stock Reserved for Potential Future Issuances	Common stock has been reserved for the following potential future issuances: As of December 31, 2020 As of December 31, 2019 Shares underlying outstanding stock options 832,868 579,731 Shares available for future stock option grants 267,275 230,952 Exchange of Vaccinex Products, LP units 1,147,259 1,173,500 Conversion of VX3 units 1,318,797 1,318,797 Total shares of common stock reserved 3,566,199 3,302,980

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity and Related Information	A summary of the Company’s stock option activity and related information is as follows: Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 1, 2019 405,683 $ 9.69 6.5 $ - Granted 203,936 5.02 Exercised - - $ - Canceled (29,888 ) 9.86 Balance as of December 31, 2019 579,731 8.04 7.0 $ 120 Granted 330,845 4.45 Exercised (3,783 ) 5.11 $ 3 Canceled (73,925 ) 5.82 Balance as of December 31, 2020 832,868 $ 6.83 6.9 $ 2 Exercisable as of December 31, 2020 577,006 $ 7.68 6.3 $ 2
Grant Date Fair Value of Employee Stock Options Estimated Using Black-Scholes Option-Pricing Model with Weighted-Average Assumptions	The grant date fair value of employee stock options was estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2020 2019 Expected term (in years) 6.3 6.0 Expected volatility 75 % 75 % Risk-free interest rate 0.9 % 2.5 % Expected dividend yield - % - %
Total Stock-Based Compensation Expense Recognized in Condensed Consolidated Statements of Operations and Comprehensive Loss	Total stock-based compensation expense recognized in the consolidated statements of operations and comprehensive loss is as follows (in thousands): Year Ended December 31, 2020 2019 Research and development $ 129 $ 100 General and administrative 603 347 Total stock-based compensation expense $ 732 $ 447

Income Tax (Tables)

Income Tax (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation of federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2020 2019 Expected income tax benefit at the federal statutory rate 21.0 % 21.0 % State taxes, net of federal benefit 5.1 5.1 Research and development credit, net 8.2 10.9 Non-deductible items and others (0.2 ) 0.1 Change in valuation allowance (34.1 ) (37.1 ) Total 0.0 % 0.0 %
Schedule of Deferred Tax Assets and Liabilities	The principal components of the Company’s deferred tax assets consisted of the following as of December 31, 2020 and 2019 (in thousands): As of December 31, 2020 2019 Deferred tax assets: Federal and state net operating loss carryforwards $ 67,737 $ 60,467 Research and development tax credits 20,513 18,161 Depreciation and amortization 424 439 Reserves and accruals 229 168 Other 381 274 Total deferred tax assets 89,284 79,509 Less: valuation allowance (89,284 ) (79,509 ) Net deferred tax assets - - Deferred tax liability: Net deferred tax assets and liability $ - $ -

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Weighted-Average Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share as They Had Anti-Dilutive Effect	The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented as they had an anti-dilutive effect: Year Ended December 31, 2020 2019 Options to purchase common stock 766,638 555,611 Contingently issuable common stock upon exchange of Vaccinex Products, LP units 1,164,791 1,197,479 Contingently issuable common stock upon exchange of VX3 units 1,318,797 1,318,797

Company and Nature of Business

Company and Nature of Business - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Loss from operations	$ (28,851)	$ (31,863)
Cash flow from operations	(28,647)	(30,715)
Accumulated deficit	$ 277,481	$ 248,630

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)

Aug. 03, 2020USD ($)$ / shares

May 08, 2020USD ($)

Mar. 27, 2020USD ($)

Jan. 21, 2020shares

Jul. 26, 2019USD ($)shares

Sep. 30, 2020USD ($)

Jul. 31, 2020USD ($)

Jan. 31, 2020USD ($)

Nov. 30, 2017USD ($)

Sep. 30, 2020USD ($)shares

Jun. 30, 2020USD ($)shares

Dec. 31, 2020USD ($)Segmentshares

Dec. 31, 2019USD ($)shares

Summary Of Significant Accounting Policies [Line Items]

Sale of stock, consideration received

$ 37,600,000

Proceeds from private offering of common stock

11,475,000

$ 13,800,000

Proceeds from capital contribution

$ 11,500,000

Deferred offering costs

0

0

Asset impairment charges

$ 0

$ 0

Treasury stock repurchased | shares

0

0

Grant revenue

$ 575,000

Interest related to income taxes

0

Penalties related to income taxes

$ 0

Number of operating segments | Segment

1

Right of use assets and corresponding lease liabilities

$ 3,000,000

PPP Loan

Summary Of Significant Accounting Policies [Line Items]

Debt instrument interest rate

1.00%

Debenture maturity date

May 8, 2022

Amount of loan received

$ 1,133,600

PPP Loan | Five Star Bank

Summary Of Significant Accounting Policies [Line Items]

Amount of loan received

$ 1,100,000

Maximum

Summary Of Significant Accounting Policies [Line Items]

Sale of stock, consideration received

$ 113,000,000

Alzheimers Association

Summary Of Significant Accounting Policies [Line Items]

Grant revenue

575,000

$ 0

Open Market Sale Agreement

Summary Of Significant Accounting Policies [Line Items]

Proceeds from the sale of shares

$ 12,300,000

$ 1,200,000

Stock Purchase Agreement | Keystone Capital Partners, LLC

Summary Of Significant Accounting Policies [Line Items]

Stock purchase program number of shares agree to purchase

5,000,000

Proceeds from the sale of shares

$ 1,200,000

$ 300,000

Securities Purchase Agreement

Summary Of Significant Accounting Policies [Line Items]

Debt instrument interest rate

7.00%

Debt instrument principal amount

$ 8,640,000

Purchase price of convertible debentures

$ 8,000,000

Debt instrument, discount rate

8.00%

Debenture maturity date

Aug. 3, 2021

Common stock conversion price | $ / shares

$ 9.4125

Common Stock

Summary Of Significant Accounting Policies [Line Items]

Proceeds from private offering of common stock

$ 2,000,000

$ 4,000,000

$ 7,500,000

13,800,000

Common Stock | Open Market Sale Agreement

Summary Of Significant Accounting Policies [Line Items]

Number of common stock sold | shares

3,815,600

317,688

Common Stock | Stock Purchase Agreement

Summary Of Significant Accounting Policies [Line Items]

Number of common stock sold | shares

1,468,563

3,382,332

Proceeds from the sale of shares

$ 13,800,000

Common Stock | Stock Purchase Agreement | Keystone Capital Partners, LLC

Summary Of Significant Accounting Policies [Line Items]

Number of common stock sold | shares

324,424

47,319

Additional Paid-in Capital | ATM Facility | Keystone Capital Partners, LLC

Summary Of Significant Accounting Policies [Line Items]

Deferred offering costs

$ 713,000

Vaccinex Products

Summary Of Significant Accounting Policies [Line Items]

Gain or loss from VIE

$ 0

$ 0

Proceeds from capital contribution

$ 23,900,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Estimated Useful Lives for Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Leasehold Improvements, Useful Life	Lesser of estimated useful life or remaining lease term
Research Equipment
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Computer Equipment
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 7,296	$ 7,167
Less: accumulated depreciation and amortization	(6,880)	(6,573)
Property and equipment, net	416	594
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,174	3,161
Research Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,499	3,442
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	350	350
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 273	$ 214

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation	$ 307,000	$ 249,000

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued clinical trial cost	$ 987	$ 3,252
Accrued payroll and related benefits	428	262
Accrued consulting and legal	225	79
Accrued interest	250
Accrued other	47	77
Accrued expenses	$ 1,937	$ 3,670

Fair Value of Financial Measu_3

Fair Value of Financial Measurements - Summary of Fair Value of Financial Assets by Level within Fair Value Hierarchy (Details) - Fair Value Measurements Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financial Assets:
Total Financial Assets	$ 1,026	$ 1,464
Money Market Funds
Financial Assets:
Cash equivalents, Fair value disclosure	1,026	1,464
Level 1
Financial Assets:
Total Financial Assets	1,026	1,464
Level 1 | Money Market Funds
Financial Assets:
Cash equivalents, Fair value disclosure	$ 1,026	$ 1,464

Fair Value of Financial Measu_4

Fair Value of Financial Measurements - Additional Information (Details) - USD ($)	Dec. 31, 2020	Aug. 03, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded derivative liability	$ 0	$ 65,000
Fair Value Measurements Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial assets, level 1 to level 2 transfers, amount	0		$ 0
Financial assets, level 2 to level 1 transfers, amount	$ 0		$ 0

License and Services Agreement

License and Services Agreement - Additional Information (Details) - USD ($)	Mar. 27, 2020	Nov. 30, 2017	Dec. 31, 2020	Dec. 31, 2019
License And Services Agreement [Line Items]
Proceeds from capital contribution	$ 11,500,000
VX3
License And Services Agreement [Line Items]
Proceeds from capital contribution		$ 23,900,000
Percentage of voting interest			90.00%	90.00%
VX3 License Agreement
License And Services Agreement [Line Items]
Research and development, milestone payments to company		$ 32,000,000
License agreement received amount			$ 0	$ 0
Terms of license agreement upon termination			the Company will issue to VX3 or its designees the number of shares of the Company’s common stock equal to the lesser of (1) the aggregate of all payments made to VX3 by its partners divided by $18.20 and (2) the then fair market value of VX3 divided by the then fair market value of one share of the Company’s common stock.
Base amount to determine issuance of common stock upon termination		$ 18.20

Collaboration Agreements - Addi

Collaboration Agreements - Additional Information (Details)	1 Months Ended	12 Months Ended
	Nov. 30, 2017USD ($)TargetAntigenMilestone	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue		$ 50,000	$ 523,000
Surface Oncology, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of target antigens against which antibodies are to be identified and selected | TargetAntigen	2
Upfront payments fee received	$ 250,000	0	123,276
Number of designated milestones | Milestone	4
Revenue			400,000
Surface Oncology, Inc. | Exclusive Product License Option
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue			300,000
Annual maintenance fee		$ 50,000
Surface Oncology, Inc. | Exclusive Research Tool License
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue			$ 100,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	12 Months Ended		26 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Oct. 31, 2022
Commitments And Contingencies [Line Items]
Royalty payments, percent of net sales	1.00%
Future minimum operating leases payment in 2020	$ 174,132
Future minimum operating leases payment in 2021	145,110,000
Future minimum operating leases payment in 2022	145,110,000
Rent expense incurred under operating lease	169,000	$ 168,000
Scenario Forecast
Commitments And Contingencies [Line Items]
Monthly rental payments			$ 14,511
General and Administrative
Commitments And Contingencies [Line Items]
Rent expense incurred under operating lease	169,000	$ 168,000
Contract Termination
Commitments And Contingencies [Line Items]
Termination payment	$ 25,500,000

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Details) - USD ($)	May 08, 2020	Dec. 31, 2020
Debt Instrument [Line Items]
Interest expense		$ 297,000
PPP Loan
Debt Instrument [Line Items]
Amount of loan received	$ 1,133,600
Maturity date	May 8, 2022
Annual interest rate	1.00%
Payments commencement date	Nov. 8, 2020
Accrued interest		7,400
Interest expense		$ 7,400

Convertible Debenture - Schedul

Convertible Debenture - Schedule of Senior Secured Convertible Debt (Details) - Senior Secured Convertible Debenture $ in Thousands	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Senior secured convertible debenture	$ 8,531
Unamortized original issuance discount and debt issuance costs	(458)
Total convertible debt	$ 8,074

Convertible Debenture - Additio

Convertible Debenture - Additional Information (Details) - USD ($)	Aug. 03, 2020	Jul. 30, 2020	Dec. 31, 2020
Short Term Debt [Line Items]
Embedded derivative liability	$ 65,000		$ 0
Interest expense			297,000
Senior Secured Convertible Debenture
Short Term Debt [Line Items]
Debt instrument principal amount		$ 8,640,000
Purchase price of convertible debentures		$ 8,000,000
Debt instrument, discount rate		8.00%
Maturity date	Aug. 3, 2021
Annual interest rate	7.00%
Common stock conversion price	$ 9.4125
Debenture redemption percentage	115.00%
Percentage of funds used to redeem outstanding debentures	20.00%
Payments under mandatory redemption provision			116,329
Embedded derivative liability			0
Annual effective interest rate	16.54%
Interest expense			554,303
Change in fair value of derivative liability			65,000
Senior Secured Convertible Debenture | 3i
Short Term Debt [Line Items]
Fees paid in connection with issuance of debentures	$ 50,000
Senior Secured Convertible Debenture | Effective Interest Method
Short Term Debt [Line Items]
Embedded derivative liability	65,000
Fees paid in connection with issuance of debentures	50,000
Original issuance discount	640,000
Senior Secured Convertible Debenture | Interest Make-Whole Feature
Short Term Debt [Line Items]
Embedded derivative liability	$ 65,000
Senior Secured Convertible Debenture | Principal Repayments
Short Term Debt [Line Items]
Payments under mandatory redemption provision			108,719
Senior Secured Convertible Debenture | Accrued and Make-whole Interest
Short Term Debt [Line Items]
Payments under mandatory redemption provision			$ 7,610

Common Stock Reserved For Iss_3

Common Stock Reserved For Issuance - Common Stock Reserved For Potential Future Issuances (Details) - shares	Dec. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Total shares of common stock reserved	3,566,199	3,302,980
Shares Underlying Outstanding Stock Options
Class Of Stock [Line Items]
Total shares of common stock reserved	832,868	579,731
Shares Available For Future Stock Option Grants
Class Of Stock [Line Items]
Total shares of common stock reserved	267,275	230,952
Exchange of Vaccinex Products, LP Units
Class Of Stock [Line Items]
Total shares of common stock reserved	1,147,259	1,173,500
Conversion of VX3 Units
Class Of Stock [Line Items]
Total shares of common stock reserved	1,318,797	1,318,797

Common Stock Reserved For Iss_4

Common Stock Reserved For Issuance - Additional Information (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Common stock, par value	$ 0.0001	$ 0.0001
Vaccinex Products, LP Interests | Common Stock
Class Of Stock [Line Items]
Limited partnership interests exchanged	26,241	29,066

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	Jan. 01, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total shares of common stock reserved		3,566,199	3,302,980
Weighted-average grant date fair value of stock options granted to employees and directors		$ 2.70	$ 3.35
Options granted		330,845	203,936
Aggregate grant date fair value of stock options vested		$ 732,408	$ 161,613
Intrinsic value of exercisable awards		2,000		$ 2,212
Total unrecognized compensation cost related to stock options granted to employees		$ 628,036	$ 627,129
Maximum contractual life for options granted		10 years
Expected dividend yield		0.00%
2018 Omnibus Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total shares of common stock reserved		425,000
Percentage of total shares of common stock reserved		2.00%
Additional shares of common stock	297,743
2018 Omnibus Incentive Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of voting power of all classes of stock to be owned by optionee to determine the exercise price		10.00%
Exercise price as a percentage of fair value of common stock on grant date if optionee owns stock representing more than 10 percent of voting power of all classes of stock		110.00%
Employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost related to stock options granted to employees, weighted-average recognition period		2 years 6 months	2 years 4 months 24 days
Expected term of stock option		6 years 3 months 18 days	6 years
Employee Stock Options | 2011 Employee Equity Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, expiration year		5 years
Employee Stock Options | 2011 Employee Equity Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, expiration year		10 years
Employee Stock Options | 2018 Omnibus Incentive Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, expiration year		5 years
Employee Stock Options | 2018 Omnibus Incentive Plan | Minimum | Board of Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of stock option grants		0 years
Employee Stock Options | 2018 Omnibus Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, expiration year		10 years
Employee Stock Options | 2018 Omnibus Incentive Plan | Maximum | Board of Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of stock option grants		8 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity and Related Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options, Balance	579,731	405,683
Stock Options, Granted	330,845	203,936
Stock Options, Exercised	(3,783)
Stock Options, Cancelled	(73,925)	(29,888)
Stock Options, Balance	832,868	579,731	405,683
Stock Options, Exercisable	577,006
Weighted-Average Exercise Price, Balance	$ 8.04	$ 9.69
Weighted-Average Exercise Price, Granted	4.45	5.02
Weighted-Average Exercise Price, Exercised	5.11
Weighted-Average Exercise Price, Canceled	5.82	9.86
Weighted-Average Exercise Price, Balance	6.83	$ 8.04	$ 9.69
Weighted-Average Exercise Price, Exercisable	$ 7.68
Weighted-Average Remaining Contractual Life (Years), Balance	6 years 10 months 24 days	7 years	6 years 6 months
Weighted-Average Remaining Contractual Life (Years), Exercisable	6 years 3 months 18 days
Aggregate Intrinsic Value, Balance	$ 120,000
Aggregate Intrinsic Value, Exercised	3,000
Aggregate Intrinsic Value, Balance	2,000	$ 120,000
Aggregate Intrinsic Value, Exercisable	$ 2,000		$ 2,212

Stock-Based Compensation - Gran

Stock-Based Compensation - Grant Date Fair Value of Employee Stock Options Estimated Using Black-Scholes Option-Pricing Model with Weighted-Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0.00%
Employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 3 months 18 days	6 years
Expected volatility	75.00%	75.00%
Risk-free interest rate	0.90%	2.50%

Stock-Based Compensation - Tota

Stock-Based Compensation - Total Stock-Based Compensation Expense Recognized in Condensed Consolidated Statements of Operations and Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 732	$ 447
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	129	100
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 603	$ 347

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 0	$ 0
Increase (decrease) in valuation allowance for deferred tax asset	$ 9,800,000	11,800,000
Tax credit carryforwards, expiration date	Dec. 31, 2021
Unrecognized tax benefits that would impact effective tax rate	$ 0	$ 0
Description of tax years open to examination by major jurisdictions	from January 1, 2017 to December 31, 2020
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 257,000,000
Operating loss carryforwards, expiration date	Dec. 31, 2024
Federal | Research
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	$ 20,500,000
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 268,100,000
Operating loss carryforwards, expiration date	Dec. 31, 2034

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Expected income tax benefit at the federal statutory rate	21.00%	21.00%
State taxes, net of federal benefit	5.10%	5.10%
Research and development credit, net	8.20%	10.90%
Non-deductible items and others	(0.20%)	0.10%
Change in valuation allowance	(34.10%)	(37.10%)
Total	0.00%	0.00%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Federal and state net operating loss carryforwards	$ 67,737	$ 60,467
Research and development tax credits	20,513	18,161
Depreciation and amortization	424	439
Reserves and accruals	229	168
Other	381	274
Total deferred tax assets	89,284	79,509
Less: valuation allowance	(89,284)	(79,509)
Deferred tax liability:
Net deferred tax assets and liability	$ 0	$ 0

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Weighted-Average Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share as They Had Anti-Dilutive Effect (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock equivalents excluded from calculation of diluted net loss per share	766,638	555,611
Vaccinex Products, LP Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock equivalents excluded from calculation of diluted net loss per share	1,164,791	1,197,479
VX3 Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock equivalents excluded from calculation of diluted net loss per share	1,318,797	1,318,797

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Maximum employee contribution to plan	100.00%	100.00%

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	Jul. 09, 2020USD ($)$ / sharesshares	Jan. 21, 2020USD ($)$ / sharesshares	Jul. 26, 2019USD ($)$ / sharesshares	Nov. 30, 2017USD ($)TargetAntigen	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)shares
Related Party Transaction [Line Items]
Rent expense incurred under operating lease					$ 169,000	$ 168,000
Revenue					50,000	$ 523,000
Gross proceeds from issuance of common stock					$ 17,000,000
Common stock, shares issued | shares					22,388,027	14,887,999
Dr. Maurice Zauderer
Related Party Transaction [Line Items]
Gross proceeds from issuance of common stock		$ 4,999,999
Common stock, shares issued | shares		982,318
Chief Executive Officer
Related Party Transaction [Line Items]
Gross proceeds from issuance of common stock		$ 499,996
Common stock, shares issued | shares		98,231
Jacob Frieberg
Related Party Transaction [Line Items]
Gross proceeds from issuance of common stock		$ 199,996
Common stock, shares issued | shares		39,292
Stock Purchase Agreement
Related Party Transaction [Line Items]
Sale of stock, transaction date		Jan. 21, 2020	Jul. 26, 2019
Private placement closing date			Jul. 30, 2019
Stock Purchase Agreement | Common Stock
Related Party Transaction [Line Items]
Aggregate number of shares issued | shares		1,468,563	3,382,332
Shares issued, price per share | $ / shares		$ 5.09	$ 4.08
Gross proceeds from issuance of common stock		$ 7,500,000
Proceeds from the sale of shares			$ 13,800,000
July 2020 Stock Purchase Agreement | Friedberg Global-Macro Hedge Fund, Ltd
Related Party Transaction [Line Items]
Sale of stock, transaction date	Jul. 9, 2020
July 2020 Stock Purchase Agreement | Common Stock | Friedberg Global-Macro Hedge Fund, Ltd
Related Party Transaction [Line Items]
Aggregate number of shares issued | shares	1,126,760
Shares issued, price per share | $ / shares	$ 3.55
Gross proceeds from issuance of common stock	$ 4,000,000
Surface Oncology, Inc.
Related Party Transaction [Line Items]
Number of target antigens against which antibodies are to be identified and selected | TargetAntigen				2
Service fee payment received				$ 250,000	$ 0	$ 123,276
Revenue						400,000
Surface Oncology, Inc. | Exclusive Product License Option
Related Party Transaction [Line Items]
Annual maintenance fee					50,000
Revenue						300,000
Surface Oncology, Inc. | Exclusive Research Tool License
Related Party Transaction [Line Items]
Revenue						$ 100,000
Surface Oncology, Inc. | Exclusive Product License
Related Party Transaction [Line Items]
Annual maintenance fee					$ 50,000,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($)	1 Months Ended			3 Months Ended
	Mar. 31, 2021	Feb. 28, 2021	Jan. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2020
Senior Secured Convertible Debenture
Subsequent Event [Line Items]
Payments under mandatory redemption provision						$ 116,329
Senior Secured Convertible Debenture | Principal Repayments
Subsequent Event [Line Items]
Payments under mandatory redemption provision						108,719
Senior Secured Convertible Debenture | Accrued and Make-whole Interest
Subsequent Event [Line Items]
Payments under mandatory redemption provision						$ 7,610
Open Market Sale Agreement
Subsequent Event [Line Items]
Proceeds from the sale of shares				$ 12,300,000	$ 1,200,000
Common Stock | Open Market Sale Agreement
Subsequent Event [Line Items]
Aggregate number of shares issued and sell				3,815,600	317,688
Subsequent Event | Senior Secured Convertible Debenture
Subsequent Event [Line Items]
Payments under mandatory redemption provision		$ 6,372,575,000	$ 6,372,575,000
Subsequent Event | Senior Secured Convertible Debenture | Principal Repayments
Subsequent Event [Line Items]
Payments under mandatory redemption provision		5,955,678,000	5,955,678,000
Subsequent Event | Senior Secured Convertible Debenture | Accrued and Make-whole Interest
Subsequent Event [Line Items]
Payments under mandatory redemption provision		$ 416,897,000	$ 416,897,000
Subsequent Event | Common Stock | VX3 Interests
Subsequent Event [Line Items]
Limited partnership interests exchanged	109,900
Subsequent Event | Common Stock | Open Market Sale Agreement
Subsequent Event [Line Items]
Aggregate number of shares issued and sell		5,415,628	522,272
Shares issued, price per share		$ 5.82	$ 2.58
Proceeds from the sale of shares		$ 30,600,000	$ 1,300,000