NexImmune (NEXI) 10-Q 17 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page	3 Months Ended
	Mar. 31, 2021shares
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2021
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2021
Entity Registrant Name	NexImmune, Inc.
Entity Central Index Key	0001538210
Entity Address, State or Province	MD
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock
Trading Symbol	NEXI
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding	22,579,219

Balance Sheets

Balance Sheets - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 118,102,945	$ 5,031,079
Restricted cash	67,500	67,500
Prepaid expenses and other current assets	4,788,019	3,293,858
Total current assets	122,958,464	8,392,437
Property and equipment, net	3,584,412	2,885,260
Other non-current assets	23,373	23,373
Total assets	126,566,249	11,301,070
Current liabilities:
Accounts payable	2,406,537	2,760,129
Accrued expenses	2,842,998	2,603,027
Derivative liability		1,702,359
Other current liabilities	843,619	843,619
Convertible notes issued to related parties		7,324,267
Convertible notes		11,793,397
Total current liabilities	6,093,154	27,026,798
Deferred rent, net of current portion	11,764	23,529
Other non-current liabilities		4,935
Total liabilities	6,104,918	27,055,262
Commitments and contingencies
Redeemable convertible preferred stock
Total redeemable convertible preferred stock		53,620,749
Stockholders' deficit
Common Stock, $0.0001 par value, 250,000,000 shares authorized, 22,579,219 issued and outstanding as of March 31, 2021 and 1,256,609 shares issued and outstanding as of December 31, 2020.	2,258	126
Additional  paid-in-capital	205,847,571	8,206,938
Accumulated deficit	(85,388,498)	(77,582,005)
Total stockholders' deficit	120,461,331	(69,374,941)
Total liabilities, redeemable convertible preferred stock and stockholders' deficit	$ 126,566,249	11,301,070
Series A Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock
Total redeemable convertible preferred stock		35,047,435
Series A-2 Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock
Total redeemable convertible preferred stock		7,685,865
Series A-3 Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock
Total redeemable convertible preferred stock		$ 10,887,449

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	22,579,219	1,256,609
Common stock, shares outstanding	22,579,219	1,256,609
Series A Redeemable Convertible Preferred Stock
Temporary equity, per share	$ 0.0001	$ 0.0001
Temporary equity, shares authorized		121,735,303
Temporary equity, shares issued		121,735,303
Temporary equity, shares outstanding	0	121,735,303
Temporary equity, liquidation preference		$ 42,314,789
Series A-2 Redeemable Convertible Preferred Stock
Temporary equity, per share	$ 0.0001	$ 0.0001
Temporary equity, shares authorized		28,384,899
Temporary equity, shares issued		22,047,361
Temporary equity, shares outstanding	0	22,047,361
Temporary equity, liquidation preference		$ 8,683,746
Series A-3 Redeemable Convertible Preferred Stock
Temporary equity, per share	$ 0.0001	$ 0.0001
Temporary equity, shares authorized		34,061,879
Temporary equity, shares issued		31,209,734
Temporary equity, shares outstanding	0	31,209,734
Temporary equity, liquidation preference		$ 11,699,176

Statements Of Operations

Statements Of Operations - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 0
Operating expenses:
Research and development	6,012,608	$ 4,272,167
General and administrative	4,057,592	2,088,401
Total operating expenses	10,070,200	6,360,568
Loss from operations	(10,070,200)	(6,360,568)
Other (expense) income:
Interest income	3,613	18,684
Interest expense	(904,119)	(989)
Change in fair value of derivative liabilities	2,424,877
Other income (expense)	(722)	27,365
Other income (expense)	1,523,649	45,060
Net loss	(8,546,551)	(6,315,508)
Accumulated dividends on Redeemable Convertible Preferred Stock	(377,562)	(815,516)
Net loss available to common stockholders'	$ (8,924,113)	$ (7,131,024)
Basic and diluted net loss available to common stockholders per common share	$ (0.71)	$ (5.68)
Basic and diluted weighted-average number of common shares outstanding	12,633,123	1,254,681

Statements Of Comprehensive Los

Statements Of Comprehensive Loss - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (8,546,551)	$ (6,315,508)
Other comprehensive loss:
Unrealized (loss) gain on available-for-sale marketable securities, net of tax		(506)
Comprehensive loss	$ (8,546,551)	$ (6,316,014)

Statements Of Changes In Redeem

Statements Of Changes In Redeemable Convertible Preferred Stock And Stockholders' Deficit - USD ($)	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock	Additional Paid-In Capital	Additional Paid-In CapitalCumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Deficit	Accumulated DeficitCumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Income/ (Loss)	Series A Redeemable Convertible Preferred Stock	Series A-2 Redeemable Convertible Preferred Stock	Series A-3 Redeemable Convertible Preferred Stock
Temporary equity, Balance at Dec. 31, 2019									$ 35,047,435	$ 7,685,865	$ 10,887,449
Temporary equity, Balance, shares at Dec. 31, 2019									121,735,303	22,047,361	31,209,734
Balance at Dec. 31, 2019	$ (43,009,568)		$ 126	$ 4,705,808		$ (47,716,008)		$ 506
Balance, Shares at Dec. 31, 2019			1,254,681
Net loss	(6,315,508)					(6,315,508)
Stock-based compensation	318,962			318,962
Change in unrealized gains on marketable available-for-sale securities	(506)							$ (506)
Balance at Mar. 31, 2020	(49,006,620)		$ 126	5,024,770		(54,031,516)
Balance, Shares at Mar. 31, 2020			1,254,681
Temporary equity, Balance at Mar. 31, 2020									$ 35,047,435	$ 7,685,865	$ 10,887,449
Temporary equity, Balance, shares at Mar. 31, 2020									121,735,303	22,047,361	31,209,734
Temporary equity, Balance at Dec. 31, 2020	53,620,749								$ 35,047,435	$ 7,685,865	$ 10,887,449
Temporary equity, Balance, shares at Dec. 31, 2020									121,735,303	22,047,361	31,209,734
Balance at Dec. 31, 2020	(69,374,941)	$ (1,537,274)	$ 126	8,206,938	$ (2,277,332)	(77,582,005)	$ 740,058
Balance, Shares at Dec. 31, 2020			1,256,609
Issuance of Series A redeemable preferred stock upon exercise of warrants									$ 1,450
Issuance of Series A redeemable preferred stock upon exercise of warrants, shares									145,000
Conversion of preferred stock into common stock, Temporary equity									$ (35,048,885)	$ (7,685,865)	$ (10,887,449)
Conversion of preferred stock into common stock, Temporary equity, shares									(121,880,303)	(22,047,361)	(31,209,734)
Conversion of preferred stock into common stock	53,622,199		$ 1,014	53,621,185
Conversion of preferred stock into common stock, Shares			10,144,052
Conversion of convertible debt into common stock	30,252,056		$ 367	30,251,689
Conversion of convertible debt into common stock, shares			3,669,010
Issuance of common stock in connection with the initial public offering. net of transaction costs	114,551,315		$ 744	114,550,571
Issuance of common stock in connection with the initial public offering. net of transaction costs, Shares			7,441,650
Exercise of stock options	$ 297,083		$ 7	297,076
Exercise of stock options, Shares	65,013		65,013
Exercise of warrants, Shares			2,896
Net loss	$ (8,546,551)					(8,546,551)
Stock-based compensation	1,197,444			1,197,444
Balance at Mar. 31, 2021	$ 120,461,331		$ 2,258	$ 205,847,571		$ (85,388,498)
Balance, Shares at Mar. 31, 2021			22,579,219
Temporary equity, Balance, shares at Mar. 31, 2021									0	0	0

Statements Of Cash Flows

Statements Of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net loss	$ (8,546,551)	$ (6,315,508)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	174,331	143,518
Gain (loss) on asset disposal	(464)	398
Stock-based compensation	1,197,444	318,962
Non-cash interest expense	903,919
Change in fair value of derivative liability	(2,424,877)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(2,446,793)	(929,007)
Accounts payable	(645,847)	(191,877)
Accrued expenses, deferred rent and other	633,307	463,090
Net cash used in operating activities	(11,155,532)	(6,510,424)
Cash flows from investing activities
Purchase of property and equipment	(581,228)	(241,519)
Proceeds from disposal of equipment	464	550
Employee advances		(494)
Proceeds from maturities and sales of available-for-sale marketable securities		999,780
Net cash provided by (used in) investing activities	(580,764)	758,317
Cash flows from financing activities
Proceeds from initial public offering, net of transaction costs	115,503,948
Proceeds from the exercise of stock options	297,083
Proceeds from the exercise of warrants	1,450
Principal payments on capital leases	(5,212)	(4,832)
Proceeds from the issuance of convertible notes from related parties	56,500
Proceeds from the issuance of convertible notes	8,974,980
Issuance costs associated with convertible notes	(20,587)
Net cash provided by (used in) financing activities	124,808,162	(4,832)
Net increase (decrease) in cash, cash equivalents and restricted cash	113,071,866	(4,097,908)
Net cash, cash equivalents and restricted cash at beginning of period	5,098,579	9,196,487
Net cash, cash equivalents and restricted cash at end of period	118,170,445	5,098,579
Supplemental disclosure of cash flow information:
Cash paid during the year for interest	200	1,999
Supplemental disclosure of noncash investing and financing activities:
Property and equipment purchases included in accounts payable and accrued expenses	$ 292,255	$ 7,887

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the business and basis of presentation NexImmune, Inc. (the “Company” or “NexImmune”), a Delaware corporation headquartered in Gaithersburg, Maryland, was incorporated on June 7, 2011. The Company is an emerging biopharmaceutical company advancing a new generation of immunotherapies based on its proprietary Artificial Immune Modulation (AIM) technology. The AIM nanotechnology platform, originally developed at Johns Hopkins University, is the foundation for an innovative approach to immunotherapy in which the body’s own immune system is stimulated to orchestrate a targeted T cell response against a disease. Central to the AIM technology are AIM nanoparticles, which act as synthetic dendritic cells. These AIM nanoparticles can be programmed to present specific antigens and co-stimulatory

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of presentation	2. Basis of Presentation Basis of Presentation The accompanying unaudited financial statements were prepared in accordance with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, they do not include all of the information required by U.S. generally accepted accounting principles (“GAAP”) for complete financial statements. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). These financial statements should be read in conjunction with our audited financial statements and the accompanying notes to our financial statements contained in our Annual Report on Form 10-K In our management’s opinion, the accompanying financial statements contain all adjustments, including normal, recurring adjustments, necessary to fairly present our financial position as of March 31, 2021 and December 31, 2020, and our statements of operations and comprehensive loss, changes in redeemable convertible preferred stock and stockholders’ deficit, and cash flows for the three month periods ended March 31, 2021 and 2020. Interim results are not necessarily indicative of results for an entire year. Recent accounting standards and pronouncements Recently Adopted In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options, and ASC Topic 815, Subtopic – 4, Derivatives and Hedging - Contracts in Entity’s Own Equity 2020-06 2020-06 of million recorded in accumulated deficit, a reduction of additional paid-in capital of $2.2 million and an increase to the carrying value of the convertible notes of $1.5 million on January 1, 2021. Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2019-10 2020-05 right-of-use In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) available-for-sale 2016-13

Cash and Cash Equivalents and R

Cash and Cash Equivalents and Restricted Cash	3 Months Ended
	Mar. 31, 2021
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents and Restricted cash	3. Cash and Cash Equivalents and Restricted cash The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows. March 31, 2021 December 31, 2020 Cash and cash equivalents $ 118,102,945 $ 5,031,079 Restricted cash 67,500 67,500 Total $ 118,170,445 $ 5,098,579 Cash and cash equivalents consist of investment in money market funds with commercial banks and financial institutions. The Company considers all investments in highly liquid financial instruments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash equivalents are stated at amortized cost, plus accrued interest, which approximates fair value. Amounts included in restricted cash represent those required as collateral on corporate credit cards.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair value measurements	4. Fair Value Measurements The Company’s financial instruments include cash and cash equivalents, accounts payable, accrued expenses, convertible notes and derivative liabilities. The fair values of the cash and cash equivalents, accounts payable and accrued expenses approximated their carrying values as of March 31, 2021 and December 31, 2020 due to their short-term maturities. The Convertible Notes as discussed in Note 10 contain embedded derivative features that are required to be bifurcated and remeasured to fair value at each reporting period. The Company accounts for recurring and nonrecurring fair value measurements in accordance with ASC 820, Fair Value Measurements (“ASC 820”). ASC 820 defines fair value, establishes a fair value hierarchy for assets and liabilities measured at fair value, and requires expanded disclosures about fair value measurements. The ASC hierarchy ranks the quality of reliability of inputs, or assumptions, used in the determination of fair value, and requires assets and liabilities carried at fair value to be classified and disclosed in one of the following three categories: Level 1 - Fair value is determined by using unadjusted quoted prices that are available in active markets for identical assets and liabilities. Level 2 - Fair value is determined by using inputs, other than Level 1 quoted prices that are directly and indirectly observable. Inputs can include quoted prices for similar assets and liabilities in active markets or quoted prices for identical assets and liabilities in inactive markets. Related inputs can also include those used in valuation or other pricing models that can be corroborated by observable market data. Level 3 - Fair value is determined by inputs that are unobservable and not corroborated by market data. Use of these inputs involves significant judgments to be made by a reporting entity. In instances where the determination of the fair value measurement is based on inputs from different levels of fair value hierarchy, the fair value measurement will fall within the lowest level input that is significant to the fair value measurement in its entirety. The Company periodically evaluates financial assets and liabilities subject to fair value measurements to determine the appropriate level at which to classify them each reporting period. This determination requires the Company to make judgments as to the significance of inputs used in determining fair value and where such inputs lie within the ASC 820 hierarchy. The Company’s derivative liability related to certain features embedded within the Company’s Convertible Notes as discussed in Note 10. The derivative is accounted for as a liability and remeasured to fair value as of each balance sheet date until the Convertible Note is settled or cancelled. The Convertible Notes were converted into shares of common stock upon the Company’s completion of the Initial Public Offering (“IPO”) on February 11, 2021. The related remeasurement adjustments are recognized in the accompanying statements of operations. During the period ended March 31, 2021 and December 31, 2020 the Company did not have any transfers between levels. There were no Level 3 recurring fair value measurements as of March 31, 2021. The following table presents activity related to the Company’s fair value measurements categorized as Level 3 of the valuation hierarchy, valued on a recurring basis: Balance as of December 31, 2020 $ 1,702,359 Fair value of derivative liabilities issued 722,518 Reduction in (2,424,877 ) Balance as of March 31, 2021 $ — The fair value of the derivative liability was determined using a binomial lattice model by calculating and comparing the fair value of the Convertible Notes with and without the embedded features. Key inputs into this valuation model are ( l) the probability of various events which result in conversion prior to the maturity of the Convertible Notes; (2) the estimated timing of conversion; (3) time period to maturity; (4) the fair value of the Company’s stock underlying the Convertible Notes within each scenario; (5) the expected volatility of the Company’s stock through the various events resulting in conversion; (6) the risk-adjusted discount rate; and (7) the Company’s stock dividend yield. The recurring Level 3 fair value measurements of the embedded features of the Convertible Notes issued in January 2021 include the following significant unobservable inputs: Unobservable Input Assumptions Probabilities of conversion provisions 5%-50% Estimated timing of conversion (years) 0.13-0.31 Time period to maturity (years) 0.31 Fair value of the Company’s stock $0.45-$0.56 Stock price volatility 76-90% Risk-adjusted discount rate 25.56% Dividend yield 0% Significant changes to these assumptions would result in increases or decreases to the fair value of the derivative liability. There were no Convertible Notes issued after January 2021. Immediately before the conversion of the Convertible Notes on February 11, 2021, the derivative liability was remeasured to fair value which the Company concluded was immaterial. The derivative liability was remeasured to All derivative instruments were eliminated following the conversion of the Convertible Notes on February 11, 2021.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	3 Months Ended
	Mar. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses and other current assets	5. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following at March 31, 2021 and December 31, 2020: March 31, 2021 December 31, Prepaid research and development expenses $ 1,922,643 $ 1,894,785 Prepaid maintenance agreements 113,059 144,575 Prepaid insurance 2,608,493 98,421 Prepaid other 143,824 124,929 Deferred financing costs — 952,633 Other current assets — 78,515 $ 4,788,019 $ 3,293,858

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Property and equipment	6. Property and Equipment Property and equipment consist of the following at March 31, 2021 and December 31, 2020: March 31, 2021 December 31, Laboratory equipment $ 4,631,962 $ 3,801,545 Computer equipment and software 336,524 305,214 Furniture and fixtures 47,877 47,877 Leasehold improvements 167,972 153,965 5,184,335 4,308,601 Less accumulated depreciation and amortization (1,599,923 ) (1,423,341 ) Property and equipment, net $ 3,584,412 $ 2,885,260 Depreciation and amortization expense was $174,331 and $141,178 for the three months ended March 31, 2021 and 2020, respectively.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
Accrued expenses	7. Accrued Expenses A summary of the components of accrued expenses is as follows as of March 31, 2021 and December 31, 2020: March 31, 202 1 December 31, 2020 Accrued professional fees $ 135,033 $ 135,033 Accrued salaries, benefits and related expenses 2,567,071 1,924,405 Accrued severance — 26,724 Accrued interest 3,491 408,315 Other accrued expenses 137,403 108,550 $ 2,842,998 $ 2,603,027

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	8. Commitments and Contingencies Maryland Biotechnology Center Grant The Company entered into a Translational Research Award Agreement effective May 23, 2012 with the Department of Business & Economic Development with the State of Maryland, Maryland Biotechnology Center (“MBC”). The mission of MBC is to integrate entrepreneurial strategies to stimulate the transformation of scientific discovery and intellectual assets into capital formation and business development. Under the agreement, MBC provided $200,000 to NexImmune for research on its artificial aAPC for cancer immunotherapy. In 2013, an amendment increased the amount by $125,000 for a total grant of $325,000. This grant was recorded as income in 2012 and 2013, as the Company incurred the expenses which qualified it for the grant. The Company must repay the funds through annual payments calculated at 3% of annual revenues for the preceding year. Payments shall continue for 10 years after the first payment date and may total up to 200% of the total grant amount. The end date of the agreement is defined as January 31, 2024, or when any and all repayments due to MBC have been made. If the Company does not earn any revenue, the grant does not need to be repaid. Through March 31, 2021, no revenue has been recorded, therefore, no payments to MBC are due. Johns Hopkins University Exclusive License Agreement The Company entered into an Exclusive License Agreement with Johns Hopkins University (“JHU”) effective June 2011, which was amended and restated in January 2017, under which there are license fees, royalties, and milestone payments. As part of the agreement, the Company acquired a perpetual, exclusive license from JHU covering its invention related to Antigen Specific T cells. In consideration for the Exclusive License Agreement, the Company made an upfront payment of $155,000 and issued 26,918 shares of Common Stock. JHU was also entitled to milestone fees of $75,000 in connection with clinical trial milestones. For the first licensed product or licensed service in the therapeutic field, the Company may be required to pay JHU additional aggregate milestone fees of $1.6 million for clinical and regulatory milestone fees. The Company may be required to pay JHU reduced milestone fees for the second and third licensed products or licensed services in the therapeutic field in connection with clinical and regulatory milestones. In the diagnostic field, the Company may be required to pay JHU aggregate milestone fees of $400,000 for the first licensed product or licensed service and reduced milestone fees for the second and third licensed products or licensed services in connection with regulatory and commercial milestones. The Company may be required to pay JHU aggregate milestone fees of $100,000 for commercial milestones for the first licensed product or licensed service in the non-clinical non-clinical mid-single non-clinical JHU under the A&R JHU License Agreement through the term of the agreement. The Company may also be required to pay JHU a low double digit percentage of any non-royalty The Company will record a liability when such events become probable. The Company has not reached any of the milestones or transacted its first commercial sale as of March 31, 2021. The Company must make minimum royalty payments, which began upon the 4th anniversary of the agreement and upon every anniversary thereafter during the term of the agreement, which offset future royalties per above owed to JHU. The Company has incurred $350,000 in cumulative minimum royalties from inception. Future annual minimum royalties consist of $100,000 due each year during the remaining term of the agreement. The Company records milestones, royalties and minimum royalties at the time when payments become probable. During the three months ended March 31, 2021 and 2020, the Company incurred $25,000 each quarter, related to minimum royalties owed, included in research and development expenses on the accompanying statement of operations. The Company has accrued royalties of $75,000 as of March 31, 2021 and 2020. Paycheck Protection Program Loan On April 23, 2020, the Company applied for an unsecured $843,619 loan under the Paycheck Protection Program (the “PPP Loan”). The Paycheck Protection Program (or “PPP”) was established under the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) and is administered by the U.S. Small Business Administration (“SBA”). On May 1, 2020, the PPP loan was approved and funded. The Company entered into a promissory note of $843,619, which is recorded within other current liabilities in the accompanying balance sheet. The Company treats the PPP loan as debt under ASC 470. The use of loan proceeds must be for payroll costs, payment of interest on covered mortgage obligations, rent and utility costs over either an eight-week or 24-week The PPP Loan has a maturity date of April 23, 2022 and accrues interest at an annual rate of 0.98%. Interest and principal payments are deferred for the first six months of the loan. Thereafter, monthly interest and principal payments are due until the loan is fully satisfied. The promissory note evidencing the PPP Loan contains customary events of default resulting from, among other things, default in the payments. The PPP Loan indebtedness may be forgiven in whole or in part upon request and the Company must provide documentation in accordance with the SBA requirements and the Company must certify that the amounts requested to be forgiven qualify under those requirements. The SBA may approve or deny the Company’s loan forgiveness application, in whole or part. The amount of potential loan forgiveness may be reduced if NexImmune fails to maintain employee and salary levels during the applicable eight-week or 24-week Contingencies From time to time, the Company may be subject to various litigation and related matters arising 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. As of March 31, 2021 and December 31, 2020, the Company was not

Convertible Notes

Convertible Notes	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Convertible notes	9. Convertible Notes During April 2020, the Company authorized the sale of up to $15,000,000 6% Convertible Notes (“Agreement”). The Agreement specified an initial closing date of April 23, 2020 and allowed additional closings within 90 days of the initial closing. The Convertible Notes had a scheduled maturity date of April 23, 2021. The terms of the Convertible Notes required a mandatory conversion upon certain qualified financing events (“Mandatory Conversion”) and allowed for conversion at the option of the holder upon certain non-qualified If the Mandatory Conversion and Optional Conversion 1 did not occur by the maturity date, the outstanding principal amount plus all accrued and unpaid interest would be converted at the option of the holder into Company’s common stock at the price per share obtained by dividing $85 million by the Company’s fully-diluted capitalization (“Optional Conversion 2”). If the Company (i) consummates a change in control or (ii) the Company’s common stock becomes publicly listed on a stock exchange, the outstanding principal amount plus all accrued and unpaid interest would automatically convert into shares of the Company’s most senior series of capital stock outstanding at the time of such change in control or public listing, at a price equal to the lower of (a) 90% of the price per share paid by the purchasers of such stock in such a transaction and (b) the price per share obtained by dividing $125 million by the Company’s fully-diluted capitalization (“Change in Control”). The Agreement was amended in July 2020 to allow the sale of up to $50,000,000 convertible notes and to allow for additional closings within 150 days of the initial closing date. The Agreement was amended in September 2020 to allow for additional closings within 190 days of the initial closing date. In addition, the provisions of Mandatory Conversion and Optional Conversion 1 were amended to allow for conversion upon an equity financing at a price equal to the lower of (a) 80% of the price per share paid by the purchasers of such stock in such a transaction and (b) the price per share obtained by dividing $125,000,000 by the Company’s fully-diluted capitalization. The Company evaluated the amendments and concluded that the amendments represented a debt modification. In October 2020, the Agreement was further amended to allow additional closings through December 31, 2020, and in January 2021 it was amended again to allow closings through January 31, 2021. In January 2021, the Company issued convertible notes with a principal amount of The Company evaluated the Convertible Notes and determined that the Mandatory Conversion feature, Optional Conversion 1 feature and Change in Control meet the definition of an embedded derivative liability that is required to be bifurcated from the host instrument and measured at fair value. The fair value of the derivative liability for the convertible notes issued in January 2021 was $722,518. The Company amortized the debt issuance costs of $256,212 and the debt discount from of the initial value of the derivative liability of . The Company completed an IPO on February 11, 2021 which triggered the mandatory conversion of all the outstanding Convertible Notes principal plus accrued interest into shares of common stock (Note 10). Upon conversion of the Convertible Notes, the outstanding Convertible Notes principal plus accrued interest thereon, net of unamortized debt discounts totaling $30,252,056 was derecognized into stockholders’ deficit.

Series A Redeemable Convertible

Series A Redeemable Convertible Preferred Stock and Stockholders' Deficit	3 Months Ended
	Mar. 31, 2021
Redeemable Convertible Preferred Stock And Stockholders Equity Disclosure [Abstract]
Series A Redeemable Convertible Preferred Stock and Stockholders' Deficit	10. Series A Redeemable Convertible Preferred Stock and Stockholders’ Deficit Issuances of Common Stock On February 11, 2021, the Company completed its IPO, pursuant to which it issued and sold 7,441,650 shares of its common stock at a public offering price of $17.00 per share, resulting in net proceeds of $115,191,259, after deducting underwriting discounts and commissions and other offering expenses. Upon the closing of the IPO, all of the 175,137,398 outstanding shares of the Company’s Redeemable Convertible Preferred Stock automatically converted into 10,144,052 shares of common stock after giving effect to the reverse stock split, and all of the outstanding Convertible Notes principal and accrued but unpaid interest thereon of $31,272,224 converted to 3,669,010 shares of common stock . Upon completion of the offering on February 11, 2021, the Company’s authorized capital stock consists of 250,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of preferred stock, par value $0.0001 per share, all of which shares of preferred stock are undesignated. In January 2021, 145,000 warrants were exercised at an exercise price of $0.01 and 145,000 shares of Series A redeemable convertible stock were issued and then converted into common stock upon the closing of the IPO. The remaining outstanding warrants outstanding as of December 31, 2020 were exercised and settled in January 2021 with 2,896 shares of common stock issued in a cashless exercise.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-based compensation	11. Stock-Based Compensation During January 2017, the Company adopted the 2017 Equity Incentive Plan (the “2017 Plan”), which provides for granting of restricted stock, options to purchase shares of common stock and other awards to employees, directors and consultants. In March 2017, the Company amended the 2017 Plan to increase the number of available shares to 660,838 The number of options to be granted under the 2021 Plan, the option exercise prices, and other terms of the options are determined by the Board of Directors in accordance with the terms of the 202 1 Plan. Generally , stock options are granted at fair value, become exercisable over a period of one to four years, expire in ten years or less and are subject to the employee’s continued employment Stock-based compensation expense was recorded in the following financial statement line items within the statement of operations for the years ended March 31, 2021 and 2020: 2021 2020 Research and development expenses $ 204,330 $ 82,743 General and administrative expenses 993,114 236,219 Total stock-based compensation expense $ 1,197,444 $ 318,962 The following is a summary of option activity under the Company’s Stock Option Plans: Stock Weighted Weighted Aggregate Outstanding as of January 1, 2021 2,233,185 $ 3.52 Granted 1,170,891 17.00 Exercised (65,013 ) 4.56 Cancelled (772 ) 4.31 Forfeited (192,243 ) 4.83 Outstanding as of March 31, 2021 3,146,048 $ 8.44 7.98 $ 33.5 Vested or expected to vest as of March 31, 2021 3,146,048 $ 8.44 7.98 $ 33.5 Exercisable as of March 31, 2021 1,730,292 $ 3.18 6.64 $ 27.5 Shares unvested as of March 31, 2021 1,415,786 $ 14.86 9.63 $ 6.0 The weighted average fair value of the options granted during the three months ended March 31, 2021 and 2020 was $11.64 and $4.04, respectively. The options were valued using the Black-Scholes option-pricing model for the three months ended March 31, 2021 and 2020 with the following assumptions: 2021 2020 Expected volatility 79.8 % 100% Risk-free interest rate 0.6 % to 0.7 % to Expected dividend yield 0% 0% Expected term 5.5 to 5.3 to The total fair value of stock options vested during the three months ended March 31, 2021 and 2020 was approximately $0.8 million, and $0.4 million, respectively. The intrinsic value of stock options exercised for the three months ended March 31, 2021 and 2020 was approximately $232,268 and $0, respectively. As of March 31, 2021, there was $15.3 million of total unrecognized compensation expense related to unvested options that will be recognized over a weighted average period of 3.38 years.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	12. Net Loss Per Share Attributable to Common Stockholders Basic net loss per common share is determined by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents. Diluted net loss per share is computed by dividing net loss attributable to common stockholders by the weighted-average number of common stock and common stock equivalents outstanding for the period. The Company adjusts net loss to arrive at the net loss attributable to common stockholders to reflect the amount of dividends accumulated during the period on the Company’s redeemable convertible preferred stock. Such dividends are only payable if and when declared by the Board of Directors. The treasury stock method is used to determine the dilutive effect of the Company’s stock option grants and warrants and the if-converted method is used to determine the dilutive effect of the Company’s redeemable convertible preferred stock and Convertible Notes. For the three months ended March 31, 2021 and 2020, the Company had a net loss attributable to common stockholders, and as such, all outstanding stock options and shares of redeemable convertible preferred stock were excluded from the calculation of diluted loss per share. Under the if converted method, convertible instruments that are in the money, are assumed to have been converted as of the beginning of the period or when issued, if later. Additionally, the effects of any interest expense and changes in fair value of bifurcated derivatives is added back to the numerator of the diluted net loss per share calculation if the conversion of the Convertible Notes is dilutive. The following table sets forth the computation of basic and diluted earnings per share for the three months ended March 31, 2021 and 2020: March 31, 2021 March 31, 2020 Net loss $ (8,332,414 ) $ (6,315,508 ) Accumulated dividends on Redeemable Convertible Preferred Stock (377,562 ) (815,516 ) Net loss attributable to common stockholders $ (8709,976 ) $ (7,131,024 ) Basic and diluted net loss per common share $ (0.80 ) $ (5.68 ) Basic and diluted weighted average common shares outstanding 12,633,123 1,254,681 The following potentially dilutive securities outstanding at March 31, 2021 and 2020 have been excluded from the computation of diluted weighted average common shares outstanding, as the effect would be anti-dilutive: March 31, 2021 March 31, 2020 Stock options 3,146,048 2,242,145 Redeemable convertible preferred stock — 10,135,735 Convertible debt — — Warrants — 14,480 Total 3,146,048 14,374,460 Shares of redeemable convertible preferred stock also participate in dividends with shares of common stock (if and when declared) and therefore are deemed participating securities. The holders of redeemable convertible preferred stock do not contractually share in losses and therefore no additional net loss per share has been disclosed under the two-class

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes The Company has not recorded any tax provision or benefit for the three months ended March 31, 2021. The Company has provided a valuation allowance for the full amount of its net deferred tax assets since realization of any future benefit from deductible temporary differences, net operating loss carryforwards, and research and development credits is not more-likely-than-not The Company has not recorded any accruals related to uncertain tax positions as of March 31, 2021 and December 31, 2020. We file U.S. and state income tax returns in jurisdictions with varying statutes of limitations. The 2016 through 2019 tax years remain subject to examination by federal and state tax authorities.

Employee Benefit Plan

Employee Benefit Plan	3 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
Employee Benefit Plan	14. Employee Benefit Plan The Company has a defined contribution plan under the Internal Revenue Code Section 401(k). The plan covers all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited financial statements were prepared in accordance with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, they do not include all of the information required by U.S. generally accepted accounting principles (“GAAP”) for complete financial statements. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). These financial statements should be read in conjunction with our audited financial statements and the accompanying notes to our financial statements contained in our Annual Report on Form 10-K In our management’s opinion, the accompanying financial statements contain all adjustments, including normal, recurring adjustments, necessary to fairly present our financial position as of March 31, 2021 and December 31, 2020, and our statements of operations and comprehensive loss, changes in redeemable convertible preferred stock and stockholders’ deficit, and cash flows for the three month periods ended March 31, 2021 and 2020. Interim results are not necessarily indicative of results for an entire year.
Recent accounting standards and pronouncements	Recent accounting standards and pronouncements Recently Adopted In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options, and ASC Topic 815, Subtopic – 4, Derivatives and Hedging - Contracts in Entity’s Own Equity 2020-06 2020-06 of million recorded in accumulated deficit, a reduction of additional paid-in capital of $2.2 million and an increase to the carrying value of the convertible notes of $1.5 million on January 1, 2021. Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2019-10 2020-05 right-of-use In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) available-for-sale 2016-13

Cash and Cash Equivalents and_2

Cash and Cash Equivalents and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2021
Cash and Cash Equivalents [Abstract]
Summary of reconciliation of cash, cash equivalents, and restricted cash	The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows. March 31, 2021 December 31, 2020 Cash and cash equivalents $ 118,102,945 $ 5,031,079 Restricted cash 67,500 67,500 Total $ 118,170,445 $ 5,098,579

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Summary of fair value measurements categorized as Level 3	The following table presents activity related to the Company’s fair value measurements categorized as Level 3 of the valuation hierarchy, valued on a recurring basis: Balance as of December 31, 2020 $ 1,702,359 Fair value of derivative liabilities issued 722,518 Reduction in (2,424,877 ) Balance as of March 31, 2021 $ —
Summary of fair value measurements of the convertible notes	The recurring Level 3 fair value measurements of the embedded features of the Convertible Notes issued in January 2021 include the following significant unobservable inputs: Unobservable Input Assumptions Probabilities of conversion provisions 5%-50% Estimated timing of conversion (years) 0.13-0.31 Time period to maturity (years) 0.31 Fair value of the Company’s stock $0.45-$0.56 Stock price volatility 76-90% Risk-adjusted discount rate 25.56% Dividend yield 0%

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	3 Months Ended
	Mar. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following at March 31, 2021 and December 31, 2020: March 31, 2021 December 31, Prepaid research and development expenses $ 1,922,643 $ 1,894,785 Prepaid maintenance agreements 113,059 144,575 Prepaid insurance 2,608,493 98,421 Prepaid other 143,824 124,929 Deferred financing costs — 952,633 Other current assets — 78,515 $ 4,788,019 $ 3,293,858

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Summary of property and equipment	Property and equipment consist of the following at March 31, 2021 and December 31, 2020: March 31, 2021 December 31, Laboratory equipment $ 4,631,962 $ 3,801,545 Computer equipment and software 336,524 305,214 Furniture and fixtures 47,877 47,877 Leasehold improvements 167,972 153,965 5,184,335 4,308,601 Less accumulated depreciation and amortization (1,599,923 ) (1,423,341 ) Property and equipment, net $ 3,584,412 $ 2,885,260

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
Summary of the components of accrued expenses	A summary of the components of accrued expenses is as follows as of March 31, 2021 and December 31, 2020: March 31, 202 1 December 31, 2020 Accrued professional fees $ 135,033 $ 135,033 Accrued salaries, benefits and related expenses 2,567,071 1,924,405 Accrued severance — 26,724 Accrued interest 3,491 408,315 Other accrued expenses 137,403 108,550 $ 2,842,998 $ 2,603,027

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of stock-based compensation expense	Stock-based compensation expense was recorded in the following financial statement line items within the statement of operations for the years ended March 31, 2021 and 2020: 2021 2020 Research and development expenses $ 204,330 $ 82,743 General and administrative expenses 993,114 236,219 Total stock-based compensation expense $ 1,197,444 $ 318,962
Summary of option activity	The following is a summary of option activity under the Company’s Stock Option Plans: Stock Weighted Weighted Aggregate Outstanding as of January 1, 2021 2,233,185 $ 3.52 Granted 1,170,891 17.00 Exercised (65,013 ) 4.56 Cancelled (772 ) 4.31 Forfeited (192,243 ) 4.83 Outstanding as of March 31, 2021 3,146,048 $ 8.44 7.98 $ 33.5 Vested or expected to vest as of March 31, 2021 3,146,048 $ 8.44 7.98 $ 33.5 Exercisable as of March 31, 2021 1,730,292 $ 3.18 6.64 $ 27.5 Shares unvested as of March 31, 2021 1,415,786 $ 14.86 9.63 $ 6.0
Summary of black-scholes option pricing model	The options were valued using the Black-Scholes option-pricing model for the three months ended March 31, 2021 and 2020 with the following assumptions: 2021 2020 Expected volatility 79.8 % 100% Risk-free interest rate 0.6 % to 0.7 % to Expected dividend yield 0% 0% Expected term 5.5 to 5.3 to

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Summary of basic and diluted earnings per share	The following table sets forth the computation of basic and diluted earnings per share for the three months ended March 31, 2021 and 2020: March 31, 2021 March 31, 2020 Net loss $ (8,332,414 ) $ (6,315,508 ) Accumulated dividends on Redeemable Convertible Preferred Stock (377,562 ) (815,516 ) Net loss attributable to common stockholders $ (8709,976 ) $ (7,131,024 ) Basic and diluted net loss per common share $ (0.80 ) $ (5.68 ) Basic and diluted weighted average common shares outstanding 12,633,123 1,254,681
Summary of antidilutive securities outstanding	The following potentially dilutive securities outstanding at March 31, 2021 and 2020 have been excluded from the computation of diluted weighted average common shares outstanding, as the effect would be anti-dilutive: March 31, 2021 March 31, 2020 Stock options 3,146,048 2,242,145 Redeemable convertible preferred stock — 10,135,735 Convertible debt — — Warrants — 14,480 Total 3,146,048 14,374,460

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Entity Incorporation date	Jun. 7, 2011

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) - USD ($)	Mar. 31, 2021	Jan. 01, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transition adjustment recorded in accumulated deficit	$ 120,461,331		$ (69,374,941)	$ (49,006,620)	$ (43,009,568)
Convertible notes			11,793,397
Cumulative Effect, Period of Adoption, Adjustment [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transition adjustment recorded in accumulated deficit			(1,537,274)
Convertible notes		$ 1,500,000
Retained Earnings [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transition adjustment recorded in accumulated deficit	(85,388,498)		(77,582,005)	(54,031,516)	(47,716,008)
Retained Earnings [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transition adjustment recorded in accumulated deficit		700,000	740,058
Additional Paid-in Capital [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transition adjustment recorded in accumulated deficit	$ 205,847,571		8,206,938	$ 5,024,770	$ 4,705,808
Additional Paid-in Capital [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transition adjustment recorded in accumulated deficit		$ 2,200,000	$ (2,277,332)

Cash and Cash Equivalents and_3

Cash and Cash Equivalents and Restricted Cash - Summary of Reconciliation of Cash, Cash Equivalents And Restricted Cash (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 118,102,945	$ 5,031,079
Restricted cash	67,500	67,500
Total	$ 118,170,445	$ 5,098,579	$ 5,098,579	$ 9,196,487

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value Measurements Categorized As Level 3 (Detail) - Embedded Derivative Financial Instruments - Fair Value, Recurring	3 Months Ended
	Mar. 31, 2021USD ($)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 1,702,359
Fair value of derivative liabilities issued	722,518
Reduction in expense related to fair value changes in derivative liabilities	(2,424,877)
Ending balance	$ 0

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Fair Value Measurements of the Convertible Notes (Detail) - Embedded Derivative Financial Instruments - Level 3	Jan. 01, 2021yr
Probabilities of conversion provisions | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	5,000
Probabilities of conversion provisions | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	500
Estimated timing of conversion | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	0.31
Estimated timing of conversion | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	0.13
Time period to maturity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	0.31
Fair value of the Company's stock | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	0.56
Fair value of the Company's stock | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	0.45
Stock price volatility | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	9,000
Stock price volatility | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	7,600
Risk-adjusted discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	2,556
Dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Input	0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail)	Mar. 31, 2021USD ($)
Fair Value Disclosures [Abstract]
Derivative liability	$ 0

Prepaid Expenses And Other Cu_3

Prepaid Expenses And Other Current Assets - Summary of Prepaid Expenses And Other Current Assets (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid research and development expenses	$ 1,922,643	$ 1,894,785
Prepaid maintenance agreements	113,059	144,575
Prepaid insurance	2,608,493	98,421
Prepaid other	143,824	124,929
Deferred financing costs		952,633
Other current assets		78,515
Prepaid expenses and other current assets	$ 4,788,019	$ 3,293,858

Property and Equipment - Summar

Property and Equipment - Summary of Property And Equipment (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$ 5,184,335	$ 4,308,601
Less accumulated depreciation and amortization	(1,599,923)	(1,423,341)
Property and equipment, net	3,584,412	2,885,260
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	4,631,962	3,801,545
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	336,524	305,214
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	47,877	47,877
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment gross	$ 167,972	$ 153,965

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 174,331	$ 141,178

Accrued Expenses - Summary of C

Accrued Expenses - Summary of Components of Accrued Expenses (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued professional fees	$ 135,033	$ 135,033
Accrued salaries, benefits and related expenses	2,567,071	1,924,405
Accrued severance		26,724
Accrued interest	3,491	408,315
Other accrued expenses	137,403	108,550
Accrued expenses	$ 2,842,998	$ 2,603,027

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Jan. 01, 2017	May 23, 2013	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Apr. 23, 2020	May 23, 2012
Research and development arrangement contract to perform for others compensation earned		$ 125,000
Accrued royalties			$ 75,000	$ 75,000
Loss contingency accrual			$ 0		$ 0
Other Current Liabilities [Member]
Notes payable, current						$ 843,619
Paycheck Protection Program Loan [Member]
Debt instrument, face amount						$ 843,619
Debt instrument, maturity date			Apr. 23, 2022
Debt instrument, interest rate			0.98%
Research and development expenses [Member] | Minimum [Member]
Royalty expense			$ 25,000	$ 25,000
Maryland Biotechnology Center [Member] | Translational Research Award Agreement [Member]
Research and development arrangement contract to perform for others liability		$ 325,000	0				$ 200,000
Research and development arrangement annual payment percentage		3.00%
Research and development arrangement contractual payment period		10 years
Research and development arrangement contractual payment percentage		200.00%
Revenue from contract with customer, including assessed tax			0
Johns Hopkins University [Member] | Exclusive License Agreement [Member]
Upfront payment	$ 155,000
Stock issued during period, shares, issued for services	26,918
Milestone fees	$ 4,200,000
Minimum annual royalty payments			100,000
Cumulative minimum royalties			$ 350,000
Johns Hopkins University [Member] | Exclusive License Agreement [Member] | Clinical Trial Milestones [Member]
Milestone fees	75,000
Johns Hopkins University [Member] | Exclusive License Agreement [Member] | Therapeutic Field [Member]
Milestone fees	1,600,000
Johns Hopkins University [Member] | Exclusive License Agreement [Member] | Regulatory and Commercial Milestones [Member]
Milestone fees	400,000
Johns Hopkins University [Member] | Exclusive License Agreement [Member] | Non-clinical field [Member]
Milestone fees	$ 100,000

Convertible Notes - Additional

Convertible Notes - Additional Information (Detail) - USD ($)	Feb. 11, 2021	Sep. 30, 2020	Jul. 31, 2020	Apr. 30, 2020	Mar. 31, 2021	Jan. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Amortization of debt issuance costs					$ 256,212
Derivative liability					0
Amortization of debt issuance costs and discounts					$ 613,770
Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount				$ 15,000,000		$ 9,031,480
Debt instrument, interest rate				6.00%	6.00%
Debt instrument, additional closing lock in period		190 days	150 days	90 days
Debt instrument, maturity date					Apr. 23, 2021
Debt instrument, convertible, price percentage					80.00%
Debt instrument fully diluted capitalization					$ 85,000,000
Debt instrument, redemption price, percentage of principal amount redeemed					90.00%
Debt instrument, redemption amount			$ 50,000,000		$ 125,000,000
Derivative liability					1,982,594
Interest expense					$ 217,593
Fair value of derivative liability of convertible notes							$ 722,518
Debt conversion converted instrument net of amortization of debt discounts derecognized Into equity	$ 30,252,056
Debt instrument effective interest rate during the period					25.00%
Debt instrument unamortized debt issuance costs								$ 116,636
Debt instrument unamortized debt discount								$ 2,383,986

Series A Redeemable Convertib_2

Series A Redeemable Convertible Preferred Stock and Stockholders' Deficit - Additional Information (Detail) - USD ($)	Feb. 11, 2021	Jan. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Proceeds From Issuance Of IPO			$ 115,503,948
Common stock, shares authorized	250,000,000		250,000,000	250,000,000
Common stock, par value	$ 0.0001		$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	10,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.0001
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		2,896
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.01
Convertible Debt
Class of Stock [Line Items]
Debt conversion, converted instrument, amount	$ 31,272,224
Debt conversion, converted instrument, shares issued	3,669,010
Common Class A | IPO
Class of Stock [Line Items]
Stock issued during period shares	7,441,650
Shares issued price per share	$ 17
Proceeds From Issuance Of IPO	$ 115,191,259
Redeemable convertible preferred stock
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	175,137,398
Convertible Preferred Stock, Shares Issued upon Conversion	10,144,052
Series A Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Convertible Preferred Stock, Shares Issued upon Conversion			145,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		145,000
Temporary Equity Stock Issued During Period Shares New Issues		145,000	145,000

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2018	Jun. 01, 2018	Mar. 01, 2017
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share based compensation shares reserved	2,757,556		1,741,770
Share based compensation shares available for issuance	1,586,365
Share based compensation weighted average fair value of the options granted	$ 11.64	$ 4.04
Share based compensation fair value of stock options vested	$ 800,000	$ 400,000
Share based compensation intrinsic value of stock options exercised	232,268	$ 0
Stock options unrecognized compensation expense	$ 15.3
Stock options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock options unrecognized compensation expense period for recognition	3 years 4 months 17 days
The 2017 Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share based compensation shares reserved					660,838
The 2018 Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share based compensation shares reserved				1,809,143
The 2021 Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share based payment award expiration period	10 years
The 2021 Plan | Minimum [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share based payment award vesting period	1 year
The 2021 Plan | Maximum [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share based payment award vesting period	4 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Based Compensation Expense (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 1,197,444	$ 318,962
Research and development expenses [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	204,330	82,743
General and administrative expenses [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 993,114	$ 236,219

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Option Activity (Detail) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
Share-based Payment Arrangement [Abstract]
Stock options beginning balance | shares	2,233,185
Stock options granted | shares	1,170,891
Stock options exercised | shares	(65,013)
Stock options cancelled | shares	(772)
Stock options forfeited | shares	(192,243)
Stock options ending balance | shares	3,146,048
Stock options vested or expected to vest | shares	3,146,048
Stock options exercisable | shares	1,730,292
Stock options shares unvested | shares	1,415,786
Weighted average exercise price beginning balance | $ / shares	$ 3.52
Weighted average exercise price granted | $ / shares	17
Weighted average exercise price exercised | $ / shares	4.56
Weighted average exercise price cancelled | $ / shares	4.31
Weighted average exercise price forfeited | $ / shares	4.83
Weighted average exercise price ending balance | $ / shares	8.44
Weighted average exercise price vested or expected to vest | $ / shares	8.44
Weighted average exercise price exercisable | $ / shares	3.18
Weighted average exercise price unvested | $ / shares	$ 14.86
Weighted average remaining contractual term	7 years 11 months 23 days
Weighted average remaining contractual term vested or expected to vest	7 years 11 months 23 days
Weighted average remaining contractual term exercisable	6 years 7 months 20 days
Weighted average remaining contractual term unvested	9 years 7 months 17 days
Aggregate intrinsic value | $	$ 33.5
Aggregate intrinsic value vested or expected to vest | $	33.5
Aggregate intrinsic value exercisable | $	27.5
Aggregate intrinsic value unvested | $	$ 6

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Black-Scholes Option Pricing Model (Detail)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected volatility	79.80%
Expected volatility	81.00%
Expected volatility		100.00%
Risk-free interest rate	0.60%	0.70%
Risk-free interest rate	0.70%	0.74%
Expected dividend yield	0.00%	0.00%
Minimum [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term	5 years 6 months	5 years 3 months 18 days
Maximum [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term	6 years	6 years

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Summary of Basic and Diluted Earnings Per Share (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net loss	$ (8,546,551)	$ (6,315,508)
Accumulated dividends on Redeemable Convertible Preferred Stock	(377,562)	(815,516)
Net loss available to common stockholders'	$ (8,924,113)	$ (7,131,024)
Basic and diluted net loss per common share	$ (0.71)	$ (5.68)
Basic and diluted weighted average common shares outstanding	12,633,123	1,254,681

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders - Summary of Antidilutive Securities Outstanding (Detail) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average common shares outstanding	9,939,688	14,374,460
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average common shares outstanding	3,146,048	2,242,145
Redeemable convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average common shares outstanding	4,733,929	10,135,735
Convertible debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average common shares outstanding	2,059,100	0
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average common shares outstanding	611	14,480

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Effective tax rate	0.00%	0.00%
Uncertain tax positions	$ 0

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Retirement Benefits [Abstract]
Employer discretionary contribution amount	$ 40,233	$ 32,749