NRx Pharmaceuticals (NRXP) S-1 25 Jun 21 IPO registration Financial data

Cover

Cover	3 Months Ended
	Mar. 31, 2021
Cover [Abstract]
Document Type	S-1
Amendment Flag	false
Entity Registrant Name	NRX Pharmaceuticals, Inc.
Entity Central Index Key	0001719406
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash	$ 13,271,579	$ 1,858,513	$ 877,421
Account receivable, net of allowance of $3,676,826 and $257,463 as of March 31, 2021 and December 31, 2020, respectively		831,390
Prepaid expenses and other current assets	290,090	240,352	97,585
Total current assets	13,561,669	2,930,255	975,006
Other assets	10,438	10,914	10,930
Total assets	13,572,107	2,941,169	985,936
Current liabilities:
Accounts payable (includes $190,102, $149,067 and $92,744 due to related parties, respectively)	4,382,711	3,153,310	2,073,402
Accrued settlement expense		39,486,139
Accrued clinical site costs	956,833	1,547,432
Accrued and other current liabilities	1,160,907	1,728,483	9,649
Dividends payable	7,589	7,589	7,589
Convertible notes payable and accrued interest			130,251
Notes payable and accrued interest	171,134	248,861	154,190
Total current liabilities	6,679,174	46,171,814	2,375,081
Notes payable and accrued interest	509,925	547,827
Convertible notes payable and accrued interest			3,461,805
Total liabilities	7,189,099	46,719,641	5,836,886
Stockholders' equity (deficit):
Common stock, $0.001 par value, 20,000,000, 20,000,000 and 14,060,001 shares authorized; 11,806,580, 11,227,676 and 10,686,191 shares issued and outstanding at March 31, 2021, December 31, 2020 and 2019, respectively	11,807	11,228	10,686
Additional paid-incapital	122,037,424	46,387,649	33,538,813
Accumulated deficit	(115,668,594)	(90,179,720)	(38,402,816)
Total stockholders' equity (deficit)	6,383,008	(43,778,472)	(4,850,950)
Total liabilities and stockholders' equity (deficit)	13,572,107	2,941,169	985,936
Convertible Series A Preferred Stock [Member]
Stockholders' equity (deficit):
Convertible preferred stock	1,000	1,000	1,000
Total stockholders' equity (deficit)	1,000	1,000	1,000
Convertible Series B-1 Preferred Stock [Member]
Stockholders' equity (deficit):
Convertible preferred stock	1,050	1,050	1,050
Total stockholders' equity (deficit)	1,050	1,050	1,050
Convertible Series B-1A Preferred Stock [Member]
Stockholders' equity (deficit):
Convertible preferred stock	317	317	317
Total stockholders' equity (deficit)	317	317	$ 317
Convertible Series B-2 Preferred Stock [Member]
Stockholders' equity (deficit):
Convertible preferred stock	4	4
Total stockholders' equity (deficit)	$ 4	$ 4

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for accounts receivable	$ 3,676,826	$ 257,463
Accounts payable, due to related parties	$ 190,102	$ 149,067	$ 92,744
Common stock, par value	$ 0.001	$ 0.001	$ 0.001
Common stock, shares authorized	20,000,000	20,000,000	14,060,001
Common stock, shares issued	11,806,580	11,227,676	10,686,191
Common stock, shares outstanding	11,806,580	11,227,676	10,686,191
Convertible Series A Preferred Stock [Member]
Convertible preferred stock, par value	$ 0.001	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	1,000,000	1,000,000	1,000,000
Convertible preferred stock, shares issued	1,000,000	1,000,000	1,000,000
Convertible preferred stock, shares outstanding	1,000,000	1,000,000	1,000,000
Convertible preferred stock, liquidation preference	$ 1,000,000	$ 1,000,000	$ 1,000,000
Convertible Series B-1 Preferred Stock [Member]
Convertible preferred stock, par value	$ 0.001	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	1,050,695	1,050,695	1,050,695
Convertible preferred stock, shares issued	1,050,695	1,050,695	1,050,695
Convertible preferred stock, shares outstanding	1,050,695	1,050,695	1,050,695
Convertible preferred stock, liquidation preference	$ 7,964,268	$ 7,964,268	$ 7,964,268
Convertible Series B-1A Preferred Stock [Member]
Convertible preferred stock, par value	$ 0.001	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	316,848	316,848	316,848
Convertible preferred stock, shares issued	316,848	316,848	316,848
Convertible preferred stock, shares outstanding	316,848	316,848	316,848
Convertible preferred stock, liquidation preference	$ 2,159,608	$ 2,159,608	$ 2,159,608
Convertible Series B-2 Preferred Stock [Member]
Convertible preferred stock, par value	$ 0.001	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	100,000	100,000	100,000
Convertible preferred stock, shares issued	4,167	4,167	0
Convertible preferred stock, shares outstanding	4,167	4,167	0
Convertible preferred stock, liquidation preference	$ 50,004	$ 50,004	$ 0

Condensed Consolidated Statemen

Condensed Consolidated Statement of Operations - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 2,908,705	$ 604,334	$ 10,625,032	$ 3,495,648
General and administrative	2,101,402	615,653	11,435,658	2,767,590
Settlement expense	21,365,641		39,486,139
Reimbursement of expenses from Relief Therapeutics	(771,245)		(10,160,421)
Total operating expenses	25,604,503	1,219,987	51,386,408	6,263,238
Loss from operations	(25,604,503)	(1,219,987)	(51,386,408)	(6,263,238)
Other (income) expenses:
Gain on extinguishment of debt	(120,810)
Interest expense	5,181	36,268	56,695	303,057
Change in fair value of embedded put		27,160	27,160	162,866
Loss on conversion of convertible notes payable		306,641	306,641
Total other income (expenses)	115,629	(370,069)	(390,496)	(465,923)
Loss before tax	(25,488,874)	(1,590,056)	(51,776,904)	(6,729,161)
Tax expense	0	0	0	0
Net loss	$ (25,488,874)	$ (1,590,056)	$ (51,776,904)	$ (6,729,161)
Net loss per share Basic and Diluted	$ (2.26)	$ (0.15)	$ (4.77)	$ (0.63)
Weighted average common shares outstanding Basic and Diluted	11,284,247	10,689,811	10,845,240	10,690,209

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Changes in Stockholders' Equity (Deficit) - USD ($)	Total	Convertible Series A Preferred Stock [Member]	Convertible Series B-1A Preferred Stock [Member]	Convertible Series B-1 Preferred Stock [Member]	Convertible Series B-2 Preferred Stock [Member]	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ (10,357,695)	$ 1,000	$ 317	$ 1,050		$ 10,450	$ 21,302,460	$ (31,672,972)
Beginning balance, shares at Dec. 31, 2018		1,000,000	316,848	1,050,695		10,449,837
Common stock issued	5,802,002					$ 536	5,801,466
Common stock issued, shares						536,354
Settlement consideration paid by shareholders in common stock	5,999,994						5,999,994
Stock-based compensation	433,910						433,910
Change in accounting method upon adopting ASU 2018-07							683	(683)
Retired founder shares						$ (300)	300
Retired founder shares, shares						(300,000)
Net Loss	(6,729,161)							(6,729,161)
Ending balance at Dec. 31, 2019	(4,850,950)	$ 1,000	$ 317	$ 1,050		$ 10,686	33,538,813	(38,402,816)
Ending balance, shares at Dec. 31, 2019		1,000,000	316,848	1,050,695		10,686,191
Common stock issued	176,990					$ 16	176,974
Common stock issued, shares						16,090
Stock-based compensation	88,803						88,803
Net Loss	(1,590,056)							(1,590,056)
Ending balance at Mar. 31, 2020	(6,125,209)	$ 1,000	$ 317	$ 1,050	$ 4	$ 10,702	33,854,590	(39,992,872)
Ending balance, shares at Mar. 31, 2020		1,000,000	316,848	1,050,695	4,167	10,702,281
Beginning balance at Dec. 31, 2019	(4,850,950)	$ 1,000	$ 317	$ 1,050		$ 10,686	33,538,813	(38,402,816)
Beginning balance, shares at Dec. 31, 2019		1,000,000	316,848	1,050,695		10,686,191
Common stock issued	2,579,114					$ 172	2,578,942
Common stock issued, shares						171,796
Common stock issued to settle note conversion	3,962,079					$ 360	3,961,719
Common stock issued to settle note conversion, shares						360,189
Common stock issued to settle accounts payable	144,875					$ 10	144,865
Common stock issued to settle accounts payable, shares						9,500
Reclassification of settlement liability upon issuance of warrant	5,382,905						5,382,905
Stock-based compensation	730,405						730,405
Net Loss	(51,776,904)							(51,776,904)
Ending balance at Dec. 31, 2020	(43,778,472)	$ 1,000	$ 317	$ 1,050	$ 4	$ 11,228	46,387,649	(90,179,720)
Ending balance, shares at Dec. 31, 2020		1,000,000	316,848	1,050,695	4,167	11,227,676
Series B-2 convertible preferred stock issued	50,004				$ 4		50,000
Series B-2 convertible preferred stock issued, shares					4,167
Series B-2 convertible preferred stock issued	50,004				$ 4		50,000
Series B-2 convertible preferred stock issued, shares					4,167
Common stock issued	6,926,858					$ 105	6,926,753
Common stock issued, shares						105,418
Issuance of common stock for exercise of warrant	7,500,018					$ 474	7,499,544
Issuance of common stock for exercise of warrant, shares						473,486
Reclassification of settlement liability upon issuance of warrant	60,851,780						60,851,780
Stock-based compensation	371,698						371,698
Net Loss	(25,488,874)							(25,488,874)
Ending balance at Mar. 31, 2021	$ 6,383,008	$ 1,000	$ 317	$ 1,050	$ 4	$ 11,807	$ 122,037,424	$ (115,668,594)
Ending balance, shares at Mar. 31, 2021		1,000,000	316,848	1,050,695	4,167	11,806,580

Condensed Consolidated Statem_3

Condensed Consolidated Statement of Cash Flows - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Loss	$ (25,488,874)	$ (1,590,056)	$ (51,776,904)	$ (6,729,161)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	476		1,517	859
Stock-based compensation	371,698	88,803	730,405	433,910
Warrant expense			5,382,905
Gain on extinguishment of debt	(120,810)
Change in fair value of embedded put		27,160	27,160	162,866
Amortization of debt discount		16,454	16,475	130,433
Non-cash interest expense	5,181	24,460	65,103	167,979
Non-cash consulting expense				499,994
Non-cash settlement expense	21,365,641		39,486,139
Loss on conversion of notes payable		306,641	306,641
Loss on common stock issued to settle accounts payable			41,617
Changes in operating assets and liabilities:
Accounts receivable	831,390		(831,390)
Prepaid expenses and other assets	(49,738)		(142,788)	(44,937)
Accounts payable	1,229,401	298,528	1,183,143	(52,181)
Accrued expenses and other liabilities	(1,158,175)	(4,647)	3,243,610	(112,087)
Net cash used in operating activities	(3,013,810)	(832,657)	(2,266,367)	(5,542,325)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of computer equipment			(1,501)	(3,552)
Net cash used in investing activities			(1,501)	(3,552)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from notes payable			619,842
Proceeds from issuance of series B-2 Preferred stock		50,004	50,004
Proceeds from issuance of Common stock, net of transaction costs	14,426,876	176,990	2,579,114	5,802,002
Net cash provided by financing activities	14,426,876	226,994	3,248,960	5,802,002
Net increase in cash	11,413,066	(605,663)	981,092	256,125
Cash at beginning of year	1,858,513	877,421	877,421	621,296
Cash at end of year	13,271,579	$ 271,758	1,858,513	877,421
Non-cash investing and financing activities
Common stock issued to settle accounts payable			144,875
Issuance of common stock for exercise of warrant	7,500,018
Conversion of notes payable into common stock			3,655,438
Reclassification of settlement liability upon issuance of warrant	60,851,780
Issuance of common stock warrants as offering costs			$ 30,536	63,337
Extinguishment of Paycheck Protection Program Loan	$ 120,810
Settlement consideration paid by shareholders in common stock				5,500,000
Short-term note payable issued to settle accounts payable				$ 154,190

Organization

Organization	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Organization	1. Organization The Business NeuroRx, Inc. (the “Company” or “NeuroRx”) was formed on May 20, 2015 and is incorporated in the State of Delaware. The Company established a wholly owned subsidiary, NeuroRx 2015 LTD (Israel), in December 2015, for the purpose of managing the continued development of a subset of the Company’s technology. The Company is a clinical stage pharmaceutical research and development company primarily engaged in the development of a drug regimen to treat patients with depression and suicidal ideation or behavior.	1. Organization The Business NeuroRx, Inc. (the “Company” or “NeuroRx”) was formed on May 20, 2015 and is incorporated in the State of Delaware. The Company established a wholly owned subsidiary, NeuroRx 2015 LTD (Israel), in December 2015, for the purpose of managing the continued development of a subset of the Company’s technology. The Company is a clinical stage pharmaceutical research and development company primarily engaged in the development of a drug regimen to treat patients with depression and suicidal ideation or behavior.

Liquidity

Liquidity	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Text Block [Abstract]
Liquidity	2. Liquidity As of March 31, 2021, the Company had $13,271,579 in cash. Since inception the Company has experienced net losses and negative cash flows from operations each fiscal year. The Company has no revenues and expects to continue to incur operating losses for the foreseeable future, and may never become profitable. The Company is dependent on its ability to continue to raise equity and/or debt financing to continue operations, and the attainment of profitable operations. The Company has a collaboration agreement with Relief Therapeutics Holdings (“Relief”), which provided for funding by Relief of certain research and development expenses related to the U.S. development of ZYESAMI and the portion of corporate overhead attributable to that program. The proceeds received amounted to $771,245 for the three months ended March 31, 2021. On March 28, 2021, the Company received $7,500,018 from the exercise of a warrant for the purchase of 473,486 shares. Subsequent to December 31, 2020, Relief has declined to reimburse the Company for any additional expenses related to the IV clinical trials for the ZYESAMI. The IV clinical trails for the ZYESAMI were completed on February 24, 2021. Subsequent to March 31, 2021, the Company sold 19,736 shares of common stock for gross proceeds of $1,421,024. Accordingly, the Company believes that it currently has sufficient funds to support operations through the next twelve months from the date the condensed consolidated financial statements are issued. The Company cannot make any assurances that additional financings will be available to it and, if available, on acceptable terms or at all. This could negatively impact the Company’s business and operations and could also lead to the reduction of the Company’s operations. COVID-19 On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus originating in Wuhan, China (the “COVID-19 COVID-19 The full impact of the COVID-19 COVID-19 COVID-19 COVID-19	2. Liquidity As of December 31, 2020, the Company had $1,858,513 in cash. Since inception the Company has experienced net losses and negative cash flows from operations each fiscal year. The Company has no revenues and expects to continue to incur operating losses for the foreseeable future, and may never become profitable. The Company is dependent on its ability to continue to raise equity and/or debt financing to continue operations, and the attainment of profitable operations. The Company has a collaboration agreement with Relief Therapeutics Holdings (“Relief”), which provided for funding by Relief of certain research and development expenses related to the U.S. development of ZYESAMI and the portion of corporate overhead attributable to that program. The proceeds received amounted to $10,160,421 for the year ended December 31, 2020. Subsequent to December 31, 2020, Relief has not reimbursed the Company for any additional expenses related to the IV clinical trials for the ZYESAMI. The IV clinical trials for the ZYESAMI were completed on February 24, 2021. During the first quarter of 2021, the Company sold 43,018 shares of common stock for gross proceeds of $2,495,058, and 79,400 shares of common stock for gross proceeds of $5,716,800. On March 28, 2021, the Company received $7,500,018 from the exercise of a warrant for the purchase of 473,486 shares. Accordingly, the Company believes that it currently has sufficient funds to support operations through the next twelve months from the date the financial statements are issued. The Company intends to use the proceeds of the merger transaction to fund the ZYESAMI inhaled trial for COVID-19. The Company cannot make any assurances that additional financings will be available to it and, if available, on acceptable terms or at all. This could negatively impact the Company’s business and operations and could also lead to the reduction of the Company’s operations. COVID-19 On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus originating in Wuhan, China (the “COVID-19 COVID-19 The full impact of the COVID-19 COVID-19 COVID-19 COVID-19

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) as determined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited interim condensed financial statements reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the balances and results for the periods presented. The results of operations for any interim periods are not necessarily indicative of the results that may be expected for the entire fiscal year or any other interim period. Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in its financial statements and the reported amounts of expenses during the reporting period. The most significant estimates in the Company’s financial statements relate to the valuation of common and preferred stock, stock options, warrants, and the valuation allowance of deferred tax assets resulting from net operating losses. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected. Certain Risks and Uncertainties The Company’s activities are subject to significant risks and uncertainties including the risk of failure to secure additional funding to properly execute the Company’s business plan. The Company is subject to risks that are common to companies in the pharmaceutical industry, including, but not limited to, development by the Company or its competitors of new technological innovations, dependence on key personnel, reliance on third party manufacturers, protection of proprietary technology, and compliance with regulatory requirements. Fair Value of Financial Instruments ASC 820, Fair Value Measurements The accounting guidance classifies fair value measurements in one of the following three categories for disclosure purposes: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Inputs other than Level 1 prices for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and values determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. Fair value measurements discussed herein are based upon certain market assumptions and pertinent information available to management as of and during the three months ended March 31, 2021 and the year ended December 31, 2020. The carrying amount of accounts payable approximated fair value as they are short term in nature. The fair value of warrants issued for settlement and services are estimated based on the Black-Scholes model during the three months ended March 31, 2021 and the year ended December 31, 2020. The carrying value of notes payable approximated the estimated fair values due to their recent issuances. The estimated fair value of the warrants and embedded put, represent Level 3 measurements. Accounts Receivable Accounts receivable consist of balances due from collaborative partners. In determining collectability, historical trends are evaluated, and specific partner issues are reviewed on a periodic basis to arrive at appropriate allowances. As of March 31, 2021, the Company has recorded an allowance for doubtful accounts of $3,676,826 as the Company does not expect to collect on amounts due to the Company owed from Relief. Concentration of Credit Risk and Off-Balance Cash is the only financial instrument that is potentially subject to concentrations of credit risk. The Company’s cash is deposited in accounts at large financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash is held. The Company has no financial instruments with off-balance Research and Development Costs The Company’s research and development expenses consist primarily of costs associated with the Company’s clinical trials, salaries, payroll taxes, employee benefits, and stock-based compensation charges for those individuals involved in ongoing research and development efforts. Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received. Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees Income Taxes Income taxes are recorded in accordance with ASC 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company recognizes any interest and penalties accrued related to unrecognized tax benefits as income tax expense. Loss Per Share Basic loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted loss per share excludes, when applicable, the potential impact of stock options, common stock warrant shares, and convertible preferred stock because their effect would be anti-dilutive due to our net loss. Since the Company had a net loss in each of the periods presented, basic and diluted net loss per common share are the same. The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share attributable to common stock for the periods presented because their effect would have been anti-dilutive. Three Months Ended 2021 2020 Convertible preferred stock as if converted 2,371,710 2,371,710 Stock options 489,255 220,255 Common stock warrants 1,200,307 57,474 Recent Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes	3. Summary of Significant Accounting Policies Basis of Presentation The Company’s financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”) as determined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”). Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in its financial statements and the reported amounts of expenses during the reporting period. The most significant estimates in the Company’s financial statements relate to the valuation of common and preferred stock, stock options, warrants, the embedded put feature in convertible notes and the valuation allowance of deferred tax assets resulting from net operating losses. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected. Certain Risks and Uncertainties The Company’s activities are subject to significant risks and uncertainties including the risk of failure to secure additional funding to properly execute the Company’s business plan. The Company is subject to risks that are common to companies in the pharmaceutical industry, including, but not limited to, development by the Company or its competitors of new technological innovations, dependence on key personnel, reliance on third party manufacturers, protection of proprietary technology, and compliance with regulatory requirements. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents. As of December 31, 2020 and 2019, the Company does not have any cash equivalents. Fair Value of Financial Instruments ASC 820, Fair Value Measurements The accounting guidance classifies fair value measurements in one of the following three categories for disclosure purposes: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Inputs other than Level 1 prices for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and values determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. Fair value measurements discussed herein are based upon certain market assumptions and pertinent information available to management as of and during the years ended December 31, 2020 and 2019. The carrying amount of accounts payable approximated fair value as they are short term in nature. The fair value of warrants issued for services is estimated based on the Black-Scholes model during the years ended December 31, 2020 and 2019. The carrying value of notes payable and convertible notes payable approximated the estimated fair values due to their recent issuances. The estimated fair value of the warrants and embedded put, represent Level 3 measurements. Foreign Currency The Company’s functional currency is the U.S. dollar. The functional currency of our foreign operation is the respective local currency. Assets and liabilities of foreign operation denominated in local currencies are translated at the spot rate in effect at the applicable reporting date. The consolidated statements of operations are translated at the weighted average rate of exchange during the applicable period. The resulting unrealized cumulative translation adjustment is not material to the financial statements. Accounts Receivable Accounts receivable consist of balances due from collaborative partners. In determining collectability, historical trends are evaluated, and specific partner issues are reviewed on a periodic basis to arrive at appropriate allowances. As of December 31, 2020, the Company has recorded an allowance for doubtful accounts of $257,463. Concentration of Credit Risk and Off-Balance Cash is the only financial instrument that is potentially subject to concentrations of credit risk. The Company’s cash is deposited in accounts at large financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash is held. The Company has no financial instruments with off-balance Research and Development Costs The Company’s research and development expenses consist primarily of costs associated with the Company’s clinical trials, salaries, payroll taxes, employee benefits, and stock-based compensation charges for those individuals involved in ongoing research and development efforts. Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received. Derivative Financial Instruments The Company does not use derivative instruments to hedge exposures to interest rate, market, or foreign currency risks. The Company evaluates all of its financial instruments, to determine if such instruments contain features that qualify as embedded derivatives. Embedded derivatives must be separately measured from the host contract if all the requirements for bifurcation are met. The assessment of the conditions surrounding the bifurcation of embedded derivatives depends on the nature of the host contract. Bifurcated embedded derivatives are recognized at fair value, with changes in fair value recognized in the statement of operations each period. Bifurcated embedded derivatives are classified with the related host contract in the Company’s balance sheet. Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees Income Taxes Income taxes are recorded in accordance with ASC 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company recognizes any interest and penalties accrued related to unrecognized tax benefits as income tax expense. Loss Per Share Basic loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted loss per share excludes, when applicable, the potential impact of stock options, common stock warrant shares, and convertible preferred stock because their effect would be anti-dilutive due to our net loss. Since the Company had a net loss in each of the periods presented, basic and diluted net loss per common share are the same. The calculation of basic and diluted net loss per share attributable to common stock was as follows: As of December 31, 2020 2019 Numerator: Net loss attributable to common stock—basic and diluted $ (51,776,904 ) $ (6,729,161 ) Denominator: Weighted average shares—basic and diluted 10,845,240 10,690,209 Net loss per share attributable to common stock—basic and diluted $ (4.77 ) $ (0.63 ) The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share attributable to common stock for the periods presented because their effect would have been anti-dilutive. Year Ended December 31, 2020 2019 Convertible preferred stock as if converted 2,371,710 2,367,543 Stock options 486,755 333,588 Common stock warrants 620,054 57,473 Recent Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, 2018-07

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued and Other Current Liabilities	4. Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following at the dates indicated: March 31, December 31, (Unaudited) Accrued and other current liabilities: Accrued research and development expenses $ 568,155 $ 586,426 Accrued employee expenses 530,500 530,500 Professional services 45,705 606,553 Other accrued liabilities 16,547 5,004 Total accrued and other current liabilities $ 1,160,907 $ 1,728,483	4. Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following at the dates indicated: December 31, 2020 2019 Accrued and other current liabilities: Professional services $ 606,553 $ — Accrued research and development expenses 586,426 — Accrued employee expenses 530,500 — Other accrued liabilities 5,004 9,649 Total accrued and other current liabilities $ 1,728,483 $ 9,649

Debt Disclosure

Debt Disclosure	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Convertible Notes Payable [Member]
Debt Disclosure	5. Convertible Notes Payable On February 12, 2020, a Qualified Financing Event (as defined below) occurred when the Company received cumulative investment proceeds in excess of $10,000,000 from the sale and issuance of common shares. The fair value of the Company’s common shares were $11.00 per share. The 2017 Notes (as defined below) and the 2018 Notes (as defined below) in the aggregate principal amount of $2,800,000 were converted into 318,183 common shares (at the discounted price of $8.80 per share), and the related unpaid and accrued interest totaling $369,660 were also converted into 42,006 common shares of the Company (at the discounted price of $8.80 per share). Additionally, the Company recognized a loss on extinguishment for the difference between the carrying value of the convertible notes, unamortized debt discount, and the value of the embedded put option and the fair value of the common shares of $306,641 during the three months ended March 31, 2020. The Company issued the shares of common stock pursuant to this conversion on September 23, 2020. 2017 Convertible Notes Payable On November 16, 2017 and November 19, 2017, the Company issued convertible notes (“2017 Notes”), as amended for aggregate gross proceeds of $2,500,000. The 2017 Notes accrued interest at a rate of 6% per annum and principal and interest were due and payable four years from the date of issuance. Upon either a sale of the Company’s assets or all of its capital stock, or a change of control, the principal balance would double and be repaid. Upon closing of either a sale of the Company’s shares for at least $10,000,000 or a public offering of the Company’s securities (“Qualified Financing Event”), the outstanding principal balance will be converted into the number of such securities sold at a conversion price equal to 80% of the securities negotiated share price. 2018 Convertible Notes Payable On January 5, 2018 and April 25, 2018, the Company issued convertible notes (“2018 Notes”), as amended for aggregate gross proceeds of $300,000. The 2018 Notes accrued interest at a rate of 6% per annum and were due and payable four years from the date of issuance. Upon either a sale of the Company’s assets or all of its capital stock, or a change of control, the principal balance would double and be repaid. Upon closing of either a sale of the Company’s shares for at least $10,000,000 or a public offering of the Company’s securities (“Qualified Financing Event”), the outstanding principal balance will be converted into the number of such securities sold at a conversion price equal to 80% of the securities negotiated share price. The January 5, 2018 note for $100,000 was not amended and interest was unpaid, as such, that note and related accrued interest were classified as current liabilities. The April 25, 2018 note for $200,000 was amended similar to the 2017 Notes to accrue interest and to be paid at maturity with the principal. The proceeds received upon issuing the 2017 Notes and 2018 Notes were first allocated to the fair value of the embedded put with the remainder to the debt host instrument. The Company recognized a loss of $0 and $27,160 during the three months ended March 31, 2021 and 2020, respectively, due to the estimated increase in fair value of the embedded put. The discount is amortized to interest expense over the term of the debt. The Company amortized debt discount of $0 and $16,454 to interest expense during the three months ended March 31, 2021 and 2020, respectively. The Company paid no interest during the three months ended March 31, 2021 and 2020.	5. Convertible Notes Payable December 31, 2020 2019 Convertible Notes: 2017 convertible notes payable due November 2021 $ — $ 2,500,000 2018 convertible note payable due January 2022 — 100,000 2018 convertible notes payable due April 2022 — 200,000 Fair value of embedded put — 738,602 Debt discount — (296,437 ) Carrying value of convertible notes $ — $ 3,242,165 Accrued interest — 349,891 Total convertible notes payable and accrued interest $ — $ 3,592,056 December 31, 2020 2019 Convertible Notes: Convertible notes payable and accrued interest, current $ — $ 130,251 Convertible notes payable and accrued interest, non-current — 3,461,805 Total convertible notes payable and accrued interest $ — $ 3,592,056 On February 12, 2020, a Qualified Financing Event (as defined below) occurred when the Company received cumulative investment proceeds in excess of $10,000,000 from the sale and issuance of common shares. The fair value of the Company’s common shares were $11.00 per share. The 2017 Notes (as defined below) and the 2018 Notes (as defined below) in the aggregate principal amount of $2,800,000 were converted into 318,183 common shares (at the discounted price of $8.80 per share), and the related unpaid and accrued interest totaling $369,660 were also converted into 42,006 common shares of the Company (at the discounted price of $8.80 per share). Additionally, the Company recognized a loss on extinguishment for the difference between the carrying value of the convertible notes, unamortized debt discount, and the value of the embedded put option and the fair value of the common shares issued of $306,641 during the year ended December 31, 2020. 2017 Convertible Notes Payable On November 16, 2017 and November 19, 2017, the Company issued convertible notes (“2017 Notes”), as amended for aggregate gross proceeds of $2,500,000. The 2017 Notes accrued interest at a rate of 6% per annum and principal and interest were due and payable four years from the date of issuance. Upon either a sale of the Company’s assets or all of its capital stock, or a change of control, the principal balance would double and be repaid. Upon closing of either a sale of the Company’s shares for at least $10,000,000 or a public offering of the Company’s securities (“Qualified Financing Event”), the outstanding principal balance will be converted into the number of such securities sold at a conversion price equal to 80% of the securities negotiated share price. 2018 Convertible Notes Payable On January 5, 2018 and April 25, 2018, the Company issued convertible notes (“2018 Notes”), as amended for aggregate gross proceeds of $300,000. The 2018 Notes accrued interest at a rate of 6% per annum and were due and payable four years from the date of issuance. Upon either a sale of the Company’s assets or all of its capital stock, or a change of control, the principal balance would double and be repaid. Upon closing of either a sale of the Company’s shares for at least $10,000,000 or a public offering of the Company’s securities (“Qualified Financing Event”), the outstanding principal balance will be converted into the number of such securities sold at a conversion price equal to 80% of the securities negotiated share price. The January 5, 2018 note for $100,000 was not amended and interest was unpaid, as such, that note and related accrued interest were classified as current liabilities. The April 25, 2018 note for $200,000 was amended similar to the 2017 Notes to accrue interest and to be paid at maturity with the principal. Upon closing of a public offering of the Company’s common stock, each of the 2017 Notes and 2018 Notes settle by providing the holder with a variable number of shares sold in the offering with an aggregate fair value determined by reference to the debt principal. In this scenario, the value that the holder receives at settlement does not vary with the value of the Company’s common stock, so the settlement provision was not a typical conversion option. Rather, the share settlement feature was considered a contingent redemption provision (i.e., a contingent embedded put). The Company evaluated the embedded put features in accordance with ASC 815-15-25. The proceeds received upon issuing the 2017 Notes and 2018 Notes were first allocated to the fair value of the embedded put with the remainder to the debt host instrument. The Company recorded a $493,982 and $57,204 debt discount upon issuance of the 2017 and 2018 convertible notes, respectively. The Company recognized a loss of $27,160 and $162,866 during the years ended December 31, 2020 and 2019, respectively, due to the estimated increase in fair value of the embedded put. Management used a scenario-based analysis to estimate the fair value of the embedded put features at issuance of the 2017 Notes and 2018 Notes and as of December 31, 2019. The discount is amortized to interest expense over the term of the debt. The Company amortized debt discount of $16,475 and $130,433 to interest expense during the years ended December 31, 2020 and 2019, respectively. The Company paid no interest during the years ended December 31, 2020 and 2019.
Notes Payable [Member]
Debt Disclosure	6. Notes Payable March 31, December 31, (Unaudited) Note Payable — Related Party $ 154,190 $ 154,190 Relief Therapeutics Loan 500,000 500,000 Paycheck Protection Program Loan — 119,842 Carrying value of notes payable 654,190 774,032 Accrued interest 26,869 22,656 Note payable $ 681,059 $ 796,688 March 31, December 31, (Unaudited) Notes payable: Notes payable and accrued interest, current $ 171,134 $ 248,861 Notes payable and accrued interest, non-current 509,925 547,827 Total notes payable and accrued interest $ 681,059 $ 796,688 Note Payable — Related Party On July 1, 2019, the Company converted certain accounts payable into a loan (the “Note Payable — Related Party”) with a related party in the amount of $154,190. The loan, in the form of a promissory note, matures on July 1, 2020. The principal amount of the loan and any accrued but unpaid interest shall be due and payable beginning July 1, 2019. All payments shall be applied first to accrued but unpaid interest, and then to outstanding principal. If not sooner paid, the entire remaining indebtedness (including accrued interest) shall be due and payable on July 1, 2020. The loan bears interest, compounded daily, at 6% annual interest. The loan continues to accrue interest as it was not paid off upon maturity. Relief Therapeutics Loan On April 6, 2020, the Company entered into a loan agreement with Relief Therapeutics (the “Relief Therapeutics Loan”) in the amount of $500,000. The loan matures on April 6, 2022 and bears interest at 2% per annum payable in arrears. Paycheck Protection Program Loan On April 28, 2020, the Company received $119,842 in loan funding from the Paycheck Protection Program (the “PPP Loan”), established pursuant to the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) and administered by the U.S. Small Business Administration (“SBA”). The unsecured PPP Loan accrues interest on the outstanding principal at the rate of 1% per annum, and there is a six month deferment period until equal installment payments of $6,744 of principal and interest are due. The term of the PPP Loan is two years. To the extent the loan amount is not forgiven under the PPP, the Company is obligated to make equal monthly payments of principal and interest, beginning seven months from the date of the Note, until the maturity date. The Loan amount may be eligible for forgiveness pursuant to (1) at least 75% of the loan proceeds are used to cover payroll costs and the remainder is used for mortgage interest, rent and utility costs over the eight week period after the loan is made, and (2) the number of employees and compensation levels are generally maintained. Forgiveness of the loan is dependent on the Company having initially qualified for the loan and qualifying for the forgiveness of such loan based on future adherence to the forgiveness criteria. The Company used the entire PPP Loan for qualifying payroll expenses, and filed for loan forgiveness on December 30, 2020. The Company received full forgiveness of all outstanding principal and accrued and unpaid interest on the PPP Loan as of February 11, 2021. The forgiveness of the PPP Loan qualified for debt extinguishment in accordance with ASC 470-50, Debt Modifications and Extinguishments	6. Notes Payable December 31, 2020 2019 Note Payable — Related Party $ 154,190 $ 154,190 Relief Therapeutics Loan 500,000 — Paycheck Protection Program Loan 119,842 — Carrying value of notes payable 774,032 154,190 Accrued interest 22,656 — Total notes payable and accrued interest $ 796,688 $ 154,190 December 31, 2020 2019 Notes payable: Notes payable and accrued interest, current $ 248,861 $ 154,190 Notes payable and accrued interest, non-current 547,827 — Total notes payable and accrued interest $ 796,688 $ 154,190 Note Payable — Related Party On July 1, 2019, the Company converted certain accounts payable into a loan (the “Note Payable — Related Party”) with a related party in the amount of $154,190. The loan, in the form of a promissory note, matures on July 1, 2020. The principal amount of the loan and any accrued but unpaid interest shall be due and payable beginning July 1, 2019. All payments shall be applied first to accrued but unpaid interest, and then to outstanding principal. If not sooner paid, the entire remaining indebtedness (including accrued interest) shall be due and payable on July 1, 2020. The loan bears interest, compounded daily, at 6% annual interest. The loan continues to accrue interest as it was not paid off upon maturity. Relief Therapeutics Loan On April 6, 2020, the Company entered into a loan agreement with Relief Therapeutics (the “Relief Therapeutics Loan”) in the amount of $500,000. The loan matures on April 6, 2022 and bears interest at 2% per annum payable in arrears. Paycheck Protection Program Loan On April 28, 2020, the Company received $119,842 in loan funding from the Paycheck Protection Program (the “PPP Loan”), established pursuant to the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) and administered by the U.S. Small Business Administration (“SBA”). The unsecured PPP Loan accrues interest on the outstanding principal at the rate of 1% per annum, and there is a six month deferment period until equal installment payments of $6,744 of principal and interest are due. The term of the PPP Loan is two years. To the extent the loan amount is not forgiven under the PPP, the Company is obligated to make equal monthly payments of principal and interest, beginning seven months from the date of the Note, until the maturity date. The Loan amount may be eligible for forgiveness pursuant to (1) at least 75% of the loan proceeds are used to cover payroll costs and the remainder is used for mortgage interest, rent and utility costs over the eight week period after the loan is made, and (2) the number of employees and compensation levels are generally maintained. Forgiveness of the loan is dependent on the Company having initially qualified for the loan and qualifying for the forgiveness of such loan based on future adherence to the forgiveness criteria. The Company used the entire PPP Loan for qualifying payroll expenses, and filed for loan forgiveness on December 30, 2020, though no assurance is provided that the Company will obtain forgiveness of the PPP Loan in whole or in part.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Operating Lease The Company leases office space on a month-to-month Sponsored Research Agreement with National Jewish Health On February 8 2021, the Company entered into a Sponsored Research Agreement (“Research Agreement”) with National Jewish Health (“NJ Health”), a Colorado not-for-profit SARS-CoV-2 Aviptadil Manufacturing, Production, Supply and Distribution Agreements On August 25, 2020, NeuroRx and Nephron Pharmaceuticals Corporation (“Nephron”) signed an agreement for the manufacturing of finished pharmaceutical product of Aviptadil intravenous formulation and the development of an inhaled (nebulizer) formulation of Aviptadil. Nephron will serve as the exclusive and primary supplier of the product for both clinical and commercial purposes, supplying 100% of the Company’s annual requirements. The Company has agreed to purchase products from Nephron for a fixed price. On September 29, 2020, NeuroRx and Cardinal Health signed an exclusive distribution agreement, as well as a 3rd party logistics agreement on October 1, 2020. Cardinal Health will manage warehousing, distribution, invoicing for the potential sale of Aviptadil in the United States and Puerto Rico. On October 9, 2020, NeuroRx signed an agreement with Polypeptide for the supply of GMP grade Active Pharmaceutical Ingredient (API) Aviptadil (VIP). This gives NeuroRx a second source of procuring API. The Company has agreed to purchase a total of $1,010,000 worth of product and services over the contract. On January 4, 2021 NeuroRx and Aerogen Limited (“Aerogen”) signed a supply agreement for the supply of certain products, including the Areogen Solo Nebulizer System and Aerogen Ultra, solely for the purposes of carrying out clinical trials relating to inhalation delivery of Aviptadil for treatment of pulmonary insufficiency and respiratory distress in COVID-19 Relief Therapeutics Collaboration Agreement On September 18, 2020, the Company entered into a collaboration agreement with Relief for the clinical development and if approved the sale of Aviptadil. The collaboration provides for funding by Relief of certain clinical trials. If such candidate is approved by the FDA, the Company shall receive 50% of net product profits from the product sales in the NeuroRx territory, which includes the United States, Canada, and Israel; 15% of net product profits from the product sales in the Relief Therapeutics territory, which includes the European Union, Switzerland, Iceland, Norway, the UK, the Channel Islands, Liechtenstein, Monaco, Andorra, Malta, San Marino, and Vatican City; and 20% of net product profits from the product sales in all other countries. During 2021, the Company invoiced Relief $4,190,608 for reimbursable expenses and received $770,444 in payments from Relief for these reimbursable expenses. The Company recorded an allowance for doubtful accounts of $3,676,826 as of March 31, 2021, due to the fact that the Company does not expect to receive payment for the remaining invoices, thus fully reserving for the accounts receivable balance. As of May 14, 2021, Relief has reimbursed NeuroRx $10,904,065 for expenses, but has subsequently declined to pay approximately $4 million in invoiced costs associated with conduct of the IV clinical trial, reformulation, and manufacture of ZYESAMI. Relief has additionally declined to fund the costs of the inhaled trial. NeuroRx has advised Relief that NeuroRx is funding those costs with other capital. Share Subscription Facility Agreement — GEM The Company previously entered into a share subscription facility agreement (“GEM Agreement”) with GEM Global Yield LLC SCS and GEM Yield Bahamas Limited (collectively, referred to as “GEM”) with a three-year term. Subject to the successful listing of the shares of NeuroRx on an Exchange (any nationally recognized stock exchange or exchange platform in the world on which the Company will list its shares), GEM grants the Company an option to require GEM to subscribe for shares from the Company for up to an aggregate value of approximately $95.6 million. The agreement also included certain provisions which would not meet the U.S. requirements to issue registered shares. If NeuroRx was listed or completes a private transaction which results in a change of control of the Company, the Company would issue GEM a warrant and pay a commitment fee of $1.9 million. Absent a listing of NeuroRx shares or a private transaction with a change of control during the three-year term, the Company would have no obligations under the agreement. A reverse merger would not result in a listing of NeuroRx shares or a change in control. In November 2020, GEM introduced the Company to Big Rock. To resolve uncertainties around the application of the GEM Agreement, the Company and GEM agreed in March 2021 to issue a warrant to GEM and for the parties to use their good faith efforts to amend the GEM Agreement to meet U.S. requirements to issue registered shares. The warrant is not conditional upon any further events or completion of the merger. The warrant was issued March 28, 2021, for 1,053,738 shares of NeuroRx common stock at an exercise price of $15.84 per share (the “GEM Warrant”) and the parties agreed that GEM would immediately partially exercise the warrant for the purchase of 473,486 shares (“Initial Exercised Shares”) for $7,500,018. The GEM Warrant will be valid for a period of three years from the date the Company’s stock is listed for trading on a national securities exchange or consummation of a reverse merger transaction. This contingent liability at December 31, 2020, represented an obligation that resulted in the issuance of certain equity at a discounted per share price. As the amount was deemed probable and estimable by the Company at December 31, 2020, the Company recorded a liability of $39,486,139 to reflect the fair value of the GEM Warrant. On March 28, 2021, the Company recorded additional settlement liability of $21,365,641 to reflect the change in the fair value of the Company’s common stock. On March 28, 2021, the Company reclassed the settlement liability to equity upon the issuance of the GEM Warrant. The Company was required to register the Initial Exercised Shares on (a) the same registration statement on Form S-4 Merger with Big Rock Partners Acquisition Corp. On December 13 2020, the Company entered into an Agreement and Plan of Merger (“Merger Agreement”) with Big Rock. Under the terms of the transaction, Big Rock will issue to NeuroRx’s current equity holders an aggregate of 50 million shares (“Per Share Merger Consideration”) of Big Rock common stock for their interests in NeuroRx. Subject to certain conditions, an aggregate of 25 million additional shares of Big Rock common stock (“Earnout Shares”) will be issued to NeuroRx pre-merger COVID-19 COVID-19 pre-merger COVID-19 COVID-19 The Boards of Directors of both NeuroRx and Big Rock have unanimously approved the proposed transaction. Completion of the transaction is subject to approval by stockholders of NeuroRx and Big Rock and other customary closing conditions.	7. Commitments and Contingencies Operating Lease The Company leases office space on a month-to-month Litigation - Settlement Liability In September of 2018, Sarah Herzog Memorial Hospital Ezrat Nashim filed suit against NeuroRx, Inc., the founding shareholders alleging a dispute as to the ownership and use of intellectual property related to anti-depressants and anti-psychotics. Prior to service of the lawsuit, in December of 2018 all parties to the referenced action submitted to voluntary non-binding In October of 2019, the founding shareholders of the Company transferred 45,454 shares of common stock with a fair value of $499,994 to a former adviser to release and discharge the Company from any obligation to the former adviser or transfer any additional securities. This charge was recorded as of September 30, 2019, by the Company as consulting expense even though the consideration was paid from the stock accounts of the founders without dilution to the Company pursuant to ASC 260, which deems consideration paid by control parties to have been paid by the Company. As of December 31, 2020, there was no further litigation against the Company. Milestone Payments Pursuant to the legal settlement, which included the license of intellectual property rights from SHMH, an ongoing royalty of 1% – 2.5% of NRX-101 NRX-101. Aviptadil Manufacturing, Production and Distribution Agreements On August 25, 2020, NeuroRx and Nephron Pharmaceuticals Corporation (“Nephron”) signed an agreement for the manufacturing of finished pharmaceutical product of Aviptadil intravenous formulation and the development of an inhaled (nebulizer) formulation of Aviptadil. Nephron will serve as the exclusive and primary supplier of the product for both clinical and commercial purposes, supplying 100% of the Company’s annual requirements. The Company has agreed to purchase products from Nephron for a fixed price. On September 29, 2020, NeuroRx and Cardinal Health signed an exclusive distribution agreement, as well as a 3rd party logistics agreement on October 1, 2020. Cardinal Health will manage warehousing, distribution, invoicing for the potential sale of Aviptadil in the United States and Puerto Rico. On October 9, 2020, NeuroRx signed an agreement with Polypeptide for the supply of GMP grade Active Pharmaceutical Ingredient (API) Aviptadil (VIP). This gives NeuroRx a second source of procuring API. The Company has agreed to purchase a total of $1,010,000 worth of product and services over the contract. Relief Therapeutics Collaboration Agreement On September 18, 2020, the Company entered into a collaboration agreement with Relief for the clinical development and if approved the sale of Aviptadil. The collaboration provides for funding by Relief of certain clinical trials. If such candidate is approved by the FDA, the Company shall receive 50% of net product profits from the product sales in the NeuroRx territory, which includes the United States, Canada, and Israel; 15% of net product profits from the product sales in the Relief Therapeutics territory, which includes the European Union, Switzerland, Iceland, Norway, the UK, the Channel Islands, Liechtenstein, Monaco, Andorra, Malta, San Marino, and Vatican City; and 20% of net product profits from the product sales in all other countries. During 2020, the Company invoiced Relief $10,160,421 for reimbursable expenses and received $9,329,031 in payments from Relief for these reimbursable expenses. As of December 31, 2020, the Company had an accounts receivable balance due from Relief of $831,390, net of an allowance for doubtful accounts of $257,463. As of May 11, 2021, Relief has reimbursed NeuroRx $10,612,750 for expenses, but has not paid approximately $4,000,000 in invoiced costs associated with conduct of the IV clinical trial, reformulation, and manufacture of ZYESAMI. As of May 11, 2021, Relief has not funded the costs of the inhaled trial. NeuroRx has advised Relief that NeuroRx is funding those costs with other capital. Share Subscription Facility Agreement - GEM The Company previously entered into a share subscription facility agreement (“GEM Agreement”) with GEM Global Yield LLC SCS and GEM Yield Bahamas Limited (collectively, referred to as “GEM”) with a three-year term. Subject to the successful listing of the shares of NeuroRx on an Exchange (any nationally recognized stock exchange or exchange platform in the world on which the Company will list its shares), GEM grants the Company an option to require GEM to subscribe for shares from the Company for up to an aggregate value of approximately $95.6 million. The agreement also included certain provisions which would not meet the U.S. requirements to issue registered shares. If NeuroRx was listed or completes a private transaction which results in a change of control of the Company, the Company would issue GEM a warrant and pay a commitment fee of $1.9 million. Absent a listing of NeuroRx shares or a private transaction with a change of control during the three-year term, the Company would have no obligations under the agreement. A reverse merger would not result in a listing of NeuroRx shares or a change in control. In November 2020, GEM introduced the Company to Big Rock. Although the Company has taken the position that the reverse merger transaction contemplated by the Merger Agreement (as defined below) would not require the issuance of the warrant, to resolve uncertainties around the application of the GEM Agreement, the Company and GEM agreed in March 2021 to issue a warrant to GEM and for the parties to use their good faith efforts to amend the GEM Agreement to meet U.S. requirements to issue registered shares. The warrant is not conditional upon any further events or completion of the merger. The warrant was issued March 28, 2021, for 1,053,738 shares of NeuroRx common stock at an exercise price of $15.84 per share (the “GEM Warrant”) and the parties agreed that GEM would immediately partially exercise the warrant for the purchase of 473,486 shares (“Initial Exercised Shares”) for $7.5 million. The GEM Warrant will be valid for a period of three years from the date the Company’s stock is listed for trading on a national securities exchange or consummation of a reverse merger transaction. This contingent liability at December 31, 2020, represented an obligation that resulted in the issuance of certain equity at a discounted per share price. As the amount was deemed probable and estimable by the Company at December 31, 2020, the Company recorded a liability of $39,486,139 to reflect the fair value of the GEM Warrant. The Company is required to register the Initial Exercised Shares on (a) the same registration statement on Form S-4 Merger with Big Rock Partners Acquisition Corp. On December 13 2020, the Company entered into an Agreement and Plan of Merger (“Merger Agreement”) with Big Rock. Under the terms of the transaction, Big Rock will issue to NeuroRx’s current equity holders an aggregate of 50 million shares (“Per Share Merger Consideration”) of Big Rock common stock for their interests in NeuroRx. Subject to certain conditions, an aggregate of 25 million additional shares of Big Rock common stock (“Earnout Shares”) will be issued to NeuroRx pre-merger COVID-19 COVID-19 pre-merger COVID-19 COVID-19 The Boards of Directors of both NeuroRx and Big Rock have unanimously approved the proposed transaction. Completion of the transaction is subject to approval by stockholders of NeuroRx and Big Rock and other customary closing conditions.

Equity

Equity	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Equity	8. Equity Common Stock The Company sold 105,418 and 16,090 shares of common stock during three months ended March 31, 2021 and 2020, respectively and received gross proceeds of $6,926,858 and $176,990, respectively. Preferred Stock Series A, B-1, B-1A The Company has authorized and issued 1,000,000 shares of Series A convertible preferred stock, 1,050,695 shares of Series B-1 B-1A as-converted B-1 B-1A Series B-2 In 2020, the Company authorized the issuance of 100,000 shares of Series B-2 B-2 B-2 B-2 as-converted B-2 B-2 Common Stock Warrants On March 28, 2021, the Company issued 1,053,738 fully vested common stock warrants, exercisable at a per share price of $15.84 until they expire on March 27, 2024 to GEM (See Note 7). The fair value on the date of issuance was $60,851,779. Upon issuance, 473,486 warrants were immediately exercised generating gross proceeds of $7,500,018. The following table provides the activity in warrants for the respective periods. Total Warrants Weighted Weighted Aggregate Outstanding as of December 31, 2020 620,055 11.08 $ 14.61 $ 22,127,594 Issued 1,053,738 3.00 15.84 59,177,926 Exercised (473,486 ) (15.84 ) (26,590,974 ) Outstanding as of March 31, 2021 1,200,306 6.80 $ 15.21 $ 54,714,546 The grant date fair value of common stock warrants is determined using the Black Scholes option-pricing model. The Company is a private company and estimates its expected stock volatility based on historical volatility of publicly traded peer companies. The estimated fair value of the Company’s common stock is based on sales to third parties. The following assumptions were used during the following periods: March 31, December 31, Strike price $15.84 $15.25 Volatility rate 80.0% 80.0% Risk-free rate 0.31% 0.19%-0.28% Expected term 3.00 3.00-5.00 Dividend yield — —	8. Equity Common Stock On March 1, 2020, the Company’s board of directors authorized an increase to the authorized share capital from 14,060,001 shares of common stock to 20,000,000 shares of common stock with a par value of $0.001 per share. The Company sold 171,796 and 536,354 shares of common stock during the years ended December 31, 2020 and 2019, respectively and received gross proceeds of $2,579,114 and net proceeds of $5,802,002, respectively. The Company issued 9,500 shares of common stock with a fair value of $144,875 in settlement of accounts payable worth $103,258, and recognized a loss of $41,617 for the difference during the year ended December 31, 2020 and did not issue any such shares during the year ended December 31, 2019. Preferred Stock Series A, B-1, B-1A The Company has authorized and issued 1,000,000 shares of Series A convertible preferred stock, 1,050,695 shares of Series B-1 B-1A as-converted B-1 B-1A Series B-2 In 2020, the Company authorized the issuance of 100,000 shares of Series B-2 B-2 B-2 B-2 as-converted B-2 B-2 Common Stock Warrants On January 31, 2019, the Company issued 8,846 fully vested common stock warrants, exercisable at a per share price of $11.00 until they expire on January 30, 2024, to a vendor for financial advisory services provided in connection with the sale of the Company’s common stock. The fair value on the date of issuance was $7.16 per warrant for a total fair value of $63,337. On July 6, 2020, the Company issued 4,000 fully vested common stock warrants, exercisable at a per share price of $15.25 until they expire on July 5, 2023, to a vendor for financial advisory services provided in connection with the sale of the Company’s common stock. The fair value on the date of issuance was $7.63 per warrant for a total fair value of $30,536. On July 15, 2020, the Company issued 279,291 fully vested common stock warrants, exercisable at a per share price of $15.25 until they expire on July 14, 2025, to a board member. The fair value on the date of issuance was $9.63 per warrant for a total fair value of $2,689,684. On October 23, 2020, the Company issued 139,645 and 139,645 fully vested common stock warrants, exercisable at a per share price of $15.25 until they expire on October 22, 2025, to a board member, respectively. The fair value on the date of issuance was $9.64 per warrant for a total fair value of $2,693,221. The following table provides the activity in warrants for the respective periods. Total Warrants Weighted Weighted Average Outstanding as of December 31, 2018 48,627 2.88 $ 7.90 $ — Issued 8,846 5.00 11.00 — Outstanding as of December 31, 2019 57,473 2.22 $ 8.38 $ — Issued 562,581 4.99 15.25 20,112,271 Outstanding as of December 31, 2020 620,054 11.08 $ 14.61 $ 22,127,594 The grant date fair value of common stock warrants is determined using the Black Scholes option-pricing model. The Company is a private company and estimates its expected stock volatility based on historical volatility of publicly traded peer companies. The estimated fair value of the Company’s common stock is based on sales to third parties. The following assumptions were used during the following periods: December 31, 2020 2019 Strike price $15.25 $11.00 Volatility rate 80.0% 80.0% Risk-free rate 0.19%-0.28% 2.40% Expected term 3.00-5.00 5.00 Dividend yield — —

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation The Company’s 2016 Omnibus Incentive Plan (the “Plan”) permits the granting of incentive stock options, restricted stock awards, other stock-based award or other cash-based awards. The maximum aggregate shares of common stock that may be subject to awards and issued under the Plan is 700,000. At March 31, 2021, 489,255 shares have been awarded and 210,745 shares remain available for issuance under the Plan. Option Awards The fair value of each employee and non-employee NRX-101, The fair value of the Company’s common stock, which equaled the exercise price of stock options granted during the three months ended March 31, 2021 and 2020, respectively, was determined based on sales of the Company’s shares at arm’s length to unrelated third parties. The grant date fair value of employee and non-employee March 31, 2021 December 31, 2020 Exercise price $58.00 $11.00-$15.25 Risk-free rate of interest 0.20%-0.34% 0.30%-0.49% Expected term (years) 6.0 5.5-6.5 Expected stock price volatility 80% 80% Dividend yield — — The following table summarizes the Company’s employee and non-employee Number of Weighted Weighted Aggregate Outstanding as of December 31, 2020 486,755 $ 10.79 8.8 $ 19,571,655 Granted 42,500 58.00 9.8 595,000 Forfeited (40,000 ) — — — Outstanding as of March 31, 2021 489,255 $ 14.58 8.7 $ 30,388,510 Options vested and exercisable as of March 31, 2021 376,493 $ 6.21 4.0 $ 24,771,202 The aggregate intrinsic value in the above table is calculated as the difference between fair value of the Company’s common stock price and the exercise price of the stock options. The weighted average grant date fair value per share for employee stock and non-employee non-employee Stock-based compensation expense related to stock options, in aggregate, has been reported in general and administrative expense in the amount of $344,034 and $66,588 and research and development expense in the amount of $27,664 and $22,215 in the Company’s statements of operations for the three months ended March 31, 2021 and 2020, respectively.	9. Stock-Based Compensation The Company’s 2016 Omnibus Incentive Plan (the “Plan”) permits the granting of incentive stock options, restricted stock awards, other stock-based award or other cash-based awards. The maximum aggregate shares of common stock that may be subject to awards and issued under the Plan is 500,000. In December 2020, the Company’s board of directors authorized an additional 200,000 shares of common stock options to be authorized under the Plan for a total of 700,000 authorized shares. At December 31, 2020, 486,755 shares have been awarded and 213,245 shares remain available for issuance under the Plan. Option Awards The fair value of each employee and non-employee NRX-101, The fair value of the Company’s common stock, which equaled the exercise price of stock options granted during the years ended December 31, 2020 and 2019, respectively, was determined based on sales of the Company’s shares at arm’s length to unrelated third parties. The grant date fair value of employee and non-employee December 31, 2020 2019 Exercise price $11.00-$15.25 $11.00 Risk-free rate of interest 0.30%-0.49% 1.54%-1.73% Expected term (years) 5.5-6.5 6.0-6.5 Expected stock price volatility 80% 80% Dividend yield — — The following table summarizes the Company’s employee and non-employee Number of shares Weighted exercise price Weighted Aggregate value Outstanding as of December 31, 2018 355,408 $ 5.74 8.2 $ 1,782,729 Granted 28,180 11.00 9.6 Forfeited/Cancelled (50,000 ) — — — Outstanding as of December 31, 2019 333,588 $ 5.74 7.2 $ 1,782,729 Granted 266,500 14.37 9.7 9,761,125 Forfeited /Cancelled (113,333 ) — — — Outstanding as of December 31, 2020 486,755 $ 10.79 8.8 $ 19,571,655 Options vested and exercisable as of December 31, 2020 329,489 $ 6.31 4.0 $ 14,723,342 The aggregate intrinsic value in the above table is calculated as the difference between fair value of the Company’s common stock price and the exercise price of the stock options. The weighted average grant date fair value per share for employee stock and non-employee non-employee Stock-based compensation expense related to stock options, in aggregate, has been reported in general and administrative expense in the amount of $332,065 and $321,087 and research and development expense in the amount of $398,340 and $112,823 in the Company’s statements of operations for the years ended December 31, 2020 and 2019, respectively.

Income Taxes

Income Taxes	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company recorded no provision or benefit for income tax expense for the three months ended March 31, 2021. For all periods presented, the pretax losses incurred by the Company received no corresponding tax benefit because the Company concluded that it is more likely than not that the Company will be unable to realize the value of any resulting deferred tax assets. The Company will continue to assess its position in future periods to determine if it is appropriate to reduce a portion of its valuation allowance in the future. On March 27, 2020, Congress enacted the CARES Act to provide certain relief as a result of the COVID-19 The Company has no open tax audits with any taxing authority as of March 31, 2021.	10. Income Taxes A reconciliation of the statutory U.S. federal income tax rate to the Company’s effective tax rate consist of the following: For the Years 2020 2019 Statutory federal income tax benefit (21.00 )% (21.00 )% Permanent items (0.04 )% 0.01 % Foreign rate differential 0.01 % (0.02 )% State taxes, net of federal tax benefit (1.74 )% 0.60 % Change in valuation allowance 23.01 % 22.23 % R&D credit (0.24 )% (1.90 )% Other — % 0.07 % Effective tax rate — % — % The components of income tax provision (benefit) are as follows: As of December 31, 2020 2019 Federal: Current $ — $ — Deferred (11,015,759 ) (1,496,712 ) State and Local: Current — — Deferred (900,789 ) 39,574 Foreign: Current — — Deferred 2,867 (8,412 ) Change in valuation allowance 11,913,681 1,465,550 Total $ — $ — Deferred income taxes reflect the net tax effects of temporary differences between the carrying value of assets and liabilities for financial reporting purposes and amounts used for income tax purposes. The temporary differences that give rise to deferred tax assets and liabilities are as follows: As of December 31, 2020 2019 Deferred tax assets (liabilities): Net operating loss carryforwards $ 8,243,959 $ 6,943,988 Convertible notes payable discount and embedded derivative — 101,521 Common stock warrants 1,405,796 179,271 Israel net operating loss carryforwards 128,469 131,336 Founder share options 469,062 472,195 Stock-based compensation 681,446 497,315 Settlement liability 9,005,860 — Bonus accrual 120,995 — Other 58,721 — R&D credit 375,000 250,000 20,489,308 8,575,626 Valuation allowance (20,489,308 ) (8,575,626 ) Deferred tax assets, net of allowance $ — $ — As of December 31, 2020 and 2019, the Company had federal and state net operating loss carryforwards of approximately $37,000,000 and $31,200,000, respectively. As of December 31, 2020 and 2019, the Company had approximately $559,000 and $547,000 of foreign net operating loss carryforwards, respectively. The federal, state and foreign net operating loss carryforwards generated in the tax years from 2015 to 2020 will begin to expire, if not utilized, by 2035. Utilization of the net operating loss carryforwards may be subject to an annual limitation according to Section 382 of the Internal Revenue Code of 1986 as amended, and similar provisions. The Company has determined, based upon available evidence, that it is more likely than not that all of the net deferred tax asset will not be realized and, accordingly, has provided a full valuation allowance against its net deferred tax asset. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, net operating loss carryback potential, and tax planning strategies in making these assessments. The Company recorded approximately $1,000,000 as a reduction of the deferred tax asset due to uncertain tax positions that if recognized would reduce Federal and state net operating loss carryforwards and R&D credit carryforwards. In the next twelve months, the Company plans to file amended returns to reduce a portion of its uncertain tax position recorded in the current year. The Company recognizes interest accrued to unrecognized tax benefits and penalties as income tax expense. The Company accrued total penalties and interest of $0 during the years ended December 31, 2020 and 2019 and in total, as of December 31, 2020 and 2019 has recognized penalties and interest of $0. The Company files tax returns as prescribed by the tax laws of the jurisdictions in which they operate. In the normal course of business, the Company is subject to examination by federal and foreign jurisdictions where applicable based on the statute of limitations that apply in each jurisdiction. As of December 31, 2020, open years related to all jurisdictions are 2019, 2018, 2017, 2016 and 2015. The Company has no open tax audits with any taxing authority as of December 31, 2020.

Related Party Transactions

Related Party Transactions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	11. Related Party Transactions The Company licenses patents that are owned by Glytech, LLC, pursuant to a license agreement (the Glytech Agreement). Glytech, LLC is owned by a co-founder co-founder The Fourth Amendment to the Glytech Agreement, effective as of December 31, 2020, includes an equity value-triggered transfer of Excluded Technology from Glytech to NeuroRx. The Excluded Technology is defined in the Glytech Agreement as any technology, and any know-how NRX-100 NRX-101. The CEO of the Company is a major shareholder in the Company. Therefore, his services are deemed to be a related party transaction. He serves the company on a full-time basis and has an employment agreement with the Company and received compensation of $148,750 and $68,750 during the three months ended March 31, 2021 and 2020, respectively. The services are ongoing. The CEO’s son provides services related to website, IT, and marketing support under the supervision of the Company’s Chief Commercial Officer, who is responsible for assuring that the services are provided on financial terms that are at market. NeuroRx paid this family member a total of $18,640 and $22,165 during the three months ended March 31, 2021 and 2020, respectively. In addition, NeuroRx pays Pill Tracker 2015 Ltd. (“Pill Tracker”) for services relating to the development of the inhaled use form of aviptadil. The CEO’s son and our CEO are the chief executive officer and the board chairman, respectively, of Pill Tracker. NeuroRx paid Pill Tracker $140,821 and $0 during the three months ended March 31, 2021 and 2020. The CEO’s other son, as a medical doctor, provides research services related to the development of the inhaled use form of aviptadil, under the supervision of the CEO, who is responsible for assuring that the services are provided on financial terms that are at market. NeuroRx paid this family member a total of $1,495 and $0 during the three months ended March 31, 2021 and 2020. Included in accounts payable were $348,942 and $149,067 due to the above related parties as of March 31, 2021 and December 31, 2020, respectively.	11. Related Party Transactions The Company licenses patents that are owned by Glytech, LLC, pursuant to a license agreement (the Glytech Agreement). Glytech, LLC is owned by a co-founder co-founder The Fourth Amendment to the Glytech Agreement, effective as of December 31, 2020, includes an equity value-triggered transfer of Excluded Technology from Glytech to NeuroRx. The Excluded Technology is defined in the Glytech Agreement as any technology, and any know-how D-cycloserine NRX-100 NRX-101. The CEO of the Company is a major shareholder in the Company. Therefore, his services are deemed to be a related party transaction. He serves the company on a full-time basis and has an employment agreement with the Company and received compensation of $456,459 and $452,400 during the years ended December 31, 2020 and 2019, respectively. The services are ongoing. The CEO’s son provides services related to website, IT, and marketing support under the supervision of the Company’s Chief Commercial Officer, who is responsible for assuring that the services are provided on financial terms that are at market. NeuroRx paid this family member a total of $85,915 and $48,000 during the years ended December 31, 2020 and 2019, respectively. In addition, NeuroRx pays Pill Tracker 2015 Ltd. (“Pill Tracker”) for services relating to the development of the inhaled use form of aviptadil. The CEO’s son and our CEO are the chief executive officer and the board chairman, respectively, of Pill Tracker. NeuroRx paid Pill Tracker $271,082 during the year ended December 31, 2020. NeuroRx made no payments to Pill Tracker in 2019. The CEO’s other son, as a medical doctor, provides research services related to the development of the inhaled use form of aviptadil, under the supervision of the CEO, who is responsible for assuring that the services are provided on financial terms that are at market. NeuroRx paid this family member a total of $11,650 during the year ended December 31, 2020. NeuroRx made no payments to this family member in 2019. Included in accounts payable were $149,067 and $92,744 due to the above related parties as of December 31, 2020 and 2019, respectively.

Subsequent Events

Subsequent Events	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events Issuance of Common Stock Subsequent to March 31, 2021, the Company sold 19,736 shares of common stock for net proceeds of $1,421,024, and 1,000 shares of common stock for net proceeds of $15,250. Issuance of Stock Option Awards Subsequent to March 31, 2021, the Company granted 3,500 stock option awards. The stock options will vest three years from the date of grant.	12. Subsequent Events Issuance of Common Stock Subsequent to December 31, 2020, the Company sold 43,018 shares of common stock for gross proceeds of $2,495,058, and 79,400 shares of common stock for gross proceeds of $5,716,800. Issuance of Stock Option Awards Subsequent to December 31, 2020, the Company granted 42,500 stock option awards. The stock options will vest three years from the date of grant. Aviptadil Supply Agreement On January 4, 2021 NeuroRx and Aerogen Limited (“Aerogen”) signed a supply agreement for the supply of certain products, including the Areogen Solo Nebulizer System and Aerogen Ultra, solely for the purposes of carrying out clinical trials relating to inhalation delivery of RLF-100 COVID-19 Merger with Big Rock Acquisition Corp. On May 24, 2021, the Company completed the merger with Big Rock (see Note 7) with the Company being the surviving entity. Upon the closing, Big Rock changed its name to NRX Pharmaceuticals, Inc. (“NRx Pharmaceuticals or NRXP”). At the effective time of the Business Combination, or the Effective Time, each share of NeuroRx preferred stock and common stock issued and outstanding immediately prior to the Effective Time converted into the right to receive 3.16 shares of Big Rock common stock plus two contingent value rights. The first contingent value right was the right to receive 1.58 additional shares of NRXP stock if, prior to December 31, 2022, the NeuroRx COVID-19 Drug receives Emergency Use Authorization by the FDA and NRXP submits and the FDA files for review a new drug application for the NeuroRx COVID-19 Drug. The second contingent value right was the right to receive approximately $5 per share of NeuroRx common stock upon the earlier to occur of (a) FDA approval of the NeuroRx COVID-19 Drug and the listing of the NeuroRx COVID-19 Drug in the FDA’s “Orange Book” and (b) FDA approval of the NeuroRx Antidepression Drug Regimen and the listing of the NeuroRx Antidepression Drug Regimen in the FDA’s “Orange Book”, in each case prior to December 31, 2022.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) as determined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited interim condensed financial statements reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the balances and results for the periods presented. The results of operations for any interim periods are not necessarily indicative of the results that may be expected for the entire fiscal year or any other interim period.	Basis of Presentation The Company’s financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”) as determined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”).
Use of Estimates	Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in its financial statements and the reported amounts of expenses during the reporting period. The most significant estimates in the Company’s financial statements relate to the valuation of common and preferred stock, stock options, warrants, and the valuation allowance of deferred tax assets resulting from net operating losses. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected.	Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in its financial statements and the reported amounts of expenses during the reporting period. The most significant estimates in the Company’s financial statements relate to the valuation of common and preferred stock, stock options, warrants, the embedded put feature in convertible notes and the valuation allowance of deferred tax assets resulting from net operating losses. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected.
Certain Risks and Uncertainties	Certain Risks and Uncertainties The Company’s activities are subject to significant risks and uncertainties including the risk of failure to secure additional funding to properly execute the Company’s business plan. The Company is subject to risks that are common to companies in the pharmaceutical industry, including, but not limited to, development by the Company or its competitors of new technological innovations, dependence on key personnel, reliance on third party manufacturers, protection of proprietary technology, and compliance with regulatory requirements.	Certain Risks and Uncertainties The Company’s activities are subject to significant risks and uncertainties including the risk of failure to secure additional funding to properly execute the Company’s business plan. The Company is subject to risks that are common to companies in the pharmaceutical industry, including, but not limited to, development by the Company or its competitors of new technological innovations, dependence on key personnel, reliance on third party manufacturers, protection of proprietary technology, and compliance with regulatory requirements.
Cash and Cash Equivalents		Cash and Cash Equivalents The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents. As of December 31, 2020 and 2019, the Company does not have any cash equivalents.
Fair Value of Financial Instruments	Fair Value of Financial Instruments ASC 820, Fair Value Measurements The accounting guidance classifies fair value measurements in one of the following three categories for disclosure purposes: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Inputs other than Level 1 prices for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and values determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. Fair value measurements discussed herein are based upon certain market assumptions and pertinent information available to management as of and during the three months ended March 31, 2021 and the year ended December 31, 2020. The carrying amount of accounts payable approximated fair value as they are short term in nature. The fair value of warrants issued for settlement and services are estimated based on the Black-Scholes model during the three months ended March 31, 2021 and the year ended December 31, 2020. The carrying value of notes payable approximated the estimated fair values due to their recent issuances. The estimated fair value of the warrants and embedded put, represent Level 3 measurements.	Fair Value of Financial Instruments ASC 820, Fair Value Measurements The accounting guidance classifies fair value measurements in one of the following three categories for disclosure purposes: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Inputs other than Level 1 prices for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and values determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. Fair value measurements discussed herein are based upon certain market assumptions and pertinent information available to management as of and during the years ended December 31, 2020 and 2019. The carrying amount of accounts payable approximated fair value as they are short term in nature. The fair value of warrants issued for services is estimated based on the Black-Scholes model during the years ended December 31, 2020 and 2019. The carrying value of notes payable and convertible notes payable approximated the estimated fair values due to their recent issuances. The estimated fair value of the warrants and embedded put, represent Level 3 measurements.
Foreign Currency		Foreign Currency The Company’s functional currency is the U.S. dollar. The functional currency of our foreign operation is the respective local currency. Assets and liabilities of foreign operation denominated in local currencies are translated at the spot rate in effect at the applicable reporting date. The consolidated statements of operations are translated at the weighted average rate of exchange during the applicable period. The resulting unrealized cumulative translation adjustment is not material to the financial statements.
Accounts Receivable	Accounts Receivable Accounts receivable consist of balances due from collaborative partners. In determining collectability, historical trends are evaluated, and specific partner issues are reviewed on a periodic basis to arrive at appropriate allowances. As of March 31, 2021, the Company has recorded an allowance for doubtful accounts of $3,676,826 as the Company does not expect to collect on amounts due to the Company owed from Relief.	Accounts Receivable Accounts receivable consist of balances due from collaborative partners. In determining collectability, historical trends are evaluated, and specific partner issues are reviewed on a periodic basis to arrive at appropriate allowances. As of December 31, 2020, the Company has recorded an allowance for doubtful accounts of $257,463.
Concentration of Credit Risk and Off-Balance Sheet Risk	Concentration of Credit Risk and Off-Balance Cash is the only financial instrument that is potentially subject to concentrations of credit risk. The Company’s cash is deposited in accounts at large financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash is held. The Company has no financial instruments with off-balance	Concentration of Credit Risk and Off-Balance Cash is the only financial instrument that is potentially subject to concentrations of credit risk. The Company’s cash is deposited in accounts at large financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash is held. The Company has no financial instruments with off-balance
Concentration of Credit Risk and Off-Balance Sheet Risk	Concentration of Credit Risk and Off-Balance Cash is the only financial instrument that is potentially subject to concentrations of credit risk. The Company’s cash is deposited in accounts at large financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash is held. The Company has no financial instruments with off-balance	Concentration of Credit Risk and Off-Balance Cash is the only financial instrument that is potentially subject to concentrations of credit risk. The Company’s cash is deposited in accounts at large financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash is held. The Company has no financial instruments with off-balance
Research and Development Costs	Research and Development Costs The Company’s research and development expenses consist primarily of costs associated with the Company’s clinical trials, salaries, payroll taxes, employee benefits, and stock-based compensation charges for those individuals involved in ongoing research and development efforts. Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received.	Research and Development Costs The Company’s research and development expenses consist primarily of costs associated with the Company’s clinical trials, salaries, payroll taxes, employee benefits, and stock-based compensation charges for those individuals involved in ongoing research and development efforts. Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received.
Derivative Financial Instruments		Derivative Financial Instruments The Company does not use derivative instruments to hedge exposures to interest rate, market, or foreign currency risks. The Company evaluates all of its financial instruments, to determine if such instruments contain features that qualify as embedded derivatives. Embedded derivatives must be separately measured from the host contract if all the requirements for bifurcation are met. The assessment of the conditions surrounding the bifurcation of embedded derivatives depends on the nature of the host contract. Bifurcated embedded derivatives are recognized at fair value, with changes in fair value recognized in the statement of operations each period. Bifurcated embedded derivatives are classified with the related host contract in the Company’s balance sheet.
Stock-Based Compensation	Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees	Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees
Income Taxes	Income Taxes Income taxes are recorded in accordance with ASC 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company recognizes any interest and penalties accrued related to unrecognized tax benefits as income tax expense.	Income Taxes Income taxes are recorded in accordance with ASC 740, Income Taxes (“ASC 740”), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company recognizes any interest and penalties accrued related to unrecognized tax benefits as income tax expense.
Loss Per Share	Loss Per Share Basic loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted loss per share excludes, when applicable, the potential impact of stock options, common stock warrant shares, and convertible preferred stock because their effect would be anti-dilutive due to our net loss. Since the Company had a net loss in each of the periods presented, basic and diluted net loss per common share are the same. The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share attributable to common stock for the periods presented because their effect would have been anti-dilutive. Three Months Ended 2021 2020 Convertible preferred stock as if converted 2,371,710 2,371,710 Stock options 489,255 220,255 Common stock warrants 1,200,307 57,474	Loss Per Share Basic loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted loss per share excludes, when applicable, the potential impact of stock options, common stock warrant shares, and convertible preferred stock because their effect would be anti-dilutive due to our net loss. Since the Company had a net loss in each of the periods presented, basic and diluted net loss per common share are the same. The calculation of basic and diluted net loss per share attributable to common stock was as follows: As of December 31, 2020 2019 Numerator: Net loss attributable to common stock—basic and diluted $ (51,776,904 ) $ (6,729,161 ) Denominator: Weighted average shares—basic and diluted 10,845,240 10,690,209 Net loss per share attributable to common stock—basic and diluted $ (4.77 ) $ (0.63 ) The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share attributable to common stock for the periods presented because their effect would have been anti-dilutive. Year Ended December 31, 2020 2019 Convertible preferred stock as if converted 2,371,710 2,367,543 Stock options 486,755 333,588 Common stock warrants 620,054 57,473
Recent Accounting Pronouncements	Recent Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes	Recent Accounting Pronouncements In June 2018, the FASB issued ASU 2018-07, 2018-07

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Calculation of Basic and Diluted Net Loss Per Share Attributable to Common Stock		The calculation of basic and diluted net loss per share attributable to common stock was as follows: As of December 31, 2020 2019 Numerator: Net loss attributable to common stock—basic and diluted $ (51,776,904 ) $ (6,729,161 ) Denominator: Weighted average shares—basic and diluted 10,845,240 10,690,209 Net loss per share attributable to common stock—basic and diluted $ (4.77 ) $ (0.63 )
Schedule of Outstanding Shares of Common Stock Equivalents Excluded From Diluted Net Loss Per Share	The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share attributable to common stock for the periods presented because their effect would have been anti-dilutive. Three Months Ended 2021 2020 Convertible preferred stock as if converted 2,371,710 2,371,710 Stock options 489,255 220,255 Common stock warrants 1,200,307 57,474	The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share attributable to common stock for the periods presented because their effect would have been anti-dilutive. Year Ended December 31, 2020 2019 Convertible preferred stock as if converted 2,371,710 2,367,543 Stock options 486,755 333,588 Common stock warrants 620,054 57,473

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of accrued and other current liabilities	Accrued and other current liabilities consisted of the following at the dates indicated: March 31, December 31, (Unaudited) Accrued and other current liabilities: Accrued research and development expenses $ 568,155 $ 586,426 Accrued employee expenses 530,500 530,500 Professional services 45,705 606,553 Other accrued liabilities 16,547 5,004 Total accrued and other current liabilities $ 1,160,907 $ 1,728,483	Accrued and other current liabilities consisted of the following at the dates indicated: December 31, 2020 2019 Accrued and other current liabilities: Professional services $ 606,553 $ — Accrued research and development expenses 586,426 — Accrued employee expenses 530,500 — Other accrued liabilities 5,004 9,649 Total accrued and other current liabilities $ 1,728,483 $ 9,649

Debt Disclosure (Tables)

Debt Disclosure (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of convertible notes payable and accrued interest		December 31, 2020 2019 Convertible Notes: 2017 convertible notes payable due November 2021 $ — $ 2,500,000 2018 convertible note payable due January 2022 — 100,000 2018 convertible notes payable due April 2022 — 200,000 Fair value of embedded put — 738,602 Debt discount — (296,437 ) Carrying value of convertible notes $ — $ 3,242,165 Accrued interest — 349,891 Total convertible notes payable and accrued interest $ — $ 3,592,056 December 31, 2020 2019 Convertible Notes: Convertible notes payable and accrued interest, current $ — $ 130,251 Convertible notes payable and accrued interest, non-current — 3,461,805 Total convertible notes payable and accrued interest $ — $ 3,592,056
Notes payable and accrued interest		December 31, 2020 2019 Note Payable — Related Party $ 154,190 $ 154,190 Relief Therapeutics Loan 500,000 — Paycheck Protection Program Loan 119,842 — Carrying value of notes payable 774,032 154,190 Accrued interest 22,656 — Total notes payable and accrued interest $ 796,688 $ 154,190 December 31, 2020 2019 Notes payable: Notes payable and accrued interest, current $ 248,861 $ 154,190 Notes payable and accrued interest, non-current 547,827 — Total notes payable and accrued interest $ 796,688 $ 154,190
Notes Payable and Accrued Interest	March 31, December 31, (Unaudited) Note Payable — Related Party $ 154,190 $ 154,190 Relief Therapeutics Loan 500,000 500,000 Paycheck Protection Program Loan — 119,842 Carrying value of notes payable 654,190 774,032 Accrued interest 26,869 22,656 Note payable $ 681,059 $ 796,688 March 31, December 31, (Unaudited) Notes payable: Notes payable and accrued interest, current $ 171,134 $ 248,861 Notes payable and accrued interest, non-current 509,925 547,827 Total notes payable and accrued interest $ 681,059 $ 796,688

Equity (Tables)

Equity (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Summary of activity in warrants	The following table provides the activity in warrants for the respective periods. Total Warrants Weighted Weighted Aggregate Outstanding as of December 31, 2020 620,055 11.08 $ 14.61 $ 22,127,594 Issued 1,053,738 3.00 15.84 59,177,926 Exercised (473,486 ) (15.84 ) (26,590,974 ) Outstanding as of March 31, 2021 1,200,306 6.80 $ 15.21 $ 54,714,546	The following table provides the activity in warrants for the respective periods. Total Warrants Weighted Weighted Average Outstanding as of December 31, 2018 48,627 2.88 $ 7.90 $ — Issued 8,846 5.00 11.00 — Outstanding as of December 31, 2019 57,473 2.22 $ 8.38 $ — Issued 562,581 4.99 15.25 20,112,271 Outstanding as of December 31, 2020 620,054 11.08 $ 14.61 $ 22,127,594
Schedule of Assumptions	The following assumptions were used during the following periods: March 31, December 31, Strike price $15.84 $15.25 Volatility rate 80.0% 80.0% Risk-free rate 0.31% 0.19%-0.28% Expected term 3.00 3.00-5.00 Dividend yield — —	The following assumptions were used during the following periods: December 31, 2020 2019 Strike price $15.25 $11.00 Volatility rate 80.0% 80.0% Risk-free rate 0.19%-0.28% 2.40% Expected term 3.00-5.00 5.00 Dividend yield — —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of option pricing model	The following assumptions were used during the following periods: March 31, 2021 December 31, 2020 Exercise price $58.00 $11.00-$15.25 Risk-free rate of interest 0.20%-0.34% 0.30%-0.49% Expected term (years) 6.0 5.5-6.5 Expected stock price volatility 80% 80% Dividend yield — —	The following assumptions were used during the following periods: December 31, 2020 2019 Exercise price $11.00-$15.25 $11.00 Risk-free rate of interest 0.30%-0.49% 1.54%-1.73% Expected term (years) 5.5-6.5 6.0-6.5 Expected stock price volatility 80% 80% Dividend yield — —
Disclosure of share-based compensation arrangements by share-based payment award	The following table summarizes the Company’s employee and non-employee Number of Weighted Weighted Aggregate Outstanding as of December 31, 2020 486,755 $ 10.79 8.8 $ 19,571,655 Granted 42,500 58.00 9.8 595,000 Forfeited (40,000 ) — — — Outstanding as of March 31, 2021 489,255 $ 14.58 8.7 $ 30,388,510 Options vested and exercisable as of March 31, 2021 376,493 $ 6.21 4.0 $ 24,771,202	The following table summarizes the Company’s employee and non-employee Number of shares Weighted exercise price Weighted Aggregate value Outstanding as of December 31, 2018 355,408 $ 5.74 8.2 $ 1,782,729 Granted 28,180 11.00 9.6 Forfeited/Cancelled (50,000 ) — — — Outstanding as of December 31, 2019 333,588 $ 5.74 7.2 $ 1,782,729 Granted 266,500 14.37 9.7 9,761,125 Forfeited /Cancelled (113,333 ) — — — Outstanding as of December 31, 2020 486,755 $ 10.79 8.8 $ 19,571,655 Options vested and exercisable as of December 31, 2020 329,489 $ 6.31 4.0 $ 14,723,342

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Effective Tax Rate to Statutory Federal Rate	A reconciliation of the statutory U.S. federal income tax rate to the Company’s effective tax rate consist of the following: For the Years 2020 2019 Statutory federal income tax benefit (21.00 )% (21.00 )% Permanent items (0.04 )% 0.01 % Foreign rate differential 0.01 % (0.02 )% State taxes, net of federal tax benefit (1.74 )% 0.60 % Change in valuation allowance 23.01 % 22.23 % R&D credit (0.24 )% (1.90 )% Other — % 0.07 % Effective tax rate — % — %
Schedule of Components of Income Tax Provision (Benefit)	The components of income tax provision (benefit) are as follows: As of December 31, 2020 2019 Federal: Current $ — $ — Deferred (11,015,759 ) (1,496,712 ) State and Local: Current — — Deferred (900,789 ) 39,574 Foreign: Current — — Deferred 2,867 (8,412 ) Change in valuation allowance 11,913,681 1,465,550 Total $ — $ —
Schedule of Deferred Tax Assets and Liabilities	The temporary differences that give rise to deferred tax assets and liabilities are as follows: As of December 31, 2020 2019 Deferred tax assets (liabilities): Net operating loss carryforwards $ 8,243,959 $ 6,943,988 Convertible notes payable discount and embedded derivative — 101,521 Common stock warrants 1,405,796 179,271 Israel net operating loss carryforwards 128,469 131,336 Founder share options 469,062 472,195 Stock-based compensation 681,446 497,315 Settlement liability 9,005,860 — Bonus accrual 120,995 — Other 58,721 — R&D credit 375,000 250,000 20,489,308 8,575,626 Valuation allowance (20,489,308 ) (8,575,626 ) Deferred tax assets, net of allowance $ — $ —

Liquidity - Additional Informat

Liquidity - Additional Information (Detail) - USD ($)	Mar. 28, 2021	Feb. 12, 2020	Apr. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Liquidity [Line Items]
Cash				$ 13,271,579	$ 271,758	$ 1,858,513	$ 877,421	$ 621,296
Proceeds from collaboration agreement				771,245		10,160,421
Proceeds from issuance of common stock		$ 10,000,000		$ 14,426,876	$ 176,990	$ 2,579,114	$ 5,802,002
Proceeds from exercise of warrants	$ 7,500,018
Warrants and rights outstanding	473,486			1,200,306		620,054	57,473	48,627
Subsequent Event [Member]
Schedule of Liquidity [Line Items]
Common stock, issued			19,736
Proceeds from issuance of common stock			$ 1,421,024
Subsequent Event [Member] | Transaction one [Member]
Schedule of Liquidity [Line Items]
Common stock, issued			19,736	43,018
Proceeds from issuance of common stock			$ 1,421,024	$ 2,495,058
Subsequent Event [Member] | Transaction two [Member]
Schedule of Liquidity [Line Items]
Common stock, issued			1,000	79,400
Proceeds from issuance of common stock			$ 15,250	$ 5,716,800

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Summary Of Significant Accounting Policies [Abstract]
Allowance for doubtful accounts	$ 3,676,826	$ 257,463

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Calculation of Basic and Diluted Net Loss Per Share Attributable to Common Stock (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss attributable to common stock-basic and diluted	$ (25,488,874)	$ (1,590,056)	$ (51,776,904)	$ (6,729,161)
Denominator:
Weighted average shares-basic and diluted	11,284,247	10,689,811	10,845,240	10,690,209
Net loss per share attributable to common stock-basic and diluted	$ (2.26)	$ (0.15)	$ (4.77)	$ (0.63)

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Outstanding Shares of Common Stock Equivalents Excluded From Diluted Net Loss Per Share (Detail) - shares	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share	2,371,710	2,371,710	2,371,710	2,367,543
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share	489,255	220,255	486,755	333,588
Common stock warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share	1,200,307	57,474	620,054	57,473

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities - Summary of accrued and other current liabilities (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accrued and other current liabilities:
Professional services	$ 45,705	$ 606,553
Accrued research and development expenses	568,155	586,426
Accrued employee expenses	530,500	530,500
Other accrued liabilities	16,547	5,004	$ 9,649
Total accrued and other current liabilities	$ 1,160,907	$ 1,728,483	$ 9,649

Convertible Notes Payable - Tot

Convertible Notes Payable - Total convertible notes payable and accrued interest (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Note payable	$ 681,059	$ 796,688	$ 154,190
Fair value of embedded put			738,602
Debt discount			(296,437)
Carrying value of convertible notes			3,242,165
Accrued interest			349,891
Total convertible notes payable and accrued interest			3,592,056
Convertible notes payable and accrued interest, current			130,251
Convertible notes payable and accrued interest, non-current			3,461,805
Total convertible notes payable and accrued interest			3,592,056
2017 Convertible Notes Payable Due November 2021 [Member]
Note payable			2,500,000
2018 Convertible Notes Payable Due January 2022 [Member]
Note payable			100,000
2018 Convertible Notes Payable Due April 2022 [Member]
Note payable			$ 200,000

Convertible Notes Payable - Add

Convertible Notes Payable - Additional Information (Detail) - USD ($)	Apr. 28, 2020	Feb. 12, 2020	Apr. 25, 2018	Jan. 05, 2018	Nov. 19, 2017	Nov. 16, 2017	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Apr. 06, 2020
Schedule of Convertible Notes [Line Items]
Sale and issuance of common shares		$ 10,000,000
Fair value per share		$ 11
Accrued interest converted into common stock		42,006
Discounted price per share		$ 8.80
Accrued interest		$ 369,660					$ 26,869		$ 22,656
Fair value of the common shares issued									$ 306,641
Interest rate							6.00%		6.00%		2.00%
Accrued interest										$ 349,891
Debt discount										296,437
Amortization debt discount							$ 0	$ 16,454	$ 16,475	130,433
Interest paid									0	0
Proceeds from issuance from common stock		$ 10,000,000					$ 14,426,876	176,990	$ 2,579,114	$ 5,802,002
Common stock par value		$ 11					$ 0.001		$ 0.001	$ 0.001
Common stock fair value							$ 306,641
Accrued interest payable duration	2 years
Interest paid							0	0
Convertible Debt [Member]
Schedule of Convertible Notes [Line Items]
Aggregate principal amount of convertible notes		$ 2,800,000
Accrued interest converted into common stock		318,183
Discounted price per share		$ 8.80
Two Thousand Ans Seventeen Convertible Notes [Member]
Schedule of Convertible Notes [Line Items]
Convertible notes gross proceeds					$ 2,500,000
Interest rate					6.00%
Principal and interest maturity date					4 years
Sale of stock					$ 10,000,000
Conversion price description					Outstanding principal balance will be converted into the number of such securities sold at a conversion price equal to 80% of the securities negotiated share price.
Accrued interest			$ 200,000
Two Thousand And Eighteen Note [Member]
Schedule of Convertible Notes [Line Items]
Convertible notes gross proceeds			$ 300,000
Interest rate			6.00%
Principal and interest maturity date			4 years
Sale of stock			$ 10,000,000
Conversion price description			Outstanding principal balance will be converted into the number of such securities sold at a conversion price equal to 80% of the securities negotiated share price.
Accrued interest				$ 100,000
Two Thousand Seventeen And Eighteen Convertible Notes Payable[Member]
Schedule of Convertible Notes [Line Items]
Debt discount									$ 493,982	$ 57,204
Recognized loss									$ 27,160	$ 162,866
Two Thousand Seventeen And Eighteen Convertible Notes Payable[Member]
Schedule of Convertible Notes [Line Items]
Convertible common stock		318,183
Aggregate convertible note value		$ 2,800,000
Discount price per share		$ 8.80
Accrued and unpaid interest		$ 369,660
Recognized gain (loss)at fair value							0	$ (27,160)
Two Thousand Seventeen And Eighteen Convertible Notes Payable[Member] | Accrued Income Receivable [Member]
Schedule of Convertible Notes [Line Items]
Convertible common stock		42,006
Two Thousand Ans Seventeen Convertible Notes [Member]
Schedule of Convertible Notes [Line Items]
Convertible notes gross proceeds			$ 200,000	100,000	$ 2,500,000	$ 2,500,000
Common stock fair value							$ 10,000,000
Accrued interest rate							6.00%
Accrued interest payable duration							4 years
Two Thousand Eighteen Convertible Notes Payable [Member]
Schedule of Convertible Notes [Line Items]
Convertible notes gross proceeds			$ 300,000	$ 300,000
Common stock fair value							$ 10,000,000
Accrued interest rate							6.00%
Accrued interest payable duration							4 years

Notes Payable - Notes payable a

Notes Payable - Notes payable and Accrued Interest (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Feb. 12, 2020
Note Payable - Related Party	$ 154,190	$ 154,190	$ 154,190
Carrying value of notes payable	654,190	774,032	154,190
Accrued interest	26,869	22,656		$ 369,660
Note payable	681,059	796,688	154,190
Notes payable and accrued interest, current	171,134	248,861	154,190
Notes payable and accrued interest, non-current	509,925	547,827
Total notes payable and accrued interest	681,059	796,688	$ 154,190
Relief Therapeutics Loan [Member]
Note Payable - Related Party	$ 500,000	500,000
Paycheck Protection Program Loans [Member]
Note Payable - Related Party		$ 119,842

Notes Payable - Additional Info

Notes Payable - Additional Information (Detail) - USD ($)	Apr. 28, 2020	Apr. 06, 2020	Jul. 01, 2019	Mar. 31, 2021	Dec. 31, 2020
Related party loan			$ 154,190
Interest rate		2.00%		6.00%	6.00%
Related party loan		$ 500,000
Debt Instrument, Maturity Date		Apr. 6, 2022
Loan funding	$ 119,842
Principal and interest due	6744
Outstanding principal rate	1.00%
Loan term	2 years
Loan forgiveness, description	The Loan amount may be eligible for forgiveness pursuant to (1) at least 75% of the loan proceeds are used to cover payroll costs and the remainder is used for mortgage interest, rent and utility costs over the eight week period after the loan is made, and (2) the number of employees and compensation levels are generally maintained.
Outstanding principal written off				$ 119,842
Outstanding accrued and unpaid interest written off				969
Gain on extinguishment of debt				$ 120,810
Pay Check Protection Program [Member]
Loan funding	$ 119,842
Principal and interest due	6744
Outstanding principal rate	1.00%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)

May 14, 2021

May 11, 2021

Jan. 04, 2021

Dec. 13, 2020

Aug. 25, 2020

Mar. 28, 2021

Dec. 13, 2020

Oct. 31, 2019

Apr. 30, 2019

Dec. 31, 2018

Mar. 31, 2021

Mar. 31, 2020

Dec. 31, 2020

Dec. 31, 2019

Oct. 09, 2020

Commitments and Contingencies [Line Items]

Rent expense

$ 6,617

$ 8,815

$ 54,649

$ 42,040

Settlement liability expense

$ 5,616,732

Transfer of shares, value

5,500,000

Legal costs

5,616,732

Founder returned shares

300,000

Percentage of company's annual requirements

100.00%

Account receivable, net

831,390

Allowance for doubtful accounts

$ 3,676,826

257,463

Warrant issued

1,053,738

Exercise price of warrant

$ 15.84

Warrants expire period

The GEM Warrant will be valid for a period of three years from the date the Company's stock is listed for trading on a national securities exchange or consummation of a reverse merger transaction.

Accrued settlement expense

39,486,139

Allowance for doubtful accounts

$ 3,676,826

257,463

Warrant issued

1,053,738

Exercise price of warrant

$ 15.84

Warrants to purchase shares

473,486

Warrants to purchase shares, amount

$ 7,500,018

Warrants expire period

The GEM Warrant will be valid for a period of three years from the date the Company's stock is listed for trading on a national securities exchange or consummation of a reverse merger transaction.

Accrued settlement expense

39,486,139

Additional settlement liability

$ 21,365,641

$ 21,365,641

$ 39,486,139

GEM Warrant [Member]

Commitments and Contingencies [Line Items]

Warrant issued

1,053,738

Exercise price of warrant

$ 15.84

Warrants to purchase shares

473,486

Warrants to purchase shares, amount

$ 7,500,000

Warrants expire period

The GEM Warrant will be valid for a period of three years from the date the Company's stock is listed for trading on a national securities exchange or consummation of a reverse merger transaction.

Accrued settlement expense

$ 39,486,139

Warrant issued

1,053,738

Exercise price of warrant

$ 15.84

Warrants expire period

The GEM Warrant will be valid for a period of three years from the date the Company's stock is listed for trading on a national securities exchange or consummation of a reverse merger transaction.

Accrued settlement expense

$ 39,486,139

Former Adviser [Member]

Commitments and Contingencies [Line Items]

Transfer of shares

45,454

Transfer of shares, value

$ 499,994

Maximum [Member]

Commitments and Contingencies [Line Items]

Annual maintenance fees

$ 150,000

Jonathan Javitt Living Trust [Member]

Commitments and Contingencies [Line Items]

Transfer of shares

250,000

Glytech L- L- C- [Member]

Commitments and Contingencies [Line Items]

Transfer of shares

250,000

Sarah Herzog Memorial Hospital Ezrat Nashim [Member]

Commitments and Contingencies [Line Items]

Transfer of shares

500,000

500,000

Milestone payments

$ 250,000

Transfer of shares, value

$ 5,500,000

Sarah Herzog Memorial Hospital Ezrat Nashim [Member] | Minimum [Member]

Commitments and Contingencies [Line Items]

Royalty percentage

100.00%

Sarah Herzog Memorial Hospital Ezrat Nashim [Member] | Maximum [Member]

Commitments and Contingencies [Line Items]

Annual maintenance fees

$ 150,000

Royalty percentage

250.00%

Development Milestone [Member] | Minimum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

$ 100,000

Development Milestone [Member] | Maximum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

750,000

Development Milestone [Member] | Sarah Herzog Memorial Hospital Ezrat Nashim [Member] | Minimum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

$ 100,000

Development Milestone [Member] | Sarah Herzog Memorial Hospital Ezrat Nashim [Member] | Maximum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

750,000

Commercial Milestone [Member] | Minimum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

100,000

Commercial Milestone [Member] | Maximum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

$ 750,000

Commercial Milestone [Member] | Sarah Herzog Memorial Hospital Ezrat Nashim [Member] | Minimum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

100,000

Commercial Milestone [Member] | Sarah Herzog Memorial Hospital Ezrat Nashim [Member] | Maximum [Member]

Commitments and Contingencies [Line Items]

Milestone payments

750,000

Relief Therapeutics Collaboration Agreement [Member]

Commitments and Contingencies [Line Items]

Reimbursable expenses

$ 10,904,065

$ 10,612,750

4,190,608

10,160,421

Account receivable, net

831,390

Reimbursable expenses received

770,444

9,329,031

Allowance for doubtful accounts

3,676,826

257,463

Invoiced costs

4,000,000

4,000,000,000,000

Reimbursable expenses

10,904,065

10,612,750

4,190,608

10,160,421

Reimbursable expenses received

770,444

9,329,031

Allowance for doubtful accounts

$ 3,676,826

$ 257,463

Invoiced costs

$ 4,000,000

$ 4,000,000,000,000

Big Rock Partners Acquisition Corp [Member] | Merger Agreement [Member]

Commitments and Contingencies [Line Items]

Closing Consideration shares

50,000,000

Earnout Shares Milestone

25,000,000

25,000,000

Earnout Cash Milestone

$ 100,000,000

$ 100,000,000

Earnout Shares Milestone Description

An aggregate of 25 million additional shares of Big Rock common stock ("Earnout Shares") will be issued to NeuroRx pre-merger equity holders if, prior to December 31, 2022, (1) the Company's COVID-19 drug receives emergency use authorization by the FDA and (2) the FDA accepts the Company's filing of its application to approve the Company's COVID-19drug.

Earnout Cash Milestone Description

In addition, subject to certain conditions, $100 million ("Earnout Cash") may be payable to NeuroRx pre-merger equity holders if, prior to December 31, 2022, either (1) FDA approval of the Company's COVID-19Drug is obtained and the Company's COVID-19 Drug is listed in the FDA's "Orange Book" and (2) FDA approval of the Company's Antidepressant Drug Regimen is obtained and the Company's Antidepressant Drug Regimen is listed in the FDA's "Orange Book".

Closing Consideration shares

50,000,000

Earnout Shares Milestone

25,000,000

25,000,000

Earnout Cash Milestone

$ 100,000,000

$ 100,000,000

Earnout Shares Milestone Description

An aggregate of 25 million additional shares of Big Rock common stock ("Earnout Shares") will be issued to NeuroRx pre-merger equity holders if, prior to December 31, 2022, (1) the Company's COVID-19 drug receives emergency use authorization by the FDA and (2) the FDA accepts the Company's filing of its application to approve the Company's COVID-19drug.

Earnout Cash Milestone Description

In addition, subject to certain conditions, $100 million ("Earnout Cash") may be payable to NeuroRx pre-merger equity holders if, prior to December 31, 2022, either (1) FDA approval of the Company's COVID-19Drug is obtained and the Company's COVID-19 Drug is listed in the FDA's "Orange Book" and (2) FDA approval of the Company's Antidepressant Drug Regimen is obtained and the Company's Antidepressant Drug Regimen is listed in the FDA's "Orange Book".

GEM Share Subcription Facility Agreement [Member]

Commitments and Contingencies [Line Items]

Share subscription agreement term

3 years

3 years

Share subscription value

$ 95,600,000

$ 95,600,000

Commitment fee

$ 1,900,000

$ 1,900,000

Share subscription agreement term

3 years

3 years

Share subscription value

$ 95,600,000

$ 95,600,000

Commitment fee

$ 1,900,000

$ 1,900,000

Merger Agreement With Neurorx And Merger Sub [Member] | Big Rock Partners Acquisition Corp [Member]

Commitments and Contingencies [Line Items]

Closing Consideration shares

50,000,000

Closing Consideration shares

50,000,000

Contingent Milestone Payments [Member] | Merger Agreement With Neurorx And Merger Sub [Member] | Big Rock Partners Acquisition Corp [Member]

Commitments and Contingencies [Line Items]

Earnout Shares Milestone

25,000,000

Earnout Cash Milestone

$ 100,000,000

Earnout Shares Milestone Description

An aggregate of 25 million additional shares of Big Rock common stock ("Earnout Shares") will be issued to NeuroRx pre-merger equity holders if, prior to December 31, 2022, (1) the Company's COVID-19 drug receives emergency use authorization by the FDA and (2) the FDA accepts the Company's filing of its application to approve the Company's COVID-19drug.

Earnout Cash Milestone Description

$100 million ("Earnout Cash") may be payable to NeuroRx pre-merger equity holders if, prior to December 31, 2022, either (1) FDA approval of the Company's COVID-19Drug is obtained and the Company's COVID-19 Drug is listed in the FDA's "Orange Book" and (2) FDA approval of the Company's Antidepressant Drug Regimen is obtained and the Company's Antidepressant Drug Regimen is listed in the FDA's "Orange Book".

Earnout Shares Milestone

25,000,000

Earnout Cash Milestone

$ 100,000,000

Earnout Shares Milestone Description

An aggregate of 25 million additional shares of Big Rock common stock ("Earnout Shares") will be issued to NeuroRx pre-merger equity holders if, prior to December 31, 2022, (1) the Company's COVID-19 drug receives emergency use authorization by the FDA and (2) the FDA accepts the Company's filing of its application to approve the Company's COVID-19drug.

Earnout Cash Milestone Description

$100 million ("Earnout Cash") may be payable to NeuroRx pre-merger equity holders if, prior to December 31, 2022, either (1) FDA approval of the Company's COVID-19Drug is obtained and the Company's COVID-19 Drug is listed in the FDA's "Orange Book" and (2) FDA approval of the Company's Antidepressant Drug Regimen is obtained and the Company's Antidepressant Drug Regimen is listed in the FDA's "Orange Book".

Polypeptide [Member]

Commitments and Contingencies [Line Items]

Purchase commitments

$ 1,010,000

Purchase commitments

$ 1,010,000

Aerogen Limited [Member]

Commitments and Contingencies [Line Items]

Purchase order of products

$ 54,315

Sponsored Research Agreement [Member]

Commitments and Contingencies [Line Items]

Research commitments

$ 360,450

Research commitments paid

$ 126,157

Equity - Additional Information

Equity - Additional Information (Detail) - USD ($)	Mar. 28, 2021	Oct. 23, 2020	Jul. 15, 2020	Jul. 06, 2020	Feb. 12, 2020	Jan. 31, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Mar. 01, 2020	Dec. 31, 2018
Stockholders Equity [Line Items]
Common stock, shares authorized							20,000,000		20,000,000	14,060,001	14,060,001
Proceeds from issuance of common stock					$ 10,000,000		$ 14,426,876	$ 176,990	$ 2,579,114	$ 5,802,002
Debt conversion, converted instrument, amount									$ 3,655,438
Loss on settlement of accounts payable							$ (120,810)
Warrant issued							1,053,738		562,581	8,846
Warrant, exercise price per share							$ 15.21		$ 14.61	$ 8.38		$ 7.90
Accounts Payable [Member]
Stockholders Equity [Line Items]
Common shares issued									9,500
Debt conversion, converted instrument, amount									$ 144,875
Debt conversion, original debt, amount									103,258
Loss on settlement of accounts payable									$ 41,617
Convertible Series A Preferred Stock [Member]
Stockholders Equity [Line Items]
Convertible preferred stock, shares authorized							1,000,000		1,000,000	1,000,000
Convertible preferred stock, shares issued							1,000,000		1,000,000	1,000,000
Convertible preferred stock, par value							$ 0.001		$ 0.001	$ 0.001
Preferred stock, conversion basis									One share of Common Stock for each preferred share
Convertible preferred stock,liquidation preference per share							$ 1		$ 1
Convertible Series B-1 Preferred Stock [Member]
Stockholders Equity [Line Items]
Convertible preferred stock, shares authorized							1,050,695		1,050,695	1,050,695
Convertible preferred stock, shares issued							1,050,695		1,050,695	1,050,695
Convertible preferred stock, par value							$ 0.001		$ 0.001	$ 0.001
Preferred stock, conversion basis									One share of Common Stock for each preferred share
Convertible preferred stock,liquidation preference per share							$ 7.58		$ 7.58
Convertible Series B-1A Preferred Stock [Member]
Stockholders Equity [Line Items]
Convertible preferred stock, shares authorized							316,848		316,848	316,848
Convertible preferred stock, shares issued							316,848		316,848	316,848
Convertible preferred stock, par value							$ 0.001		$ 0.001	$ 0.001
Preferred stock, conversion basis									One share of Common Stock for each preferred share
Convertible preferred stock,liquidation preference per share							$ 6.82		$ 6.82
Convertible Series B-2 Preferred Stock [Member]
Stockholders Equity [Line Items]
Convertible preferred stock, shares authorized							100,000	100,000	100,000	100,000
Convertible preferred stock, shares issued							4,167	4,167	4,167	0
Convertible preferred stock, par value							$ 0.001	$ 0.001	$ 0.001	$ 0.001
Preferred stock, conversion basis									One share of Common Stock for each share of Series B-2 Convertible Preferred Stock
Convertible preferred stock,liquidation preference per share								$ 12	$ 12
Common stock warrants [Member]
Stockholders Equity [Line Items]
Warrant issued	1,053,738	139,645	279,291	4,000		8,846
Warrant, exercise price per share	$ 15.84	$ 15.25	$ 15.25	$ 15.25		$ 11
Warrant expiry date	Mar. 27, 2024	Oct. 22, 2025	Jul. 14, 2025	Jul. 5, 2023		Jan. 30, 2024
Fair value on the date of issuance	$ 60,851,779	$ 2,693,221	$ 2,689,684	$ 30,536		$ 63,337
Warrant, fair valued price per share		$ 9.64	$ 9.63	$ 7.63		$ 7.16
warrants vested		139,645
Warrants exercised	473,486
Gross proceeds from exercise of warrants	$ 7,500,018
Common Stock
Stockholders Equity [Line Items]
Common shares issued							105,418	16,090	171,796	536,354
Proceeds from issuance of common stock							$ 6,926,858	$ 176,990

Equity - Schedule of Warrants (

Equity - Schedule of Warrants (Detail) - USD ($)	Mar. 28, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Beginning Balance		620,054		57,473	48,627
Issued		1,053,738		562,581	8,846
Exercised		(473,486)
Ending Balance	473,486	1,200,306	620,054	620,054	57,473	48,627
Weighted average remaining term, issued		3 years		4 years 11 months 26 days	5 years
Outstanding, weighted average remaining term		6 years 9 months 18 days	11 years 29 days	11 years 29 days	2 years 2 months 19 days	2 years 10 months 17 days
Outstanding, weighted average exercise price		$ 14.61		$ 8.38	$ 7.90
Weighted average exercise price,issued		15.84		15.25	11
Weighted average exercise price,exercised		(15.84)
Outstanding, weighted average exercise price		$ 15.21	$ 14.61	$ 14.61	$ 8.38	$ 7.90
Outstanding, average intrinsic value		$ 22,127,594
Average intrinsic value,issued		59,177,926		$ 20,112,271
Average intrinsic value,exercised		(26,590,974)
Outstanding, average intrinsic value		$ 54,714,546	$ 22,127,594	$ 22,127,594

Equity - Schedule of Assumption

Equity - Schedule of Assumptions (Detail) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class of Warrant or Right [Line Items]
Strike price	$ 58
Expected term	6 years	6 years 6 months
Dividend yield		0.00%	0.00%
Common stock warrant [Member]
Class of Warrant or Right [Line Items]
Strike price	$ 15.84	$ 15.25	$ 11
Volatility rate	80.00%	80.00%	80.00%
Risk-free rate	0.31%		2.40%
Expected term	3 years		5 years
Dividend yield	0.00%	0.00%	0.00%
Minimum [Member]
Class of Warrant or Right [Line Items]
Strike price		$ 11	$ 11
Expected term		5 years 6 months	6 years
Minimum [Member] | Common stock warrant [Member]
Class of Warrant or Right [Line Items]
Risk-free rate		0.19%
Expected term		3 years
Dividend yield		0.00%
Maximum [Member]
Class of Warrant or Right [Line Items]
Strike price		$ 15.25	$ 0
Expected term		6 years 6 months	6 years 6 months
Maximum [Member] | Common stock warrant [Member]
Class of Warrant or Right [Line Items]
Risk-free rate		0.28%
Expected term		5 years
Dividend yield		0.00%

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares	Mar. 31, 2020USD ($)$ / shares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2016shares
Equity Incentive Plan [Line Items]
Expected dividend yield			0.00%
Weighted average grant date fair value | $ / shares	$ 41.97	$ 0	$ 9.64	$ 7.69
Unrecognized compensation | $			$ 2,193,874
Weighted-average period			2 years 1 month 2 days
Non vested weighted average grant date fair value | shares	3,188,792
Weighted average period	0	0
General and Administrative Expense [Member]
Equity Incentive Plan [Line Items]
Stock-based compensation expense allocated | $	$ 344,034,000	$ 66,588,000	$ 332,065	$ 321,087
Stock-based compensation expense allocated | $	344,034,000	66,588,000	332,065	321,087
Research and Development Expense [Member]
Equity Incentive Plan [Line Items]
Stock-based compensation expense allocated | $	27,664,000	22,215,000	398,340	112,823
Stock-based compensation expense allocated | $	$ 27,664,000	$ 22,215,000	$ 398,340	$ 112,823
2016 Omnibus Inventive Plan [Member]
Equity Incentive Plan [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized | shares	700,000		700,000		500,000
Share-based compensation arrangement by share-based payment award, number of additional shares authorized | shares			200,000
Share-based compensation arrangement by share-based payment award, shares granted | shares	489,255		486,755
Share-based compensation arrangement by share-based payment award, number of shares available for grant | shares	210,745		213,245

Stock Based Compensation - Summ

Stock Based Compensation - Summary of grant date of stock option award (Detail) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price	$ 58
Exercise price minimum		$ 11
Exercise price maximum		$ 15.25
Risk-free rate of interest	20.00%	30.00%
Risk-free rate of interest	34.00%	49.00%
Expected term (years)	6 years	6 years 6 months
Expected stock price volatility	80.00%	80.00%	80.00%
Dividend yield		0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price		$ 11	$ 11
Risk-free rate of interest		30.00%	154.00%
Expected term (years)		5 years 6 months	6 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price		$ 15.25	$ 0
Risk-free rate of interest		49.00%	173.00%
Expected term (years)		6 years 6 months	6 years 6 months

Share based compensation - Summ

Share based compensation - Summary of stock option activity (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, Number of shares	486,755	333,588	355,408
Granted	42,500	266,500	28,180
Forfeited /Cancelled	(40,000)	(113,333)	(50,000)
Outstanding, Number of shares	489,255	486,755	333,588	355,408
Options vested and exercisable	376,493	329,489
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding, Weighted average exercise price	$ 10.79	$ 5.74	$ 5.74
Granted	58	14.37	11
Forfeited	0	0	0
Outstanding, Weighted average exercise price	14.58	10.79	$ 5.74	$ 5.74
Options vested and exercisable	$ 6.21	$ 6.31
Outstanding, intrinsic value
Outstanding, intrinsic value	$ 19,571,655	$ 1,782,729	$ 1,782,729
Granted	595,000	9,761,125
Forfeited	0	0	0
Outstanding, intrinsic value	$ 30,388,510	$ 19,571,655	$ 1,782,729	$ 1,782,729
Options vested and exercisable, Weighted remaining contractual life (in years)	4 years	4 years
Options vested and exercisable	$ 24,771,202	$ 14,723,342
Outstanding, weighted remaining contractual life (in years)
Granted	9 years 9 months 18 days	9 years 8 months 12 days	9 years 7 months 6 days
Outstanding, weighted remaining contractual life (in years)	8 years 8 months 12 days	8 years 9 months 18 days	7 years 2 months 12 days	8 years 2 months 12 days

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Effective Tax Rate to Statutory Federal Rate (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory federal income tax benefit	(21.00%)	(21.00%)
Permanent items	(0.04%)	0.01%
Foreign rate differential	0.01%	(0.02%)
State taxes, net of federal tax benefit	(1.74%)	0.60%
Change in valuation allowance	23.01%	22.23%
R&D credit	$ (0.0024)	$ (0.0190)
Other		0.07%
Effective tax rate	0.00%	0.00%

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Provision (Benefit) (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Federal
Current			$ 0	$ 0
Deferred			(11,015,759)	(1,496,712)
State and Local
Current			0	0
Deferred			(900,789)	39,574
Foreign
Current			0	0
Deferred			2,867	(8,412)
Change in valuation allowance			11,913,681	1,465,550
Total	$ 0	$ 0	$ 0	$ 0

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 8,243,959	$ 6,943,988
Convertible notes payable discount and embedded derivative		101,521
Common stock warrants	1,405,796	179,271
Israel net operating loss carryforwards	128,469	131,336
Founder share options	469,062	472,195
Stock-based compensation	681,446	497,315
Settlement liability	9,005,860
Bonus accrual	120,995
Other	58,721
R&D credit	375,000	250,000
Total deferred tax assets before valuation allowance	20,489,308	8,575,626
Valuation allowance	(20,489,308)	(8,575,626)
Deferred tax assets, net of allowance	$ 0	$ 0

Income taxes - Additional Infor

Income taxes - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Deferred tax asset due to uncertain tax posistions			$ 1,000,000
Accrued penalties and interest,total			0	$ 0
Recognized penalties and interest			0	0
Provision or benefit for income tax expense	$ 0	$ 0	0	0
Federal and State [Member]
Net operating losses carryforwards			37,000,000	31,200,000
Foreign Tax Authority [Member]
Net operating losses carryforwards			$ 559,000	$ 547,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Aaccounts payable due to related parties	$ 348,942		$ 149,067	$ 92,744
CEO [Member]
Related Party Transaction [Line Items]
Compensation amount received related to related party transaction	148,750	$ 68,750	456,459	452,400
Neuro Rx [Member] | Chief Executive Officer Son [Member]
Related Party Transaction [Line Items]
Payment to related party	1,495	0
Neuro Rx [Member] | Chief Executive Officer and Chairman of Board [Member]
Related Party Transaction [Line Items]
Payment to related party	140,821	0	271,082	0
Neuro Rx [Member] | Chief Commercial Officer [Member]
Related Party Transaction [Line Items]
Payment to related party	18,640	22,165	85,915	48,000
Neuro Rx [Member] | CEO [Member]
Related Party Transaction [Line Items]
Payment to related party			11,650	0
Neuro Rx [Member] | Glytech Agreement [Member]
Related Party Transaction [Line Items]
Continuing technology support services and reimbursed expenses	$ 0	$ 82,569	$ 272,929	$ 464,720
Related party transaction description	The Excluded Technology will transfer to the Company for no additional consideration if the value of NeuroRx equity held by Glytech exceeds $50,000,000 at any time prior to August 6, 2022. After August 6, 2022, the additional IP will transfer to the Company at no cost.		The Excluded Technology will transfer to the Company for no additional consideration if the value of NeuroRx equity held by Glytech exceeds $50,000,000 at any time prior to August 6, 2022. After August 6, 2022, the additional IP will transfer to the Company at no cost.

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($)	May 24, 2021	Apr. 01, 2021	Jan. 04, 2021	Jan. 01, 2021	Feb. 12, 2020	Apr. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Net proceeds from issuance of common stock					$ 10,000,000		$ 14,426,876	$ 176,990	$ 2,579,114	$ 5,802,002
Stock option awards granted							42,500		266,500	28,180
Aerogen Limited [Member]
Subsequent Event [Line Items]
Purchase order for products amounted			$ 54,315
Subsequent Event [Member]
Subsequent Event [Line Items]
Issuance of common stock shares						19,736
Net proceeds from issuance of common stock						$ 1,421,024
Stock option awards granted		3,500		42,500
Stock options, vesting period		3 years		3 years
Subsequent Event [Member] | Big Rock Partners Acquisition Corp [Member] | Merger Agreement [Member]
Subsequent Event [Line Items]
Business combination description	At the effective time of the Business Combination, or the Effective Time, each share of NeuroRx preferred stock and common stock issued and outstanding immediately prior to the Effective Time converted into the right to receive 3.16 shares of Big Rock common stock plus two contingent value rights. The first contingent value right was the right to receive 1.58 additional shares of NRXP stock if, prior to December 31, 2022, the NeuroRx COVID-19 Drug receives Emergency Use Authorization by the FDA and NRXP submits and the FDA files for review a new drug application for the NeuroRx COVID-19 Drug. The second contingent value right was the right to receive approximately $5 per share of NeuroRx common stock upon the earlier to occur of (a) FDA approval of the NeuroRx COVID-19 Drug and the listing of the NeuroRx COVID-19 Drug in the FDA’s “Orange Book” and (b) FDA approval of the NeuroRx Antidepression Drug Regimen and the listing of the NeuroRx Antidepression Drug Regimen in the FDA’s “Orange Book”, in each case prior to December 31, 2022.
Right to receive common stock	3.16
Contingent value right to receive additional shares	1.58
Contingent value right to receive per shares	$ 5
Subsequent Event [Member] | Aerogen Limited [Member]
Subsequent Event [Line Items]
Purchase order for products amounted			$ 54,315
Subsequent Event [Member] | Transaction one [Member]
Subsequent Event [Line Items]
Issuance of common stock shares						19,736	43,018
Net proceeds from issuance of common stock						$ 1,421,024	$ 2,495,058
Subsequent Event [Member] | Transaction two [Member]
Subsequent Event [Line Items]
Issuance of common stock shares						1,000	79,400
Net proceeds from issuance of common stock						$ 15,250	$ 5,716,800
Issuance of common stock shares							79,400
Net proceeds from issuance of common stock							$ 5,716,800