United States securities and exchange commission logo





                              May 5, 2021

       Richard Ackerman
       Chief Executive Officer
       Big Rock Partners Acquisition Corp.
       2645 N. Federal Highway, Suite 230
       Delray Beach, FL 33483

                                                        Re: Big Rock Partners
Acquisition Corp.
                                                            Amendment No. 1 to
Registration Statement on Form S-4
                                                            Filed April 16,
2021
                                                            File No. 333-252479

       Dear Mr. Ackerman:

             We have reviewed your amended registration statement and have the
following
       comments. In some of our comments, we may ask you to provide us with
information so we
       may better understand your disclosure.

              Please respond to this letter by amending your registration
statement and providing the
       requested information. If you do not believe our comments apply to your
facts and
       circumstances or do not believe an amendment is appropriate, please tell
us why in your
       response.

              After reviewing any amendment to your registration statement and
the information you
       provide in response to these comments, we may have additional comments.
Unless we note
       otherwise, our references to prior comments are to comments in our
February 26, 2021 letter.

       Amendment No. 1 to Registration Statement on Form S-4

       Cover Page

   1.                                                   Please revise your
disclosure here and elsewhere in the prospectus to clarify what
                                                        percentage of the
shares in the combined company will be owned by the Sponsor and what
                                                        percentage of shares in
the combined company will be owned by BRPA's public
                                                        stockholders.
   2.                                                   We note your revised
cover page disclosure in response to prior comment 5. Given that
                                                        the listing condition
is waivable, please revise the cover page to prominently disclose that
                                                        shareholders will not
have certainty at the time they vote regarding whether the Common
                                                        Stock and Warrants will
be listed on a national securities exchange following the business
                                                        combination. Also,
reference the risk factor disclosure on page 72.
 Richard Ackerman
Big Rock Partners Acquisition Corp.
May 5, 2021
Page 2


Summary of the Proxy Statement / Prospectus / Consent Solicitation Statement,
page 22

3.       With reference to your disclosure on page 46, please update the
Summary section to
         discuss NeuroRx's dispute with Relief Therapeutics Holding AG. Also,
revise the second
         paragraph of the coverpage to provide a cross reference to the
"Division of Profits"
         disclosure on page 211.
Risk Factors
Our product candidates are in Phase IIb/III of clinical testing, page 45

4.       Please reconcile this risk factor with your disclosures on page 180
and elsewhere. In this
         regard, it should be clear in the risk factor which drug or drug
candidates you are
         referencing and whether the trials are completed or remain open. Also,
we note your
         disclosure that you will need to commit substantial time and
additional resources to
         conducting further nonclinical studies and clinical trials before you
can submit an NDA.
         Accordingly, revise, if appropriate, to discuss the funding and the
trials needed to
         commercialize NRX-101, or revise to clarify the risk factor
disclosure.

We do not anticipate maintaining orphan drug protection for the treatment of
COVID-19..., page
49

5.       Please revise to disclose the dates that the parties received and/or
transferred the orphan
         drug designations covering RLF-100 and NRX-101.
We must enter into agreements with, and depend upon, one or more partners...,
page 69

6.       We note your response to prior comment 7 and updated disclosure and
re-issue. In this
         regard, it remains unclear whether your plan is for the collaboration
agreement with Relief
         Therapeutics to provide the funding necessary to commercialize ZYESAMI
in the markets
         covered under the agreement.
Proposal No. 1 -- The Business Combination Proposal
Merger Consideration, page 103

7.     We note your response to prior comment 8 and revised disclosure. Please
revise to clarify
       whether the terms of the Earnout Cash Milestone (i) require the cash to
be delivered to
       NeuroRx stockholders within a specified period of time and (ii) allow
for any contingency
       or delay in payment if NRX Pharmaceuticals does not have sufficient
capital and is unable
FirstName LastNameRichard Ackerman
       to raise sufficient capital in order to pay the Earnout Cash,
particularly if NRX
Comapany    NameBig Rock
       Pharmaceuticals       Partners
                         is still in theAcquisition Corp.
                                        process of beginning to commercialize
ZYESAMI when the
May 5,Earnout
        2021 PageCash
                    2 becomes due.
FirstName LastName
 Richard Ackerman
FirstName  LastNameRichard
Big Rock Partners AcquisitionAckerman
                              Corp.
Comapany
May  5, 2021NameBig Rock Partners Acquisition Corp.
May 5,
Page 3 2021 Page 3
FirstName LastName
Big Rock's Board of Directors' Reasons for Approval of the Merger Agreement,
page 112

8.       We refer to prior comment 10 and note the disclosure that EBC
presented a comparable
         companies analysis to the Board. Please explain whether this analysis
served as a basis
         for the Board's valuation of the company or either of the two lead
drug candidates. If it
         did, then please revise to clarify this point and present the
comparable companies analysis
         in the prospectus. If it did not serve as a basis, then revise to
explain how the Board came
         to that conclusion concerning the comparable companies analysis.
9.       Please revise to explain whether the Board's valuation of NeuroRx was
predicated on any
         material assumptions regarding the timing of regulatory approval
and/or authorization for
         either of the two lead product candidates. Also revise to indicate
whether NeuroRx
         provided the Board with financial projections. To the extent that
projections were
         provided, please indicate when the projections were provided and
whether the Board used
         such projections to value NeuroRx.
BRPA's Management's Discussion and Analysis of Financial Condition and Results
of
Operations
Liquidity and Capital Resources, page 174

10.      We note your response to prior comment 12 and revised disclosure. We
further note your
         disclosure on page F-8 indicates that BRAC is affiliated with the
"underwriter." Please
         revise throughout to clarify, if true, that BRAC Lending Group is
affiliated with Early
         Bird Capital, the underwriter of BRPA's initial public offering, and
discuss any associated
         conflicts of interest.
Beneficial Ownership of Securities of BRPA and NRX Pharmaceuticals, page 176

11.      Please revise to identify the natural persons with voting and/or
dispositive control of the
         shares held by GEM Yield Bahamas Limited in footnote 10 to the
beneficial ownership
         table.
Business of NeuroRx, page 179

12.      We note your statements that ZYESAMI has "demonstrated clear benefit
in both survival
         and recovery from respiratory failure" and that it is the first
COVID-19 therapeutic to
         "demonstrate advantages in both survival and recovery from critical
COVID-19." Please
         revise to avoid stating that ZYESAMI has demonstrated "clear benefit"
or "advantages" as
         this may create an inference that your product is likely to be
declared safe and effective,
         which is a determination solely in the authority of regulatory
agencies such as the
         FDA. You may present clinical trial end points and objective data
resulting from trials
         without concluding efficacy. In your revisions, please also clarify
that the results from
         your clinical trials of ZYESAMI do not provide a guarantee that
ZYESAMI will be
         deemed to be safe or effective for the treatment of COVID-19, and that
extensive clinical
         testing and regulatory approval will be required before ZYESAMI can be
commonly
 Richard Ackerman
Big Rock Partners Acquisition Corp.
May 5, 2021
Page 4
         prescribed for the treatment of COVID-19.
13.      We note your response to prior comment 18 and re-issue. Please revise
the Business of
         NeuroRx section, where appropriate, to disclose the nature of
NeuroRx's material
         intellectual property including the scope of the patent protection for
NeuroRx's product
         candidates and whether such patents are owned or licensed as well as
the duration of any
         patents, trademarks, licenses, franchises and concessions held by
NeuroRx.
ZYESAMI Phase IIb/III Clinical Trial for treatment of Respiratory Failure in
Critical COVID-
19, page 180

14.      We note your statement on page 181 that ZYESAMI demonstrated a
meaningful benefit in
         survival after controlling for ventilation status and treatment site.
Please revise to clearly
         explain the meaning of the term "meaningful benefit" and whether the
results were
         statistically significant. Also explain why and how NeuroRx
"controlled for ventilation
         status and treatment site". Present the results before controlling for
ventilation status and
         treatment site.
Initial Human Studies of ZYESAMI in COVID-19 with Respiratory Failure, page 186

15.      Please revise your disclosure in this section to provide a brief
overview of statistical
         significance and how the FDA assesses whether trial data demonstrates
statistical
         significance.
16.      We refer to a December 30, 2020 joint press release with Relief
Therapeutics and a
         February 23, 2021 article by Endpoints News (as updated on February
26, 2021) which
         both indicate that in December 2020 FDA denied your September 2020
emergency use
         authorization application. Please advise or revise the prospectus
summary, as well as
         other appropriate sections of the prospectus, to discuss this
regulatory determination,
         including the stated basis, if any, for FDA   s decision. Also revise
the Business section to
         present the 28-day data and discuss any and all changes to endpoints
used during the
         course of the clinical trial.
Critical COVID-19 with Respiratory Failure, page 192

17.    We note your response to prior comment 23 and re-issue. Please revise
your description of
       the trial under this heading, as well as the trial under the heading
"Critical COVID-19 with
       Severe Comorbidity Expanded Access", to disclose who is conducting the
trial, the phase
       of the trial, the primary and secondary endpoints, metrics utilized, the
number and nature
       of any drug-related adverse events and the planned duration of the
trial. To the extent any
       of these trials has been completed, please disclose whether the trial
achieved its primary
FirstName LastNameRichard Ackerman
       and secondary endpoints. If the disclosure in these sections is
duplicative of disclosure
Comapany    NameBig
       that appears     Rock Partners
                      elsewhere in the Acquisition Corp. consider removing this
disclosure or
                                       document, please
May 5,including
        2021 Pagea 4cross-reference.
FirstName LastName
 Richard Ackerman
FirstName  LastNameRichard
Big Rock Partners AcquisitionAckerman
                              Corp.
Comapany
May  5, 2021NameBig Rock Partners Acquisition Corp.
May 5,
Page 5 2021 Page 5
FirstName LastName
General

18.      Please ensure that the opinions and consents of both Marcum and KPMG
are included in
         your next amendment in order for the Staff to timely process it.
       You may contact Tracie Mariner at (202) 551-3744 or Al Pavot at (202)
551-3738 if you
have questions regarding comments on the financial statements and related
matters. Please
contact Alan Campbell at (202) 551-4224 or Joe McCann at (202) 551-6262 with
any other
questions.



                                                           Sincerely,

                                                           Division of
Corporation Finance
                                                           Office of Life
Sciences
cc:      Jeffrey M. Gallant, Esq.