SecProbe.io

CORRESP
 1
 filename1.htm

 CORRESP

 September 4, 2025
 VIA EDGAR U.S. Securities and Exchange Commission
 Division of Corporation Finance 100 F Street,
N.E. Washington, D.C. 20549

 Attn:

 Joshua Gorsky

 Re:

 Rein Therapeutics, Inc.

 Registration Statement on Form S-1

 File No. 333-290016

 Acceleration Request

 Requested Date:

 Friday, September 5, 2025

 Requested Time:

 4:30 p.m., Eastern Daylight Time
 Ladies and Gentlemen:
 In accordance with Rule 461 under the Securities Act of 1933, as amended, the undersigned registrant, Rein Therapeutics,
Inc. (the “ Registrant ”), hereby requests that the Securities and Exchange Commission (the “ Commission ”) take appropriate action to cause the Registration Statement on Form S-1 (File No. 333-290016) (the “ Registration Statement ”) to become effective on September 5, 2025, at 4:30 p.m., Eastern Daylight Time, or
as soon as practicable thereafter, or at such later time as the Registrant may orally request via telephone call to the staff of the Commission (the “ Staff ”). The Registrant hereby authorizes Daniel Donahue of Greenberg
Traurig, LLP, counsel to the Registrant, to make such request on its behalf. Once the Registration Statement has been
declared effective, please orally confirm that event with Daniel Donahue of Greenberg Traurig, LLP, counsel to the Registrant, at (949) 732-6557.
 In connection with this request, the Registrant acknowledges that:

 •

 should the Commission or the Staff, acting pursuant to delegated authority, declare the Registration Statement
effective, it does not foreclose the Commission from taking any action with respect to the Registration Statement;

 •

 the action of the Commission or the Staff, acting pursuant to delegated authority, in declaring the
Registration Statement effective, does not relieve the Registrant from its full responsibility for the adequacy and accuracy of the disclosure in the Registration Statement; and

 •

 the Registrant may not assert Staff comments and the declaration of effectiveness as a defense in any
proceeding initiated by the Commission or any person under the federal securities laws of the United States.

 Very truly yours,

 Rein Therapeutics, Inc.

 By:

 /s/ Brian Windsor

 Brian Windsor, Ph.D.,

 President and Chief Executive Officer

 cc:
 Daniel Donahue, Greenberg Traurig, LLP

<DOCUMENT>
<TYPE>TEXT-EXTRACT
<SEQUENCE>2
<FILENAME>filename2.txt
<TEXT>
 September 4, 2025

Brian Windsor
Chief Executive Officer
Rein Therapeutics, Inc.
12407 N. Mopac Expy., Suite 250 #390
Austin, TX 78758

 Re: Rein Therapeutics, Inc.
 Registration Statement on Form S-1
 Filed September 3, 2025
 File No. 333-290016
Dear Brian Windsor:

 This is to advise you that we have not reviewed and will not review your
registration
statement.

 Please refer to Rules 460 and 461 regarding requests for acceleration.
We remind you
that the company and its management are responsible for the accuracy and
adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action
by the staff.

 Please contact Joshua Gorsky at 202-551-7836 with any questions.

 Sincerely,

 Division of
Corporation Finance
 Office of Life
Sciences
cc: Daniel K. Donahue
</TEXT>
</DOCUMENT>

<DOCUMENT>
<TYPE>TEXT-EXTRACT
<SEQUENCE>2
<FILENAME>filename2.txt
<TEXT>
 May 21, 2025

Brian Windsor, Ph.D.
President and Chief Executive Officer
Rein Therapeutics, Inc.
12407 N. Mopac Expy., Suite 250 #390
Austin, TX 78758

 Re: Rein Therapeutics, Inc.
 Registration Statement on Form S-3
 Filed May 16, 2025
 File No. 333-287342
Dear Brian Windsor Ph.D.:

 This is to advise you that we have not reviewed and will not review your
registration
statement.

 Please refer to Rules 460 and 461 regarding requests for acceleration.
We remind you
that the company and its management are responsible for the accuracy and
adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action
by the staff.

 Please contact Chris Edwards at 202-551-6761 with any questions.

 Sincerely,

 Division of
Corporation Finance
 Office of Life
Sciences
cc: Molly W. Fox
</TEXT>
</DOCUMENT>

CORRESP
 1
 filename1.htm

 CORRESP

 REIN THERAPEUTICS, INC.
 12407 N. Mopac Expy., Suite 250 #390
 Austin, Texas 78758 May 21, 2025
 VIA EDGAR United States Securities and Exchange
Commission Division of Corporation Finance 100 F Street,
N.E. Washington, D.C. 20549 Attn: Christopher Edwards

 Re:
 Rein Therapeutics, Inc.
 Registration Statement on Form S-3
 File No. 333-287342
 Request for Acceleration Ladies and
Gentlemen: Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Rein Therapeutics, Inc. (the
“ Registrant ”) hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-287342), so that it may
become effective at 4:00 p.m. Eastern time on May 22, 2025, or as soon thereafter as practicable, or at such later time as the Registrant or its counsel may orally request via telephone call to the staff.

 Very truly yours,

 REIN THERAPEUTICS, INC.

 By:

 /s/ Brian Windsor

 Name:

 Brian Windsor, Ph.D.

 Title:

 President and Chief Executive Officer

 cc:
 Stuart Falber, Wilmer Cutler Pickering Hale and Dorr LLP
 Molly Fox, Wilmer Cutler Pickering Hale and Dorr LLP

CORRESP
1
filename1.htm

Acceleration Request

 February 1, 2024

VIA EDGAR SUBMISSION

 Securities and Exchange
Commission

 Division of Corporation Finance

 100 F Street, NE

 Washington, DC 20549

 Attention: Lauren Hamill

Re:
 Aileron Therapeutics, Inc.

Registration Statement on Form S-3

File No. 333-276746

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the “Registrant”) hereby
requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-276746), so that it may become effective at 4:30 p.m.,
Eastern time, on February 5, 2024, or as soon thereafter as practicable, or at such later time as the Registrant or its counsel may orally request via telephone call to the staff.

Very truly yours,

By:

 /s/ Manuel C. Alves Aivado, M.D., Ph.D.

Manuel C. Alves-Aivado, M.D., Ph.D.

Chief Executive Officer

cc:
 Stuart Falber, Wilmer Cutler Pickering Hale and Dorr LLP

Craig Hilts, Wilmer Cutler Pickering Hale and Dorr LLP

United States securities and exchange commission logo
February 1, 2024
Manuel Alves-Aivado
Chief Executive Officer
Aileron Therapeutics Inc.
738 Main Street #398
Waltham, MA 02451
Re:Aileron Therapeutics Inc.
Registration Statement on Form S-3
Filed January 29, 2024
File No. 333-276746
Dear Manuel Alves-Aivado:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you
that the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Lauren Hamill at 303-844-1008 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Craig Hilts

CORRESP
1
filename1.htm

CORRESP

 AILERON THERAPEUTICS, INC.

285 Summer Street, Suite 101

Boston, Massachusetts 02210

 June 14, 2022

 VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
 Aileron Therapeutics, Inc.

Registration Statement on Form S-3

File No. 333-265470

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the
“Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-265470), so that it may
become effective at 4:30 p.m. Eastern time on June 16, 2022, or as soon thereafter as practicable, or at such later time as the Registrant or its counsel may orally request via telephone call to the staff.

Very truly yours,

AILERON THERAPEUTICS, INC.

By:

 /s/ Manuel Aivado

Name:

Manuel Aivado

Title:

President and Chief Executive Officer

cc:
 Stuart Falber, Wilmer Cutler Pickering Hale and Dorr LLP

Craig Hilts, Wilmer Cutler Pickering Hale and Dorr LLP

United States securities and exchange commission logo
June 14, 2022
Manuel C. Alves Aivado, M.D., Ph.D.
President and Chief Executive Officer
Aileron Therapeutics, Inc.
285 Summer Street, Unit 101
Boston, MA 02210
Re:Aileron Therapeutics, Inc.
Registration Statement on Form S-3
Filed June 8, 2022
File No. 333-265470
Dear Dr. Aivado:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration.  We remind you
that the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Joshua Gorsky at 202-551-7836 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Craig Hilts, Esq.

CORRESP
1
filename1.htm

CORRESP

 AILERON THERAPEUTICS, INC.

290 Pleasant Street, Unit 112

Watertown, MA 02472

 February 5, 2021

VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

 Re:

 Aileron Therapeutics, Inc.

 Registration Statement on Form S-3

 File No. 333-252587

 Request for Acceleration

 Ladies and Gentlemen:

Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the “Registrant”)
hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-252587), so that it may become effective at 4:00 p.m.
Eastern time on February 9, 2021, or as soon thereafter as practicable, or at such later time as the Registrant or its counsel may orally request via telephone call to the staff.

 Very truly yours,

AILERON THERAPEUTICS, INC.

By:

 /s/ Richard J.
Wanstall

Name:

 Richard J. Wanstall

 Title:

 Chief Financial Officer and Treasurer

cc:
 Stuart M. Falber

Wilmer Cutler Pickering Hale and Dorr LLP

United States securities and exchange commission logo
February 4, 2021
Manuel C. Alves Aivado, M.D., Ph.D.
President and Chief Executive Officer
Aileron Therapeutics, Inc.
290 Pleasant Street, Unit 112
Watertown, Massachusetts 02472
Re:Aileron Therapeutics, Inc.
Registration Statement on Form S-3
Filed January 29, 2021
File No. 333-252587
Dear Dr. Alves Aivado:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration.  We remind you
that the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Deanna Virginio at 202-551-4530 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Stuart M. Falber, Esq.

CORRESP
1
filename1.htm

CORRESP

 AILERON THERAPEUTICS, INC.

490 Arsenal Way, Suite 210

Watertown, MA 02472

 October 13, 2020

VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
 Aileron Therapeutics, Inc.

Registration Statement on Form S-1

File No. 333-249319

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the
“Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-1 (File No. 333-249319) (the
“Registration Statement”), so that it may become effective at 4:00 p.m. Eastern time on October 15, 2020, or as soon thereafter as practicable.

Very truly yours,

AILERON THERAPEUTICS, INC.

By:

 /s/ Richard J. Wanstall

Name: Richard J. Wanstall

Title:   Chief Financial Officer

cc:
 Stuart M. Falber

Wilmer Cutler Pickering Hale and Dorr LLP

United States securities and exchange commission logo
October 8, 2020
Richard J. Wanstall
Chief Financial Officer
Aileron Therapeutics, Inc.
490 Arsenal Way, Suite 210
Watertown, Massachusetts 02472
Re:Aileron Therapeutics, Inc.
Registration Statement on Form S-1
Filed October 5, 2020
File No. 333-249319
Dear Mr. Wanstall:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration.  We remind you
that the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Abby Adams at (202) 551-6902 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Stuart M. Falber, Esq.

CORRESP
1
filename1.htm

CORRESP

 AILERON THERAPEUTICS, INC.

490 Arsenal Way, Suite 210

Watertown, MA 02472

 August 19, 2020

VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
 Aileron Therapeutics, Inc.

Registration Statement on Form S-3

File No. 333-244367

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the
“Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-244637), so that it may
become effective at 4:00 p.m. Eastern time on August 21, 2020, or as soon thereafter as practicable, or at such later time as the Registrant or its counsel may orally request via telephone call to the staff.

Very truly yours,

AILERON THERAPEUTICS, INC.

By:

 /s/ Richard J. Wanstall

Name:

Richard J. Wanstall

Title:

Chief Financial Officer and Treasurer

cc:
 Stuart M. Falber

Wilmer Cutler Pickering Hale and Dorr LLP

United States securities and exchange commission logo
August 17, 2020
Manuel C. Alves Aivado, M.D., Ph.D.
President and Chief Executive Officer
Aileron Therapeutics, Inc.
490 Arsenal Way, Suite 210
Watertown, MA 02472
Re:Aileron Therapeutics, Inc.
Registration Statement on Form S-3
Filed August 11, 2020
File No. 333-244367
Dear Dr. Aivado:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration.  We remind you
that the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Jeffrey Gabor at 202-551-2544 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Stuart M. Falber, Esq.

CORRESP
1
filename1.htm

CORRESP

 AILERON THERAPEUTICS, INC.

490 Arsenal Way, Suite 210

Watertown, MA 02472

 July 11, 2019

VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
 Aileron Therapeutics, Inc.

Registration Statement on Form S-3

File No. 333-226650

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the
“Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-226650), so that it may
become effective at 4:00 p.m. Eastern time on July 15, 2019, or as soon thereafter as practicable, or at such later time as the Registrant or its counsel may orally request via telephone call to the staff.

Very truly yours,

AILERON THERAPEUTICS, INC.

By:

/s/ Donald V. Dougherty

Name:

Donald V. Dougherty

Title:

Senior Vice President, Chief Financial Officer

cc:
 Stuart M. Falber

Wilmer Cutler Pickering Hale and Dorr LLP

May 23, 2019
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
Manuel C. Alves Aivado, M.D., Ph.D.
Chief Executive Officer
Aileron Therapeutics, Inc.
490 Arsenal Way, Suite 210
Watertown, MA 02472
Re:Aileron Therapeutics, Inc.
Registration Statement on Form S-3
Filed August 7, 2018
File No. 333-226650
Dear Mr. Alves Aivado:
            It has been more than nine months since you filed this registration statement and it is now
out of date.  Within 30 days from the date of this letter, you should either:
•amend it to comply with the applicable requirements of the Securities Act of 1933, the rules
and regulations under the Act, and the requirements of the form; or
•file a request for withdrawal.

            If you requested confidential treatment for portions of any exhibits to your registration
statement and you request withdrawal of that registration statement, please submit a concurrent
request for withdrawal of your application for confidential treatment.
            If you do not amend the registration statement or file a request for withdrawal (or provide
us with a satisfactory explanation of why you have not done either) within 30 days, we may enter
an order declaring the registration statement abandoned under rule 479 of the Act.
            Please contact Ada D. Sarmento at 202-551-3798 with any questions.
Sincerely,

 FirstName LastNameManuel C. Alves Aivado, M.D., Ph.D.
 Comapany NameAileron Therapeutics, Inc.
 May 23, 2019 Page 2
 FirstName LastName
Manuel C. Alves Aivado, M.D., Ph.D.
Aileron Therapeutics, Inc.
May 23, 2019
Page 2
Division of Corporation Finance
Office of Healthcare & Insurance
cc:       The Corporation Trust Company
            CERTIFIED MAIL
            RETURN RECEIPT REQUESTED

CORRESP
1
filename1.htm

CORRESP

 AILERON THERAPEUTICS, INC.

490 Arsenal Way, Suite 210

Watertown, MA 02472

 May 10, 2019

VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
 Aileron Therapeutics, Inc.

Registration Statement on Form S-1

File No. 333-231143

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the
“Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-1 (File No. 333-231143) (the
“Registration Statement”), so that it may become effective at 4:00 p.m. Eastern time on May 14, 2019, or as soon thereafter as practicable.

 Very truly yours,

AILERON THERAPEUTICS, INC.

By:

/s/ Donald V. Dougherty

 Name:

 Title:

 Donald V. Dougherty

 Senior Vice President,
Chief Financial Officer

cc:
 Stuart M. Falber

Wilmer Cutler Pickering Hale and Dorr LLP

May 7, 2019
Manuel C. Alves Aivado, M.D., Ph.D.
President and Chief Executive Officer
Aileron Therapeutics, Inc.
490 Arsenal Way, Suite 210
Watertown, MA 02472
Re:Aileron Therapeutics, Inc.
Registration Statement on Form S-1
Filed May 1, 2019
File No. 333-231143
Dear Dr. Aivado:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration.  We remind you
that the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Jeffrey Gabor at 202-551-2544 with any questions.
Sincerely,
Division of Corporation Finance
Office of Healthcare & Insurance
cc:       Stuart M. Falber, Esq.

August 15, 2018
John P. Longenecker
Chief Executive Officer
Aileron Therapeutics, Inc.
281 Albany Street
Cambridge, MA 02139
Re:Aileron Therapeutics, Inc.
Registration Statement on Form S-3
Filed August 7, 2018
File No. 333-226650
Dear Mr. Longenecker:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration.  We remind you
that the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Ada D. Sarmento at 202-551-3798 with any questions.
Sincerely,
Division of Corporation Finance
Office of Healthcare & Insurance
cc:       Stuart M. Falber, Esq.

CORRESP
1
filename1.htm

Acceleration Request

 AILERON THERAPEUTICS, INC.

281 Albany Street

 Cambridge, MA
02139

 June 26, 2017

 VIA EDGAR

 Securities and Exchange Commission

 Division of
Corporation Finance

 100 F Street, N.E.

 Washington, D.C.
20549

Re:
Aileron Therapeutics, Inc.

Registration Statement on Form S-1

File No. 333-218474

Request for Acceleration

 Ladies and Gentlemen:

Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Aileron Therapeutics, Inc. (the “Registrant”)
hereby requests acceleration of the effective date of its Registration Statement on Form S-1 (File No. 333-218474), as amended (the “Registration Statement”), so that it may become effective at 4:00 p.m. Eastern
time on June 28, 2017, or as soon thereafter as practicable.

 *  *  *  *

Very truly yours,

AILERON THERAPEUTICS, INC.

By:

/s/ Joseph A. Yanchik III

Name:

Joseph A. Yanchik III

Title:

President and Chief Executive Officer

cc:
Stuart M. Falber, Wilmer Cutler Pickering Hale and Dorr LLP

Joshua D. Fox, Wilmer Cutler Pickering Hale and Dorr LLP

Peter N. Handrinos, Latham & Watkins LLP

CORRESP
1
filename1.htm

Acceleration Request

 June 26, 2017

Securities and Exchange Commission

 100 F Street, N.E.

Washington, D.C. 20549

Re:
Aileron Therapeutics, Inc.

Registration Statement on Form S-l (File No. 333-218474)

 Ladies and Gentlemen:

As representatives of the several underwriters for the Company’s proposed public offering of up to 4,312,500 shares of common stock, we
hereby join the Company’s request for acceleration of the above-referenced Registration Statement, requesting effectiveness for 4:00 p.m. Eastern time on June 28, 2017, or as soon thereafter as is practicable.

Pursuant to Rule 460 of the General Rules and Regulations of the Securities and Exchange Commission under the Securities Act of 1933, as
amended, we wish to advise you that we have effected the following distribution of the Company’s Preliminary Prospectus dated June 19, 2017, through the date hereof:

Preliminary Prospectus dated June 19, 2017:

Approximately 1,300 copies to prospective underwriters, institutional investors, dealers and others

The undersigned advise that they have complied and will continue to comply, and that they have been informed by the participating underwriters
and dealers that they have complied with and will continue to comply, with Rule 15c2-8 under the Securities Exchange Act of 1934.

 ***

Very truly yours,

 MERRILL LYNCH, PIERCE, FENNER & SMITH

    INCORPORATED

JEFFERIES LLC

As Representatives of the several Underwriters

 By: MERRILL LYNCH, PIERCE, FENNER & SMITH

          INCORPORATED

By:

/s/ Michele A.H. Allong

Authorized Signatory

By: JEFFERIES LLC

By:

/s/ Michael Judlowe

Authorized Signatory

CORRESP
1
filename1.htm

CORRESP

 +1 617 526 6000(t)

+1 617 526 5000(f)

 wilmerhale.com

 June 19, 2017

 By Electronic Submission

Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.E.

 Washington, D.C. 20549

Attention: Suzanne Hayes

Re:
Aileron Therapeutics, Inc.

 Registration Statement on Form S-1

 Filed June 2, 2017

File No. 333-218474

Ladies and Gentlemen:

 On behalf of Aileron Therapeutics, Inc.
(the “Company”) set forth below is the Company’s response to the comment of the staff (the “Staff”) of the Securities and Exchange Commission provided orally by Joseph McCann of the Staff on June 13, 2017
(the “Oral Comment”) with respect to the Company’s Registration Statement on Form S-1 (the “Registration Statement”).

This letter is being filed with Amendment No. 1 to the Registration Statement (“Amendment No. 1”). For convenience, a
summary of the Oral Comment is set forth below. The Company has responded to the Oral Comment by making changes to the disclosure in the Registration Statement.

1.
Please expand the discussion of the Company’s rights and obligations under the Harvard and Dana Farber Cancer Institute license agreement with respect to third party proposed products.

 Response: In response to the Oral Comment, the Company has revised the disclosure on page 114 of Amendment
No. 1.

 Wilmer Cutler
Pickering Hale and Dorr LLP, 60 State Street, Boston, Massachusetts 02109

Beijing    Berlin    Boston    Brussels    Denver
  Frankfurt    London    Los Angeles    New York    Palo Alto    Washington

 Securities and Exchange Commission

Division of Corporation Finance

 June 19, 2017

Page 2

 If you have any further questions or comments, or if you require any additional information,
please contact the undersigned by telephone at (617) 526-6663 or facsimile at (617) 526-5000. Thank you for your assistance.

Best regards,

 /s/ Stuart M. Falber

Stuart M. Falber

cc:
Vanessa Robertson, Securities and Exchange Commission

 James Rosenberg, Securities
and Exchange Commission

 Jeffrey Gabor, Securities and Exchange Commission

Joseph McCann, Securities and Exchange Commission

Joseph A. Yanchik III, Aileron Therapeutics, Inc.

 Wilmer Cutler Pickering Hale and Dorr LLP, 60 State
Street, Boston, Massachusetts 02109

Beijing    Berlin    Boston    Brussels    Denver
  Frankfurt    London    Los Angeles    New York    Palo Alto    Washington

CORRESP
1
filename1.htm

CORRESP

+1 617 526 6000 (t)

 +1 617 526 5000
(f)

 FOIA CONFIDENTIAL TREATMENT REQUEST

The entity requesting confidential treatment is:

Aileron Therapeutics, Inc.

 281 Albany Street

Cambridge, Massachusetts 02139

 Attn: Joseph A.
Yanchik, III

 President and Chief Executive Officer

(617) 995-0900

 June 7, 2017

BY EDGAR SUBMISSION

 Securities and Exchange
Commission

 Division of Corporation Finance

 100 F Street, NE

 Washington, DC 20549

 Attention: Suzanne Hayes

Re:
Aileron Therapeutics, Inc.

Registration Statement on Form S-1

Filed June 2, 2017

File No. 333-218474

 Ladies and Gentlemen:

On behalf of Aileron Therapeutics, Inc. (the “Company”), set forth below is information in response to comment 5 contained in the letter to
the Company dated October 5, 2015 from the staff (the “Staff”) of the Securities and Exchange Commission (the “Commission”) relating to the Draft Registration Statement on Form S-1 originally submitted by the
Company to the Commission on September 10, 2015. Such Draft Registration Statement has been updated by the Company as reflected in the registration statement referenced above (File No. 333-218474), which was publicly filed by the Company
on June 2, 2017 (the “Registration Statement”). The supplemental response set forth below is based upon information provided to Wilmer Cutler Pickering Hale and Dorr LLP by the Company.

*            *
 *

 Securities and Exchange Commission

June 7, 2017

 Page 2

 Determining the Fair Value of Common Stock Prior to the IPO

As disclosed in the Registration Statement, the Board of Directors of the Company (the “Board”), with input from management, has historically
determined the fair value of the Company’s common stock on the date of each equity grant based on a variety of factors, including third-party valuations of the common stock and the Board’s assessments of additional objective and subjective
factors that it believed were relevant. The common stock valuations were performed using a hybrid method, which is a probability-weighted expected return method, where the equity value in one or more scenarios is calculated using an option-pricing
method. The valuation analyses included judgments and estimates, including the time to completing an initial public offering (“IPO”) or other liquidity event, the probabilities assigned to such events, and the related valuations
under each scenario, among other factors. Contemporaneous valuations were performed as of March 1, 2016 and December 31, 2016 and a retrospective valuation was performed as of March 2, 2017.

Initial Public Offering Price Range

 Rule 83
Confidential Treatment Request by Aileron Therapeutics, Inc. Request #1

 The Company has taken into consideration guidance and market data from its
underwriting team that have been presented to and reviewed by the Board and management on May 26, 2017. To provide further information for the Staff’s consideration, the Company supplementally advises the Staff that the Company currently
anticipates that the price range for this IPO will be within the range of $[**] to $[**] per share (before giving effect to a reverse stock split that the Company plans to implement prior to effectiveness of the Registration Statement). This
anticipated price range is based on a number of factors, including the Company’s future prospects and those of the Company’s industry in general, progress of the Company’s development programs, the market prices of securities of
companies engaged in activities similar to the Company’s, existing conditions in the public capital markets and preliminary discussions with the underwriters regarding potential valuations of the Company. The actual price range to be included
in a subsequent amendment to the Registration Statement (which will comply with the Staff’s interpretation regarding the parameters of a bona fide price range) has not yet been determined and remains subject to adjustment based on factors
outside of the Company’s control. However, the Company believes that the foregoing indicative price range will not be subject to significant change.

The anticipated price range for this IPO was determined with reference to several quantitative and qualitative factors, each of which contributed to the
difference between the Company’s most

Securities and Exchange Commission

 June 7, 2017

Page 3

recent determination of the fair value of its common stock as of March 2, 2017 of $0.65 per share and the midpoint of the anticipated offering price
range of $[**] per share. Specifically, the Company believes that the difference between the fair value of its common stock determined as of March 2, 2017 and the midpoint of the anticipated price range for this IPO is primarily the result of
the following factors:

 Aileron Therapeutics, Inc. respectfully requests that the information contained in the response be treated as confidential
information and that the Commission provide timely notice to Joseph A. Yanchik, III, President and Chief Executive Officer, Aileron Therapeutics, Inc., 281 Albany Street, Cambridge, Massachusetts 02139, (617) 995-0900, before it permits any
disclosure of the bracketed information in Request #1.

•

The estimated price range for this IPO is based only upon a scenario in which the Company completes this IPO and is not probability weighted, in contrast to the Company’s prior third-party valuations of its common
stock. The prior third-party valuations also considered a scenario whereby the Company was acquired by a third party (“M&A Exit”), which would have resulted in a lower fair value of the Company’s common stock than in the
IPO scenario. In the March 2, 2017 retrospective valuation, the probability weighting for the IPO scenario was 60% and the probability weighting for the M&A Exit scenario was 40%. If the Company had applied a weighting of 100% to the IPO
scenario, the fair value of the Company’s common stock in the March 2, 2017 retrospective valuation would have been $1.16 per share, after applying a discount of 15% for lack of marketability.

•

The estimated price range for this IPO necessarily assumes that the Company’s IPO has occurred and a public market for the Company’s common stock has been created, and therefore excludes any discount for lack
of marketability of the Company’s common stock. If the Company had applied a weighting of 100% to the IPO scenario, the fair value of the Company’s common stock in the March 2, 2017 retrospective valuation would have been $1.36 per
share, before giving effect to any discount for lack of marketability and time value of money.

•

The estimated price range for this IPO necessarily assumes that all of the Company’s preferred stock has converted into common stock in connection with this IPO. The Company’s preferred stock currently has
substantial economic rights and preferences over the Company’s common stock. Upon the closing of this IPO, all outstanding shares of the Company’s preferred stock will convert into common stock, thus eliminating the superior rights and
preferences of the preferred stock as compared to the common stock.

 Securities and Exchange Commission

June 7, 2017

 Page 4

•

In “testing-the-waters” meetings held in May 2017, the Company received positive feedback from potential investors.

•

The Company has taken further steps towards the completion of an IPO, including on June 2, 2017, the Company publicly filed the Registration Statement with the Commission.

•

In June 2017, the Company announced data from its ongoing Phase 1 All-comers trial of ALRN-6924 at The American Society of Clinical Oncology 2017 Annual Meeting. Specifically, the Company reported positive interim
safety and efficacy data, including that ALRN-6924 was well tolerated and demonstrated evidence of encouraging anti-tumor activity in this trial.

•

The proceeds of a successful IPO would substantially strengthen the Company’s balance sheet by increasing its cash resources. In addition, the completion of this IPO would provide the Company with more ready access
to the public company equity and debt markets.

•

In the public markets, the Company believes there are investors who may apply more qualitative and subjective valuation criteria to certain of its clinical assets than the valuation methods applied in the Company’s
valuations, although there can be no assurance that this will in fact be the case. As a private company, the Company used a more quantitative methodology to determine the fair value of its common stock and this methodology differs from the
methodology used to determine the estimated price range for this IPO. The estimated price range for this IPO was not derived using a formal determination of fair value, but rather was determined by the estimated price range that we expect will be
negotiated between the Company and the underwriters.

•

The price that investors are willing to pay in this IPO, for which the price range is intended to serve as an estimate, may take into account other factors that have not been expressly considered in the Company’s
prior valuations, are not objectively determinable, and that valuation models are not able to quantify.

 The Company respectfully submits
that the difference between the latest valuation and the midpoint of the anticipated offering price range is reasonable. Please see “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical
Accounting Policies and Use of Estimates—Stock-Based Compensation,” for an additional discussion of the valuation of the Company’s common stock.

 Securities and Exchange Commission

June 7, 2017

 Page 5

 The Company respectfully requests that the Staff return to the undersigned this letter
pursuant to Rule 418 of the Securities Act of 1933, as amended, once the Staff has completed its review. For the convenience of the Staff, we have provided a self-addressed stamped envelope for this purpose. We respectfully reserve the right to
request that this letter be returned to us at an earlier date.

 In addition, the Company requests confidential treatment under 17 C.F.R. § 200.83 for
the contents of this letter and has submitted a separate request for confidential treatment in accordance therewith to the Commission’s Office of Freedom of Information and Privacy Act Operations.

*            *
 *

 Securities and Exchange Commission

June 7, 2017

 Page 6

 If you have any further questions or comments, or if you require any additional
information, please contact the undersigned by telephone at (617) 526-6663. Thank you for your assistance.

 Very truly yours,

/s/ Stuart M. Falber

 Stuart M. Falber

cc:
Jeffrey Gabor, Securities and Exchange Commission

 Joseph McCann, Securities
and Exchange Commission

 Christina De Rosa, Securities and Exchange Commission

Dietrich A. King, Securities and Exchange Commission

Joseph A. Yanchik III, Aileron Therapeutics, Inc.

Joshua D. Fox, Wilmer Cutler Pickering Hale and Dorr LLP

Peter N. Handrinos, Latham & Watkins LLP

Office of Freedom of Information and Privacy Act Operations

Securities and Exchange Commission

100 F Street N.E., Mail Stop 2736

Washington, D.C. 20549

Mail Stop 4546

May 12 , 2017

Joseph A. Yanchik III
President and Chief Executive Officer
Aileron Therapeutics, Inc.
281 Albany Street
Cambridge, MA 02139

Re: Aileron Therapeutics, Inc.
  Amendment No. 3  to Draft Registration Statement on Form S -1
Submitted April  17, 2017
  CIK No. 0001420565

Dear Mr. Yanchik :

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

Please respond to this letter by providing the requested information and either submitting
an amended draft registration statement or publicly filing your registration stateme nt on
EDGAR.  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 the information you provide in response to these  comments  and your
amended draft registration statement or filed registration statement,  we may have  additional
comments.

Overview, page 1

1. We refer to the first sentence in the second paragraph of the Summary.  Please revise to
explain briefly the basis for your disclos ure that ALRN -6924 “has been generally well
tolerated” by patients in your clinical trials in light of your disclosures on pages 19 and
98 concerning the frequency of adverse events.  Also, revise your disclosures on page 1,
19, and 98 to clarify whether t he conclusion concerning tolerability represents the
company’s assessment of the trial results or that of the “trial’s investigators.”  To the
extent that it is the latter, please identify the investigators and provide their consent.
Refer to Rule 436.

Joseph A. Yanchik III
Aileron Therapeutics, Inc.
May 12, 2017
Page 2

 2. Please revise the disclosure on page 2 to explain briefly the meaning of the term
“equipotently.”

Our Development Pipeline, page 4

3. Please revise your development pipeline chart on page 4 to remove the program that is in
the discovery phase.  Because you have not identified a product candidate for these
programs, it is premature to highlight this program in your development table.

4. Please include a column for Phase 3 in your development pipeline chart on pages 4 and
87.

5. We refer to your disclosure on page 2 indicating that you are currently conducting a
Phase 1 All -comers trials.  Please revise the development pipeline chart on pages 4 and
87 to show that you are in the midst of this Phase 1 trial.  In this regard, we not e that your
current presentation in the chart suggests that you have reached the end of this trial.

Use of Proceeds, page 61

6. Please revise to disclose the approximate amounts intended to be used for each of the
ALRN -6924 indications that you highlight in  the pipeline chart presented on page 4 of
the Summary.  Disclose the sufficiency of the allocated funds to advance though the
present stage and/or subsequent  stages of development.  If you will need additional
funding to complete a particular stage of dev elopment, please disclose this point.

In Vitro, page 103

7. We note your disclosure that all but two of the 207 mutant p53 cells had no discernable
effect and “nearly all of the 105 WT p53 cell lines showed tumor cell death” and that
“[m]ost WT p53 cell li nes that did not show tumor cell death were derived from HPV -
related cancers.”  Accordingly, please revise to disclose the number of cell lines that
showed tumor cell death and the number of cell lines that did not show tumor cell death.

Management, page  133

8. Please revise to clarify the business experience during the past five years for Kira A.
Nelson.  In this regard, please revise to identify the consultancy where she was employed
as well as the companies where she served as director of accounting and finance.  Refer
to Item 401(e)(1) of Regulation S -K.

Joseph A. Yanchik III
Aileron Therapeutics, Inc.
May 12, 2017
Page 3

 You may contact Vanessa Robertson  at (202) 551 -3649  or James Rosenberg  at (202)
551-3679 if you have questions regarding comments on the financial statements and related
matters.  Please contact Jeffre y Gabor at (202) 551 -2544 or Joseph McCann at (202) 551 -6262
with any other questions.

Sincerely,

 /s/ Joseph McCann for

Suzanne Hayes
Assistant Director
Office of Healthcare and Insurance

cc: Stuart M. Falber, Esq.
 Wilmer Cutler Pickering Hale and Dorr LLP

Mail Stop 4720

October 5 , 2015

Via E -mail
Joseph A. Yanchik III
President and Chief Executive Officer
Aileron Therapeutics, Inc.
281 Albany Street
Cambridge, MA 02139

Re: Aileron Therapeutics, Inc.
Draft Registration Statement on Form S -1
Submitted September 10, 2015
  CIK No. 0001420565

Dear Mr. Yanchik:

We have reviewed your draft 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 providing the requested information and either submitting
an amended draft registration statement or publicly filing your registration sta tement on
EDGAR.  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 the information you provide in response to these comments and your
amended draft registration statement or filed registration statement, we may have additional
comments.

Prospectus Summary

Overview , page 1

1. Please add to this section, if true,  that to date neither your  company nor any ot her
company has received marketing approval to market therapeutics utilizing stapled
peptides.

Joseph A. Yanchik III
Aileron Therapeutics, Inc.
October 5, 2015
Page 2

 Risks Associated with Our Business, page 3

2. Please expand the first bullet on page 4 to clarify that you believe your cash, cash
equivalents and investments as of June 30, 2015 will be sufficient to fund your operating
expenses and capital expenditure requirements only through December 31, 2015.

Implications of Being an Emerging Growth Company, page 5

3. Please expand your disclosure to discuss the ways in which you may lose emerg ing
growth company status.

Special Note Regarding Forward -Looking Statements and Industry Data, page 56

4. We note your statement on page 57 that you have not independently verified certain
market and industry data included in your registration statement.  This statement
represents an inappropriate disclaimer of your responsibility for the accuracy and
completeness of information presented in the prospectus.  Accordingly, please revise
your disclosure to remove this statement from the prospectus.

Management ’s Discussion and Analysis of Financial Condition and Results of Operations

Determination of Fair Value of Common Stock, page 74

5. We may have additional comments on your accounting for equity issuances including
stock compensation and beneficial conversion features.  Once you have an estimated
offering price, please provide us an analysis explaining the reasons for the differences
between recent valuations of your common stock leadin g up to the IPO and the estimated
offering price.

Business, page 84

6. Please briefly clarify the status and current importance to your business of your other
product candidates.

Overview, page 84

7. Please disclose all investigational new drug applications (“INDs”) that you have
submitted to the FDA as well as the indication(s) and sponsor(s) for any active INDs
related to your product candidates.  For clinical studies conducted outside of the United
States, please indicate the countries in which specific studies occurred.

Joseph A. Yanchik III
Aileron Therapeutics, Inc.
October 5, 2015
Page 3

 Preclinical Studies, page 92

8. Please explain the scientific term “nanomolar  affinities” to enable a lay person to
understand the meaning of such term.

In Vivo, page 94

9. Please provide a brief explanation of the terms “statistically significant” and “p -value” at
first use.

Clinical Development of ALRN -6924, page 95

10. We note your  statement that although your Phase 1 clinical trial “is not designed for a
formal efficacy analysis,” you “are also assessing clinical activity or response to ALRN -
6924 through the use of both PD biomarkers and imaging assessment.”  Please clarify
whether  your analysis of clinical activity or response to ALRN -6924 in this Phase 1 trial
will be submitted to and considered by the FDA or other comparable foreign regulatory
authority when determining whether to grant marketing approval for your product
candida te.

11. Please provide a brief explanation of the following scientific terms to enable a lay
investor to understand the meaning of such terms:

  “IWG criteria”
 “thrombocytopenia”
 “neutropenia”
 “grade 4 neutropenia”
 “grade 3 neutropenia”

General

12. Please confirm that the images included in your draft registration statement are all of the
graphic, visual or photographic information you will be including.  If you intend to use
any additional images, please provide us proofs of such materials.  Please note that we
may have comments regarding this material.

13. Please supplementally provide us with copies of all written communications, as defined
in Rule 405 under the Securities Act, that you, or anyone authorized to do so on your
behalf, present to potent ial investors in reliance on Section 5(d) of the Securities Act,
whether or not they retain copies of the communications.

Joseph A. Yanchik III
Aileron Therapeutics, Inc.
October 5, 2015
Page 4

 You may contact Vanessa Robertson at (202) 551 -3649 or Joel Parker at (202) 551 -3651
if you have questions regarding comments on the  financial statements and related matters.
Please contact Christina De Rosa at (202) 551 -3577, Dietrich King at (202) 551 -3338 or me at
(202) 551 -3675 with any other questions.

Sincerely,

 /s/ Dietrich A. King for

 Suzanne Hayes
Assistant Director

cc: Joshua D . Fox, Esq.