SecProbe.io

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CORRESP

 February 17, 2026

VIA EDGAR

 Securities and Exchange Commission

 Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
 Enanta Pharmaceuticals, Inc.

Registration Statement on Form S-3

File No. 333-293390

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended (the “Act”), Enanta Pharmaceuticals,
Inc. (the “Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-293390) (the
“Registration Statement”), so that it may become effective at 4:00 pm Eastern time on February 20, 2026, or as soon thereafter as practicable, or at such other time as the Registrant or its outside counsel, Foley Hoag LLP, requests
by telephone that such Registration Statement be declared effective. The Registrant hereby confirms that it is aware of its responsibilities under the Act.

It would be appreciated if, promptly after the Registration Statement has become effective, you would so inform our outside counsel, Stacie
Aarestad of Foley Hoag LLP, by telephone at (617) 832-1108 or by email at saarestad@foleyhoag.com.

Very truly yours,

ENANTA PHARMACEUTICALS, INC.

/s/ Jay R. Luly, Ph.D.

Jay R. Luly, Ph.D.

President and Chief Executive Officer

cc:
 Matthew Kowalsky, Chief Legal Officer

<DOCUMENT>
<TYPE>TEXT-EXTRACT
<SEQUENCE>2
<FILENAME>filename2.txt
<TEXT>
 February 17, 2026

Jay R. Luly, Ph.D.
Chief Executive Officer
Enanta Pharmaceuticals Inc.
4 Kingsbury Avenue
Watertown, Massachusetts 02472

 Re: Enanta Pharmaceuticals Inc.
 Registration Statement on Form S-3
 Filed February 11, 2026
 File No. 333-293390
Dear Jay R. Luly, 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 Jimmy McNamara at 202-551-7349 with any questions.

 Sincerely,

 Division of
Corporation Finance
 Office of Life
Sciences
cc: Stacie Aarestad
</TEXT>
</DOCUMENT>

United States securities and exchange commission logo
February 26, 2024
Paul Mellett
Chief Financial Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown, MA 02472
Re:Enanta Pharmaceuticals, Inc.
Form 10-K for Fiscal Year Ended September 30, 2023
File No. 001-35839
Dear Paul Mellett:
            We have completed our review of your filing. 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.
Sincerely,
Division of Corporation Finance
Office of Life Sciences

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  CORRESP

  February 14, 2024

  United States Securities and Exchange Commission

  Division of Corporation Finance

  Office of Life Sciences

  Washington, D.C. 20549

  Attention: Tracie Mariner and Vanessa Robertson

  Re: Enanta Pharmaceuticals, Inc.,

  Form 10-K for the fiscal year ended September 30, 2023

  File No. 001-35839

  Ladies and Gentlemen:

  This letter sets forth responses of Enanta Pharmaceuticals, Inc. (the “Company” or “we”) to the comment of the staff of the Division of Corporation Finance (the “Staff”) of the United States Securities and Exchange Commission set forth in your letter dated February 7, 2024, with respect to the Form 10-K for the fiscal year ended September 30, 2023 (the “Form 10-K”).

  The text of the Staff’s comment has been included in this letter for your convenience, and the Company’s response to the comment has been provided immediately thereafter.

  Form 10-K for the Fiscal Year Ended September 30, 2023

  Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

  Results of Operations

  Research and development expenses, page 57

  1. You disclose that you do not report information regarding costs incurred for your early-stage research and drug discovery programs on a project-specific basis. Please revise your future filings to address the following:

  •Revise to clarify the extent to which you track these costs on a project-specific basis or disease-specific basis.

  Response: The Company acknowledges the Staff’s comment. The Company disclosed in its most recent Form 10-Q for the quarterly period ended December 31, 2023, filed on February 8, 2024 (the “Recent 10-Q”), the methodology the Company utilizes for tracking its research and development costs. Please see disclosure below, which can be found on pages 20-21 of the Recent 10-Q:

  At any given time, we have later stage programs in clinical development as well as several active early-stage research and drug discovery projects. Our internal resources, employees and infrastructure are utilized across multiple projects, including our early-stage discovery projects. As such, we report information regarding costs incurred based on our programs (i.e. disease area) rather than on a project specific basis.

  •To the extent you do track this information, revise your future filings to break out clinical research and development program expenses by product candidate (i.e. EDP-938, EDP-323). Alternatively, break out the Virology expense line item by disease target (i.e. RSV, HBV, COVID-19).

  Response: The Company acknowledges the Staff’s comment. The Company disclosed in the Recent 10-Q a further breakdown of total costs related to clinical research and development programs by disease area. Please see disclosure below, which can be found on page 22 of the Recent 10-Q:

  Enanta Pharmaceuticals, Inc.

500 Arsenal Street, Watertown, Massachusetts 02472
P: (617) 607-0800

  •If you do not track expenses at a more granular level, revise to explain why not.

  Response: As noted above, the Company provided a further breakdown of total costs related to clinical research and development programs by disease area in the Recent 10-Q.

  •For all unallocated expenses, revise to provide a breakdown by nature of expense.

  Response: The Company acknowledges the Staff’s comment. The Company disclosed in the Recent 10-Q the methodology for allocating indirect expenses to research and development programs. Please see disclosure below, which can be found on pages 20-21 of the Recent 10-Q:

  At any given time, we have later stage programs in clinical development as well as several active early-stage research and drug discovery projects. Our internal resources, employees and infrastructure are utilized across multiple projects, including our early-stage discovery projects. As such, we report information regarding costs incurred based on our programs (i.e. disease area) rather than on a project specific basis. All indirect costs are allocated to programs based on headcount and square footage of our facilities.

  The Company will include disclosure in its future filings that is similar to the disclosure included in the Recent 10-Q described above, as applicable.

  We hope that the foregoing has been responsive to the Staff’s comments. If you have any questions related to this letter, please contact me at (617) 607-0761.

  Sincerely,

   /s/ Paul J. Mellett

  Paul J. Mellett

  Chief Financial and Administrative Officer

  Enanta Pharmaceuticals, Inc.

500 Arsenal Street, Watertown, Massachusetts 02472
P: (617) 607-0800

United States securities and exchange commission logo
February 7, 2024
Paul Mellett
Chief Financial Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown
MA
02472
Re:Enanta Pharmaceuticals, Inc.
Form 10-K for Fiscal Year Ended September 30, 2023
File No. 001-35839
Dear Paul Mellett:
            We have limited our review of your filing to the financial statements and related
disclosures and have the following comment.
            Please respond to this letter within ten business days by providing the requested
information or advise us as soon as possible when you will respond. If you do not believe
the comment applies to your facts and circumstances, please tell us why in your response.
            After reviewing your response to this letter, we may have additional comments.
Form 10-K for Fiscal Year Ended September 30, 2023
Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations
Results of Operations
Research and development expenses, page 57
1.You disclose that you do not report information regarding costs incurred for your early-
stage research and drug discovery programs on a project-specific basis. Please revise your
future filings to address the following:
•Revise to clarify the extent to which you track these costs on a project-specific basis
or disease-specific basis.
•To the extent you do track this information, revise your future filings to break out
clinical research and development program expenses by product candidate (i.e. EDP-
938, EDP-323). Alternatively, break out the Virology expense line item by disease
target (i.e. RSV, HBC, COVID-19).
•If you do not track expenses at a more granular level, revise to explain why not.

 FirstName LastNamePaul Mellett
 Comapany NameEnanta Pharmaceuticals, Inc.
 February 7, 2024 Page 2
 FirstName LastName
Paul Mellett
Enanta Pharmaceuticals, Inc.
February 7, 2024
Page 2
•For all unallocated expenses, revise to provide a breakdown by nature of expense.
            In closing, 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 Tracie Mariner at 202-551-3744 or Vanessa Robertson at 202-551-3649
with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences

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CORRESP

 February 5, 2024

VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
 Enanta Pharmaceuticals, Inc.

Registration Statement on Form S-3

File No. 333-275723

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended (the “Act”), Enanta Pharmaceuticals,
Inc. (the “Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-275723), as amended
(the “Registration Statement”), so that it may become effective at 4:00 pm Eastern time on February 8, 2024, or as soon thereafter as practicable, or at such other time as the Registrant or its outside counsel, Foley Hoag LLP,
requests by telephone that such Registration Statement be declared effective. The Registrant hereby confirms that it is aware of its responsibilities under the Act.

It would be appreciated if, promptly after the Registration Statement has become effective, you would so inform our outside counsel, Ryan
Rourke Reed of Foley Hoag LLP, by telephone at (617) 832-1181 or by email at rrourkereed@foleyhoag.com.

[Remainder of this page intentionally left blank]

 Very truly yours,

ENANTA PHARMACEUTICALS, INC.

By:

 /s/ Paul J. Mellett

 Name: Paul J. Mellett

 Title: Chief Financial
and Administrative Officer

 [Signature Page to Acceleration Request]

United States securities and exchange commission logo
November 27, 2023
Nathaniel S. Gardiner
Senior Vice President and General Counsel
ENANTA PHARMACEUTICALS INC
500 Arsenal Street
Watertown, MA 02472
Re:ENANTA PHARMACEUTICALS INC
Registration Statement on Form S-3
Filed November 22, 2023
File No. 333-275723
Dear Nathaniel S. Gardiner:
            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 Jimmy McNamara at 202-551-7349 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Stacie S. Aarestad

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Acceleration Request

 Enanta Pharmaceuticals, Inc.

500 Arsenal Street

Watertown, MA 02472

 March 18,
2013

 VIA EDGAR TRANSMISSION

United States Securities and Exchange Commission

Division of Corporate Finance

 100 F Street,
N.E.

 Washington, D.C. 20549-6010

Re:
Enanta Pharmaceuticals, Inc.

Registration Statement on Form S-1

File No. 333-184779

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Enanta Pharmaceuticals, Inc.
(the “Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-1 (File No. 333-184779), as amended (the “Registration Statement”), so that it may become effective at 3:00 p.m.
Eastern Standard Time on March 20, 2013, or as soon thereafter as practicable.

 The Registrant hereby authorizes each of
Stacie S. Aarestad and Nathaniel S. Gardiner, both of whom are attorneys with the Registrant’s outside legal counsel, Edwards Wildman Palmer LLP, to orally modify or withdraw this request for acceleration.

The Registrant hereby acknowledges that:

(i)
should the Securities and Exchange Commission (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;

(ii)
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

(iii)
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.

 The Registrant requests that it be notified of such effectiveness
by a telephone call to Ms. Aarestad at (617) 239-0314, or in her absence, Mr. Gardiner at (617) 239-0293.

Very truly yours,

ENANTA PHARMACEUTICALS, INC.

By:

 /s/ Jay R. Luly

Jay R. Luly

President and Chief Executive Officer

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Acceleration Request

 J.P. MORGAN SECURITIES LLC

383 Madison Avenue

New York, NY 10179

 CREDIT SUISSE SECURITIES (USA) LLC

Eleven Madison Avenue

 New York, NY 10010

 March 18, 2013

 Re:

 Enanta Pharmaceuticals, Inc.

 Registration Statement on Form S-1

 Registration File No.
333-184779

 Securities and Exchange Commission

 Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

 Dear Sir/Madam:

 Pursuant to Rule 460 of the General Rules and Regulations under the Securities Act of 1933 (the “Act”), we,
as representatives of the several Underwriters, wish to advise you that 6,704 copies of the Preliminary Prospectus dated March 5, 2013, were distributed during the period March 5, 2013 through 5:00 p.m. New York City Time, March 15,
2013, to prospective underwriters, institutions, dealers and others.

 We were advised on January 18, 2013 by the
Corporate Financing Department of the Financial Industry Regulatory Authority that it has reviewed the above-captioned proposed offering and that it has determined to raise no objections with respect to the fairness of the terms and arrangements of
the offering.

 We have been informed by the participating underwriters that they will comply with the requirements of Rule
15c2-8 under the Securities Exchange Act of 1934.

 In accordance with Rule 461 of the Act, we hereby join in the request of
Enanta Pharmaceuticals, Inc. for acceleration of the effective date of the above-named Registration Statement so that it becomes effective at 3:00 p.m. New York City Time on March 20, 2013, or as soon thereafter as practicable.

[Remainder of page intentionally left blank]

Very truly yours,

By:

J.P. MORGAN SECURITIES LLC

By:

/s/ Sri Kosaraju

Name: Sri Kosaraju

Title: Managing Director

By:

CREDIT SUISSE SECURITIES (USA) LLC

By:

/s/ Charles W. Newton

Name: Charles W. Newton

Title: Managing Director

 2

March 13 , 2013

Via E -mail
Jay R. Luly, Ph.D.
President and Chief Executive Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown, Massachusetts 02472

Re: Enanta  Pharmaceuticals, Inc.
Amendment No. 4 to Registration Statement on Form S -1
Filed March 5 , 2012
  File No. 333 -184779

Dear Dr. Luly:

We have reviewed your amendment dated March 5 , 2013 and have the following
comment.  Please respond to this letter by amending your registration statemen t as requested.   If
you do not believe th is comment app lies to your facts and circumstances or do not believe a n
amendment is appropriate, please tell us why in a response.

After reviewing any further amendment to your  registration statement and the
information you provide in response to this comment, we may have additional comments.

Dilution, page 45

1. Please revise the dilution disclosure to present line items for historical net tangible book
value per share and the  amounts attributable to pro forma adjustments to arrive at pro
forma net tangible book value per share.

We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing to be certain that the filing includes the infor mation the Securities Act of 1933 and
all applicable Securities Act rules require.   Since the company and its management are in
possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosure s they have made.

Notwithstanding our comment, in the event you request acceleration of the effective date
of the pending registration statement please provide a written statement from the company
acknowledging that:

 should the Commission or the staff,  acting pursuant to delegated authority, declare the
filing effective, it does not foreclose the Commission from taking any action with respect
to the filing;

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
March 13 , 2013
Page 2

  the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the adequacy and accuracy of the disclosure in the filing; and

 the company may not assert staff comments and the declaration of effectiveness as a
defense in any proceedi ng initiated by the Commission or any person under the federal
securities laws of the United States.

Please refer to Rules 460 and 461 regarding requests for acceleration.  We will consider a
written request for acceleration of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Exchange Act of 1934 as they relate to the proposed
public offering of the securities specified in the above registration statement.  Please allow
adequate time for us to rev iew any amendment prior to the requested effective date of the
registration statement.

Sincerely,

 /s/ Jeffrey P. Riedler

Jeffrey Riedler
Assistant Director

cc: Nathaniel S. Gardiner, Esq.
 Stacie S. Aarestad, Esq.
Edwards Wildman Palmer LLP
111 Huntington Avenue
Boston, Massachusetts 02199

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Correspondence

 Stacie S. Aarestad

 FOIA Confidential Treatment Requested

 Pursuant to 17 C.F.R. §200.83

 The entity requesting confidential treatment
is

 Enanta Pharmaceuticals, Inc.

 500 Arsenal Street

 +1 617 239 0314

 fax +1 866 955 8599

 saarestad@edwardswildman.com

 Watertown, MA 02472

Attn: Jay R. Luly, Ph.D.

 President and
Chief Executive Officer

 Telephone (617) 607-0800

 VIA EDGAR AND ELECTRONIC MAIL

 February 8, 2013

 United States Securities and Exchange Commission

Division of Corporation Finance

 100 F Street,
N.E.

 Washington, D.C. 20549

Attn:
Christine Allen

 Scot Foley

 Mary Mast

Re:
Enanta Pharmaceuticals, Inc.

Registration Statement on Form S-1

 File No. 333-184779

 Ladies and Gentlemen:

On behalf of Enanta Pharmaceuticals, Inc. (the “Company”), set forth below is updated information to assist the staff (the
“Staff”) of the Securities and Exchange Commission (the “Commission”) in its review of the above-referenced registration statement on Form S-1 (the “Registration Statement”). The responses set forth below are based
upon information provided to Edwards Wildman Palmer LLP by the Company. All information in this letter is presented before giving effect to a reverse stock split that the Company plans to implement prior to effectiveness of the Registration
Statement.

 Enanta Pharmaceuticals, Inc. respectfully requests that the bracketed information contained herein be treated as confidential
information and that the Commission provide timely notice to Jay R. Luly, Ph.D., President and Chief Executive Officer, Enanta Pharmaceuticals, Inc., 500 Arsenal Street, Watertown, MA 02472, before it permits any disclosure of the bracketed
information in Request #1.

 CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-1

 United States Securities and Exchange Commission

February 8, 2013

  Page
 2

 Rule 83 Confidential Treatment Request by Enanta Pharmaceuticals, Inc.
Request #1

 The Company supplementally advises the Staff on a confidential basis that the Company currently
anticipates that the price range for this offering will be approximately $[****] 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
indicative price range is based on a number of factors, including existing conditions in the public capital markets; the Company’s prospects and the history of and prospects for the Company’s industry; the recent market prices of, and the
demand for, publicly-traded common stock of generally comparable companies; and preliminary discussions with the underwriters regarding potential valuations of the Company.

 Accordingly, we are submitting this letter to update the proposed price range and the expected difference between such price range and the valuations used by the Company in its most recent grants of stock
options, which were 105,000 stock options issued as recruitment awards on November 14, 2012 at a per share exercise price of $3.12, 518,000 stock options issued on December 26, 2012 to employees as annual year-end awards at a per share
exercise price of $3.29, and 30,540 stock options issued on January 17, 2013 as additional annual year-end awards at a per share exercise price of $3.29. The exercise prices of each of those awards were equal to the fair value per share of our
common stock, as determined by our Board of Directors, as of each grant date. The December 26, 2012 and January 17, 2013 stock options have an exercise price that [****] the $[****] midpoint of the projected price range of the offering,
and the November 14, 2012 stock options have an exercise price that [****] the $[****] midpoint of the projected price range of the offering, assuming a range of $[****] to $[****] per share. The Company’s basis for the valuations used in
determining the fair value of its common stock for purposes of these awards was previously described in the Company’s correspondence to the Staff dated January 15, 2013 and January 23, 2013 and was included in Amendment No. 3 to the
Registration Statement filed on February 5, 2013.

 In addition, the Company advises the Staff that, in its next amendment to
the Registration Statement, the Company plans to include new disclosure to reflect that it anticipates certain of its existing stockholders to participate in the offering in an amount up to [****]% of the offered shares as directed by us through a
directed share program.

 A draft of the proposed disclosure, which will be included on the prospectus cover page, the offering
page in the summary box, the dilution section and the related party transaction section, is as follows:

 Certain of our
existing stockholders have indicated an interest in purchasing an aggregate of up to              shares in this offering at the initial public offering price. However, because indications
of interest are not binding agreements or commitments to purchase, these entities may determine to purchase fewer shares than they have indicated an interest in purchasing or not to purchase any shares in this offering.

CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-2

 United States Securities and Exchange Commission

February 8, 2013

  Page
 3

 The Company will also note in the underwriting section that it has directed the
underwriters to reserve up to approximately              shares of its common stock in the offering for sale at the initial public offering price to certain of its existing investors. It
will indicate that the number of shares of the Company’s common stock available for sale to the general public in the offering will be reduced to the extent these investors purchase any reserved shares and that shares not so purchased will be
offered by the underwriters to the general public on the same basis as other shares offered pursuant to the prospectus.

 The
Company and the underwriters are currently preparing to begin the road show for the offering on or about [****]. To the extent it is feasible, we would appreciate the Staff’s efforts to provide any further comments as soon as possible.

 If you require additional information, please telephone either the undersigned at the telephone number indicated above, or
Nathaniel Gardiner of this firm at (617) 239-0293.

Very truly yours,

/s/ Stacie S. Aarestad

Stacie S. Aarestad

SSA

CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-3

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Letter to the SEC

 January 23, 2013

 By EDGAR Submission

 United States Securities and Exchange Commission

Division of Corporation Finance

 100 F Street,
N.E.

 Washington, D.C. 20549

Attn:
Christine Allen

Mary Mast

Re:
Enanta Pharmaceuticals, Inc.

Registration Statement on Form S-1

File No. 333-184779

 Ladies and Gentlemen:

 On behalf of Enanta Pharmaceuticals, Inc. (the “Company”), set forth below are responses to the comments provided to the Company by
the staff (the “Staff”) of the Securities and Exchange Commission (the “Commission”) in a letter dated January 22, 2013 (the “Letter”). The responses set forth below are based upon information provided to Edwards
Wildman Palmer LLP by the Company. The responses are keyed to the numbering of the comments and the headings used in the Staff’s Letter. All information in this letter is presented before giving effect to a reverse stock split that the
Company plans to implement prior to effectiveness of the Company’s Registration Statement on Form S-1 (the “Registration Statement”).

 Note 14: Stock-Based Awards

 Stock Option Valuation, page F-33

1.
Please provide us a list of any equity issuances since the latest balance sheet date, the related fair value of the stock, and any compensation or other costs that
have been recorded for those issuances. Provide additional disclosure in the filing as appropriate.

Response:
 The Company confirms to the Staff that its proposed disclosure as set forth in its correspondence to the Staff dated January 15, 2013
details all of the stock options granted by the Company since the September 30, 2012 balance sheet date through December 31, 2012. The Company

 United States Securities and Exchange Commission

 January 23, 2013

 Page 2

supplementally advises the Staff that its only equity issuances since December 31, 2012 were a de minimis number of stock options for 30,540 shares of
common stock in the aggregate, which represent less than 0.06% of the Company’s outstanding shares on an as-converted basis and less than 0.4% of the Company’s outstanding stock options. On that basis, the Company respectfully submits that
it believes disclosure of those grants in the current fiscal period is not meaningful to investors and, therefore, not warranted in the Registration Statement. The Company also supplementally advises the Staff that the exercise price of those stock
options is equal to the exercise price of its December 26, 2012 option grants ($3.29 per share).

2.
Please disclose in the second paragraph of your proposed disclosure the risk-adjusted discount rate and discount for the lack of marketability.

Response:
In response to the Staff’s comment, the Company will revise its disclosures on page 57 in its next amendment to the Registration Statement to disclose the
discount rates it used in each of its common stock valuations since May 2012. The Company proposes to amend its disclosure, so that, in its entirety, it will appear as follows on the top of page 57:

“In our common stock valuations as of May 31, 2012, September 30, 2012, October 17, 2012 and
December 10, 2012, we applied risk-adjusted discount rates of 12.8%, 12.8%, 13.1% and 12.7%, respectively, and in each case we applied a discount for lack of marketability of 10% to the common stock to account for the lack of access to an
active public market and the increased probability that we would achieve a public offering and listing on a national exchange.”

 United States Securities and Exchange Commission

 January 23, 2013

 Page 3

3.
You have stated that you have used two valuation methods to estimate enterprise value: the guideline public company method and guideline transaction method under the
market approach and the discounted future cash flow method under the income approach. Please clarify in the filing how you used the market and income methods to ultimately determine your enterprise method. Confirm to us that the methods resulted in
similar valuations and if not, how you ultimately determined the enterprise valuation. For the market approach, in which you used two methods to determine the valuation, clarify in the filing how both methods were used in determining the ultimate
valuation under the market approach.

Response:
In response to the Staff’s comment, the Company advises the Staff that, in its next amendment to the Registration Statement, the Company will revise its
disclosures in the fourth paragraph on page 56 to clarify how it used the market and income methods to ultimately determine its enterprise value, as follows:

 “To derive our ultimate enterprise value at each valuation date, we calculated a simple average of the enterprise value resulting from the market approach and the enterprise value resulting from the
income approach.”

 The Company supplementally advises the Staff that the market and income methods resulted in
enterprise values that varied at each valuation date by as little as 16% and no more than 21%, which it considered to be reasonably similar valuations.

 In addition, in response to the Staff’s comment, the Company will revise its disclosures in the fourth paragraph on page 56 to specify how it determined the enterprise value under the market
approach, as follows:

 “To derive our enterprise value under the market approach at each valuation date, we calculated a
simple average of the enterprise values resulting from the guideline public company method and the guideline transaction method.”

 * * *

 United States Securities and Exchange Commission

 January 23, 2013

 Page 4

 Please direct your questions or comments regarding this letter or the Registration Statement to the undersigned at (617) 239-0314 or to Nathaniel Gardiner at (617) 239-0293. Thank you for your
assistance.

 Respectfully submitted,

/s/ Stacie S. Aarestad

 Stacie S. Aarestad

cc:
Jay R. Luly, President and Chief Executive Officer

 Enanta Pharmaceuticals, Inc.

 Richard D. Truesdell, Jr., Esq.

Davis Polk & Wardwell LLP

January 22, 2013

Via E -mail
Jay R. Luly, Ph.D.
President and Chief Executive Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown, Massachusetts 02472

Re: Enanta  Pharmaceuticals, Inc.
Registration Statement on Form S -1
 Response Letter Dated January 15, 2013
  File No. 333 -184779

Dear Dr. Luly:

We have reviewed your correspondence dated January 15, 2013 and have the following
comment s.  Please respond to this letter by amending your registration statement or providing the
requested information , as appropriate .  If you do not believe th ese comment s apply to your facts
and circumstances or do not believe a n amendment is appropriate, plea se tell us why in a
response.

After reviewing any further amendment to your registration statement and the
information you provide in response to this comment, we may have additional comments.

Note 14: Stock -Based Awards

Stock Option Valuation , page  F-33

1. Please provide us a list of any equity issuances since the latest balance sheet date, the
related fair value of the stock, and any compensation or other costs that have been
recorded for those issuances.  Provide additional disclosure in the filing as appropriate.

2. Please disclose in the second paragraph of your proposed disclosure the risk -adjusted
discount rate and discount for the lack of marketability.

3. You have stated that you have used two valuation methods to estimate enterprise value:
the gui deline public company method and guideline transaction method under the market
approach and the discounted future cash flow method under the income approach.  Please
clarify in the filing how you used the market and income methods to ultimately determine
your enterprise method.  Confirm to us that the methods resulted in similar valuations and
if not, how you ultimately determined the enterprise valuation.  For the market approach,

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
January 22, 2013
Page 2

 in which you used two methods to determine the valuation, clarify in the fil ing how both
methods were used in determining the ultimate valuation under the market approach.

We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing to be certain that the filing includes the information th e Securities Act of 1933 and
all applicable Securities Act rules require.   Since the company and its management are in
possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they ha ve made.

Notwithstanding our comment, in the event you request acceleration of the effective date
of the pending registration statement please provide a written statement from the company
acknowledging that:

 should the Commission or the staff, acting p ursuant to delegated authority, declare the
filing effective, it does not foreclose the Commission from taking any action with respect
to the filing;

 the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the adequacy and accuracy of the disclosure in the filing; and

 the company  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.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
January 22, 2013
Page 3

 Please refer to Rules 460 and 461 regarding requests for acceleration.  We will consider a
written request for acceleration of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Exchange Act of 1934 as they relate to the proposed
public offering of the securities specified in the above registration statement.  Please allow
adequate time for us to rev iew any amendment prior to the requested effective date of the
registration statement.

Sincerely,

 /s/ Jeffrey P. Riedler

Jeffrey Riedler
Assistant Director

cc: Nathaniel S. Gardiner, Esq.
 Stacie S. Aarestad, Esq.
Edwards Wildman Palmer LLP
111 Huntington Avenue
Boston, Massachusetts 02199

CORRESP
1
filename1.htm

SEC Response Letter

 EDWARDS WILDMAN PALMER LLP

 111 HUNTINGTON AVENUE

 BOSTON, MA 02199

+1 617 239 0100 main    +1 617 227 4420 fax

 edwardswildman.com

 FOIA Confidential Treatment Requested

Pursuant to 17 C.F.R. §200.83

The entity requesting confidential treatment is

 Enanta Pharmaceuticals, Inc.

 500 Arsenal Street Watertown, MA 02472

Attn: Jay R. Luly, Ph.D.

 President and
Chief Executive Officer

 Telephone (617) 607-0800

 Stacie S. Aarestad

 +1 617 239 0314

 fax +1 866 955 8599

saarestad@edwardswildman.com

 VIA EDGAR AND ELECTRONIC MAIL

 January 15, 2013

 United States Securities and Exchange Commission

Division of Corporation Finance

 100 F Street,
N.E.

 Washington, D.C. 20549

 Attn:

 Christine Allen

 Mary
Mast

 Re:

 Enanta Pharmaceuticals, Inc.

Registration Statement on Form S-1

 File No.
333-184779

 Ladies and Gentlemen:

On behalf of Enanta Pharmaceuticals, Inc. (the “Company”), set forth below is additional information to assist the accounting
staff (the “Staff”) of the Securities and Exchange Commission (the “Commission”) in its review of the above-referenced registration statement on Form S-1 (the “Registration Statement”). The responses set forth
below are based upon information provided to Edwards Wildman Palmer LLP by the Company. The responses are keyed to the numbering of the comments and the headings used in the Staff’s letter to the Company dated September 26, 2012. All
information in this letter is presented before giving effect to a reverse stock split that the Company plans to implement prior to effectiveness of the Registration Statement.

 Enanta Pharmaceuticals, Inc. respectfully requests that the bracketed information contained herein be treated as confidential information and that the Commission provide timely notice to Jay R. Luly,
Ph.D., President and Chief Executive Officer, Enanta Pharmaceuticals, Inc., 500 Arsenal Street, Watertown, MA 02472, before it permits any disclosure of the bracketed information in Request #1.

CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-1

 BOSTON
• CHICAGO • FT LAUDERDALE • HARTFORD • HONG KONG • LONDON • LOS ANGELES • MADISON NJ

 NEW YORK •
ORANGE COUNTY • PROVIDENCE • STAMFORD • TOKYO • WASHINGTON DC • WEST PALM BEACH

 United States Securities and Exchange Commission

January 15, 2013

 Page 2

 Note 14: Stock-Based Awards

 Stock Option Valuation

22.
You have issued 513,500 stock options in the six months ended June 30, 2012. We will evaluate the accounting treatment for these and any other equity issuances
once an IPO price has been set.

 Rule 83 Confidential Treatment Request by Enanta
Pharmaceuticals, Inc. Request #1

 Response:  The Company supplementally advises the Staff on a
confidential basis that the Company currently anticipates that the price range for this offering 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 indicative price range is based on a number of factors, including existing conditions in the public capital markets; the Company’s prospects and the history of and prospects for the
Company’s industry; the recent market prices of, and the demand for, publicly-traded common stock of generally comparable companies; 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.

 Accordingly, we are submitting this letter to
provide context for this proposed price range and to assist the Staff in understanding the expected difference between such price range and the valuations used by the Company in its most recent grants of stock options, which were 105,000 stock
options issued as recruitment awards on November 14, 2012 at a per share exercise price of $3.12, and 518,000 stock options issued on December 26, 2012 to employees as annual year-end awards at a per share exercise price of $3.29. The
exercise prices of each of those awards were equal to the fair value per share of our common stock, as determined by our Board of Directors, as of each grant date. The December 26, 2012 stock options have an exercise price that [****] the
$[****] midpoint of the projected price range of the offering, and the November 14, 2012 stock options have an exercise price that [****] the $[****] midpoint of the projected price range of the offering, assuming a range of $[****] to $[****]
per share. Further, by way of background, the Board of Directors of the Company engaged a third-party valuation firm to assist it with each of the valuations of its common stock as of the two stock option grant dates.

In connection with the Staff’s comments to the Registration Statement, the Company advises the Staff that, in its next amendment to
the Registration Statement, the Company plans to revise its disclosures in Management’s Discussion and Analysis of Financial Condition and Results of Operations regarding the discussions of valuations of common stock and of stock-based
compensation to reflect the new equity awards. A draft of that proposed revised discussion is attached hereto as Appendix A.

CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-2

 United States Securities and Exchange Commission

January 15, 2013

 Page 3

 The Company and the underwriters are currently preparing to begin the road show for the
offering on or about [****]. To the extent it is feasible, we would appreciate the Staff’s efforts to provide any further comments as soon as possible.

 If you require additional information, please telephone either the undersigned at the telephone number indicated above, or Nathaniel Gardiner of this firm at (617) 239-0293.

 Very truly yours,

 /s/ Stacie S. Aarestad

 Stacie S. Aarestad

 SSA

CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-3

  APPENDIX A

To derive the value of the common stock, the proceeds to the common stockholders were calculated based on the preferences and priorities
of the preferred and common stock, including the participation features of certain series of the preferred shares. A discount for lack of marketability of 25% was applied to reflect the increased risk arising from the inability to readily sell the
shares.

  Our common stock valuations as of May 31, 2012, September 30, 2012, October 17, 2012 and December 10,
2012 were prepared utilizing a hybrid of the OPM and the probability-weighted expected return method, or PWERM. Under the PWERM methodology, the fair market value of common stock is estimated based upon an analysis of future values for our company
assuming various outcomes. The common stock value is based on the probability-weighted present value of expected future investment returns considering each of the possible outcomes available to us as well as the rights of each class of stock. The
future value of the common stock under each outcome is discounted back to the valuation date at an appropriate risk-adjusted discount rate and probability weighted to arrive at an indication of value for the common stock. A discount for lack of
marketability, to account for the illiquidity of the common stock, is applied to the indicated common stock value to determine the fair value of the common stock.

 Three types of future event scenarios were considered: an IPO in the near term, a sale in the near term, and a longer-term liquidity event. The IPO and sale scenarios were valued using the PWERM and the
longer-term liquidity event was valued using the OPM. As of May 31, 2012, management and our board of directors determined that the total probability for the IPO scenario was 80%, for the near-term sale scenario 10%, and for the longer-term
liquidity event 10%. As of September 30, 2012 and October 17, 2012, management and our board of directors determined that the total probability for the IPO scenario was 90%, for the near-term sale scenario 5%, and for the longer-term liquidity event
5%. As of December 10, 2012, management and our board of directors determined the total probability for the IPO scenario was 85%, for the near-term sale scenario 5% and for the longer-term liquidity event 10%. Management and our board of directors
made these allocations based on an analysis of current market conditions at the time, including current IPO valuations of similarly situated companies, and their expectations as to the timing and likely prospects of these future-event scenarios.

 The scenarios referred to above utilized two valuation approaches to estimate enterprise value in order to derive the value of
the common stock. We estimated enterprise value using the guideline public company method and guideline transaction method under the market approach and using the discounted future cash flow method under the income approach. Under the guideline
public company method, we considered an average of pre-money values for selected IPOs completed by life sciences companies from 2010 through the respective valuation date for the May 31, 2012, September 30, 2012 and October 17, 2012 valuations and
from January 2012 to December 2012 for the December 10, 2012 valuation. In addition, we considered a median multiple of invested capital as indicated by the IPOs. Under the guideline transaction method, we considered the equity values indicated by
four acquisitions completed in 2010 and 2011 for the May 31, 2012 valuation and by six acquisitions completed in 2011 and 2012 for the September 30, 2012, October 17, 2012 and December 10, 2012 valuations. The companies used for comparison were
selected based on a number of factors, including, but not limited to, the similarity of their industry, business model, financial risk and stage of development to those of ours. The discounted future cash flow method involves applying appropriate
discount rates to estimated cash flows that were based on forecasts of revenue, costs and capital requirements. Our assumptions underlying the estimates were consistent with the plans and estimates that we use to manage the business. The risks
associated with achieving our forecasts were assessed in selecting the appropriate discount rates and selecting probability weights for forecasted cash flows.

 The longer-term liquidity event scenario referred to above utilized the OPM to allocate equity value to the preferred and common stock. We allocated the equity value using the OPM assuming 2.6 years to
liquidity as of May 31, 2012, 2.3 years to liquidity as of September 30, 2012, 2.2 years to liquidity as of October 17, 2012 and 2.1 years to liquidity as of December 10, 2012. The anticipated timing and probability of a liquidity event was based on
then-current plans and estimates of our board of directors and management assuming an IPO or sale were not completed in the near term. We assumed volatility of 74% as of May 31, 2012, 75% as of September 30, 2012 and October 17, 2012, and 77%
as of December 10, 2012, based on historical trading volatility for our peer companies.

 CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-4

 To derive the value of the common stock for each scenario, the proceeds to the common
stockholders were calculated based on the preferences and priorities of the preferred and common stock. We applied a discount for lack of marketability of 10% to the common stock to account for the lack of access to an active public market and the
increased probability that we would achieve a public offering and listing on a national exchange.

 Option Grants

  The following table summarizes by grant date the number of shares subject to options granted between October 1,
2010 and December 31, 2012, the per share exercise price of the options, the fair value of common stock underlying the options on date of grant, and the per share estimated fair value of the options:

 Grant Date

Number of Shares
Subject to
Options Granted

Per Share
Exercise Price
of Options(1)

Fair Value of
Common Stock
on Date of
Option Grant

Per Share
Estimated Fair
Value of Options(2)

 April 15, 2011

636,000

$
0.59

$
0.59

$
0.46

 June 17, 2011

63,313

$
0.59

$
0.59

$
0.44

 September 23, 2011

125,000

$
0.59

$
0.59

$
0.43

 June 20, 2012

513,500

$
2.73

$
2.73

$
1.81

 November 14, 2012

105,000

$
3.12

$
3.12

$
2.01

 December 26, 2012

518,000

$
3.29

$
3.29

$
2.14

(1)
The Per Share Exercise Price of Options represents the determination by our board of directors of the fair market value of our common stock on the date of grant, as
determined taking into account our most recently available valuation of common stock as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the date of grant.

(2)
The Per Share Estimated Fair Value of Options reflects the weighted average fair value of options granted on each grant date as estimated at the date of grant using the
Black-Scholes option-pricing model. This model estimates the fair value using as inputs the exercise price of the option and assumptions of the risk-free interest rate, expected term of the option, expected share price volatility of the underlying
common stock and expected dividends on the underlying common stock.

  We determined that the fair value of our
common stock increased from $0.28 per share on October 1, 2010 to $3.29 on December 26, 2012. The following discussion describes the reasons for the increases in the fair value of our common stock over this period and as compared to the
midpoint of the estimated price range set forth on the cover page of this prospectus of $[****] per share.

  Year
Ended September 30, 2011.    During the year ended September 30, 2011, or fiscal 2011, we continued to operate our business in the ordinary course. In April 2011, we obtained a third-party valuation of our common stock
as of December 31, 2010 as one of the factors considered by our board of directors in its determination of the fair value of our common stock. This valuation reflected our receipt in December 2010 of $40.0 million as our first milestone payment
from our collaboration with Abbott, based on the successful completion of a Phase 2a clinical trial of ABT-450 in combination with interferon treatment. Based on this valuation and other factors considered by our board of directors, we determined
that the fair value of our common stock increased to $0.59 per share as of December 31, 2010. From December 31, 2010 through September 23, 2011, we determined that there had been no further increase in the fair value of our common
stock because there had been no material change in our business or in the general market for biotechnology companies, including the market for HCV companies. We still had no completed clinical study to show that our lead compound could be effective
without interferon, and we had made little progress in obtaining any other collaboration for our NS5A inhibitor program or any other program. During the year ended September 30, 2011, we had no plans for an initial public offering in the near
term because we did not believe that the public markets presented a favorable environment at that time for a biotechnology company such as ours.

 Nine Months Ended June 30, 2012.    During the first eight months of fiscal 2012, which was the period ended May 31, 2012, there were several significant developments in
our lead programs, our business development efforts, the prospects for interferon-free treatment regimens for HCV and a substantial increase in

CONFIDENTIAL TREATMENT REQUESTED BY ENANTA PHARMACEUTICALS, INC.

ENANTA-5

the

November 14, 2012

Via E -mail
Jay R. Luly, Ph.D.
President and Chief Executive Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown, Massachusetts 02472

Re: Enanta  Pharmaceuticals, Inc.
Registration Statement on Form S -1
Filed November 6, 2012
  File No. 333 -184779

Dear Dr. Luly:

We have reviewed your registration statement and have the following comment.  Please
respond to this letter by amending your registration statement and providing the requested
information.   If you do not believe this comment applies to your facts and circu mstances or do
not believe an amendment is appropriate, please tell us why in a response.

After reviewing any amendment to your registration statement and the information you
provide in response to this comment, we may have additional comments.

Finan cial Statements, pages F -3 through F -7

1. Please consider the need to update your financial statements and related information for
the year ended September 30, 2012 pursuant to Rule 3 -12 of Regulation S -X.

We urge all persons who are responsible for the acc uracy and adequacy of the disclosure
in the filing to be certain that the filing includes the information the Securities Act of 1933 and
all applicable Securities Act rules require.   Since the company and its management are in
possession of all facts relat ing to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

Notwithstanding our comment, in the event you request acceleration of the effective date
of the pending registration statement please pr ovide a written statement from the company
acknowledging that:

 should the Commission or the staff, acting pursuant to delegated authority, declare the
filing effective, it does not foreclose the Commission from taking any action with respect
to the filing ;

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
November 14, 2012
Page 2

  the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the adequacy and accuracy of the disclosure in the filing; and

 the com pany 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.

Please refer to Rules 460 and 461 regarding requests for acceleration.  We will consider a
written request for acceleration of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Exchange Act of 1934 as they relate to the proposed
public offering of the securities specified in the above registration statement.  Please allow
adequate time for us to rev iew any amendment prior to the requested effective date of the
registration statement.

You may contact Christine Allen at (202) 551 -3652 or Mary Mast at (202) 551 -3613 if you
have questions regarding comments on the financial statements and related matters. Please contact
Scot Foley at (202) 551 -3383, John Krug at (202) 551 -3862 or me at (20 2) 551 -3715 with any other
questions.

Sincerely,

 /s/ Daniel  Greenspan for

Jeffrey P. Riedler
Assistant Director

cc: Nathaniel S. Gardiner, Esq.
 Stacie S. Aarestad, Esq.
Edwards Wildman Palmer LLP
111 Huntington Avenue
Boston, Massachusetts 02199

CORRESP
1
filename1.htm

Correspondence

 October 10, 2012

 United States Securities and Exchange Commission

 Division of Corporation Finance

100 F Street, N.E.

 Washington, D.C. 20549

Attn:
Jeffrey Riedler

 Christine Allen

 Mary Mast

 Scot Foley

 John Krug

Re:
Enanta Pharmaceuticals, Inc.

Confidential Draft Registration Statement on Form S-1

 Submitted August 31, 2012

 CIK No. 0001177648

Ladies and Gentlemen:

 On behalf of Enanta
Pharmaceuticals, Inc. (the “Company”), set forth below are responses to the comments provided to the Company by the staff (the “Staff”) of the Securities and Exchange Commission (the “Commission”) in a letter dated
September 26, 2012 (the “Letter”). The responses set forth below are based upon information provided to Edwards Wildman Palmer LLP by the Company. The responses are keyed to the numbering of the comments and the headings used in the
Staff’s Letter. Where appropriate, the Company has responded to the Staff’s comments by making changes to the disclosure in the Company’s Registration Statement on Form S-1 (the “Registration Statement”). These changes will
be reflected in Amendment No. 1 to the Registration Statement (“Amendment No. 1”), which is being confidentially submitted to the Commission contemporaneously with this letter. Capitalized terms used and not defined in this
letter have the meanings assigned to them in the Registration Statement.

 General

1.
We note that your draft filing omits disclosure and exhibits that you intend to provide at a later date. Please provide this information with your next submission or
as soon as possible thereafter in order to expedite the review of your filing.

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 2

Response:
The Company will complete all omitted disclosure and file all exhibits as soon as practicable and acknowledges that the Staff may have further comments upon
examination of these disclosures and exhibits.

2.
We further note that you have submitted an application for confidential treatment relating to certain of your exhibits. Please be advised that we will be performing
a separate review of this application and that the review of your registration statement will not be complete until all comments concerning your confidential treatment request, if any, have been cleared.

Response:
The Company acknowledges the Staff’s comment.

 Prospectus Summary, page 1

 Overview, page 1

3.
Please state here and wherever else applicable in your registration statement, including the risk factor beginning on page 16, that none of your product candidates
has yet advanced beyond the Phase 2 stage of clinical testing and that Phase 3 clinical trials are lengthy and typically involve at least several hundred people, if not more; please also provide an estimate of the minimum amount of time it would
take from now until a New Drug Application for one of your products could be approved.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 2, 16 and 72 of Amendment No. 1.

ABT-450/r, a Protease Inhibitor for HCV Infection, page 2

4.
Please include a statement in the last paragraph under this heading on page 3 that Abbott Laboratories’ projection may be mistaken and that your clinical trials
may take longer than anticipated to complete, that the FDA may refuse to approve your New Drug Application as submitted for a variety of reasons, and that you may be requested to perform additional clinical trials.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 3 and 76 of Amendment No. 1.

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 3

 Risk Factors

 “We may require substantial additional financing to achieve our goals if the development and commercialization of ABT-450 or EDP-239 is delayed or terminated…,” page 13

5.
Please include in this risk factor an estimate of the amount you intend to allocate toward product development in the next fiscal year.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on page 13 of Amendment No. 1 to include an estimate of the amount it intends to
allocate toward product development in fiscal 2013.

 “We have incurred a substantial cumulative net loss since our
inception and we anticipate that we may incur substantial operating losses in the future…,” page 14

6.
Please state in this risk factor and wherever else applicable in your registration statement the reason(s) your former collaborator opted to terminate its agreement
with you in 2010, to the best of your knowledge.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 14 and 48 of Amendment No. 1.

“Clinical drug development involves a lengthy and expensive process with uncertain timelines and uncertain outcomes…,” page 16

7.
Please expand the discussion in this risk factor to state, if known, the reason for the clinical hold on Novartis’ cyclophilin inhibitor.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on page 17 of Amendment No. 1.

“If we or our collaborators are required to suspend or discontinue clinical trials due to side effects or other safety risks associated with
our product candidates…,” page 17

8.
If you are aware of any instance where a clinical trial for one of your product candidates was suspended or terminated for safety reasons, please disclose it
here.

Response:
The Company advises the Staff that, to its knowledge, there has not been any instance where a clinical trial for one of its product candidates was suspended or
terminated for safety reasons.

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 4

 “Even if we or our collaborators are able to commercialize any product candidates, the
resulting products may become subject to unfavorable pricing regulations…,” page 21

9.
Please include in this risk factor a brief but specific discussion of the ramifications of the Patient Protection and Affordable Care Act on your commercial
prospects.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 21 and 22 of Amendment No. 1.

“Because a portion of our manufacturing takes place in China through third-party manufacturers…,” page 24

10.
Please amend your disclosure to state to which of your product candidates that your third-party manufacturing and supply agreements relate.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on page 24 of Amendment No. 1.

“Issued patents covering one or more of our product candidates could be found invalid or unenforceable if challenged in court,” page
26

11.
We note your disclosure on page 96 and in Note 16 to your financial statements that you are not currently party to any actual or threatened litigation. If there has
been any litigation in the past concerning one of your material patents, please describe the nature of this litigation and its resolution in this risk factor.

Response:
The Company advises the Staff that there has not been any litigation in the past concerning any of the Company’s material patents.

“We will incur increased costs as a result of operating as a public company, and our management will be required to devote substantial time to
new compliance initiatives,” page 34

12.
Please include in this risk factor an estimate of the expenses you expect to incur in completing your public offering as well as of the annual compliance costs
associated with your reporting obligations.

Response:
 In response to the Staff’s comment, the Company has revised its disclosure on page 35 of Amendment No. 1 to provide an estimate of its
expected incremental annual compliance costs associated with its

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 5

reporting obligations as a public company and will include an estimate of the expenses it expects to incur in connection with this offering in a future pre-effective amendment to the Registration
Statement.

 Use of Proceeds, page 40

13.
Please amend your disclosure to include an approximate amount of the proceeds you plan to allocate to each of the bulleted expenditures and the stage of clinical
development you anticipate you will attain with such allocation.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on page 40 of Amendment No. 1 and will provide the approximate amount of proceeds
to be allocated to each of the bulleted expenditures in a future pre-effective amendment to the Registration Statement once estimated offering proceeds have been determined.

 Management’s Discussion and Analysis of Financial Condition and Results of Operations Research and Development Expenses, page 63

14.
Please disclose on pages 61 and 63 the costs incurred from inception to date for each program or clarify why the inception to date amounts have not been
provided.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 62 and 63 of Amendment No. 1 to disclose the costs incurred from inception
to date for each of its current development programs.

 Business

Our Research and Development Pipeline, page 71

15.
 In your discussion of the scientific background of your product portfolio beginning on page 73, please state expressly whether the research you have
performed and the discoveries you have made either independently or in collaboration with Abbott Laboratories or Novartis into protease inhibitors provides conclusive evidence that your product candidates can offer an interferon-free or
interferon/ribavirin-free approach to HCV. If controversy remains in the scientific community as to any of your hypotheses, you should amend your disclosure to note this and to discuss any potential ramifications, particularly how these
uncertainties cast doubt upon the possibility of developing ABT-450/ABT-450/r. To the extent appropriate, any such controversy should also be

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 6

addressed in your prospectus summary and in an independent risk factor. Please provide a similar discussion for EDP-788, Bicyclolides and their therapeutic effects relating to MRSA and other
skin infections.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 2, 4, 76 and 82 of Amendment No. 1 to clarify that neither interferon-free
or interferon/ribavirin-free approaches to HCV nor EDP-788, Bicyclolides in the treatment of MRSA or other skin infections have been conclusively validated or resulted in FDA-approved drugs. In addition, the Company has expanded its risk factor
disclosure on page 16.

 Collaboration and License Agreements, page 81

16.
Please be more specific in your descriptions of the tiered royalties you are eligible to receive through the Abbott Laboratories and Novartis agreements, e.g.
“teens,” “twenties,” “thirties,” etc.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 2, 5, 47, 48, 53, 70, 79, 83, 84, F-21 and F-24 of Amendment No. 1.

 Manufacturing, page 96

17.
You state here that you currently manufacture a limited amount of your active pharmaceutical ingredients and you imply that you will only rely on third-party
manufacturers for these ingredients when you initiate clinical trials in the future. In your risk factor on page 24, you suggest that such third-party agreements are already in place and that you are currently receiving supplies of your APIs through
them. Please reconcile this discrepancy in your disclosure.

Response:
In response to the Staff’s comment, the Company has revised its disclosure on pages 24 and 97 of Amendment No. 1.

Executive Compensation

Narrative Disclosure to Summary Compensation Table, page 103

18.
We note that you propose to file only a form executive employment agreement as an exhibit. If there are any other material differences among these agreements other
than what you have described here, please include the other differences in this disclosure and file the individual agreements as exhibits.

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 7

Response:
The Company acknowledges the Staff’s comment. Further, the Company notes that it anticipates that one or more of its executive officers will enter into new or
amended employment agreements prior to the completion of this offering. The Company confirms that any material differences among these agreements will be described in a future pre-effective amendment to the Registration Statement and the applicable
form(s) of executive employment agreement(s) will be filed as exhibits thereto.

 Principal Stockholders, page 111

19.
Please identify the individual (s) who possess(es) voting and/or investment power over the shares held by OBP III-Holdings LLC and its affiliated
entities.

Response:
In response to the Staff’s comment, the Company has revised its disclosure in footnote 2 on page 114 of Amendment No. 1.

Shares Eligible for Future Sale

Lock-Up Agreements and Market Standoff Provisions, page 121

20.
Please file a form of the lock-up agreement as an exhibit to your registration statement.

Response:
The Company intends to file a form of lock-up agreement as an exhibit to the underwriting agreement for this offering in a future pre-effective amendment to the
Registration Statement.

 Notes to Financial Statements

 Note 8. Collaboration Agreements, page F-21

21.
You state that you are eligible to receive additional milestones relating to the Novartis contract. Please clarify in Note 8, if the additional milestones are the
result of your efforts or the collaborators’ efforts. Also, please provide the disclosure requirements of ASC 605-28-50-2c and d, if required.

Response:
 In response to the Staff’s comment, the Company has revised its disclosure in Note 8 on pages F-22 and F-24 of Amendment No. 1 to

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 8

clarify that the additional milestone payments it is eligible to receive under each of the Abbott and Novartis collaboration agreements would result solely from the efforts of Abbott or Novartis
in achieving specified clinical, regulatory and commercial milestones, and not from the efforts of the Company. In addition, the Company has revised its disclosure on pages 5, 47, 49, 53, 70, 76, 79, 83 and 84 of Amendment No. 1 to specify that
milestones would result from our respective collaborator’s efforts.

 In addition, the Company
supplementally advises the Staff that it did not elect to adopt ASU 2010-17, Revenue Recognition–Milestone Method, and therefore believes that the disclosure requirements of ASC 605-28-50-2c and d are not applicable. In response to the
Staff’s comment, the Company has revised its disclosure in Note 2 on page F-14 of Amendment No. 1 to disclose the fact that the Company did not elect to adopt the guidance of ASU 2010-17, which was available as an accounting policy
election as of the beginning of the Company’s 2011 fiscal year.

 Note 14. Stock-Based Awards

 Stock Option Valuation, page F-34

22.
You have issued 513,500 stock options in the six months ended June 30, 2012. We will evaluate the accounting treatment for these and any other equity
issuances once an IPO price has been set.

Response:
The Company acknowledges the Staff’s comment and acknowledges that the Staff may have additional comments once an estimated offering price range for the offering
has been determined.

 * * *

 United States Securities and Exchange Commission

 October 10, 2012

  Page
 9

 Please direct your questions or comments regarding this letter or Amendment No. 1 to the
undersigned at (617) 239-0314 or to Nathaniel Gardiner at (617) 239-0293. Thank you for your assistance.

Respectfully submitted,

/s/ Stacie S. Aare

October 18, 2012

Via E -mail
Jay R. Luly, Ph.D.
President and Chief Executive Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown, Massachusetts 02472

Re: Enanta  Pharmaceuticals, Inc.
Amendment No. 1 to Confidential Draft Registration Statement on Form S -1
Submitted October 10, 2012
  CIK No. 0001177648

Dear Dr. Luly:

We have reviewed your amended confidential 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 confi dential draft registration statement on EDGAR or filing your registration
statement 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 revi ewing the information you provide in response to these  comments  and your
amended confidential draft registration statement or filed registration statement,  we may have
additional comments.

Business

Our Research and Development Pipeline, page 72

1. We not e your response to our prior comment 15.  Please include in your disclosure a brief
discussion of controversy relating to your research efforts or hypotheses, if any.  If, to
your knowledge, no such controversy exists, please state this in a response to th is
comment.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
October 18, 2012
Page 2

Notes to Financial Statements

2. Summary of Significant Accounting Policies

Revenue Recognition, page F -13

2. You state that you elected not to adopt the guidance in ASU 2010 -17.  Please clarify in
the filing that you do not have any substantive milestones in your agreements and thus
the adoption of ASU 2010 -17 had no effect on your financial statements.   Refer to ASC
605-28-65-1.

Stock Option Valuation, page F -34

3. As previously acknowledged in your response to comment 22 we will eva luate the
accounting treatment for the 513,500 stock options issued in the six months ended June
30, 2012 and any other equity issuances once an IPO price has been set.  Please confirm
that no other equity issuances have been issued since the balance sheet  date or provide
additional disclosure in the filing.

If you intend to respond to these comments with an amended draft registration statement,
please submit it and any associated correspondence in accordance with the guidance we provide
in the Division’s  September 26, 2012 announcement on the SEC website at
http://www.sec.gov/divisions/corpfin/cfannouncements/drsfilingprocedures.htm .

Regardless of whether you sub mitted your correspondence in connection with your
confidential draft registration statement on EDGAR or via secure e -mail, please keep in mind
that we may publicly post filing review correspondence in accordance with our December 1,
2011 policy  (SEC Staff to Release Filing Review Correspondence Earlier) .  If you intend to use
Rule 83 (17 CFR 200.83) to request confidential treatment of information in the corresponden ce
you submit on EDGAR, please properly mark that information in each of your confidential
submissions to us so we do not repeat or refer to that information in our comment letters to you.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
October 18, 2012
Page 3

 You may contact Christine Allen at (202) 551 -3652 or Ma ry Mast at (202) 551 -3613 if
you have questions regarding comments on the financial statements and related matters.  Please
contact Scot Foley at (202) 551 -3383, John Krug at (202) 551 -3862 or me at (202) 551 -3715
with any other questions.

Sincerely,

 /s/ Jeffrey P. Riedler

Jeffrey P. Riedler
Assistant Director

October 1, 2012

Via Secure E-mail
Jay R. Luly, Ph.D.
President and Chief Executive Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown, Massachusetts 02472

Re: Enanta  Pharmaceuticals, Inc.
Draft Registration Statement on Form S-1
Originally Submitted August 3 0, 2012
  CIK No. 0001177 648

Dear Dr. Luly :

 We are sending you this letter because you have a draft registration statement under
review by the staff of the Division of Corporation Finance.

 Beginning in April, we adopted temporary policies allowing the submission of  draft
registration statement s using  either the SEC’s mail room or , in May,  a secure email system .  On
October 1, 2012 you will be able to submit  draft registration statements  using EDGAR .  You will
not be required to use EDGAR until the Commission adopts the changes to the EDGAR Filer
Manual for Release 12.2.  We will announce on the Commission’s website when you will be
required to start using EDGAR for your submissions.

 This letter is to provide guidance to you on how to start using the EDGAR system to
submit your draft registration  statements.  You already  have a Central Index Key, or CIK
number, assigned to you.   You will need your CIK number to make your initial filing on
EDGAR and you must take a number of steps to prepare for that filing.  Following the
procedures set forth in S ection 3.3.1.1  of the EDGAR Filer Manual – Volume I at
http://www.sec.gov/info/edgar/edgarfm -vol1-v13.pdf , you must:

 Submit a request to us to convert yo ur EDGAR status  to an electronic fi ler if we
generated the CIK  number  for you .

 Request access codes and passwords to file your  registration statement on the EDGAR
system.   If you already had a CIK number when you submitted your confidential draft,
we used that number and you should confi rm that you have your previously obtained
access codes available for filing.

If you need new or replacement EDGAR access codes and passwords, we suggest that
you complete the process to obtain them as soon as possible so that you can use EDGAR

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
October 1, 2012
Page 2

 when you are ready to submit your next draft filing .  Please call the Division’s Filer
Support team at 202 -551-8900 (choose option number four) if you have questions about
this process.   If you do call, please make sure to tell us that we have already assigned a
CIK number to your company and have that number readily available.

 Make  any necessary changes to your contact information and business and mailing
addresses in EDGAR prior to making your initial filing so we can contact you about your
filing.   You should make sure that you list your secure email address in your EDGAR
information, since that is the address the staff will use to send you comment letters.   See
Volume 1, section 5 of the EDGAR Filer Manual on how to make Company data
modification s.

 Once you have your EDGAR access codes, login to the EDGAR Filer Website at
https://www.edgarfiling.sec.gov .  Select “Draft Reg. Statement” on the left hand side of the
opening page and proceed to attach your draft submission  as described  in the EDGAR Filer
Manual  and the d etailed instructions that are posted on the SEC Website at
http://www.sec.gov/divisions/corpfin/guid ance/drsfilingprocedures.pdf .

 When you make your first EDGAR draft submission, you should submit it as a new draft
registration statement, even if it is an amendment to a previously submitted version.  In addition
to the new draft, i n this first EDGAR su bmission, you should  also:

 Attach each previously submitted draft registration statement , including exhibits, to your
initial registration statement as a separate Exhibit 99 document and clearly identify each
confidential submission attached as an Exhibit  99 document (e.g., EX-99.1 “Original
Draft Registration Statement, dated xx/xx/2012” ).  Do not attach submissions marked to
show changes from earlier submissions.

 Submit each item of correspondence you sent to us in connection with your draft
submissions, including your responses to our comments, as a separate “COVER”
document within the submission.

If you intend to use Rule 83 (17 CFR 200.83) to request confidenti al treatment of
information in the correspondence you submit on EDGAR, please properly mark that
information in each of your confidential submissions to us so we do not repeat or refer to
that information in our comment letters to you.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
October 1, 2012
Page 3

 You may contact Christine Allen at (202) 551 -3652 or Mary Mast at (202) 551 -3613 if
you have questions regarding comments on the financial statements and related matters.  Please
contact Scot Foley at (202) 551 -3383, John Krug at (202) 551 -3862 or me at (202) 551 -3715
with any other questions.

Sincerely,

 /s/ Daniel Greenspan for

Jeffrey P. Riedler
Assistant Director

September 26, 2012

Via E -mail
Jay R. Luly, Ph.D.
President and Chief Executive Officer
Enanta Pharmaceuticals, Inc.
500 Arsenal Street
Watertown, Massachusetts 02472

Re: Enanta Pharmaceuticals, Inc.
Confidential Draft Registration Statement on Form  S-1
Submitted August 31, 2012
  CIK No. 0001177648

Dear Dr. Luly:

We have reviewed your confidential 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 u nderstand your disclosure.

Please respond to this letter by providing the requested information and either submitting
an amended confidential draft registration statement or filing your registration statement 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 confidential draft registration statemen t or filed registration statement, we may have
additional comments.

General

1. We note that your draft filing omits disclosure  and exhibits that you intend to provide  at a
later date . Please provide this information with your next submission  or as soon as
possible thereafter in order to expedite the review of your filing.

2. We further note that you have submitted an application for confidential treatment relating
to certain of your exhibits. Please be advised that we will be performing a separate review
of this application and that the review of your registration statement will not be complete
until all comments concerning your confidential treatment request, if any, have been
cleared.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
September 26, 2012
Page 2

 Prospectus Summary

Overview,  page 1

3. Please state here and wherever else applicable in your registration statement, including
the risk factor beginning on page 16, that none of your product candidates has yet
advanced beyond the Phase 2 stage of clinical testing  and that Phase 3 clin ical trials are
lengthy and typically involve at least several hundred people, if not more ; please also
provide an estimate of the minimum amount of time it would take from now until a New
Drug Application for one of your products could be approved.

ABT -450/r, a Protease Inhibitor for HCV Infection, page 2

4. Please include a statement in the last paragraph under this heading on page 3 that Abbot
Laboratories’ projection may be mistaken and that your clinical trials may take longer
than anticipated to comp lete, that the FDA may refuse to approve your New Drug
Application as submitted for a variety of reasons, and that you may be request ed to
perform additional clinical trials.

Risk Factors

“We may require substantial additional financing to achieve our goals if the development and
commercialization of ABT -450 or EDP -239 is delayed or terminated . . .,” page 13

5. Please include in this risk factor an estimate of the amount you intend to alloc ate toward
product development in the next fiscal year.

“We have incurred a substantial cumulative net loss since our inception and we anticipate that
we may incur substantial operating losses in the future . . .,” page 14

6. Please state in this risk factor and wherever else applicable in your registration statement
the reason(s) your former collaborator opted to terminate its agreement with you in 2010,
to the best of your knowledge.

“Clinical drug development involves a l engthy and expensive process with uncertain timelines
and uncertain outcomes . . .,” page 16

7. Please expand the discussion in this risk factor to state, if known, the reason for the
clinical hold on Novartis’ cyclophilin inhibitor.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
September 26, 2012
Page 3

 “If we or our collab orators are required to suspend or discontinue clinical trials due to side
effects or other safety risks associated with our product candidates . . .,” page 17

8. If you are aware of any instance where a clinical trial for one of your product candidates
was suspended or terminated for safety reasons, please disclose it here.

“Even if we or our collaborators are able to commercialize any product candidates, the resulting
products may become subject to unfavorable pricing regulations . . .,” page 21

9. Please i nclude in this risk factor a brief but specific discussion of the ramifications of the
Patient Protection and Affordable Care Act on your commercial prospects.

“Because a portion of our manufacturing takes place in China through third -party manufacturers
. . .,” page 24

10. Please amend your disclosure to state to which of your product candidates that your third -
party manufacturing and supply agreements relate.

“Issued patents covering one or more of our product candidates could be found invalid or
unenforc eable if challenged in court,” page 26

11. We note your disclosure on page 96 and in Note 16 to your financial statements that you
are not currently party to any actual or threatened litigation. If there has been any
litigation in the past concerning one of y our material patents, please describe the nature
of this litigation and its resolution in this risk factor.

“We will incur increased costs as a result of operating as a public company, and our management
will be required to devote substantial time to new  compliance initiatives,” page 34

12. Please include in this risk factor an estimate of the expenses you expect to incur in
completing your public offering as well as of the annual compliance costs associated with
your reporting obligations.

Use of Proceeds,  page 40

13. Please amend your disclosure to include an approximate amount of the proceeds you plan
to allocate to each of the bulleted expenditures and the stage of clinical development you
anticipate you will attain with such allocation.

Management’s Discussion and Analysis of Financial Condition and Results of Operations
Research and Development Expenses, page 63

14. Please disclose on pages 61 and 63 the costs incurred from inception to date for each
program or clarify why the inception to date amounts have not been provided.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
September 26, 2012
Page 4

Business

Our Research and Development Pipeline, page 71

15. In your discussion of the scientific background of your product portfolio beginning on
page 73, please state expressly whether the research you have performed and the
discoveries you have made either independently or in collaboration with Abbott
Laboratories or Novartis into protease inhibitors provides conclusive evidence that your
product candidates can offer an interferon -free or interferon/ribavirin -free approach to
HCV.  If controversy remains in the scientific community as to any of your hypotheses,
you should amend your disclosure to note this and to discuss any potential ramifications,
particularly how these uncertainties cast doubt upon the possibility of develo ping ABT -
450/ABT -450/r. To the extent appropriate, any such controversy should also be addressed
in your prospectus summary and in an independent risk factor.  Please provide a similar
discussion for EDP -788, Bicyclolides and their therapeutic effects rela ting to MRSA and
other skin infections.

Collaboration and License Agreements, page 81

16. Please be more specific in your descriptions of the tiered royalties you are eligible to
receive through the Abbott Laboratories and Novartis agreements, e.g. “teens, ”
“twenties,” “thirties,” etc.

Manufacturing, page 96

17. You state here that you currently manufacture a limited amount of your active
pharmaceutical ingredients and you imply that you will only rely on third -party
manufacturers for these ingredients when you initiate clinical trials in the future. In your
risk factor on page 24, you suggest that such third -party agreements are already in place
and that you are currently receiving supplies of your APIs through them. Please reconcile
this discrepancy in your disclosure

Executive Compensation

Narrative Disclosu re to Summary Compensation Table, page 103

18. We note that you propose to file only a form executive employment agreement as an
exhibit. If there are any other material differences among these agreements other than
what you have described here, please includ e the other differences in this disclosure and
file the individual agreements as exhibits.

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
September 26, 2012
Page 5

 Principal Stockholders, page 111

19. Please identify the individual(s) who possess(es) voting and/or investment power over the
shares held by OBP III -Holdings LLC and its affiliated entities.

Shares Eligible for Future Sale

Lock -Up Agreements and Market Standoff Provisions, page 121

20. Please file a form of the lock -up agreement as an exhibit to your registration statement.

Notes to Financial Statements

Note 8.  Coll aboration Agreements , page F -21

21. You state that you are eligible to receive additional milestones relating to the Novartis
contract.  Please clarify in Note 8, if the additional milestones are the result of your
efforts or the collaborators’ efforts.  Also , please provide the disclosure requirements of
ASC 605 -28-50-2c and d, if required.

Note 14. Stock -Based Awards

Stock Option Valuation, page F -34

22. You have issued 513,500 stock options in the six months ended June 30, 2012.  We will
evaluate the accounting treatment for these and any other equity issuances once an IPO
price has been set.

If you intend to respond to these comments with an amended draft registration statement,
please submit it and any associated correspondence in text searchable PD F files using the secure
e-mail system we describe on our website at
http://www.sec.gov/divisions/corpfin/cfannouncements/cfsecureemailinstructions.

Please use your Central Index Key, or CIK number, in your correspondence to us about
your submissio n. You will need your CIK number to make your initial filing on EDGAR and
you must take a number of steps to prepare for that filing.  Following the procedures set forth in
Section 3.3.1.1  of the EDGAR Filer Manual – Volume I at
http://www.sec.gov/info/edg ar/edgarfm -vol1-v12., you must:

 Submit a request to us to convert your EDGAR status to an electronic filer if we
generated the CIK number for you.

 Request access codes and passwords to file your registration statement on the EDGAR
system.   If you need new or replacement EDGAR access codes and passwords, we

Jay R. Luly, Ph.D.
Enanta Pharmaceuticals, Inc.
September 26, 2012
Page 6

 suggest that you complete the process to obtain them well in advance of your targeted
filing date.  Please call the Division’s Filer Support team at 202 -551-8900 (choose option
number four) if you hav e questions about this process.   If you do call, please make sure to
tell us that we have already assigned a CIK number to your company and have that
number available.

 Make any necessary changes to your contact information and business and mailing
addre sses in EDGAR prior to making your initial filing so we can contact you about your
filing.

When you publicly file your confidential draft registration statement and amendments on
EDGAR in accordance with Section 106(a) of the JOBS Act, please:

 Attach each submission, including exhibits, to your initial registration statement as a
separate Exhibit 99 document and clearly identify each confidential submission attached
as an Exhibit 99 document (e.g., “Confidential Draft # 1”) .  Do not attach submissions
marked to show changes from earlier submissions.

 Submit each item of correspondence you sent to us in connection with your confidential
draft submissions, including your responses to our comments, as a separate “CORRESP”
submission on EDGAR.

As you pre pare correspondence to us in connection with your confidential draft
registration statement, please keep in mind that we will expect you to submit that same
correspondence on EDGAR so that we may publicly post filing review correspondence in
accordance wit h our December 1, 2011 policy (SEC Staff to Release Filing Review
Correspondence Earlier ).  If you intend to use Rule 83 (17 CFR 200.83) to request confidential
treatment of information in the correspondence you submit on EDGAR, please properly mark
that information in each of your confidential submissions to us so we do not repeat or refer to
that information in our comment letters to you.

You may contact Chris tine Allen at (202) 551 -3652 or Mary Mast at (202) 551 -3613 if
you have questions regarding comments on the financial statements and related matters.  Please
contact Scot Foley at (202) 551 -3383, John Krug at (202) 551 -3862 or me at (202) 551 -3715
with any  other questions.

Sincerely,

 /s/ Jeffrey P. Riedler

Jeffrey P. Riedler
Assistant Director