SecProbe.io

Octo ber 24, 2013

Via E -Mail
Terrence E. Winters, Ph.D.
Co-Chairman of the Board &
Chief Executive Officer
Vital Therapies, Inc.
15010 Avenue of Science, Suite 200
San Diego, CA 92128

Re: Vital Therapies, Inc.
Registration Statement on Form S -1
Filed October 11, 2013
  File No. 333 -191711

Dear Dr. Winters :

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

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

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

Critical Accounting Policies and Significant Judgments and Estimates
Stock -based Compensation, page 50

1. Please refer to prior comment 1. We are deferring a final evaluation of stock
compensat ion and other costs until your estimated offering price is specified. We may
have further comments in this regard, when the amendment containing this information is
filed.  In your response, please update your confirmation that no new equity issuances,
including future purchase rights, options and convertible preferred stock, have been
issued subsequent to the latest balance sheet date.

Terrence E. Winters, Ph.D.
Vital Therapies, Inc.
October 24, 2013
Page 2

 Notes to the Financial Statements
7. Redeemable Convertible Preferred Stock
Future Purchase Rights, page F -25

2. Please  refer to prior comment 2. Please provide us the following explanations regarding
the information in your response and your disclosure on page F -28.

 Explain the basis for granting future purchase rights to investors in the senior
preferred stock financings. In particular, explain why the number of future
purchase rights granted on page F -28 does not equal the number of senior
redeemable convertible preferred shares issued on page F -27.
 Explain the relationship between the common stock value for th e future purchase
rights granted on September 25, 2012 of $2.30 per share, as disclosed on page F -
28, and the common stock fair value of $1.17 per share, as disclosed on page 52.

In addition, your disclosure appears to indicate that this table relates on ly to future
purchase rights. However, the beneficial conversion amount of $306,000 for June 2013
includes $264,000 related to options granted to certain directors. Please revise your
disclosure to clarify that the table includes the beneficial conversion amount for the
options.

Please note that we are deferring a final evaluation of the future purchase rights and other
costs until your estimated offering price is specified.

We urge all persons who are responsible for the accuracy and adequacy of the di sclosure
in the filing to be certain that the filing includes the information the Securities Act of 193 3 and
all applicable Securities  Act rules require.   Since the company and its management are in
possession of all facts relating to a company’s disclosur e, they are responsible for the accuracy
and adequacy of the disclosures they have made.

Notwithstanding our comments, in the event you request acceleration of the effective date
of the pending regist ration statement please provide  a written statement f rom 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;

 the action of the Commi ssion 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

Terrence E. Winters, Ph.D.
Vital Therapies, Inc.
October 24, 2013
Page 3

  the company may not assert staff c omments 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 their respective responsibilities under
the Securities Act of 1933 and the Securitie s 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 review any amendment prior to the requested effective date of the
registration stat ement.

You may con tact Franklin Wyman at (202) 551-3660  or Mary Mast at (202) 551-3613  if
you have questions regarding comments on the financial statements and related matters.  Please
contact Christina De Rosa at (202 ) 551 -3577, Bryan Pitko at (202)  551-3203,  or me at (202) 551 -
3715 with any other questions.

Sincerely,

 /s/ Bryan J. Pitko for

 Jeffrey P. Riedler
Assistant Director
cc:  Via E -Mail
 Martin J. Waters
 Wilson Sonsini Goodrich & Rosati,
 Professional Corporation
 12235 El Camino Real,  Suite 200
San Diego, CA 92130 -3002