UNITED STATES
                                 SECURITIES AND EXCHANGE COMMISSION
                                              WASHINGTON, D.C. 20549


    DIVISION OF
CORPORATION FINANCE
                                                                      April 29,
2020


 Arnaud Ajdler
 Managing Member
 Engine Capital, L.P.
 1345 Avenue of the Americas   33rd Floor
 New York, New York 10105

         Re:     CymaBay Therapeutics, Inc.
                 PREC14A filed by Engine Capital L.P., et al.
                 Filed April 24, 2020
                 File No. 001-36500

 Dear Mr. Ajdler,

         We have reviewed the above-captioned filing, and have the following
comments. Some
 of our comments may ask for additional information so we may better understand
the disclosure.

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

        After reviewing any amendment to the filing and any information
provided in response to
 these comments, we may have additional comments.

 Preliminary Proxy Statement filed under cover of Schedule 14A

 General

 1. Please advise us when the participants anticipate distributing their proxy
statement. Given
    that reliance on Rule 14a-5(c) is impermissible at any time before the
registrant distributes its
    proxy statement, the participants will accept all legal risk in connection
with distributing the
    initial definitive proxy statement without all required disclosures and
should undertake to
    subsequently provide any omitted information in a supplement in order to
mitigate that risk.

 2. The disclosure on the first page indicates that the participants
"beneficially own in the
    aggregate approximately 9.4% of the outstanding shares of common stock" of
the registrant.
    As the date of the annual meeting and date of distribution for the proxy
statement remain
    unknown, please advise us how this amount of beneficial will be affirmed.
 Arnaud Ajdler
April 29, 2020
Page 2

Reasons for the Solicitation, page 8

3. Please refer to the following contention: "We question the Board's
motivation, if other than
   entrenchment..." The participants' apparent attempt to imply that incumbent
directors may
   be motivated by self-interest and are thus perpetuating a plan of
self-preservation through
   "entrenchment" ignores and is in conflict with the action undertaken by the
registrant's
   Board to reduce its size to 5 members from 9. Please revise to explicitly
support the cited
   contention in light of actions recently undertaken by the registrant's Board
since December
   of 2019, or delete the unqualified contention. Refer to Note b. of Rule
14a-9.

4. Please refer to the following contention: "..only to have our overtures
rebuffed without the
   Board ever making a counterproposal." This contention appears to be in
conflict with an
   earlier representation in the proxy statement which indicated the
participants "rejected the
   Board's offer to discuss appointing one, but not two, of Engine's
nominees..." Please
   reconcile these disclosures given that it appears the participants have
equated the rejection of
   their proposal with a failure of the current Board to meaningfully engage
with shareholders.

5. Please provide the factual foundation and/or analysis to support the
participants' assertion
   that the registrant's financial performance suffers from an alleged elevated
cash burn rate.

We Are Concerned with the Company's Prolonged Stock Price Underperformance,
page 8

6. To the extent the suspension of the studies relating to the registrant's
leading drug candidate,
   seladelpar, and the corresponding Seladelpar Investigation, may have
materially impacted the
   performance of the registrant's stock price, the disclosure should provide
this context. Please
   revise or advise. Refer to Rule 14a-9(a), which, by its terms, prohibits the
omission of any
   material fact necessary in order to make the statements made not misleading.

Voting and Proxy Procedures, page 18

7. Please refer to the following assertion: "we reserve the right to vote some
or all of our shares
   [ ] for some or all of the Company's director nominees, as we see fit, in
order to achieve a
   Board composition that we believe is in the best interest of all
stockholders." Given that the
   registrant's Board is composed of five directors, and the participants are
seeking support at
   the Annual Meeting to elect their three nominees in opposition to the
registrant's director
   nominees, Rule 14a-4(d)(4) is unavailable. Consequently, the proxy authority
sought cannot
   be used for any of the registrant's nominees. Please revise to clarify, if
true, that the cited
   reference to "some or all of our shares" is intended to mean only the
approximately 9.4% of
   shares beneficially owned by the participants. See Rule 14a-4(d)(1).

8. Please refer to the following two statements: "This Proxy Statement is
soliciting proxies to
   elect only our Nominees. Accordingly, the enclosed BLUE proxy card may only
be voted for
   the Nominees and does not confer voting power with respect to the Company's
nominees."
   Notwithstanding the inferences that may be drawn, please disclose how the
two remaining
   board vacancies will be filled if all of the participants' nominees are
elected. In addition,
 Arnaud Ajdler
April 29, 2020
Page 3

    please address how vacancies will be filled in the situation where any of
the registrant's
    nominees refuse to serve in the event any of the participants' nominees are
elected.

                                         *       *       *

        We remind you that the participants are responsible for the accuracy
and adequacy of
their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

        You may contact me at (202) 551-3266 with any questions.

                                                             Sincerely,

                                                             /s/ Nicholas P.
Panos

                                                             Nicholas P. Panos
                                                             Senior Special
Counsel
                                                             Office of Mergers
and Acquisitions
cc: Andrew Freedman, Esq.
Olshan Frome Wolosky LLP