Leading Independent Proxy Advisory Firms ISS and Glass Lewis Recommend Acer
Therapeutics Shareholders Vote “FOR” the Proposed Merger and Related Proposals

Press Releases

Acer Shareholders – Please Vote Today!

NEWTON, MA – November 2, 2023 – Acer Therapeutics Inc. (Nasdaq: ACER), a pharmaceutical
company focused on the acquisition, development and commercialization of therapies for
serious, rare and life-threatening diseases with significant unmet medical needs, today
announced that Institutional Shareholder Services Inc. (ISS) and Glass, Lewis & Co. LLC (Glass
Lewis) recommended that Acer shareholders vote “FOR” the proposed merger with Zevra
Therapeutics, Inc. and the related proposals in the Company’s proxy statement and prospectus
for the special meeting of its shareholders to be held on November 8, 2023 at 11:00 a.m.
Eastern Time.
ISS and Glass Lewis are widely recognized as the leading independent voting and corporate
governance advisory firms. Their analysis and recommendations are relied on by many major
institutional investment firms, mutual funds and fiduciaries throughout North America.
In its report, ISS stated, among other things, that “The transaction warrants support in light of
the reasonably thorough review of alternatives, the positive market reaction, the upside
potential provided by the stock and CVR forms of consideration, and the downside risk of non-
approval.”
Glass Lewis concluded that the transaction would allow Acer shareholders to participate in a
larger and better capitalized pharmaceutical company, while also retaining significant upside
potential through the CVR consideration, at a time when Acer appears to have few, if any,
viable alternatives. Glass Lewis also noted that the total implied value of the proposed
consideration represents a substantial premium to the unaffected trading price of Acer shares
and the merger consideration compares favorably with the expected outcome in a liquidation
scenario, in which Acer shareholders were not expected to receive any proceeds.
Commenting on the proxy advisors’ reports, Chris Schelling, CEO and Founder of Acer, said:
“The ISS and Glass Lewis recommendations are consistent with our view that the merger with
Zevra is in the best interest of Acer shareholders.”
The merger and related agreements have been unanimously approved by the boards of
directors of both companies. The merger and related proposals have been unanimously
approved by Acer’s board of directors.
Failure to vote or an abstention from voting will have the same effect as a vote “AGAINST” the
merger proposal. All shareholders are asked to vote “FOR” all proposals as soon as possible.

THE MERGER WILL NOT GO FORWARD UNLESS THE MERGER AND RELATED PROPOSALS ARE

APPROVED.

ACER SHAREHOLDERS – PLEASE VOTE TODAY!

If the merger is not approved on November 8, ACER will begin trading on OTC Pink Market
starting on November 9 because of the failure by the Company to regain compliance, during the
previously granted 180 calendar day grace period, with Nasdaq’s requirement of having at least
$35 million in market value of listed securities, resulting in the trading suspension of ACER on
Nasdaq.
If the merger is not subsequently consummated, Acer will not be able to fund its business
operations and will likely be forced to terminate operations, liquidate or file for bankruptcy.
If you are an Acer shareholder and you have questions or require assistance in submitting your
proxy or voting your shares, please contact Acer’s proxy solicitor:
ADVANTAGE PROXY, INC.
Toll Free: 1-877-870-8565
Collect: 1-206-870-8565
Email: ksmith@advantageproxy.com
Additional Information about the Proposed Merger between Acer and Zevra, the Special
Meeting and Where to Find It
In connection with the proposed merger, Zevra has filed a registration statement on Form S-4
with the Securities and Exchange Commission (the “SEC”), including a proxy statement /
prospectus. The registration statement was declared effective on October 10, 2023.
Additionally, Acer’s proxy statement was filed on October 10, 2023. Acer shareholders are
urged to read these materials because they contain important information about Acer, Zevra
and the proposed merger. The proxy statement / prospectus and other relevant materials, and
any other documents filed by Zevra and Acer with the SEC, may be obtained free of charge at
the SEC website at www.sec.gov. In addition, Acer shareholders will be able to attend the Acer
special meeting via the Internet at https://www.cstproxy.com/acertx/sm2023 and view the
Acer 2023 Special Meeting Proxy Statement and the Zevra Therapeutics, Inc. Forms 10-K, 10-Qs
and 8-Ks. Acer shareholders are urged to read the proxy statement / prospectus and the other
relevant materials before making any voting or investment decision with respect to the
proposed merger.
No Offer or Solicitation
This communication is for informational purposes only and not intended to and does not
constitute an offer to subscribe for, buy or sell, the solicitation of an offer to subscribe for, buy
or sell or an invitation to subscribe for, buy or sell any securities or the solicitation of any vote
or approval in any jurisdiction pursuant to or in connection with the proposed transaction or
otherwise, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in

contravention of applicable law. No offer of securities shall be made except by means of a
prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended
(the “Securities Act”), and otherwise in accordance with applicable law.
Participants in the Solicitation
Acer, Zevra and their respective directors and executive officers may be considered participants
in the solicitation of proxies in connection with the proposed transaction. Information about
the directors and executive officers of Acer is set forth in its Annual Report on Form 10-K for the
year ended December 31, 2022, which was filed with the SEC on March 27, 2023, and its proxy
statement for its 2023 annual meeting of shareholders, which was filed with the SEC on April
14, 2023. Information about the directors and executive officers of Zevra is set forth in its
Annual Report on Form 10-K for the year ended December 31, 2022, which was filed with the
SEC on March 7, 2023, and its proxy statement for its 2023 annual meeting of stockholders,
which was filed with the SEC on March 15, 2023, the definitive proxy statement filed by Daniel
J. Mangless, together with the other participants named therein, which was filed with the SEC
on March 17, 2023, and Zevra’s Current Reports on Form 8-K, filed with the SEC on March 30,
2023, May 8, 2023, May 15, 2023, and August 7, 2023. Other information regarding the
participants in the proxy solicitations and a description of their direct and indirect interests, by
security holdings or otherwise, is set forth in the proxy statement/prospectus and other
relevant materials filed with the SEC and may be obtained free of charge from the sources
indicated above.
About Acer Therapeutics
Acer is a pharmaceutical company focused on the acquisition, development and
commercialization of therapies for serious rare and life-threatening diseases with significant
unmet medical needs. In the U.S., OLPRUVA® (sodium phenylbutyrate) is approved for the
treatment of UCDs involving deficiencies of CPS, OTC, or AS. Acer is also advancing a pipeline of
investigational product candidates for rare and life-threatening diseases, including: OLPRUVA®
(sodium phenylbutyrate) for treatment of various disorders, including Maple Syrup Urine
Disease (MSUD); and EDSIVO™ (celiprolol) for treatment of vascular Ehlers-Danlos syndrome
(vEDS) in patients with a confirmed type III collagen (COL3A1) mutation. For more information,
visit www.www.acertx.com.
Forward-Looking Statements
DISCLOSURE NOTICE: This press release contains “forward-looking statements” within the
meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of
1934, as amended, related to Acer, Zevra and the proposed acquisition of Acer by Zevra. All
statements other than statements of historical fact are forward-looking statements for
purposes of federal and state securities laws. These forward-looking statements involve
uncertainties that could significantly affect the financial or operating results of Acer, Zevra or
the combined company. These forward-looking statements may be identified by terms such as
anticipate, believe, foresee, expect, intend, plan, may, will, could, should and would and the
negative of these terms or other similar expressions. Forward-looking statements in this
document include, among other things, statements about the potential benefits of the

proposed acquisition; statements about contingent cash consideration and related milestones
as contemplated by the CVR Agreement; the anticipated timing of closing of the acquisition; the
delisting of Acer’s stock from Nasdaq and resulting move to OTC Pink Market; and that, if the
merger is not subsequently consummated, Acer will not be able to fund its business operations
and will likely be forced to terminate operations, liquidate or file for bankruptcy. These
forward-looking statements involve substantial risks and uncertainties that could cause actual
results to differ materially from those expressed or implied by such statements. Risks and
uncertainties include, among other things, risks related to the satisfaction of the conditions to
closing the acquisition (including the failure to obtain necessary stockholder approval) in the
anticipated timeframe or at all; risks related to the ability to realize the anticipated benefits of
the acquisition, including the possibility that the expected benefits from the proposed
acquisition will not be realized or will not be realized within the expected time period; risks
related to the contingent cash consideration and related milestones as contemplated by the
CVR Agreement, including that such milestone may not be achieved and thus the related cash
consideration would not become payable; the risk that the businesses will not be integrated
successfully; disruption from the transaction making it more difficult to maintain business,
contractual and operational relationships; the unfavorable outcome of the legal proceedings
that have been or may be instituted against Acer, Zevra or the combined company; the ability
to retain key personnel; negative effects of this announcement or the consummation of the
proposed acquisition on the market price of the capital stock of Acer and Zevra and on Acer’s
and Zevra’s operating results; risks relating to the value of Zevra’s shares to be issued in the
transaction; significant transaction costs, fees, expenses and charges; unknown liabilities; the
risk of litigation and/or regulatory actions related to the proposed acquisition; the financing of
the transaction and Acer’s interim operations; the occurrence of any event, change or other
circumstances that could give rise to the termination of the merger agreement; other business
effects, including the effects of industry, market, economic, political or regulatory conditions;
future exchange and interest rates; changes in tax and other laws, regulations, rates and
policies; future business combinations or disposals; and competitive developments.
A further description of risks and uncertainties relating to Acer and Zevra can be found in their
respective most recent Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and
Current Reports on Form 8-K, all of which are filed with the SEC and available at www.sec.gov.
Neither Acer nor Zevra intends to update the forward-looking statements contained in this
document as the result of new information or future events or developments, except as
required by law.
Corporate Contact
Harry Palmin
Chief Financial Officer
Acer Therapeutics Inc.
investors@www.acertx.com
+1-844-902-6100

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