Filed pursuant to Rule 424(b)(3)
Registration No. 333-299142
PROSPECTUS

Up to 9,534,164 Shares of Common Stock
This prospectus relates to
the offer and resale from time to time by the selling stockholders named in this prospectus, referred to as the selling stockholders,
of up to 9,534,164 shares of common stock, par value $0.001 per share, of Tempest Therapeutics, Inc. (the “Shares”), consisting
of (i) up to 3,105,591 shares of our common stock issuable upon the exercise of pre-funded warrants (the “Pre-Funded Warrants”),
(ii) up to 3,105,591 shares of our common stock issuable upon the exercise of Series C warrants (the “Series C Warrants”),
(iii) up to 3,105,591 shares of our common stock issuable upon the exercise of Series D warrants (the “Series D Warrants,”
and, together with the Series C Warrants, the “Common Warrants”), and (iv) up to 217,391 shares of our common stock that are
issuable upon the exercise of certain placement agent warrants (the “Placement Agent Warrants,” and together with the Pre-Funded
Warrants and the Common Warrants, the “Warrants”) issued to designees of H.C. Wainwright & Co., LLC, our placement agent
(the “Placement Agent”) in connection with the private transaction pursuant to which we issued the Warrants.
Our registration of Shares
covered by this prospectus does not mean that the selling stockholders will sell any Shares. The Pre-Funded Warrants and the Common Warrants
were issued and sold to certain of the selling stockholders named herein in a private placement pursuant to a securities purchase agreement,
dated September 11, 2026 (the “Purchase Agreement”), by and among us and the parties named therein, in a transaction more
fully described in the section titled “Prospectus Summary.”
We are not selling any common
stock or other securities under this prospectus, and will not receive any proceeds from the sale of the Shares by the selling stockholders;
however, we will receive proceeds from the exercise of any Warrants for cash.
The selling stockholders
may offer and sell or otherwise dispose of the Shares described in this prospectus from time to time through public or private transactions
at prevailing market prices, at prices related to prevailing market prices or at privately negotiated prices. The selling stockholders
will bear all underwriting fees, commissions and discounts, if any, attributable to the sales of Shares and any transfer taxes. We will
bear all other costs, expenses and fees in connection with the registration of the Shares. See “Plan of Distribution” beginning
on page 10 of this prospectus for more information about how the selling stockholders may sell or dispose of
their respective Shares.
Our common stock is listed
on The Nasdaq Capital Market under the trading symbol “TPST”. On September 24, 2026, the closing price of our common stock
as reported on The Nasdaq Capital Market was $0.85 per share.
Investing
in our common stock involves a high degree of risk. You should carefully read the information under “Risk
Factors” on page 4 of this prospectus and under similar headings in any amendment or supplement to this
prospectus or in any filing with the Securities and Exchange Commission (the “SEC”) that is incorporated by reference herein.
We are a “smaller
reporting company” under applicable SEC rules and a non-accelerated filer. As such, we are eligible for reduced public company
reporting requirements. See “Prospectus Summary—Implications of Being a Smaller Reporting Company and a Non-Accelerated Filer”
for more information.
Neither the SEC nor any
state securities commission has approved or disapproved of these securities, passed upon the accuracy or adequacy of this prospectus,
or determined if this prospectus or any prospectus supplement is truthful or complete. Any representation to the contrary is a criminal
offense.
The date of this prospectus
is October 1, 2026.
TABLE OF CONTENTS
| |
|
Page |
|
| ABOUT THIS PROSPECTUS |
|
|
ii |
|
| PROSPECTUS SUMMARY |
|
|
1 |
|
| RISK FACTORS |
|
|
4 |
|
| SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS |
|
|
5 |
|
| USE OF PROCEEDS |
|
|
7 |
|
| SELLING STOCKHOLDERS |
|
|
8 |
|
| PLAN OF DISTRIBUTION |
|
|
10 |
|
| LEGAL MATTERS |
|
|
12 |
|
| EXPERTS |
|
|
12 |
|
| WHERE YOU CAN FIND ADDITIONAL INFORMATION |
|
|
12 |
|
| INCORPORATION OF CERTAIN INFORMATION BY REFERENCE |
|
|
13 |
|
ABOUT THIS PROSPECTUS
This prospectus is part of
a registration statement on Form S-3 that we filed with the SEC. Under this registration statement, the selling stockholders may sell
from time to time in one or more offerings the Shares offered pursuant to this prospectus. Information about the selling stockholders
may change over time. When the selling stockholders sell Shares under this prospectus, we will, if required by law, provide a prospectus
supplement that will contain specific information about the terms of that offering. Any prospectus supplement may also add to, update,
modify or replace information contained in this prospectus. If a prospectus supplement is provided and the description of the offering
in the prospectus supplement varies from the information in this prospectus, you should rely on the information in the prospectus supplement.
You should carefully read this prospectus and any accompanying prospectus supplement along with all of the information incorporated by
reference herein and therein, before making an investment decision.
You should rely only on the
information contained or incorporated by reference in this prospectus or any applicable prospectus supplement. Neither we nor the selling
stockholders have authorized anyone to provide you with information other than the information contained or incorporated by reference
in this prospectus and your reliance on any unauthorized information or representation is at your own risk. This prospectus may be used
only in jurisdictions where offers and sales of these securities are permitted. You should assume that the information appearing in this
prospectus is accurate only as of the date of this prospectus and that any information we have incorporated by reference is accurate only
as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus, or any sale of our common
stock. Our business, financial condition and results of operations may have changed since those dates.
Throughout this prospectus,
the terms “we,” “us,” “our,” and the “company” refer to Tempest Therapeutics, Inc., a
Delaware corporation, and its subsidiaries. The term “common stock” refers to common stock of Tempest Therapeutics, Inc.,
par value $0.001 per share.
PROSPECTUS SUMMARY
This prospectus summary highlights selected
information appearing elsewhere in this prospectus and in documents we file with the SEC that are incorporated by reference in this prospectus.
This summary may not contain all of the information that may be important to you. To understand this offering fully, you should read this
entire prospectus carefully, including the information incorporated by reference herein, the information set forth under the heading “Risk
Factors” and our financial statements and the related notes thereto incorporated by reference in this prospectus.
Company Overview
We are a clinical-stage
biotechnology company advancing a pipeline of advanced chimeric antigen receptor T-cell (“CAR-T”) product candidates, including
our lead program, TPST-4003, a dual-targeting CD19/B-cell maturation antigen (“BCMA”) in vivo CAR-T product candidate, which
we are developing for indications in immunology and oncology. In February 2026, we expanded our pipeline through a strategic transaction
under which we acquired rights to a dual-targeting CAR-T platform, which included product candidates with the potential to treat certain
blood cancers, solid tumors and immunology indications, including TPST-2003, an autologous CD19/BCMA CAR-T therapy currently in clinical
development for relapsed or refractory multiple myeloma and the rare disease, POEMS syndrome.
Our mission is to develop
therapeutic products with the potential to address high unmet medical needs by identifying promising clinical-stage candidates and advancing
their development to create products that will improve patients’ lives.
Private Placement
On September 11, 2026, we entered into the Purchase
Agreement with an institutional investor (the “Investor”), pursuant to which we issued and sold in a private placement (the
“Private Placement”) the Pre-Funded Warrants to purchase up to 3,105,591 shares of common stock accompanied by (i) the Series
C Warrants to purchase up to 3,105,591 shares of common stock and (ii) the Series D Warrants to purchase up to 3,105,591 shares of common
stock. The combined purchase price per Pre-Funded Warrant and accompanying Common Warrants was $0.804. The Private Placement closed on
September 15, 2026.
Pursuant to the Purchase Agreement, we agreed
to seek, within 90 days following the date of the Purchase Agreement, approval from our stockholders for the issuance of the Shares issuable
upon exercise of the Common Warrants (the “Stockholder Approval”). The Common Warrants have an exercise price of $0.805 per
share and will become exercisable on the effective date of Stockholder Approval (the “Stockholder Approval Date”). The Series
C Warrants have a term of six years from the later of the Stockholder Approval Date and the Effectiveness Date (as defined below). The
Series D Warrants have a term of three years from the later of the Stockholder Approval Date and the Effectiveness Date. The Pre-Funded
Warrants became exercisable immediately following the closing date of the Private Placement, have an exercise price of $0.001 per share,
and may be exercised at any time until exercised in full. The Pre-Funded Warrants and the Common Warrants contain customary adjustment
provisions for stock dividends, stock splits, pro rata distributions and similar events, and beneficial ownership limitations of 9.99%
with respect to the Pre-Funded Warrants or 4.99% (or, upon election of the holder, 9.99%) with respect to the Common Warrants. If at the
time of exercise, there is no effective registration statement registering, or the prospectus contained therein is not available for,
the resale of the Shares issuable upon exercise of the Common Warrants, then the holder thereof may elect to exercise such warrants on
a cashless basis. The holder of Pre-Funded Warrants may at any time elect to exercise such warrants on a cashless basis.
On September 11, 2026, we entered into a registration
rights agreement with the Investor (the “Registration Rights Agreement”) whereby we agreed to file a registration statement
covering the resale of the Shares issuable upon exercise of the Pre-Funded Warrants and Common Warrants no later than 15 calendar days
following the date of the Registration Rights Agreement, and to use reasonable best efforts to have the registration statement declared
effective within 45 calendar days, and in no event later than 75 calendar days in the event of a “full review” by the SEC
(the “Effectiveness Date”), in each case following the date of the Registration Rights Agreement. We are filing the registration
statement of which this prospectus forms a part in satisfaction of such obligations.
Further, pursuant to an engagement letter entered
into between us and the Placement Agent, dated May 26, 2026 (the “Engagement Letter”), the Placement Agent acted as the exclusive
placement agent in connection with the foregoing transaction, and we issued to the Placement Agent’s designees the Placement Agent
Warrants in substantially the same form as the Series C Warrants, except that the exercise price thereunder is $1.0063 per share. We also
reimbursed certain expenses of the Placement Agent in connection with the transaction. Additionally, we paid the Placement Agent an aggregate
cash fee equal to 7.0% of the gross proceeds received in the Private Placement.
Implications of Being a Smaller Reporting Company and a Non-Accelerated
Filer
We are a “smaller reporting company,”
as defined in Rule 12b-2 of the Securities Exchange Act of 1934 (the “Exchange Act”), meaning that the market value of our
common stock held by non-affiliates is less than $700 million and our annual revenue was less than $100 million during the most recently
completed fiscal year. We may continue to be a smaller reporting company if either (i) the market value of our shares held by non-affiliates
is less than $250 million or (ii) our annual revenue was less than $100 million during the most recently completed fiscal year for which
audited financial statements are available as of the determination date and the market value of our shares held by non-affiliates is less
than $700 million. As a smaller reporting company, we may continue to rely on exemptions from certain disclosure requirements that are
available to smaller reporting companies. Specifically, as a smaller reporting company, we may choose to present only the two most recent
fiscal years of audited financial statements in our Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting
companies have reduced disclosure obligations regarding executive compensation. If investors consider our common stock less attractive
as a result of our election to use the scaled disclosure permitted for smaller reporting companies, then there may be a less active trading
market for our common stock and our share price may be more volatile.
Additionally, as a non-accelerated filer, we may
continue to take advantage of the exception from compliance with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley
Act of 2002, as amended.
Company Information
We were incorporated in Delaware in April 2011.
Our principal executive offices are located at 2000 Sierra Point Parkway, Suite 400, Brisbane, CA 94005, and our telephone number is (415)
798-8589. Our website is located at http://www.tempesttx.com. We do not incorporate by reference into this prospectus the information
on, or accessible through, our website, and you should not consider it as part of this prospectus.
The Tempest logo and other trademarks or service
marks of Tempest Therapeutics, Inc. appearing in this prospectus are the property of Tempest Therapeutics, Inc. Other trademarks, service
marks or trade names appearing in this prospectus are the property of their respective owners. We do not intend our use or display of
other companies’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by,
these other companies.
The Offering
| Common stock offered by the
selling stockholders |
Up to an aggregate 9,534,164 Shares, consisting of (i) up to 3,105,591 shares of our common stock issuable upon the exercise of the Pre-Funded Warrants, (ii) up to 3,105,591 shares of our common stock issuable upon the exercise of the Series C Warrants, (iii) up to 3,105,591 shares of our common stock issuable upon the exercise of the Series D Warrants, and (iv) up to 217,391 shares of our common stock issuable upon the exercise of the Placement Agent Warrants. |
| Common stock currently outstanding |
16,889,767 shares of common stock as of September 21, 2026. |
| Common stock to be outstanding assuming exercise of the Warrants |
26,423,931 shares of common stock. |
| The Warrants |
The Pre-Funded Warrants are exercisable immediately, have an exercise price of $0.001 per share and may be exercised at any time until exercised in full. The Series C Warrants will become exercisable on the Stockholder Approval Date and have a term of six years from the later of the Stockholder Approval Date and the Effectiveness Date. The Series D Warrants will become exercisable on the Stockholder Approval Date and have a term of three years from the later of the Stockholder Approval Date and the Effectiveness Date. The Common Warrants have an exercise price of $0.805 per share. The Placement Agent Warrants have substantially the same terms as the Series C Warrants, except that the exercise price thereunder is $1.0063 per share. |
| Selling stockholders |
All of the Shares are being offered by the selling stockholders.
See “Selling Stockholders” on page 8 of this prospectus for more information on the selling stockholders. |
| Use of Proceeds |
We will not receive any of the proceeds
from the selling stockholders’ sale or other disposition of the Shares offered pursuant to this prospectus. All net proceeds
from the sale of the Shares covered by this prospectus will go to the selling stockholders. However, we will receive proceeds from
the exercise of any Warrants for cash. See the section of this prospectus titled “Use of Proceeds” on page 7 of this
prospectus. |
| Plan of Distribution |
Each selling stockholder will determine when and how it will sell the common stock offered in this prospectus, as described in “Plan of Distribution.” |
| Risk Factors |
Any investment in the Shares offered hereby is speculative and involves a high degree of risk. You should carefully consider the information set forth under “Risk Factors” on page 4 and elsewhere in this prospectus. |
| Nasdaq Capital Market symbol |
Our common stock is listed on The Nasdaq Capital Market under the symbol “TPST”. |
RISK FACTORS
Investing in our common stock involves a high
degree of risk. Before making an investment decision, you should carefully consider the risks described in the sections entitled “Risk
Factors” in our most recent Annual Report on Form 10-K and in our subsequent Quarterly Reports on Form 10-Q, as filed with the SEC,
which are incorporated herein by reference in their entirety, as well as any amendments or updates to our risk factors reflected in subsequent
filings with the SEC, including any applicable prospectus supplement. The risks so described are not the only risks facing our company.
Additional risks not presently known to us or that we currently deem immaterial may also impair our business operations. Our business,
financial condition, results of operations or prospects could be materially adversely affected by any of these risks. The trading price
of our securities could decline due to any of these risks, and you may lose all or part of your investment. This prospectus and the documents
incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Our actual results could
differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks mentioned
elsewhere in this prospectus. For more information, see the section entitled “Where You Can Find Additional Information.”
Please also read carefully the section entitled “Special Note Regarding Forward-Looking Statements.”
The sale of a substantial number of shares of our common stock
in the public market, including the resale of the Shares, could adversely affect the prevailing market price for our common stock.
We are registering for resale up to 9,534,164
shares of our common stock, consisting of the Shares issuable to the selling stockholders upon exercise of the Warrants. Sales of substantial
amounts of shares of our common stock in the public market, or the perception that such sales might occur, could adversely affect the
market price of our common stock. We cannot predict if and when the selling stockholders may sell the Shares in the public markets. Furthermore,
in the future, we may issue additional shares of our common stock or other equity or debt securities exercisable for, or convertible into,
shares of our common stock. Any such issuances could result in substantial dilution to our existing stockholders and could cause our stock
price to decline.
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS
This prospectus and any applicable prospectus
supplement or free writing prospectus, including the documents that we incorporate by reference herein and therein, contain “forward-looking
statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. These statements relate
to future events or to our future operating or financial performance and involve known and unknown risks, uncertainties and other factors
which may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements
expressed or implied by the forward-looking statements.
In some cases, you can identify forward-looking
statements by terms such as “may,” “will,” “should,” “could,” “would,” “expects,”
“plans,” “anticipates,” “believes,” “estimates,” “projects,” “predicts,”
“potential” and similar expressions intended to identify forward-looking statements. These statements reflect our current
views with respect to future events and are based on assumptions and are subject to risks and uncertainties. As such, our actual results
may differ significantly from those expressed in any forward-looking statements. Given these uncertainties, you should not place undue
reliance on these forward-looking statements. In addition, statements indicating that “we believe” and similar statements
reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date they
were made, and while we believe such information formed a reasonable basis for such statements, such information may be limited or incomplete,
and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available
relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.
These and other risks are described in greater
detail under “Risk Factors” in this prospectus and in the “Risk Factors,” “Business” and “Management’s
Discussion and Analysis of Financial Condition and Results of Operations” sections incorporated by reference from our most recent
Annual Report on Form 10-K and in our Quarterly Reports on Form 10-Q for the quarterly periods ended subsequent to our filing of such
Annual Report on Form 10-K, as well as any amendments thereto reflected in subsequent filings with the SEC.
Also, forward-looking statements represent our
estimates and assumptions only as of the date of the document containing the applicable statement. Unless required by law, we undertake
no obligation to update or revise any forward-looking statements to reflect new information or future events or developments. Thus, you
should not assume that our silence over time means that actual events are bearing out as expressed or implied in such forward-looking
statements.
Forward-looking statements contained in this prospectus,
including the documents that we incorporate by reference herein, include, but are not limited to, statements about:
| ● | our ability to continue as a going concern absent access
to sources of liquidity, as well as our history of recurring losses and negative cash flows from operating activities, significant future
commitments and the uncertainty regarding the adequacy of our liquidity to pursue our complete business objectives; |
| ● | our ability to maintain compliance with the Nasdaq listing standards; |
| ● | the size and growth potential of the markets for our product candidates, and our ability to serve those markets; |
| ● | the development, regulatory approval, efficacy and commercialization of competing products; |
| ● | the development plans, regulatory approvals, and timing for TPST-4003 and other product candidates; |
| ● | our ability to obtain stockholder approval for the issuance of the Shares upon exercise of the Warrants; |
| ● | the expected proceeds from cash exercises of Warrants, if any; |
| ● | our ability to establish sales and marketing capabilities or enter into agreements with third parties to market and sell our product
candidates; |
| ● | our ability to retain regulatory approval for our product candidates or future product candidates in the United States and in any
foreign countries in which we may seek to do business; |
| ● | our ability to retain and hire our board of directors, senior management, or operational personnel; |
| ● | our ability to develop and maintain our corporate infrastructure, including our ability to design and maintain an effective system
of internal controls; |
| ● | the general economic, political, and market conditions and overall fluctuations in the financial markets in the United States and
abroad, including as a result of bank failures, public health crises or geopolitical tensions; |
| ● | our expectation regarding the period during which we will qualify as a smaller reporting company under the federal securities laws;
and |
| ● | our expectations regarding our ability to obtain, maintain and enforce intellectual property
protection for our products and technology, as well as our ability to operate our business without infringing, misappropriating or
otherwise violating the intellectual property rights of others. |
You should read this prospectus,
any applicable prospectus supplement, together with the documents that we have filed with the SEC that are incorporated by reference,
and any free writing prospectus we have authorized for use in connection with this offering, completely and with the understanding that
our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these
cautionary statements.
USE OF PROCEEDS
We will not receive any of the proceeds from the
selling stockholders’ sale or other disposition of the Shares offered pursuant to this prospectus. All net proceeds from the sale
of the Shares covered by this prospectus will go to the selling stockholders. However, we will receive proceeds from the exercise of any
Warrants for cash.
If all of the Warrants were exercised for cash
in full, the gross proceeds to the Company would be approximately $5.22 million. We intend to use the net proceeds of such Warrant exercises,
if any, for working capital and general corporate purposes. We can make no assurances that any of the Warrants will be exercised, or if
exercised, that they will be exercised for cash, the quantity which will be exercised or in the period in which they will be exercised.
We will bear the out-of-pocket costs, expenses
and fees incurred in connection with the registration of the Shares being offered for resale by the selling stockholders pursuant to
this prospectus. Other than registration expenses, the selling stockholders will bear underwriting discounts, commissions, or other similar
expenses payable with respect to sales of the Shares offered hereby.
SELLING STOCKHOLDERS
The Shares being offered by the
selling stockholders are those shares of common stock issuable upon exercise of the Warrants issued pursuant to the Purchase
Agreement and Engagement Letter in connection with the Private Placement. For additional information regarding the issuance of the
Shares, see “Prospectus Summary—Private Placement.” We are registering the Shares in order to permit the selling
stockholders (or their respective ’s pledgees, donees, transferees, assignees and other successors-in-interes) to offer the
Shares for resale from time to time. Other than with respect to the Placement Agent, which acted as our placement agent in the
Private Placement, our June 2026 warrant inducement (the “June 2026 Warrant Inducement”), as more fully described in our
Current Report on Form 8-K as filed with the SEC on June 2, 2026, and in our March 2026 private placement (the “March 2026
PIPE”), as more fully described in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 as filed with
the SEC on March 30, 2026, and except for the ownership of the Warrants issued to the selling stockholders in the Private Placement,
and securities issued pursuant to prior financings, the selling stockholders have not had any material relationship
with us within the past three years. No selling stockholder currently holds, nor has any selling stockholder held within the past
three years, any position or office with us or any of our predecessors or affiliates.
The selling stockholders may sell some, all or
none of their Shares. See “Plan of Distribution.” We do not know whether the selling stockholders will exercise any of their
respective Warrants and acquire any Shares, nor if they do, how long the selling stockholders will hold the Shares before selling them,
and we currently have no agreements, arrangements or understandings with the selling stockholders regarding the sale or other disposition
of any of the Shares. The Shares covered hereby may be offered from time to time by the selling stockholders. As a result, we cannot estimate
the number of shares of common stock each of the selling stockholders will beneficially own after termination of sales under this prospectus.
In addition, the selling stockholders may have sold, transferred or otherwise disposed of all or a portion of their Shares since the date
on which they provided information for the table below.
Beneficial ownership is determined in accordance
with the rules of the SEC and includes voting or investment power with respect to our common stock. Generally, a person “beneficially
owns” shares of our common stock if the person has or shares with others the right to vote those shares or to dispose of them, or
if the person has the right to acquire voting or disposition rights within 60 days.
The table below lists the selling stockholders
and other information regarding the beneficial ownership of the shares of common stock by each of the selling stockholders. The second
column lists the number of shares of common stock beneficially owned by each selling stockholder, based on such selling stockholder’s
ownership of our common stock, including Shares underlying the Warrants, as of September 21, 2026, assuming the full exercise of the Warrants
held by the selling stockholders without regard to any limitations on exercise of the Warrants contained therein. The third column lists
the maximum number of the Shares of common stock being offered in this prospectus by the selling stockholders. The fourth and fifth columns
list the number of shares of common stock owned after this offering, by number of the shares of common stock and percentage of outstanding
shares of common stock, assuming the full exercise of the Warrants without regard to any limitations on exercise of the Warrants contained
therein. The percentage of shares of our common stock owned prior to and after the offering under this prospectus is based on 16,889,767
shares of our common stock outstanding as of September 21, 2026.
A selling stockholder (together with its
affiliates) of the Pre-Funded Warrants or Common Warrants may not exercise any portion of any Pre-Funded Warrant or Common Warrant, to
the extent that such exercise would cause the aggregate number of shares of common stock beneficially owned by such selling stockholder
(together with its affiliates) to exceed 9.99% with respect to the Pre-Funded Warrants or 4.99% (or, upon election of the selling stockholder,
9.99%) with respect to the Common Warrants of the number of shares of common stock outstanding immediately after giving effect to the
exercise, subject to such selling stockholder’s rights under the Pre-Funded Warrants and the Common Warrants to increase or decrease
such percentage to another percentage not in excess of 9.99% upon notice from such selling stockholder to our company (upon not less than
61 days’ prior notice in the case of an increase). As described above, the number of shares in the table below does not reflect
this limitation.
| | |
Shares of Common Stock | | |
| | |
Beneficial Ownership After this Offering(1) | |
| Name of Selling Stockholder | |
Beneficially Owned prior to this Offering | | |
Maximum Number of Shares Being Offered | | |
Number of Shares | | |
Percent of Outstanding Common Stock | |
| Armistice Capital Master Fund Ltd.(2) | |
| 10,242,699 | | |
| 9,316,773 | | |
| 925,926 | | |
| 4.99 | % |
| Augustus Trading LLC(3) | |
| 192,028 | | |
| 139,402 | | |
| 52,626 | | |
| * | |
| Noam Rubinstein(4)(5) | |
| 94,330 | | |
| 68,478 | | |
| 25,852 | | |
| * | |
| Wilson Drive Holdings LLC(6) | |
| 10,107 | | |
| 7,337 | | |
| 2,770 | | |
| * | |
| Charles Worthman(4)(7) | |
| 2,995 | | |
| 2,174 | | |
| 821 | | |
| * | |
| (1) | Assumes that the selling
stockholders exercise all Warrants and sell all Shares offered under this prospectus, but that such
selling stockholders do not sell or otherwise dispose of any of the other shares of common stock that
it beneficially owns as of the date hereof. |
| (2) |
Consists of (i) 3,105,591 shares
of common stock issuable upon the exercise of the Pre-Funded Warrants, (ii) 3,105,591 shares of common stock issuable upon the exercise
of the Series C Warrants, (iii) 3,105,591 shares of common stock issuable upon the exercise of the Series D Warrants, (iv) 462,963
shares of common stock issuable upon the exercise of series A warrants to purchase shares of common stock issued to the selling stockholder
in March 2026 at an exercise price of $2.16 per share, and (v) 462,963 shares of common stock issuable upon the exercise of series
B warrants to purchase shares of common stock issued to the selling stockholder in March 2026 at an exercise price of $2.16 per share.
The securities are directly held by Armistice Capital Master Fund Ltd., a Cayman Islands exempted company (the “Master Fund”),
and may be deemed to be beneficially owned by: (i) Armistice Capital, LLC (“Armistice Capital”), as the investment manager
of the Master Fund; and (ii) Steven Boyd, as the Managing Member of Armistice Capital. The Pre-Funded Warrants are subject to a beneficial
ownership limitation of 9.99%, and the Common Warrants, series A warrants and series B warrants are subject to a beneficial ownership
limitation of 4.99% (or, upon election of the selling stockholder, 9.99%), which such limitation restricts the selling stockholder
from exercising that portion of the Pre-Funded Warrants, Common Warrants, series A warrants or series B warrants, as applicable,
that would result in the selling stockholder and its affiliates owning, after exercise, a number of shares of common stock in excess
of the beneficial ownership limitation. The address of Armistice Capital Master Fund Ltd. is c/o Armistice Capital, LLC, 510 Madison
Avenue, 7th Floor, New York, NY 10022. |
| (3) |
The number of shares of common
stock beneficially owned prior to this offering consist of (i) 52,626 shares of common stock issuable upon exercise of certain placement
agent warrants issued to the selling stockholder in May 2026 at an exercise price of $2.1625 per share, and (ii) 139,402 shares of
common stock issuable upon exercise of the Placement Agent Warrants. Orsium Capital LLC, the authorized agent to Augustus Trading
LLC, has discretionary authority to vote and dispose of the securities held by Augustus Trading LLC and may be deemed to be the beneficial
owner of these securities (as determined under Section 13(d) of the Securities Exchange Act of 1934, as amended). Olivier Morali,
in his capacity as managing member of Orsium Capital LLC, may also be deemed to have investment discretion and voting power over
the shares held by Augustus Trading LLC. Orsium Capital LLC and Mr. Morali each disclaims any beneficial ownership of these securities.
The business address of Augustus Trading LLC is 600 Lexington Avenue, 32nd Floor, New York, New York 10022. |
| (4) | Each of these selling stockholders is affiliated with H.C. Wainwright & Co., LLC, a registered broker-dealer with a business
address of 430 Park Ave, 3rd Floor, New York, New York 10022. H.C. Wainwright & Co., LLC served as our exclusive placement agent
in connection with the Private Placement, the March 2026 PIPE and the June 2026 Warrant Inducement, for which it received
compensation. Each of the selling stockholders has the voting and dispositive power over the securities held, acquired the
securities in the ordinary course of business and, at the time the securities were acquired, the selling stockholders had no
agreement or understanding, directly or indirectly, with any person to distribute such securities. |
| (5) | Represents (i) 68,478 shares of common stock issuable upon exercise of the Placement Agent Warrants, which were issued in connection with the Private Placement, and (ii) 25,852 shares of common stock issuable upon exercise of certain placement agent warrants issued to
the selling stockholder in May 2026 at an exercise price of $2.1625 per share. |
| (6) | Represents (i) 2,770 shares of common stock issuable upon exercise of certain placement agent warrants issued to the selling
stockholder in May 2026 at an exercise price of $2.1625 per share, and (ii) 7,337 shares of common stock issuable upon exercise of
the Placement Agent Warrants, which were issued in connection with the Private Placement, and are held by Wilson
Drive Holdings LLC. Craig Schwabe is the managing member of Wilson Drive Holdings LLC and has the power to vote and dispose of the
securities held. Neither Wilson Drive Holdings LLC nor Mr. Schwabe is a broker-dealer. Mr. Schwabe is affiliated with the following
registered broker-dealers: H.C. Wainwright & Co., LLC, Rodman & Renshaw LLC and Stockblock Securities LLC. The business
address of Wilson Drive Holdings LLC is 600 Lexington Avenue, 32nd Floor, New York, NY 10022. The securities were acquired in the
ordinary course of business and, at the time the securities were acquired, the selling stockholder had no agreement or
understanding, directly or indirectly, with any person to distribute such securities. |
| (7) | Represents (i) 2,174 shares of common stock issuable upon exercise of the Placement Agent Warrants, which were issued in connection with the Private Placement, and (ii) 821 shares of common stock issuable upon exercise of certain placement agent warrants issued to the
selling stockholder in May 2026 at an exercise price of $2.1625 per share. |
PLAN OF DISTRIBUTION
The selling stockholders will act independently
of us in making decisions with respect to the timing, manner and size of each and any sale of Shares. Each selling stockholder and any
of such selling stockholder’s pledgees, donees, transferees, assignees and other successors-in-interest may, from time to time,
sell any or all of the Shares beneficially owned by them and offered hereby directly to investors, through one or more broker-dealers
or agents, or through any other manner permitted by law, on a continuous or delayed basis. The selling stockholders will be responsible
for commissions charged by any such broker-dealers or agents. The Shares may be sold in one or more transactions at fixed prices, at
prevailing market prices at the time of the sale, at varying prices determined at the time of sale, or at negotiated prices. The offering
price of the Shares from time to time will be determined by the selling stockholders and, at the time of the determination, may be higher
or lower than the market price of our common stock on The Nasdaq Capital Market or any other exchange or market. Each selling stockholder
may use any one or more of the following methods when selling the Shares covered by this registration statement:
| ● | through brokers or dealers (who may act as agent or principal
and who may receive compensation in the form of discounts, concessions or commissions from such selling stockholder, the purchaser or
such other persons who may be effecting such sales, which discounts, concessions or commissions as to any particular broker or dealer
may be in excess of those customary to the types of transactions involved) for resale to the public or to institutional investors at
various times; |
| | | |
| ● | through negotiated transactions, including, but not limited
to, block trades in which the broker or dealer so engaged will attempt to sell the Shares as agent but may position and resell a portion
of the block as principal to facilitate the transaction; |
| | | |
| ● | through purchases by a broker or dealer as principal and
resale by that broker or dealer for its account; |
| | | |
| ● | on any national securities exchange or quotation service
on which the shares may be listed or quoted at the time of sale at market prices prevailing at the time of sale, at prices related to
such prevailing market prices, or at negotiated prices; |
| | | |
| ● | in privately negotiated transactions other than exchange
or quotation service transactions; |
| | | |
| ● | short sales, purchases or sales of put, call or other types
of options, forward delivery contracts, swaps, offerings of structured equity-linked securities or other derivative transactions or securities; |
| | | |
| ● | hedging transactions, including, but not limited to: |
| | | |
| o | transactions with a broker-dealer or its affiliate, whereby
the broker-dealer or its affiliate will engage in short sales of shares and may use Shares held by such selling stockholder to close
out its short position; |
| | | |
| o | options or other types of transactions that require the delivery
of Shares to a broker-dealer or an affiliate thereof, who will then resell or transfer the Shares; or |
| | | |
| o | loans or pledges of Shares to a broker-dealer or an affiliate,
who may sell the loaned Shares or, in an event of default in the case of a pledge, sell the pledged Shares; |
| | | |
| ● | through offerings of securities exercisable, convertible
or exchangeable for shares, including, without limitation, securities issued by trusts, investment companies or other entities; |
| | | |
| ● | offerings directly to one or more purchasers, including institutional
investors; |
| | | |
| ● | through ordinary brokerage transactions and transactions
in which a broker solicits purchasers; |
| | | |
| ● | through distribution to the security holders of the selling
stockholder; |
| | | |
| ● | by pledge to secure debts and other obligations; |
| | | |
| ● | through a combination of any such methods of sale; or |
| | | |
| ● | through any other method permitted under applicable law. |
There can be no assurance that the selling stockholders
will sell any or all of the Shares registered pursuant to the registration statement of which this prospectus forms a part.
In addition, a selling stockholder may elect to
make an in-kind distribution of securities to its members, partners or stockholders pursuant to the registration statement of which this
prospectus forms a part by delivering a prospectus with a plan of distribution. Such members, partners or stockholders would thereby receive
freely tradeable securities pursuant to the distribution through a registration statement. To the extent a distributee is an affiliate
of ours (or to the extent otherwise required by law), we may file a supplement to this prospectus in order to permit the distributees
to use the prospectus to resell the securities acquired in the distribution.
The selling stockholders also may transfer the
securities in other circumstances, in which case the transferees, pledgees or other successors-in-interest will be the selling beneficial
owners for purposes of this prospectus. Upon being notified by a selling stockholder that a donee, pledgee, transferee or other successor-in-interest
intends to sell our securities, we will, to the extent required, promptly file a supplement to this prospectus under Rule 424(b)(3) or
other applicable provision of the Securities Act, amending the list of selling stockholders to include the donee, pledgee, transferee
or other successors-in-interest as a selling stockholder under this prospectus.
Broker-dealers engaged by the selling stockholders
may arrange for other broker-dealers to participate in sales. Broker-dealers may receive commissions or discounts from the selling stockholders
(or, if any broker-dealer acts as agent for the purchaser of securities, from the purchaser) in amounts to be negotiated, but, except
as set forth in a supplement to this prospectus, in the case of an agency transaction not in excess of a customary brokerage commission
in compliance with FINRA Rule 2121; and in the case of a principal transaction a markup or markdown in compliance with FINRA Rule 2121.
In connection with the sale of the Shares offered
hereby, the selling stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in
turn engage in short sales of the securities in the course of hedging the positions they assume. The selling stockholders may also sell
common stock short and deliver these Shares of common stock to close out their respective short positions, or loan or pledge the Shares
to broker-dealers that in turn may sell these securities. The selling stockholders may also enter into option or other transactions with
broker-dealers or other financial institutions or create one or more derivative securities which require the delivery to such broker-dealer
or other financial institution of the Shares offered by this prospectus, which securities such broker-dealer or other financial institution
may resell pursuant to this registration statement (as supplemented or amended to reflect such transaction).
The selling stockholders and any broker-dealers
or agents that are involved in selling the Shares covered hereby may be deemed to be “underwriters” within the meaning of
the Securities Act in connection with such sales. In such event, any commissions received by such broker-dealers or agents and any profit
on the resale of the common stock purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act.
The selling stockholders have informed us that they do not have any written or oral agreement or understanding, directly or indirectly,
with any person to distribute the Shares offered hereby.
We are required to pay certain fees and expenses
incurred by us incident to the registration of the common stock covered hereby. We have agreed to indemnify the selling stockholders against
certain losses, claims, damages and liabilities, including liabilities under the Securities Act. We shall not be responsible for any of
the selling stockholders’ selling costs incurred pursuant to any available method provided hereunder for selling securities.
We are obligated to maintain the effectiveness
of this registration statement until no holder of Pre-Funded Warrants or Common Warrants owns any Pre-Funded Warrants, Common Warrants
or Shares issuable upon exercise thereof. The Shares offered hereby will be sold only through registered or licensed brokers or dealers
if required under applicable state securities laws. In addition, in certain states, the Shares offered hereby may not be sold unless they
have been registered or qualified for sale in the applicable state or an exemption from the registration or qualification requirement
is available and is complied with.
Under applicable rules and regulations under
the Exchange Act, any person engaged in the distribution of the Shares offered hereby may not simultaneously engage in market making
activities with respect to the common stock for the applicable restricted period, as defined in Regulation M, prior to the commencement
of the distribution. In addition, the selling stockholders will be subject to applicable provisions of the Exchange Act and the rules
and regulations thereunder, including Regulation M, which may limit the timing of purchases and sales of common stock by the selling
stockholders or any other person. We will make copies of this prospectus available to the selling stockholders and have informed them
of the need to deliver a copy of this prospectus to each purchaser at or prior to the time of the sale (including by compliance with
Rule 172 under the Securities Act).
LEGAL MATTERS
Certain legal matters, including the validity
of the shares of common stock offered by this prospectus, will be passed upon by Greenberg Traurig, LLP.
EXPERTS
The consolidated financial statements of Tempest
Therapeutics, Inc. appearing in Tempest Therapeutics, Inc.’s Annual Report (Form 10-K) for the year ended December 31, 2025 have
been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their report thereon (which contains
an explanatory paragraph describing conditions that raise substantial doubt about the Company’s ability to continue as a going concern
as described in Note 1 to the consolidated financial statements), included therein, and incorporated herein by reference. Such consolidated
financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts
in accounting and auditing.
WHERE YOU CAN FIND ADDITIONAL INFORMATION
This prospectus is part of the registration statement
on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth in the registration statement.
Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete
and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated
by reference into this prospectus for a copy of such contract, agreement or other document. Because we are subject to the information
and reporting requirements of the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information
with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov.
We maintain a website at www.tempesttx.com. Information
contained in or accessible through our website does not constitute a part of this prospectus.
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE
The SEC allows us to “incorporate
by reference” information into this prospectus, which means that we can disclose important information to you by referring you
to another document filed separately with the SEC. The information incorporated by reference is considered to be part of this prospectus.
Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this
prospectus. We incorporate by reference into this prospectus the information or documents listed below that we have filed with the SEC:
| ● | our Annual Report on Form 10-K for the fiscal year ended
December 31, 2025, filed with the SEC on March 30, 2026; |
| ● | our Quarterly Reports on Form 10-Q for the quarters ended
March 31, 2026 and June 30, 2026, filed with the SEC on May 14, 2026 and August 13, 2026, respectively; |
| ● | our Current Reports on Form 8-K (not including any information
furnished under Item 2.02, 7.01 or 9.01 of such Form 8-K or any other information that is identified as “furnished” rather
than filed, which information is not incorporated by reference herein) filed with the SEC on May 6, 2026, May 22, 2026, May 22, 2026,
May 29, 2026, June 2, 2026, June 4, 2026, June 23, 2026, July 22, 2026, July 28, 2026,
August 13, 2026, August 13, 2026, August 18, 2026,
August 24, 2026, September 15, 2026, September 16, 2026 and September 17, 2026; and |
| ● | the description of our common stock set forth in our registration
statement on Form 8-A (File No. 001-35890), filed with the SEC on April 25, 2013, including any amendments thereto or reports filed for
the purposes of updating this description, including Exhibit 4.1 to our Annual Report on Form 10-K for the fiscal year ended December
31, 2025 filed with the SEC on March 30, 2026. |
Notwithstanding the statements in the preceding
paragraphs, no document, report or exhibit (or portion of any of the foregoing) or any other information that we have “furnished”
to the SEC pursuant to the Exchange Act shall be incorporated by reference into this prospectus.
We also incorporate by reference into this prospectus
all documents (excluding information furnished pursuant to Items 2.02, 7.01 and 9.01 of Form 8-K or any other information that is identified
as or is deemed “furnished” rather than filed or is otherwise not incorporated into registration statements pursuant to applicable
SEC rules) that are filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of the
initial filing of the registration statement of which this prospectus forms a part and prior to the termination of this offering.
We will provide to each person, including any
beneficial owner, to whom a prospectus is delivered, without charge upon written or oral request, a copy of any or all of the documents
that are incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits that are specifically
incorporated by reference into such documents. You should direct any requests for documents to Tempest Therapeutics, Inc., Attn: Investor
Relations, 2000 Sierra Point Parkway, Suite 400, Brisbane, California 94005; telephone: (415) 798-8589.
Tempest Therapeutics, Inc.

Up to 9,534,164 Shares of Common Stock
__________________________
PROSPECTUS
__________________________
October 1, 2026