Tempest Therapeutics, Inc.

S-11 d181522ds1.htm S-1

As filed with the Securities and Exchange Commission on August 21, 2026

**Registration No. 333- **

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

**FORMS-1 **

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

TEMPEST THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

2000 Sierra Point Parkway, Suite 400

Brisbane, CA 94005

**(415)798-8589 **

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Matthew Angel

Chief Executive Officer and President

2000 Sierra Point Parkway, Suite 400

Brisbane, CA 94005

**(415)798-8589 **

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Drew M. Altman, Esq.

Michael J. Minahan, Esq.

Greenberg Traurig, LLP

One International Place, Suite 2000

Boston, Massachusetts 02110

Telephone: (617)310-6000

Approximate date of commencement of proposed sale to the public: From time to time after this Registration Statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until this registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. The Selling Stockholder may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Tempest Therapeutics, Inc.

8,910,579 Shares of Common Stock

This prospectus relates to the offer and sale from time to time of up to 8,910,579 shares of our common stock, par value $0.001 per share (“common stock”), by Lincoln Park Capital Fund, LLC (“Lincoln Park” or the “Selling Stockholder”).

The shares included in this prospectus consist of shares of common stock that we have issued or that we may, in our discretion, elect to issue and sell to the Selling Stockholder, from time to time after the date of this prospectus and the date of the satisfaction of the conditions to the Selling Stockholder’s purchase obligations (the “Commencement Date”) as set forth in the common stock purchase agreement we entered into with Lincoln Park on August 13, 2026 (the “Purchase Agreement”). We are not selling any shares of common stock being offered by this prospectus and will not receive any of the proceeds from the sale of such shares by the Selling Stockholder. However, we may receive up to $25 million aggregate gross proceeds (the “Initial Available Amount”) from sales of common stock to Lincoln Park under the Purchase Agreement and, upon our receipt of gross proceeds equal to the full Initial Available Amount from such sales, the total aggregate dollar amount that will be available to us under the Purchase Agreement will automatically increase by an additional $25 million (such additional amount, the “Additional Available Amount”), and thereafter we may receive up to such Additional Available Amount (or up to a total of $50 million aggregate gross proceeds (the “Total Available Amount”)) from sales of common stock to Lincoln Park under the Purchase Agreement. The shares registered pursuant to this prospectus also include (i) 560,356 shares of common stock that we issued to the Selling Stockholder concurrently with our execution of the Purchase Agreement, as consideration for its irrevocable commitment (the “Initial Commitment Shares”) to purchase shares of our common stock under the Purchase Agreement at our election in our sole discretion, from time to time after the date of this prospectus, upon the terms and subject to the satisfaction of the conditions set forth in the Purchase Agreement and (ii) 350,223 shares of common stock to be issued to the Selling Stockholder as additional consideration for its irrevocable commitment to purchase shares of our common stock under the Purchase Agreement, following our receipt of gross proceeds equal to the full Initial Available Amount from sales of common stock to Lincoln Park under the Purchase Agreement (the “Additional Commitment Shares,” and together with the Initial Commitment Shares, the “Commitment Shares”), pursuant to the terms of the Purchase Agreement. See the section titled “The Lincoln Park Transaction” for a description of the Purchase Agreement and the section titled “Selling Stockholder” for additional information regarding the Selling Stockholder.

The Selling Stockholder may sell or otherwise dispose of the common stock described in this prospectus in different ways and at varying prices. See “Plan of Distribution” for more information about how the Selling Stockholder may sell or otherwise dispose of the common stock being registered pursuant to this prospectus. The Selling Stockholder is an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act of 1933, as amended (the “Securities Act”).

We will pay the expenses of registering under the Securities Act the offer and sale of the common stock to which this prospectus relates by the Selling Stockholder, including legal and accounting fees. See “Plan of Distribution.”

Our common stock is listed on the Nasdaq Capital Market under the symbol “TPST”. On August 20, 2026, the closing price of our common stock was $1.02.

INVESTING IN OUR SECURITIES INVOLVES SIGNIFICANT RISKS THAT ARE DESCRIBED IN THE “RISK FACTORS” SECTION BEGINNING ON PAGE 6 OF THIS PROSPECTUS

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued under this prospectus or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is , 2026.