Tempest Therapeutics, Inc.

You should read the following discussion of our financial condition and results of operations in conjunction with our unaudited condensed financial statements and the notes thereto included elsewhere in this Quarterly Report on Form 10-Q, and our audited consolidated financial statements and related notes for the year ended December 31, 2025, filed with the U.S. Securities and Exchange Commission ("SEC") on March 30, 2026. This discussion and other parts of this report contains forward-looking statements that involve risks and uncertainties, such as our plans, objectives, expectations, intentions, and beliefs, as well as assumptions made by, and information currently available to, our management. Our actual results could differ materially from those discussed in these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in the section of this report entitled “Risk Factors,” under Part II, Item 1A of this report and those discussed in our other disclosures and filings with the SEC.

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 candidates supported by clinical data and advancing their development to create products that will improve patients’ lives.

Recent Events

Asset Acquisition

On November 19, 2025, we executed an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Erigen LLC, a Delaware limited liability company (“Erigen”), and Factor Bioscience Inc., a Delaware corporation (“Factor” and together with Erigen, “Sellers”), pursuant to which Sellers agreed to sell and transfer to the Company all right, title and interest of Sellers in and to all of the assets primarily related to (a) the autologous BCMA/CD19 dual-targeting CAR T-cell therapy known as TPST-2003, (b) the autologous CD70/CD70 dual-targeting CAR T-cell therapy known as TPST-2206, (c) the allogeneic BCMA/CD19 dual-targeting CAR T-cell therapy with a gene edit in the TRAC locus that inactivates the T cell receptor known as TPST-3003, and (d) the allogeneic CD70/CD70 dual-targeting CAR T-cell therapy with a gene edit in the TRAC locus that inactivates the T cell receptor known as TPST-3206 (collectively referred to herein as the “Assets”), in exchange for an aggregate purchase price of 8,268,495 shares of our common stock issued to Erigen on behalf of both Sellers.

On February 3, 2026, we completed the acquisition of the Assets (the “Closing”) under the Asset Purchase Agreement (the “Asset Acquisition”) and issued to Erigen 8,268,495 shares of our common stock (the “Share Issuance”).

Master Services Agreement

In November 2025, Erigen entered into an Amended and Restated Master Services Agreement with Factor (the “Factor MSA”), which was assigned to the Company on February 3, 2026 in connection with the closing of the Asset Purchase Agreement. Under the Factor MSA, we are obligated to pay Factor a service fee and all non-cancellable obligations in the amount specified in each work order associated with the agreement for the provision of services.

On May 11, 2026, we entered into a letter agreement (the “Letter Agreement”) with Factor relating to certain payment obligations of the Company under the Factor MSA and Work Order No. 1, dated March 24, 2026 (the “Work Order”). Pursuant to the Letter Agreement, Factor agreed to permanently waive its right to receive the first $2.1 million payable by the Company to Factor under the Factor MSA and the Work Order. In addition, Factor agreed to return to the Company a deposit of $0.2

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million previously made by the Company under the Work Order, for an interim period subject to certain conditions. The Company agreed to use its best efforts to promptly raise additional funds to further expand the Company’s cash runway.

Warrant Dividend

On January 20, 2026, our Board of Directors (the "Board") declared a record date of January 30, 2026 (the “Record Date”), for the distribution of a dividend (the “Warrant Dividend”) in the form of a warrant to purchase a share of our common stock (collectively, the “Warrants”) for each share of common stock outstanding on the Record Date. The Warrants were issued on the terms and conditions described in the Warrant Agreement, dated February 3, 2026, between the Company, Computershare Inc., and its affiliate, Computershare Trust Company, N.A., as Warrant Agent (the “Warrant Agreement”), on February 3, 2026. In addition, on February 3, 2026, certain warrants that were outstanding on the Record Date also received Warrants on a one-for-one basis, pursuant to the terms of such warrants (together with the Warrant Dividend, the “Warrant Distribution”). In the aggregate, 6,784,989 Warrants were issued pursuant to the Warrant Distribution.

Private Placement

On March 20, 2026, we entered into a securities purchase agreement (the “Purchase Agreement”) with (a) two institutional investors (the “Institutional Investors”) and (b) Factor (together with the Institutional Investors, each, an “Investor” and, together, the “Investors”), pursuant to which we agreed to issue and sell in a private placement (the “Private Placement”) an aggregate of 462,964 shares (the “Shares”) of our common stock, and, in lieu of common stock, pre-funded warrants to purchase up to 462,963 shares of our common stock (the “2026 Pre-Funded Warrants”), in each case accompanied by (i) Series A warrants to purchase up to 925,927 shares of our common stock (the “Series A Warrants”) and (ii) Series B warrants to purchase up to 925,927 shares of our common stock (the “Series B Warrants” and, together with the Series A Warrants, the “Common Warrants”). The Shares and the Common Warrants were immediately separable and were issued separately. The combined purchase price per Share and accompanying Common Warrants was $2.16 and the combined purchase price per Pre-Funded Warrant and accompanying Common Warrants was $2.159. The gross proceeds to us from the Private Placement were approximately $2.0 million (excluding up to approximately $4.0 million of aggregate gross proceeds that may be received in the future upon the cash exercise of the Common Warrants), before deducting placement agent fees and other offering expenses payable by the Company.

The Series A Warrants became exercisable on June 18, 2026, the effective date of the Stockholder Approval (the “Stockholder Approval Date”) and have a term of five years therefrom. The Series B Warrants became exercisable on the Stockholder Approval Date and have a term of twenty-four months therefrom. The Common Warrants have an exercise price of $2.16 per share.

In connection with the Private Placement, we entered into a registration rights agreement with the Investors (the “Registration Rights Agreement”), pursuant to which we agreed to file registration statements under the Securities Act with the SEC covering the resale of the Shares to be issued in the Private Placement and the shares of our common stock underlying the Common Warrants and Pre-Funded Warrants no later than 15 calendar days following the date of the Purchase Agreement, and to use reasonable best efforts to have the registration statement declared effective by 45 calendar days following the date of the Purchase Agreement, and in any event no later than 75 calendar days following the date of the Purchase Agreement in the event of a “full review” by the SEC (the “Effectiveness Date”). The registration statement was filed on April 2, 2026 and declared effective on April 9, 2026.

Collaboration Agreement with Senlang Biotechnology

On July 17, 2026, the Company entered into a product development and collaboration agreement (the “Collaboration Agreement”) with Hebei Senlang Biotechnology Co., Ltd. (“Senlang”), a clinical-stage cell therapy company with expertise in CD7-targeted CAR-T development. Pursuant to the Collaboration Agreement, the Company and Senlang agreed to collaborate on product development and investigator-initiated trial activities in China for certain of the Company’s in vivo CAR-T product candidates. The Company plans to initiate the collaboration with the investigator-initiated trial ("IIT") described below, which

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will evaluate TPST-4003 in approximately 10 patients with myasthenia gravis or multiple sclerosis in China, with first patient enrollment and dosing expected to occur in the fourth quarter of 2026. The development fee payable by the Company to Senlang for each Product (as defined therein) shall be within the range of $1.5 million to $2.0 million, to be determined by the parties. The Collaboration Agreement also grants Senlang an exclusive option to negotiate and enter into a definitive license agreement for TPST-4003 in China.

TPST-2003

Earlier this year, we announced positive interim data from REDEEM-1, including a 100% complete response (“CR”) rate among all six efficacy evaluable patients according to the International Myeloma Working Group (“IMWG”) uniform response criteria, as well as a favorable safety profile, as of the January 31, 2026 data cutoff. In April 2026, we further announced the achievement of a 100% CR rate among all 15 CAR-T-naïve efficacy evaluable patients across two ongoing Phase 1 trials – REDEEM-1 evaluating TPST-2003 in relapsed/refractory multiple myeloma (“rrMM”) (10/10 according to the IMWG uniform response criteria) and POEMS-1 evaluating TPST-2003 in POEMS syndrome (5/5 CRVEGF).

To date, a total of 44 patients have received one infusion of TPST-2003, including 24 patients in a prior Phase 1/2 IIT evaluating TPST-2003 in rrMM, 13 patients in the ongoing REDEEM-1 trial, and seven patients in the ongoing POEMS-1 trial, representing one of the largest datasets evaluating a CD19/BCMA dual-targeting CAR-T therapy.

The observed safety profile (no Grade ≥3 CRS or ICANS), together with the consistency of responses observed in the REDEEM-1 trial continue to support Tempest’s plan to pursue its objective of meeting with the FDA to discuss initiating a U.S. registrational study later this year.

In April 2026, Tempest’s manufacturing partner, Cincinnati Children’s Applied Gene and Cell Therapy Center (“AGCTC”), took delivery of the TPST-2003 lentiviral vector, a critical component used in the manufacturing of TPST-2003. This milestone supports Tempest’s plans to initiate the first potentially registrational study to evaluate a dual-targeting CAR-T therapy in patients with rrMM, including patients who are experiencing extramedullary disease (“EMD”), later this year.

TPST-2003 is an autologous, dual-targeting CAR-T therapy designed to target both BMCA and CD19. TPST-2003 is being developed for the treatment of rrMM.

TPST-4003

In February 2026, we announced our plans to test TPST-4003, our lead in vivo CAR-T product candidate in an investigator-initiated clinical trial (“IIT”) trial. On July 15, 2026, the Company announced details of its next-generation in vivo CAR-T platform, CD7-tLNP, and its plans to advance TPST-4003, its lead in vivo CAR-T product candidate, into a first IIT trial in patients with nervous system autoimmune diseases, initially focusing on myasthenia gravis (“MG”) and multiple sclerosis (“MS”). TPST-4003 combines the Company’s CD7-targeted mRNA lipid nanoparticle delivery platform with the same dual-targeting CD19/BCMA CAR architecture used in TPST-2003, the Company’s clinical-stage CAR-T program. We plan to collaborate with Senlang to develop TPST-4003, beginning with the IIT in China which is expected to enroll approximately 10 patients, with first patient dosing anticipated in the fourth quarter of 2026 and initial clinical data expected in the first half of 2027.

TPST-4003 is an in vivo, dual-targeting CAR-T therapy designed to target both BCMA and CD19. TPST-4003 is being developed for immunology and oncology indications.

Going Concern

As of June 30, 2026, we had cash and cash equivalents totaling $0.8 million compared to $7.7 million as of December 31, 2025. We have incurred operating losses since inception and our accumulated deficit as of June 30, 2026 is $275.3 million. We expect that our existing cash and cash equivalents will fund our projected operating expense requirements through less than 12

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months from the date our consolidated financial statements were available to be issued. Accordingly, there is substantial doubt regarding our ability to continue as a going concern for a period of 12 months from the date of the issuance of the Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q.

While we implemented cost reductions in 2025, we have finite cash resources available to fund our operations. To date, we have not generated product revenues from our activities and have incurred substantial operating losses. We expect that we will continue to generate substantial operating losses for the foreseeable future until we complete development and approval of one of our product candidates.

On February 3, 2026, we closed the Asset Acquisition (as defined above). Pursuant to the Asset Purchase Agreement, Factor has made the Funding Commitment (as defined below under “—Liquidity and Capital Resources—Funding Commitment”) to provide us with financial support until the earlier to occur of 18 months following the closing of the Asset Acquisition and the receipt by us of at least $20.0 million in gross proceeds from the sale of its equity or debt securities, up to a maximum amount of $20.0 million that is inclusive of any amounts raised and received by us after the date of the Asset Purchase Agreement, on the terms and subject to the conditions and other provisions of a funding commitment letter (“FCL”) contemplated by and entered into concurrently with the Asset Purchase Agreement. However, there is significant uncertainty as to whether we will be able to satisfy the terms and conditions and other provisions set forth in the FCL, and, if we are unable to do so, we may be limited in the amount of funding that we are able to access under the Funding Commitment or we may not be able to access any funds under the Funding Commitment. The timing of any additional funding from Factor is uncertain.

Further, as detailed above under “Private Placement” and “Registered Direct Offering and Warrant Inducement,” we have undertaken other steps to increase our cash and cash equivalents. On March 20, 2026, we entered into a securities purchase agreement for the sale of securities for approximately $2.0 million in gross proceeds (excluding up to approximately $4.0 million of aggregate gross proceeds that may be received in the future upon the cash exercise of Common Warrants issued thereunder), before deducting placement agent fees and other offering expenses payable by us. On May 28, 2026, we further entered into a warrant exercise and inducement letter agreement with the holder of certain existing warrants originally issued in November 2025, for the exercise of existing warrants at a reduced exercise price of $1.73 per share, resulting in gross proceeds to us of approximately $2.0 million (excluding up to approximately $4.2 million of aggregate gross proceeds that may be received in the future upon the cash exercise of new warrants issued in connection therewith).

We will need to continue to rely on additional financing to achieve our business objectives, including pursuant to the Funding Commitment with Factor. As of the date of this report, we have $11.8 million available under the Funding Commitment, however, there is significant uncertainty as to whether we will be able to satisfy the terms and conditions and other provisions set forth in the Funding Commitment, and, if we are unable to do so, we may be limited in the amount of funding that we are able to access under the Funding Commitment or we may not be able to access any funds under the Funding Commitment. Adequate additional financing may not be available to us on acceptable terms, or at all. Our ability to raise additional capital has been adversely impacted by potential worsening global economic conditions, inflation expectations, and the recent disruptions to and volatility in the credit and financial markets in the United States and worldwide resulting from geopolitical tensions.

Components of Results of Operations

Research and Development Expense

Research and development expenses represent costs incurred to conduct research and development, such as the development of our product candidates.

We recognize all research and development costs as they are incurred. Research and development expenses consist primarily of the following:

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The largest component of our operating expenses has historically been the investment in research and development activities. Historically, our research and development expenses were primarily driven by our amezalpat program, which has been paused while we complete our ongoing strategic review. As a result of the ongoing strategic review and the reduction in force, we expect research and development expenses will decrease period over period. If we resume the advancement of our product candidates into and through clinical trials and pursues regulatory approvals, we expect research and development expenses will increase in the future, which will require a significant investment in costs of clinical trials, regulatory support and contract manufacturing and inventory build-up.

The process of conducting clinical trials necessary to obtain regulatory approval is costly and time consuming. We may never succeed in timely developing and achieving regulatory approval for our product candidates. The probability of success of our product candidates may be affected by numerous factors, including availability of capital, clinical data, competition, manufacturing capability and commercial viability. As a result, we are unable to determine the duration and completion costs of our development projects or when and to what extent we will generate revenue from the commercialization and sale of any of our product candidates.

General and Administrative Expenses

General and administrative expenses consist of employee-related expenses, including salaries, benefits, travel and non-cash stock-based compensation, for our personnel in executive, finance and accounting, and other administrative functions, as well as fees paid for legal, accounting and tax services, consulting fees and facilities costs not otherwise included in research and development expenses. Legal costs include general corporate legal fees and patent costs. We expect to continue to incur expenses as a result of being a public company, including expenses related to compliance with the rules and regulations of the SEC and Nasdaq, additional insurance, investor relations and other administrative expenses and professional services. As a result of the ongoing strategic review and the reduction in force, we expect general and administrative expenses will decrease period over period.

Acquired In-Process Research and Development Expense

During the first quarter of 2026 we began presenting acquired in-process research and development expense as a separate line item in our consolidated statements of income. Acquired in-process research and development, upfront and milestone expense includes costs incurred in connection with the Asset Purchase Agreement with Erigen.

For additional information on our accounting for the Asset Purchase Agreement, please see Note 12, to our consolidated financial statements included in this report.

Other Income (Expense), Net

Other income (expense), net consists primarily of interest expense, interest income, and various other income or expense items of a non-recurring nature.

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Results of Operations

Comparison of the three months ended June 30, 2026 and 2025

The following table summarizes our operating results for the three months ended June 30, 2026 and 2025:

Research and development

Our research and development expenses for the three months ended June 30, 2026 and 2025 were primarily incurred in connection with our product candidates TPST-2003, TPST-3003, TPST-4003, and our most advanced product candidate Amezalpat.

The following table shows our research and development expenses by program for the three months ended June 30, 2026 and 2025:

Research and development expenses decreased by $2.1 million to $1.8 million for the three months ended June 30, 2026, compared to three months ended June 30, 2025, which was primarily due to a decrease in costs incurred as a result of the

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re-prioritization of efforts after the Asset Acquisition in February 2026, offset by research and manufacturing costs related to the Company’s CAR-T product candidates.

The following table summarizes our research and development expenses for the three months ended June 30, 2026 and 2025: