Quarterly Report for Quarter Ending September 30, 2025 (Form 10-Q)

Management's Discussion and Analysis of Financial Condition and Results of Operations

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, 2024, filed with the U.S. Securities and Exchange Commission ("SEC") on March 27, 2025. 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 with a diverse portfolio of targeted and immune-mediated product candidates with the potential to be first-in-class to treat a wide range of cancers. Our novel programs range from early research to the lead program, amezalpat (previously known as TPST-1120), that, subject to the need for additional resources, is ready to begin a pivotal Phase 3 study in first-line hepatocellular carcinoma ("HCC"). In addition to amezalpat, our second clinical-stage therapeutic product candidate is TPST-1495, which we expect to start a Phase 2 study in Familial Adenomatous Polyposis ("FAP") late this year, subject to potential delays resulting from the ongoing U.S. government shutdown. We believe both amezalpat and TPST-1495 are the first clinical-stage molecules designed to inhibit their respective targets.

Given market conditions, in April 2025, we announced plans to explore a full range of strategic alternatives to advance our promising programs. If a strategic alternative is not available to us, we will be required to take additional actions to fund the Company's operations or we may be forced to wind down our operations.

Amezalpat (TPST-1120)

Amezalpat is an oral, small molecule, selective antagonist of peroxisome proliferator-activated receptor alpha ("PPARα") being developed for the treatment of first-line unresectable or metastatic HCC.

In June 2024, we unveiled positive survival data from the ongoing global randomized Phase 1b/2 clinical study demonstrating that amezalpat delivered a six-month improvement in median overall survival ("OS") with a hazard ratio ("HR") of 0.65 when combined with atezolizumab and bevacizumab in comparison to atezolizumab and bevacizumab alone, the standard of care, in the first-line treatment of patients with unresectable or metastatic HCC. Additionally, the survival benefit was preserved across key subpopulations, including patients with PD-L1 negative disease and β-catenin mutated disease, consistent with amezalpat's proposed mechanism of action targeting both tumor cells directly and the patient's immune system.

In August 2024, we announced the successful completion of our end-of-Phase 2 meeting with the U.S. Food and Drug Administration ("FDA") regarding the development of amezalpat for the treatment of first-line unresectable or metastatic HCC. The FDA provided positive feedback on the pivotal Phase 3 clinical trial design, which closely mirrors the positive randomized Phase 2 study. The planned Phase 3 trial is designed to use the current, Phase 2 amezalpat dose and schedule in combination with atezolizumab and bevacizumab and will be compared to atezolizumab and bevacizumab alone, the standard of care. The primary endpoint of the trial will be OS. Additionally, the FDA agreed to a pre-specified early efficacy analysis, which, if met, would potentially reduce the time to primary read-out by up to eight months.

In November 2024, we received a "Study May Proceed" letter from the FDA, authorizing the initiation of our pivotal Phase 3 trial, and in June 2025, we received the equivalent "Clearance to Proceed" letter from the National Medical Products Administration ("NMPA") in China. In January 2025, the FDA granted Orphan Drug Designation ("ODD") for amezalpat for the treatment of patients with HCC. In February 2025, the FDA granted Fast Track Designation ("FTD"), underscoring the agency's recognition of the urgent need for new treatment options for HCC. In addition to receiving ODD from the FDA, in June 2025, the European Medical Agency ("EMA") also granted ODD for the treatment of patients with HCC. These

designations provide potential regulatory benefits, including increased engagement with the FDA, eligibility for accelerated approval and priority review, and, for ODD, potential market exclusivity upon approval.

TPST-1495

Our second clinical program, TPST-1495, is a novel, small-molecule dual antagonist of the EP2 and EP4 receptors of prostaglandin E2 ("PGE2"), a pathway implicated in multiple cancers. Our development strategy for TPST-1495 includes evaluation in FAP, a rare genetic disorder that significantly increases the risk of gastrointestinal cancers and for which there are no approved systemic therapies. Given that prostaglandin signaling is also implicated in FAP and based on positive preclinical data in a relevant mouse model, we believe there is strong mechanistic support for this approach.

In March 2025, the Cancer Prevention Clinical Trials Network ("CP-CTNet") received a "Study May Proceed" letter from the FDA, authorizing the initiation of a National Cancer Institute ("NCI")-funded Phase 2 clinical trial evaluating TPST-1495 in patients with FAP. This trial, run by CP-CTNet and financially supported by the NCI's Division of Cancer Prevention, underscores the urgent need for innovative cancer prevention strategies in high-risk patient populations. In April 2025, the FDA granted ODD for TPST-1495 for the treatment of patients with FAP. The Phase 2 study is expected to begin in late 2025, subject to potential delays resulting from the ongoing U.S. government shutdown.

Potential Future Milestones

Going Concern and Ongoing Strategic Review

As of September 30, 2025, we had cash and cash equivalents totaling $7.5 million compared to $30.3 million as of December 31, 2024. We have incurred operating losses since inception and our accumulated deficit as of September 30, 2025 is $229.3 million. We expect that our existing cash and cash equivalents will fund our projected operating expense requirements through less than 12 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 unaudited condensed financial statements included elsewhere in this Quarterly Report on Form 10-Q.

In April 2025, we announced plans to explore a full range of strategic alternatives to advance its promising clinical stage programs and maximize stockholder value. Strategic alternatives under consideration may include, but are not limited to, mergers, acquisitions, partnerships, joint ventures, licensing arrangements or other strategic transactions. We have retained MTS Health Partners, L.P., an internationally recognized financial advisor with substantial experience in the biotechnology industry, to support us with the strategic evaluation process. We have not set a timetable for completion of the process for evaluating strategic alternatives and do not intend to disclose further developments or guidance on the status of our programs or the process for evaluating strategic alternatives unless and until it is determined that further disclosure is appropriate or necessary. If a strategic alternative is not available to us, we will be required to take additional actions to fund the Company's operations or we may be forced to wind down our operations.

In addition, as part of the plan to extend our capital resources, we reduced our workforce by 21 of 26 full-time employees, which became effective April 30, 2025 ("RIF"). Key employees within this group transitioned to consulting agreements and have continued to be available to us. Further, in support of such efforts, on June 5, 2025, each of Stephen Brady, the Company's Chief Executive Officer and President, Samuel Whiting, the Company's Executive Vice President and Chief Medical Officer, and Nicholas Maestas, the Company's Chief Financial Officer and Corporate Secretary, transitioned to consulting agreements with the Company, pursuant to which they will continue to serve the Company in their respective executive roles.

The above conditions raise 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 unaudited condensed financial statements included elsewhere in this Quarterly Report on Form 10-Q.

Reverse Stock Split

On April 8, 2025, we effected a one-for-thirteen (1:13) reverse stock split (the "Reverse Stock Split"). Pursuant to their terms, a proportionate adjustment was made to the per share exercise price and number of shares issuable under all of the Company's outstanding options and warrants, and the number of shares authorized for issuance pursuant to the Company's equity incentive plans have been reduced proportionately. The Reverse Stock Split did not reduce the number of authorized shares of common stock and did not alter the par value.

All share and per share amounts of common stock presented in this Quarterly Report on Form 10-Q have been retroactively adjusted to reflect the Reverse Stock Split. Refer to Note 1 of our unaudited condensed financial statements and the notes thereto included elsewhere in this Quarterly Report on Form 10-Q for further information.

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:

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 RIF, we expect research and development expenses will decrease period over period. If we resume our research and development efforts, 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 RIF, we expect general and administrative expenses will decrease period over period.

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.

Results of Operations

Comparison of the three months ended September 30, 2025 and 2024

The following table summarizes our operating results for the three months ended September 30, 2025 and 2024:

Research and development

Our research and development expenses for the three months ended September 30, 2025 and 2024 were primarily incurred in connection with our most advanced product candidate, amezalpat.

The following table shows our research and development expenses by program for the three months ended September 30, 2025 and 2024:

Research and development expenses decreased by $7.0 million to $0.6 million for the three months ended September 30, 2025, compared to three months ended September 30, 2024, which was primarily attributable to a decrease in costs incurred as a result of re-prioritizing efforts towards exploring strategic alternatives initiated in April 2025.

The following table summarizes our research and development expenses for the three months ended September 30, 2025 and 2024:

General and administrative

General and administrative expenses were $3.0 million for each of the three months ended September 30, 2025 and 2024, and were primarily related to consulting and professional services.

Other income (expense), net

For the three months ended September 30, 2025, no interest expense was incurred related to the loan with Oxford Finance LLC ("Oxford," and such loan the "Oxford Loan"), compared to $329 thousand for the three months ended September 30, 2024. For the three months ended September 30, 2025 and 2024, interest income was $86 thousand and $324 thousand, respectively. The Oxford Loan was repaid in full and terminated in accordance with its terms in April 2025.

Comparison of the nine months ended September 30, 2025 and 2024

The following table summarizes our operating results for the nine months ended September 30, 2025 and 2024:

Research and development

Our research and development expenses for the nine months ended September 30, 2025 and 2024 were primarily incurred in connection with our most advanced product candidate, amezalpat.

Research and development expenses decreased by $5.6 million to $12.1 million for the nine months ended September 30, 2025, compared to the nine months ended September 30, 2024, which was primarily attributable to a decrease in costs incurred as a result of re-prioritizing efforts towards exploring strategic alternatives initiated in April 2025. Expenses in the nine months ended September 30, 2025 included $4.5 million related to contract research and manufacturing organizations in preparation for our pivotal Phase 3 trial of amezalpat for the treatment of first-line HCC.

The following table summarizes our research and development expenses for the nine months ended September 30, 2025 and 2024:

General and administrative

General and administrative expenses increased by $0.1 million to $10.4 million for the nine months ended September 30, 2025, compared to the nine months ended September 30, 2024. The increase was primarily related to employee compensation costs, inclusive of one-time separation costs for employees terminated during the nine months ended September 30, 2025, as well as consulting and professional services.

Other income (expense), net

For the nine months ended September 30, 2025 and 2024, other income (expense), net consisted of total interest expense of $207 thousand and $1.1 million, respectively, related to the Oxford Loan, and interest income of $464 thousand and $1.1 million, respectively. The Oxford Loan was repaid in full and terminated in accordance with its terms in April 2025.

Liquidity and Capital Resources

Overview

Since inception through September 30, 2025, our operations have been financed primarily by proceeds from the sale of

our common stock, convertible preferred stock and issuance of debt. In April 2025, we announced plans to explore a full range of strategic alternatives to advance our promising programs. If a strategic alternative is not available to us, we will be required to take additional actions to fund the Company's operations or we may be forced to wind down our operations. As of September 30, 2025, we had $7.5 million in cash and cash equivalents and an accumulated deficit of $229.3 million.

Our lack of operating revenue or cash inflows and our cash resources at September 30, 2025 raise substantial doubt as to our

ability to continue as a going concern. See "-Funding Requirements" below for additional information on our future capital needs.

Loan Agreement with Oxford

On January 15, 2021, we entered into a loan and security agreement, as amended from time to time, with Oxford to borrow a term loan amount of $35.0 million to be funded in three tranches. On April 8, 2025, we repaid $3.5 million in full satisfaction of the aggregate outstanding amount, including accrued interest and exit fees as of such date. As a result of the repayment, all liens and security interests were terminated.

At-the-Market Offering

We have entered into a sales agreement (the "Sales Agreement") with Jefferies LLC ("Jefferies"), pursuant to which we may sell, from time to time at our sole discretion through Jefferies, as our sales agent, shares of our common stock (the "ATM Program"). Any shares of our common stock sold will be issued pursuant to our shelf registration statement on Form S-3 (File No. 333-280918). On June 11, 2025, in connection with the RDO (as defined below) we delivered written notice to Jefferies that we were suspending and terminating the prospectus supplement, dated February 6, 2025, related to the ATM Program (the "ATM Prospectus"). We will not make any sales of our securities pursuant to the Sales Agreement, unless and until a new prospectus, prospectus supplement or a new registration statement is filed. Other than the termination of the ATM Prospectus, the Sales Agreement remains in full force and effect. As of the nine months ended September 30, 2025, we have sold an aggregate of 312,830 shares of our common stock for proceeds of $2.8 million pursuant to the ATM Program. As of September 30, 2025, $11.6 million remained available for sale under the ATM Program.

As of the date of this Form 10-Q, our public float was less than $75.0 million. As a result, we are subject to the limitations of General Instruction I.B.6 to Form S-3 until such time as our public float exceeds $75 million, which means we only have the capacity to sell shares up to one-third of our public float under the S-3 Registration Statement, including the ATM program, in any twelve-month period. On February 6, 2025, we filed a prospectus supplement with the SEC limiting the availability under the ATM Program to $14.5 million.

Registered Direct Offering

On June 11, 2025, we sold an aggregate of 405,000 shares of our common stock and pre-funded warrants to purchase 334,000 shares of our common stock in a registered direct offering (the "RDO"). The offering price was $6.25 per share of common stock and $6.249 per pre-funded warrant, which is the price of each share of common stock sold in the offering, minus the $0.001 exercise price per pre-funded warrant. The net proceeds from the RDO were approximately $4.1 million, after deducting placement agent fees and estimated offering expenses payable by us. As of September 30, 2025, all pre-funded warrants had been exercised.

Cash Flows

The following table summarizes our cash flows for the nine months ended September 30, 2025 and 2024:

Cash flows used in operating activities

Cash used in operating activities for the nine months ended September 30, 2025 was $23.2 million, consisting of a net loss of $22.2 million, add back of non-cash adjustments for depreciation, stock-based compensation, non-cash operating lease expense and other non-cash items totaling $3.6 million, less changes in operating assets and liabilities of $4.6 million.

Cash used in operating activities for the nine months ended September 30, 2024 was $22.9 million, consisting of a net loss of $28.0 million, add back of non-cash adjustments for depreciation, stock-based compensation, non-cash operating lease expense and other non-cash items totaling $3.2 million, plus changes in operating assets and liabilities of $2.4 million.

Cash flows used in investing activities

No cash was used in investing activities for the nine months ended September 30, 2025.

Cash used in investing activities for the nine months ended September 30, 2024 was related to purchases of property and equipment, primarily related to laboratory and computer equipment.

Cash flows provided by financing activities

Cash provided by financing activities for the nine months ended September 30, 2025 was related to net proceeds from the June 2025 registered direct offering of $4.1 million as well as the issuance of common stock of $2.8 million under the ATM Program, offset by $6.4 million in outflows related to the repayment of the Oxford Loan.

Cash provided by financing activities for the nine months ended September 30, 2024 was related to proceeds from the issuance of common stock of $8.8 million, offset by $2.2 million in outflows related to the repayment of the Oxford Loan.

Funding Requirements

Our primary use of cash is to fund operating expenses, which has historically consisted primarily of research and development expenditures related to our therapeutic discovery and preclinical development efforts and clinical activities, and to a lesser extent, general and administrative expenditures. Currently, our primary use of cash is headcount cost and lease and overhead expenses as we explore strategic alternatives. Cash used to fund operating expenses is impacted by the timing of when we pay these expenses, as reflected in the change in our outstanding accounts payable and accrued expenses. If a strategic alternative is not available to us, we will be required to take additional actions to fund the Company's operations or we may be forced to wind down our operations.

Material Cash Requirements

Our material cash requirements primarily relate to our operating lease for office space, trade payables, and accrued expenses. As of September 30, 2025, we had $3.5 million payable within 12 months, including $1.1 million related to the Brisbane Lease. Refer to Note 5 to our Condensed Consolidated Financial Statements for additional information.

Except as disclosed above, we have no long-term debt and no material non-cancelable purchase commitments with service providers, as we have generally contracted on a cancelable, purchase-order basis. We enter into contracts in the normal course of business with equipment and reagent vendors, CROs, CMOs and other third parties for clinical trials, preclinical research studies and testing and manufacturing services. These contracts are cancelable by us upon prior notice. Payments due upon cancellation consist only of payments for services provided or expenses incurred, including noncancelable obligations of our service providers, up to the date of cancellation.

Critical Accounting Policies and Estimates

There have been no significant changes to our critical accounting policies since December 31, 2024. For a description of critical accounting policies that affect our significant judgments and estimates used in the preparation of our unaudited condensed consolidated financial statements, refer to Item 7 "Management's Discussion and Analysis of Financial Condition and Results of Operations" contained in our Annual Report on Form 10-K.

Recent Accounting Pronouncements

See Note 2 to our Condensed Consolidated Financial Statements for a description of recent accounting pronouncements applicable to our Condensed Consolidated Financial Statements.

Smaller Reporting Company Status and a Non-Accelerated Filer

We are a "smaller reporting company," as defined in Rule 12b-2 of the Securities Exchange Act of 1934, or the Exchange Act, meaning that the market value of our shares 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-back disclosure permitted for smaller reporting companies, 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.