Serabelisib

— Stockholders approved conversion of the Series B preferred stock issued in the February 2026 acquisition of Faeth Therapeutics and concurrent private placement — — Company changed name to Faeth Therapeutics, Inc. on June 15, 2026; common stock expected to begin trading under the ticker symbol “FTH” on June 16, 2026 — — Anand Parikh, Faeth co-founder, appointed Chairman, President and Chief Executive Officer; Brian Stephenson, Ph.D., CFA appointed Chief Financial Officer; board strengthened with the addition of former FDA Commissioner Stephen M. Hahn, M.D., and Saira Ramasastry — — PIKTOR, an investigational all-oral multi-node inhibitor of the PI3K/AKT/mTOR pathway, on track for topline Phase 2 data in advanced endometrial cancer in the second half of 2026 — AUSTIN, Texas--(BUSINESS WIRE)--Sensei Biotherapeutics, Inc. (Nasdaq: SNSE) today announced that it has changed its corporate name to Faeth Therapeutics, Inc. (the “Company”). The Company’s common stock is expected to begin trading on the Nasdaq Capital Market under the new ticker symbol “ FTH ” on June 16, 2026, and the Company has launched a new corporate website at . On June 10, 2026, stockholders approved the conversion of the Company’s Series B preferred stock issued in connection with the February 2026 acquisition of Faeth Therapeutics and concurrent private placement. As a result, outstanding shares of the Company’s Series B convertible preferred stock will automatically convert into common stock effective at 5:00 p.m. ET on June 15, 2026, subject to certain beneficial ownership limitations set by each holder. The Company received approximately $200 million in gross proceeds from the private placement that closed concurrently with its February 2026 acquisition of Faeth. “Starting tomorrow, we will begin trading on Nasdaq under our new name and ticker as a well-capitalized public company backed by a syndicate of leading life sciences investors, and focused on a clear set of clinical catalysts,” said Anand Parikh, Chairman and Chief Executive Officer. “For two decades, drugs that block a single node of the PI3K/AKT/mTOR pathway have been undone by the tumor’s ability to route around them. PIKTOR represents our answer to this challenge: an all-oral regimen that patients can take at home, designed to inhibit PI3K-alpha, mTORC1 and mTORC2 at once, close the routes tumors may use to escape, and potentially drive deeper, more durable suppression, with the potential for a best-in-class profile. We believe we now have the capital and the team to put that approach to the test, beginning with topline Phase 2 data in advanced endometrial cancer, expected in the second half of this year, and interim Phase 1b/2 data in HR+/HER2- advanced breast cancer, expected in 2027.” Leadership and Board Effective June 12, 2026, the Company appointed a new executive leadership team. Anand Parikh, a co-founder of Faeth who has led the company since its founding in 2019, has been appointed Chairman, President and Chief Executive Officer. Brian Stephenson, Ph.D., CFA, who previously served as the Company’s Head of Operations and Finance and as Chief Financial Officer of BridgeBio Pharma, Inc., has been appointed Chief Financial Officer. Oliver Maddocks, Ph.D., a co-founder of Faeth and a cancer-metabolism researcher, serves as Chief Scientific Officer, and Debbie Chirnomas, M.D., M.P.H., serves as Chief Medical Officer. The Company’s board of directors consists of five members: Anand Parikh (Chair); Bob Holmen; Phillip B. Donenberg; Stephen M. Hahn, M.D.; and Saira Ramasastry. Dr. Hahn, the 24th Commissioner of the U.S. Food and Drug Administration and a former Faeth director, and Ms. Ramasastry, a life sciences strategic advisor and experienced public-company director, joined the board on June 12, 2026. “In a career spent in oncology and at the FDA, I’ve learned how rarely a program pairs a high-prevalence target with a potentially differentiated mechanism,” said Stephen M. Hahn, M.D., the 24th Commissioner of the U.S. Food and Drug Administration and a member of the Company’s board of directors. “I believe Faeth’s multi-node, all-oral approach to the PI3K/AKT/mTOR pathway is scientifically rigorous and aimed at a real unmet need. I’m looking forward to guiding the company through this next stage of clinical development.” About PIKTOR PIKTOR is an investigational, proprietary, all-oral combination of serabelisib, a selective PI3K-alpha inhibitor, and sapanisertib, an mTORC1/mTORC2 inhibitor, designed to inhibit multiple nodes of the PI3K/AKT/mTOR pathway. According to published literature, this pathway is dysregulated in up to 50% of all solid tumors, making it one of the most prevalent therapeutic targets in oncology. PIKTOR is being evaluated in a Phase 2 trial in second-line advanced endometrial cancer (Study FTH-PIK-201), with topline data anticipated in the second half of 2026, and in a Phase 1b/2 trial in HR+/HER2- advanced breast cancer (Study FTH-PIK-101), in which the first patient was dosed in April 2026 and interim data is anticipated in 2027. About Faeth Therapeutics Faeth Therapeutics, Inc. (Nasdaq: FTH) is a clinical-stage biotechnology company focused on improving outcomes for cancer patients through multi-node inhibition of critical oncogenic pathways. The Company’s lead program is PIKTOR, an investigational all-oral combination of serabelisib and sapanisertib in development for endometrial and breast cancer. Faeth was co-founded in 2019 by Anand Parikh and Oliver Maddocks, Ph.D., together with scientific founders Lewis Cantley, Ph.D., the discoverer of the PI3K pathway; Siddhartha Mukherjee, M.D., D.Phil.; Karen Vousden, Ph.D.; Scott Lowe, Ph.D.; and Greg Hannon, Ph.D. The Company intends to use its website as a means of disclosing material non-public information and for complying with its disclosure obligations under Regulation FD. For more information, please visit and follow the Company on LinkedIn . Cautionary Note Regarding Forward-Looking Statements This press release contains “forward-looking statements” within the meaning of the federal securities laws, including the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include all statements that are not historical facts and may be identified by words such as “anticipate,” “believe,” “expect,” “intend,” “plan,” “may,” “will,” “would,” “could,” “should,” “estimate,” “potential,” “target,” “on track” and similar expressions, although not all forward-looking statements contain these words. These statements include, but are not limited to, statements regarding: the change of the Company’s corporate name to Faeth Therapeutics, Inc.; the expected commencement of trading of the Company’s common stock under the new name and ticker symbol “FTH” and the timing thereof; the Company’s expectations regarding its pipeline and development plans, including the Phase 2 trial of PIKTOR in advanced endometrial cancer and the anticipated timing of topline data, and the Phase 1b/2 trial of PIKTOR in HR+/HER2- advanced breast cancer and the anticipated timing of interim data; the potential therapeutic benefits, tolerability pro differentiation of PIKTOR; and the Company’s expectations regarding its cash runway. Forward-looking statements are based on management’s current expectations and assumptions and are subject to a number of risks and uncertainties, many of which are beyond the Company’s control, that could cause actual results to differ materially from those expressed or implied. These risks and uncertainties include, among others, risks related to clinical development and the conduct, timing and results of clinical trials; the Company’s need for additional financing; its limited operating history and history of operating losses; risks related to the integration of Faeth; the Company’s ability to satisfy applicable Nasdaq listing requirements and to maintain the listing of its common stock; and the other risks and uncertainties described under the headings “Risk Factors” and “Summary of Risk Factors” in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on March 30, 2026, its Quarterly Report on Form 10-Q filed with the SEC on May 15, 2026, and its definitive proxy statement filed with the SEC on April 27, 2026, as well as in the Company’s subsequent filings. Forward-looking statements speak only as of the date of this press release, and the Company undertakes no obligation to update any forward-looking statement, except as required by law. Contacts Investor Contact: Matthew Biegler, SVP, Investor Relations matt@faeththerapeutics.com Stephanie Ascher, Precision AQ stephanie.ascher@precisionaq.com Media Contact: Patrick Schmidt, Consort Partners faeththerapeutics@consortpartners.com

BOSTON--(BUSINESS WIRE)--Sensei Biotherapeutics, Inc. (Nasdaq: SNSE) today reported financial results for the first quarter ended March 31, 2026, and provided a corporate update. “The first quarter of 2026 was transformational for the Company, with the acquisition of Faeth Therapeutics and the concurrent $200 million private placement in February, supported by a group of leading life sciences investors,” said Christopher Gerry, President & General Counsel of Sensei Biotherapeutics. “This acquisition and injection of new capital will allow us to advance PIKTOR, a differentiated multi-node pathway inhibitor, through key clinical milestones.” “New data across the industry continues to support the significant potential of multi-node inhibition of the PI3K/AKT/mTOR pathway,” said Anand Parikh, Chief Operating Officer of Sensei Biotherapeutics. “We believe PIKTOR is differentiated as an orally administered multi-node therapy specifically targeting PI3K-alpha, mTORC1 and mTORC2, with the potential to treat a variety of solid tumors. With our Phase 2 trial in advanced endometrial cancer expected to read out by the end of the year and the recent initiation of our Phase 1b/2 trial in advanced breast cancer, we are making great strides towards delivering the next generation of solid tumor therapies.” Clinical Program Highlights Acquired through the Faeth transaction, PIKTOR is now Sensei’s lead program. The investigational, proprietary, all-oral combination of serabelisib and sapanisertib is designed to inhibit multiple nodes of the PI3K/AKT/mTOR pathway through PI3K-alpha and dual mTORC1/2 targeting. In April 2026, the first patient was dosed in the Phase 1b/2 trial evaluating PIKTOR for the treatment of HR+/HER2- advanced breast cancer (Study FTH-PIK-101). Interim data from the trial is expected in 2027. The Phase 2 trial evaluating PIKTOR in advanced endometrial cancer (Study FTH-PIK-201) is on track to report topline data in the second half of 2026. First Quarter 2026 Financial Results Cash Position: Cash, cash equivalents and marketable securities were $202.8 million as of March 31, 2026, as compared to $21.2 million as of December 31, 2025. Research and Development (R&D) Expenses: R&D expenses were $18.0 million for the quarter ended March 31, 2026, compared with $3.7 million for the quarter ended March 31, 2025. The increase in R&D expenses was primarily attributable to the inclusion of Faeth R&D operations as well as one-time costs associated with the Faeth acquisition, partially offset by a reduction in the SNS-101 clinical trial costs. General and Administrative (G&A) Expenses: G&A expenses were $19.7 million for the quarter ended March 31, 2026, compared to $3.5 million for the quarter ended March 31, 2025. The increase in G&A expense was primarily attributable to one-time costs associated with the Faeth acquisition. Acquired In-Process Research and Development (Acquired IPR&D) Expenses: Acquired IPR&D expenses were $133.0 million for the quarter ended March 31, 2026. This represents the fair value of IPR&D assets obtained in connection with asset acquisition where the acquired IPR&D has no alternative future use as of the acquisition date. Net Loss: Net loss was $170.2 million, or $131.45 per basic and diluted share, for the quarter ended March 31, 2026, compared with a net loss of $6.9 million, or $5.45 per basic and diluted share, for the quarter ended March 31, 2025. Weighted-average common shares outstanding, basic and diluted, were 1,295,052 for the quarter ended March 31, 2026, compared with 1,259,531 for the quarter ended March 31, 2025. Condensed Statements of Operations (Unaudited, in thousands except share and per share data) For the Three Months Ended March 31, 2026 2025 Operating expenses: Research and development $ 17,957 $ 3,725 General and administrative 19,713 3,549 Acquired in-process research and development 132,957 — Total operating expenses 170,627 7,274 Loss from operations (170,627 ) (7,274 ) Total other income 391 410 Net loss (170,236 ) (6,864 ) Net loss per share, basic and diluted $ (131.45 ) $ (5.45 ) Weighted-average common shares outstanding, basic and diluted 1,295,052 1,259,531 Selected Condensed Balance Sheet Data (Unaudited, in thousands) March 31, 2026 December 31, 2025 Cash and cash equivalents $ 152,325 $ 8,668 Marketable securities 50,468 12,516 Total assets 205,381 22,902 Total liabilities 14,191 4,310 Series B redeemable convertible preferred stock 328,476 — Total stockholders’ (deficit) equity (137,286 ) 18,592 About Sensei Biotherapeutics Sensei Biotherapeutics, Inc. (Nasdaq: SNSE) is a clinical-stage biotechnology company focused on improving outcomes for cancer patients through multi-node inhibition of critical oncogenic pathways. Following the acquisition of Faeth Therapeutics, Sensei's lead program is PIKTOR, an investigational multi-node inhibitor of the PI3K/AKT/mTOR pathway in development for endometrial and breast cancer. Sensei is also completing a Phase 1/2 trial of solnerstotug, its V-domain Ig suppressor of T cell activation (VISTA) inhibitor, in patients with advanced solid tumors. Sensei intends to use its website as a means of disclosing material non-public information and for complying with its disclosure obligations under Regulation FD. For more information, please visit www.senseibio.com and follow the company on X @SenseiBio and LinkedIn. Cautionary Note Regarding Forward-Looking Statements Certain statements in this press release, other than purely historical information, may constitute "forward-looking statements" within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United States Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, express or implied statements relating to the company’s expectations, hopes, beliefs, intentions or strategies regarding the future including, without limitation, statements regarding: the expected benefits or opportunities following the acquisition of Faeth Therapeutics; expectations regarding or plans for the company’s pipeline, including the Phase 2 trial evaluating PIKTOR in advanced endometrial cancer and the expected timing for topline data, the Phase 1b/2 trial evaluating PIKTOR in HR+/HER2- advanced breast cancer and the expected timing for interim data, the completion of the remaining portion of the Phase 1/2 trial of solnerstotug and other research and development programs and the expected timing for key milestones; the potential benefits of PIKTOR, including its potential to treat a variety of solid tumors; expectations regarding the use of proceeds from the private placement and cash runway expectations therefrom, including such proceeds funding the company through key clinical milestones. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words "opportunity," "potential," "milestones," "pipeline," "can," "goal," "aim," "strategy," "target," "seek," "anticipate," "achieve," "believe," "contemplate," "continue," "could," "estimate," "expect," "intends," "may," "might," "plan," "possible," "predict," "project," "should," "will," "would" and similar expressions (including the negatives of these terms or variations of them) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. These forward-looking statements are based on current expectations and beliefs concerning future developments and their potential effects. There can be no assurance that future developments affecting the company will be those that have been anticipated. These forward-looking statements involve a number of risks, uncertainties (some of which are beyond the company’s control) or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to those uncertainties and factors described under the heading "Risk Factors" and "Summary of Risk Factors" in the company’s Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission (the "SEC") on May 14, 2026, as well as discussions of potential risks, uncertainties, and other important factors included in other filings by the company from time to time, as well as risk factors associated with companies, such as Faeth, that operate in the biotechnology industry. Should one or more of these risks or uncertainties materialize, or should any of the company’s assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. You should not place undue reliance on forward-looking statements in this press release, which speak only as of the date they are made and are qualified in their entirety by reference to the cautionary statements herein. The company does not undertake or accept any duty to release publicly any updates or revisions to any forward-looking statements. This press release does not purport to summarize all of the conditions, risks and other attributes of an investment in the company.