Novel H₂CasMab-2 Antigen Binding Domain Shown to Preferentially Target HER2 Expressed on Tumor Cells in Preclinical Studies

Initial Low-Dose Cohort of FT825 / ONO-8250 as Monotherapy Shows Favorable Safety Profile in Phase 1 Solid Tumor Study

Peripheral Blood from First Three Patients Demonstrates CAR T-cell Expansion with Maintenance of Activated State at Day 8 Following Treatment

SAN DIEGO, Nov. 09, 2024 (GLOBE NEWSWIRE) -- Fate Therapeutics, Inc. (NASDAQ:FATE), a clinical-stage biopharmaceutical company dedicated to bringing a first-in-class pipeline of induced pluripotent stem cell (iPSC)-derived cellular immunotherapies to patients with cancer and autoimmune disorders, today presented initial clinical and new preclinical data for FT825 / ONO-8250, a multiplexed-engineered, chimeric antigen receptor (CAR) T-cell product candidate targeting human epidermal growth factor receptor 2 (HER2), at the 2024 Society of Immunotherapy of Cancer (SITC) 39^th Annual Meeting being held in Houston, TX on November 6-10, 2024. FT825 / ONO-8250 incorporates a novel H₂CasMab-2 binding domain targeting HER2 that is designed to overcome on-target, off-tumor toxicity and to recognize variants associated with poor clinical outcomes and tumor escape. In an ongoing Phase 1 study in advanced solid tumors, three patients were treated with FT825 / ONO-8250 in the first low-dose cohort as monotherapy, and no dose-limiting toxicities (DLTs) and no events of any grade of cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), or graft-versus-host disease (GvHD) were observed. The multi-center, Phase 1 study is currently being conducted under a strategic collaboration with Ono Pharmaceutical Co., Ltd. (Ono).

"FT825 / ONO-8250 integrates seven novel synthetic controls of CAR T-cell function designed to overcome multiple mechanisms that impede the safe and effective treatment of solid tumors. We are very pleased with initial Phase 1 clinical observations from the first low-dose cohort, which showed a favorable safety profile, product expansion, and maintenance of an activated CAR T-cell state," said Scott Wolchko, President and Chief Executive Officer of Fate Therapeutics. "In addition, new preclinical data for FT825 / ONO-8250 presented today at SITC highlighted the cancer-selective recognition profile of its novel HER2 antigen binding domain, including its potential to target variants uniquely expressed on tumor cells. Under our collaboration with Ono, we are excited to further assess the potential of FT825 / ONO-8250 to benefit patients with hard-to-treat advanced solid tumors who currently have limited treatment options."

Initial Phase 1 Clinical Observations

The Phase 1 study is designed to assess the safety, pharmacokinetics, and activity of FT825 / ONO-8250 as monotherapy and in combination with monoclonal antibody (mAb) therapy in patients with advanced solid tumors (NCT06241456). Three heavily pre-treated patients, all of whom were previously treated with at least five prior lines of therapy including HER2-targeted therapy, were administered conditioning chemotherapy and FT825 / ONO-8250 at the first dose level of 100 million cells as monotherapy. In all three patients, peak CAR T-cell expansion was observed at Day 8 following treatment. In addition, phenotyping of FT825 / ONO-8250 sourced from the patients' peripheral blood on Day 8 was indicative of an activated state (as evidenced by high levels of Granzyme B expression and maintenance of CAR expression) with no evidence of exhaustion (as evidenced by low levels of PD-1 and TIM3 expression). As of a data cutoff date of October 25, 2024, FT825 / ONO-8250 was well-tolerated with no DLTs and no events of any grade of CRS, ICANS, or GvHD. Enrollment is currently ongoing at the second dose level of 300 million cells as monotherapy and at the first dose level of 100 million cells in combination with epidermal growth factor receptor (EGFR)-targeted mAb therapy.

Preclinical Data

While HER2-directed therapies, such as trastuzumab (Herceptin) and trastuzumab deruxtecan (Enhertu), are effective in treating HER2-positive cancers, widespread HER2 expression in normal epithelial tissue can lead to significant off-tumor, on-target toxicities. At an oral presentation today at SITC entitled "Preferential targeting of HER2-expressing cancer cells by FT825 / ONO-8250, an off-the-shelf iPSC-derived CAR-T cell incorporating novel synthetic mechanisms for enhanced solid tumor activity", scientists from the Company, Ono, Osaka University, and Tohoku University highlighted that FT825 / ONO-8250 demonstrated potent HER2-specific, anti-tumor activity in both in vitro and in vivo settings with limited cytolytic targeting of HER2+ normal cells. The on-tumor selectivity of FT825 / ONO-8250 was attributed to its incorporation of a novel HER2-targeted antigen binding domain, which was derived from a cancer-specific monoclonal antibody H₂CasMab-2 (Kaneko et al., 2024), that was shown to differentially and preferentially recognize both locally misfolded HER2 and p95 truncation variants of HER2 as compared to trastuzumab. The scientists also presented preclinical data demonstrating that FT825 / ONO-8250 exhibits potent antibody-mediated cellular cytotoxicity (ADCC) through its high-affinity non-cleavable CD16 (hnCD16) Fc receptor, synergizing with trastuzumab to enhance clearance of HER2+ tumor cells and with cetuximab to enable multi-antigen targeting of HER2 and epidermal growth factor receptor (EGFR) expressed on cancer cells.

Under the terms of its partnership with Ono for FT825 / ONO-8250, Fate and Ono are jointly responsible for development and commercialization in the U.S. and Europe, and Ono maintains exclusive development and commercialization rights in the rest of the world. The parties are also conducting preclinical development of an additional solid tumor program targeting an undisclosed tumor-associated antigen.

About Fate Therapeutics' iPSC Product Platform

Human induced pluripotent stem cells (iPSCs) possess the unique dual properties of unlimited self-renewal and differentiation potential into all cell types of the body. The Company's proprietary iPSC product platform combines multiplexed-engineering of human iPSCs with single-cell selection to create clonal master iPSC lines. Analogous to master cell lines used to mass produce biopharmaceutical drug products such as monoclonal antibodies, the Company utilizes its clonal master iPSC lines as a starting cell source to manufacture engineered cell products which are well-defined and uniform in composition, can be stored in inventory for off-the-shelf availability, can be combined and administered with other therapies, and can potentially reach a broad patient population. As a result, the Company's platform is uniquely designed to overcome numerous limitations associated with the manufacture of cell therapies using patient- or donor-sourced cells. Fate Therapeutics' iPSC product platform is supported by an intellectual property portfolio of over 500 issued patents and 500 pending patent applications.

About Fate Therapeutics, Inc.

Fate Therapeutics is a clinical-stage biopharmaceutical company dedicated to bringing a first-in-class pipeline of induced pluripotent stem cell (iPSC)-derived cellular immunotherapies to patients with cancer and autoimmune diseases. Using its proprietary iPSC product platform, the Company has established a leadership position in creating multiplexed-engineered master iPSC lines and in the manufacture and clinical development of off-the-shelf, iPSC-derived cell products. The Company's pipeline includes iPSC-derived natural killer (NK) cell and T-cell product candidates, which are selectively designed, incorporate novel synthetic controls of cell function, and are intended to deliver multiple therapeutic mechanisms to patients. Fate Therapeutics is headquartered in San Diego, CA. For more information, please visit www.fatetherapeutics.com.

Forward-Looking Statements

This release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 including statements regarding the advancement of and plans related to the Company's product candidates, clinical studies and preclinical research and development programs, the Company's progress, plans and timelines for the clinical investigation of its product candidates, including the initiation and continuation of enrollment in the Company's clinical trials, the initiation of additional clinical trials and additional dose cohorts in ongoing clinical trials of the Company's product candidates, the timing and availability of data from the Company's clinical trials, the therapeutic and market potential of the Company's research and development programs and product candidates, the Company's clinical and product development strategy, and the Company's expectations regarding progress and timelines, and the objectives, plans and goals of its collaboration with Ono. These and any other forward-looking statements in this release are based on management's current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to, the risk that the Company's research and development programs and product candidates, including those product candidates in clinical investigation, may not demonstrate the requisite safety, efficacy, or other attributes to warrant further development or to achieve regulatory approval, the risk that results observed in prior studies of the Company's product candidates, including preclinical studies and clinical trials, will not be observed in ongoing or future studies involving these product candidates, the risk of a delay or difficulties in the manufacturing of the Company's product candidates or in the initiation and conduct of, or enrollment of patients in, any clinical trials, the risk that the Company may cease or delay preclinical or clinical development of any of its product candidates for a variety of reasons (including requirements that may be imposed by regulatory authorities on the initiation or conduct of clinical trials, changes in the therapeutic, regulatory, or competitive landscape for which the Company's product candidates are being developed, the amount and type of data to be generated or otherwise to support regulatory approval, difficulties or delays in patient enrollment and continuation in the Company's ongoing and planned clinical trials, difficulties in manufacturing or supplying the Company's product candidates for clinical testing, failure to demonstrate that a product candidate has the requisite safety, efficacy, or other attributes to warrant further development, and any adverse events or other negative results that may be observed during preclinical or clinical development), the risk that its product candidates may not produce therapeutic benefits or may cause other unanticipated adverse effects, the risk that the Company may not comply with its obligations under and otherwise maintain its collaboration agreement with Ono, and the risk that research funding and milestone payments received by the Company under its collaboration may be less than expected. For a discussion of other risks and uncertainties, and other important factors, any of which could cause the Company's actual results to differ from those contained in the forward-looking statements, see the risks and uncertainties detailed in the Company's periodic filings with the Securities and Exchange Commission, including but not limited to the Company's most recently filed periodic report, and from time to time in the Company's press releases and other investor communications. Fate Therapeutics is providing the information in this release as of this date and does not undertake any obligation to update any forward-looking statements contained in this release as a result of new information, future events or otherwise.

Contact:

Christina Tartaglia

Precision AQ

212.362.1200

christina.tartaglia@precisionaq.com