Fate Therapeutics Announces Updated Clinical Data for FT819 Off-the-shelf CAR T-cell Product Candidate Demonstrating Durability of Drug-free Remission for Severe Lupus Nephritis at EULAR 2025 Congress

Rhea-AI Summary

Fate Therapeutics announced promising clinical data for FT819, its off-the-shelf CAR T-cell therapy, in treating systemic lupus erythematosus (SLE). All three lupus nephritis patients treated with FT819 under a fludarabine-free conditioning regimen achieved Primary Efficacy Renal Response, with the first patient maintaining drug-free remission at 12 months. An extrarenal lupus patient showed disease improvement, while another patient treated without conditioning achieved and maintained Low Lupus Disease Activity State at 6 months. The therapy demonstrated favorable safety across 59 patients, with low-grade cytokine release syndrome, no neurotoxicity, and no graft-versus-host disease. The company plans to expand the program to other autoimmune conditions and has approximately 450 cryopreserved drug product bags available.

Positive

• All three lupus nephritis patients achieved Primary Efficacy Renal Response (PERR)
• First patient maintains drug-free remission at 12-month follow-up
• Favorable safety profile across 59 patients with minimal side effects
• Short hospitalization duration of three days, supporting potential outpatient administration
• FDA agreement to expand clinical investigation to multiple autoimmune diseases
• 450 cryopreserved drug product bags available for immediate treatment

Negative

• Early-stage clinical data with limited patient population (only 5 evaluable patients)
• One case of Grade 2 cytokine release syndrome reported

Insights

Biotechnology Analyst

FT819 shows promising durability and safety in lupus, with patients achieving remission even without intensive conditioning - significant differentiation from competitors.

Fate Therapeutics' clinical update for FT819 represents a potential paradigm shift in CAR T therapy for autoimmune diseases. The data from five SLE patients shows 100% response rate with all treated lupus nephritis patients achieving Primary Efficacy Renal Response (PERR) using a fludarabine-free conditioning regimen. Most notably, one patient maintained drug-free remission at the 12-month mark - a crucial durability milestone that addresses a key question for cell therapies in autoimmunity.

The conditioning-free approach is particularly groundbreaking. One extrarenal lupus patient achieved Low Lupus Disease Activity State (LLDAS) without any conditioning chemotherapy, merely as an add-on to maintenance therapy. This could dramatically expand the patient population by reducing treatment barriers and potentially enabling outpatient administration.

Safety data across nearly 60 patients in both autoimmunity and oncology settings reveals minimal cytokine release syndrome (only one Grade 2 event), no neurotoxicity (ICANS), and no graft-versus-host disease - significantly better than typical autologous CAR T profiles. The short 3-day hospitalization requirement further supports potential outpatient use.

The therapy's B-cell remodeling mechanism appears to create a more favorable immune repertoire with reduction of pathogenic double-negative B cells, which may explain the durable responses. With 450 cryopreserved drug product bags available and FDA agreement to expand into multiple B-cell autoimmune diseases (vasculitis, myositis, systemic sclerosis), Fate is positioned to rapidly accelerate development. The upcoming RMAT designation meeting with FDA could further expedite their path to market.

All three patients treated with FT819 following fludarabine-free conditioning regimen for severe lupus nephritis achieve Primary Efficacy Renal Response (PERR); first patient to reach 1-year follow-up continues in drug-free Definition of Remission in SLE (DORIS)

First extrarenal SLE patient on maintenance therapy treated with FT819 in the absence of conditioning achieves Low Lupus Disease Activity State (LLDAS) at 3-month follow-up and maintained at 6 months

Cumulative clinical experience in nearly 60 patients treated with off-the-shelf program across autoimmunity and oncology continues to support therapeutic differentiation with favorable safety profile and short duration of hospitalization

SAN DIEGO, June 11, 2025 (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 off-the-shelf cellular immunotherapies to patients, today announced new and updated clinical data from the first five patients dosed with FT819 for the treatment of moderate-to-severe systemic lupus erythematosus (SLE) at the European Alliance of Associations for Rheumatology (EULAR) 2025 Congress in Barcelona, Spain.

“The initial clinical profile of our FT819 off-the-shelf CAR T-cell program in moderate-to-severe SLE has shown clear therapeutic differentiation as all five patients achieved significant disease improvement with either less-intensive or no conditioning chemotherapy, with the first patient to reach 12-month follow-up showing durable drug-free remission,” said Bob Valamehr, Ph.D. MBA, President and Chief Executive Officer of Fate Therapeutics. “We remain focused and have made good progress on growing our clinical footprint in the U.S. and Europe to accelerate the pace of patient enrollment in our FT819 program in lupus, as well as in myositis, systemic sclerosis and ANCA-associated vasculitis. With promising preliminary clinical data, a favorable safety profile, shortened hospitalization requirements, reduced or no conditioning chemotherapy regimens, and unique on-demand product availability with low cost of goods, we believe FT819 is not only well-suited for administration in academic settings but also an ideal drug product to support treatment in the community setting, facilitating broad patient access and geographical reach. Notably, the treatment response of the first patient exhibiting remission in SLE without conditioning chemotherapy is supportive of our pursuit to create drug products that bring together the treatment feasibility of biologics and the efficacy of CAR T cells. We look forward to discussing these initial clinical data and the unique attributes of FT819 with the FDA this summer under our RMAT designation to align on a registrational pathway for the benefit of patients with lupus.”

New and Updated Clinical Data Summary

The Company is currently conducting a multi-center, Phase 1 clinical trial of FT819, its off-the-shelf, CD19-targeted, 1XX CAR T-cell product candidate, for the treatment of patients with moderate-to-severe SLE, including lupus nephritis and extrarenal lupus (NCT06308978). The study is designed to evaluate the safety, pharmacokinetics, and activity of a single dose of FT819 administered to relapsed / refractory patients either (i) with a fludarabine (flu)-free conditioning regimen, consisting of either cyclophosphamide alone or bendamustine alone (Flu-free Conditioning Regimen) or (ii) in the absence of conditioning to patients on standard-of-care maintenance therapy (Conditioning-free Regimen). As of the data cut-off date of May 15, 2025, five patients have been treated with FT819 with sufficient follow-up to be evaluable, providing the following key insights:

Flu-free Conditioning Regimen

• Active Lupus Nephritis. Three relapsed / refractory patients with active lupus nephritis (median prior therapies = 8 [7-8], with all patients having received prior B-cell targeted therapy; median baseline SLEDAI-2K = 20 [14-20]) were treated with a single dose of FT819 at 360 million cells in the less-intensive Flu-free Conditioning Regimen. All three patients achieved primary efficacy renal response (PERR), with a 10-point or greater reduction in SLE disease activity index (SLEDAI-2K) from baseline (SLEDAI-2K best response; Patient 1: 20 to 4 at 12 months; Patient 2: 20 to 8 at 6.5 months; Patient 3: 14 to 4 at 1 month). The first patient to reach 12-month follow-up continues on-study in drug-free DORIS (definition of remission in SLE).
• Extrarenal Lupus. One relapsed / refractory patient with extrarenal lupus (prior therapies = 6, including cyclophosphamide; SLEDAI-2K = 18) was treated with a single dose of FT819 at 900 million cells in the less-intensive Flu-free Conditioning Regimen consisting of cyclophosphamide alone. The patient was evaluable for 1-month follow-up, demonstrating improvement across multiple disease-specific scores including an 8-point reduction in SLEDAI-2K from baseline and a 1-point reduction in PGA. The initial kinetics of improvement observed at 1-month following administration of FT819 appear to be generally consistent with those patients treated for active lupus nephritis.

Conditioning-free Regimen

• Add-on to Maintenance Therapy. One patient with extrarenal lupus (prior therapies = 5, including mycophenolate mofetil), who was on a stable dose of mycophenolate mofetil (1500mg twice daily) and 5 mg / day of steroids as maintenance therapy, was treated with a single dose of FT819 at 360 million cells in the Conditioning-free Regimen as an add-on to maintenance therapy. At 3-months following administration of FT819 in the absence of conditioning, the patient achieved low lupus disease activity state (LLDAS), which was maintained at the most recent follow-up at 6 months. The SLEDAI-2K reduced to 2 from 8 at baseline, Physician’s Global Assessment to 0.5 from 2 at baseline, and tapering of steroid dose to less than 5 mg / day.
  

B-cell Remodeling

Patients in the Flu-free Conditioning Regimen showed rapid and deep B-cell depletion in the periphery within the first month of treatment, with the repopulating B-cell compartment demonstrating a shift toward a non-switched, naïve repertoire with reduction of pathogenic double-negative B cell subset within the first 60 days following administration of FT819. The first patient in the Conditioning-free Regimen also showed a reduction of B cell population in the periphery, with remodeling of the B-cell compartment towards a non-switched, naïve repertoire also within the first 60 days following administration of FT819.

In 59 patients treated with FT819 across autoimmunity and oncology, a favorable safety profile continues to be observed with low incidence of low-grade cytokine release syndrome (CRS), no events of immune effector cell-associated neurotoxicity (ICANS), and no events of graft-versus-host disease (GvHD). Specifically, in the five evaluable patients treated with FT819 for SLE as of the data cut-off date:

• there have been no events of ICANS, no events of GvHD, and one event of low-grade cytokine release syndrome (Grade 2);
• no dose-limiting toxicities were observed in any patient; and
• with no FT819 related severe adverse events (SAEs) observed, all patients were discharged following an initial short-duration hospitalization stay of three days (as mandated per the clinical protocol), supporting the potential for outpatient administration
  

Program Expansion
The Company has reached agreement with the U.S. Food and Drug Administration (FDA) to allow for clinical investigation of multiple B cell-mediated autoimmune diseases under its current Phase 1 clinical trial of FT819, establishing the basis for conduct of a single Phase 1 basket study across autoimmune indications. The Company plans to initiate independent dose-expansion cohorts in each of anti-neutrophilic cytoplasmic antibody-associated vasculitis (AAV), idiopathic inflammatory myositis (IIM), and systemic sclerosis (SSc) in the second half of 2025. In addition, the Company plans to discuss novel registrational strategies with the FDA for FT819 to treat moderate-to-severe SLE under its Regenerative Medicine Advanced Therapy (RMAT) designation at its upcoming meeting in August. The Company currently has approximately 450 cryopreserved drug product bags of FT819 in inventory available for treatment of patients.

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 administered in combination 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 patient- and donor-sourced cell therapies. 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 pipeline of induced pluripotent stem cell (iPSC)-derived cellular immunotherapies to patients. 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 T-cell and natural killer (NK) 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, the initiation and continuation of enrollment in the Company’s clinical trials, the initiation of additional clinical trials, including in new indications, and additional dose cohorts in ongoing clinical trials of the Company’s product candidates, the availability of data from the Company’s clinical trials and the Company’s plans to provide updates on its clinical trials, the Company’s plans to work with the FDA on a registrational path for FT819 in SLE, the therapeutic and market potential of the Company’s research and development programs and product candidates, and the Company’s clinical and product development strategy. 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), and the risk that its product candidates may not produce therapeutic benefits or may cause other unanticipated adverse effects. 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

FAQ

What are the clinical results of Fate Therapeutics FT819 for lupus treatment?

FT819 showed positive results with all three lupus nephritis patients achieving Primary Efficacy Renal Response, and the first patient maintaining drug-free remission at 12 months. Additionally, extrarenal lupus patients showed significant disease improvement.

How safe is FATE's FT819 CAR T-cell therapy based on current data?

Across 59 patients, FT819 showed a favorable safety profile with low incidence of low-grade cytokine release syndrome, no immune effector cell-associated neurotoxicity, and no graft-versus-host disease.

What autoimmune conditions will Fate Therapeutics expand FT819 treatment to?

Fate plans to expand FT819 treatment to anti-neutrophilic cytoplasmic antibody-associated vasculitis, idiopathic inflammatory myositis, and systemic sclerosis in the second half of 2025.

How many patients have been treated with FATE's FT819 therapy?

Nearly 60 patients have been treated with FT819 across autoimmunity and oncology conditions, with 5 evaluable patients specifically for SLE treatment.

What advantages does FT819 offer compared to traditional treatments?

FT819 offers shortened hospitalization requirements, reduced or no conditioning chemotherapy, on-demand product availability, low cost of goods, and potential for outpatient administration in community settings.