Fate Therapeutics, Inc. (NASDAQ: FATE), a clinical-stage biopharmaceutical company dedicated to the development of programmed cellular immunotherapies for cancer, today highlighted positive interim Phase 1 data from the Company’s FT516 program for patients with relapsed / refractory B-cell lymphoma at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting being held virtually June 4-8, 2021. FT516 is the Company’s universal, off-the-shelf natural killer (NK) cell product candidate derived from a clonal master induced pluripotent stem cell (iPSC) line engineered with a novel high-affinity, non-cleavable CD16 (hnCD16) Fc receptor, which is designed to maximize antibody-dependent cellular cytotoxicity (ADCC), a potent anti-tumor mechanism by which NK cells recognize, bind and kill antibody-coated cancer cells. The ongoing Phase 1 dose-escalation study of FT516 is currently enrolling patients in the fourth dose cohort of 900 million cells per dose.
As of the data cutoff date of March 11, 2021, four patients in the second dose cohort of 90 million cells per dose and seven patients in the third dose cohort of 300 million cells per dose were evaluable for assessment of safety and efficacy. Eight of eleven patients achieved an objective response, including six patients who achieved a complete response, as assessed by PET-CT scan per Lugano 2014 criteria (see Table 1). Patients had received a median of three prior lines of therapy and a median of two prior lines containing CD20-targeted therapy. Of the eleven patients, eight patients had aggressive B-cell lymphoma, five patients were refractory to their most recent prior therapy, and four patients were previously treated with autologous CD19 CAR-T cell therapy.
“These additional data from our Phase 1 study of FT516 administered off-the-shelf in the outpatient setting continue to reinforce its differentiated safety profile and underscore its potential clinical benefit,” said Wayne Chu, M.D., Senior Vice President of Clinical Development of Fate Therapeutics. “Based on the favorable therapeutic profile of FT516 that continues to emerge and the potential to treat patients on-demand without delay, we plan to initiate multiple indication-specific, dose-expansion cohorts for patients with B-cell lymphomas to broadly assess FT516 in combination with CD20-targeted monoclonal antibody regimens, including those used as standard-of-care in earlier-line settings.”
The ongoing Phase 1 clinical trial in relapsed / refractory B-cell lymphoma is assessing FT516 in an off-the-shelf treatment regimen of up to two cycles, with each cycle consisting of three days of conditioning chemotherapy (500 mg/m2of cyclophosphamide and 30 mg/m2 of fludarabine), a single-dose of rituximab (375 mg/m2), and three weekly doses of FT516 each with IL-2 cytokine support. The FT516 treatment regimen is designed to be administered in the outpatient setting.
No dose-limiting toxicities, and no FT516-related serious adverse events or FT516-related Grade 3 or greater adverse events, were observed. The FT516 treatment regimen was well tolerated, and no treatment-emergent adverse events (TEAEs) of any grade of cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, or graft-versus-host disease were reported by investigators (see Table 2). All Grade 3 or greater TEAEs were consistent with lympho-conditioning chemotherapy and underlying disease. Of note, a Grade 3 or greater TEAE of infection was reported in one patient only. There were no discontinuations due to adverse events, and no patients withdrew from the study except in the setting of disease progression. In addition, no evidence of anti-product T- or B-cell mediated host-versus-product alloreactivity was detected, supporting the potential to safely administer up to six doses of FT516 in the outpatient setting without the need for patient matching.
As of the data cutoff date of March 11, 2021, eleven relapsed / refractory patients in the second and third dose cohorts were evaluable for assessment of safety and efficacy. Of the eleven patients, nine patients completed both FT516 treatment cycles and eight patients achieved an objective response, including six patients who achieved a complete response, as assessed by PET-CT scan per Lugano 2014 criteria. Notably, two of four patients previously treated with autologous CD19 CAR-T cell therapy achieved a complete response. Two patients showed progressive disease following the first FT516 treatment cycle and discontinued treatment. The Company previously reported that two patients treated in the first dose cohort (30 million cells per dose) showed progressive disease.