Fate Therapeutics, Inc. (NASDAQ:FATE), a clinical-stage biopharmaceutical company dedicated to the development of programmed cellular immunotherapies for cancer, today showcased positive interim Phase 1 data from the
Fate Therapeutics, Inc. (NASDAQ:FATE), a clinical-stage biopharmaceutical company dedicated to the development of programmed cellular immunotherapies for cancer, today showcased positive interim Phase 1 data from the Company's FT596 program for patients with relapsed / refractory B-cell lymphoma (BCL) at the 63rd American Society of Hematology (ASH) Annual Meeting and Exposition. FT596 is the Company's off-the-shelf, multi-antigen targeted, iPSC-derived natural killer (NK) cell product candidate derived from a clonal master induced pluripotent stem cell (iPSC) line engineered with three anti-tumor functional modalities: a proprietary chimeric antigen receptor (CAR) optimized for NK cell biology that targets B-cell antigen CD19; a novel high-affinity, non-cleavable CD16 (hnCD16) Fc receptor that has been modified to prevent its down-regulation and to enhance its binding to tumor-targeting antibodies; and an IL-15 receptor fusion (IL-15RF) that augments NK cell activity.
"The interim dose-escalation clinical data from our FT596 program in relapsed / refractory B-cell lymphoma demonstrate that off-the-shelf, iPSC-derived CAR NK cells can bring substantial therapeutic benefit to heavily pre-treated patients in urgent need of therapy, with high response rates and meaningful duration of responses," said Scott Wolchko, President and Chief Executive Officer of Fate Therapeutics. "We are particularly pleased with the therapeutic profile that has emerged with FT596 in combination with rituximab, where over half of the patients treated with a single dose of FT596 at higher dose levels achieved a complete response with a favorable safety profile that is clearly differentiated from CAR T-cell therapy. We look forward to assessing a two-dose treatment schedule for FT596 to further define its potential best-in-class therapeutic profile and ability to reach more patients, including those earlier in care."
The ongoing Phase 1 study in relapsed / refractory BCL is assessing a single dose of FT596 as monotherapy (Monotherapy Arm) and in combination with a single dose of rituximab (375 mg/m2) (Combination Arm) following three days of conditioning chemotherapy (500 mg/m2 of cyclophosphamide and 30 mg/m2 of fludarabine). Certain patients are eligible for re-treatment with a second, single-dose cycle.
The ASH presentation (Session 704—Cellular Immunotherapies: Expanding Targets and Cellular Sources for Immunotherapies, Abstract 823) includes clinical data from 25 evaluable patients for safety (n=12 in Monotherapy Arm; n=13 in Combination Arm) in the first, second, and third single-dose cohorts of 30 million, 90 million, and 300 million cells, respectively, of which 24 patients were also evaluable for efficacy (n=12 in Monotherapy Arm; n=12 in Combination Arm), as of the data cutoff date of October 11, 2021. These 25 patients had received a median of four prior lines of therapy and a median of two prior lines containing CD20-targeted therapy. Of the 25 patients, 15 patients (60%) had aggressive B-cell lymphoma, 15 patients (60%) were refractory to most recent prior therapy, and 8 patients (32%) were previously treated with autologous CD19-targeted CAR T-cell therapy. Subsequent to the data cutoff date for the ASH presentation, an additional patient in the third single-dose cohort of the Combination Arm was evaluable for initial anti-tumor response, and seven patients in the fourth single-dose cohort of 900 million cells (n=1 in Monotherapy Arm; n=6 in Combination Arm) were evaluable for safety and initial anti-tumor response.
Single-dose, Single-cycle Response Data
In the second, third, and fourth dose cohorts of the Monotherapy and Combination Arms comprising a total of 26 patients, 18 patients (69%) achieved an objective response, including 12 patients (46%) that achieved a complete response, on Day 29 following a single dose of FT596 (see Table 1). Nine of these 26 patients were previously treated with autologous CD19-targeted CAR T-cell therapy and, of these nine patients, six achieved an objective response (67%) on Day 29 following a single dose of FT596. Notably, in the third and fourth dose cohorts of the Combination Arm comprising a total of 12 patients, nine patients (75%) achieved an objective response, including seven patients (58%) that achieved a complete response, on Day 29 following a single dose of FT596.
Durability of Response Data
The ASH presentation includes durability of response data from 13 responding patients in the second and third single-dose cohorts of 90 million cells and 300 million cells (n=9 in Monotherapy Arm; n=10 in Combination Arm). As of the data cutoff date of October 11, 2021, 10 patients continued in ongoing response, including three patients in ongoing complete response at least six months from initiation of treatment; two patients reached six months in complete response and subsequently had disease progression; and one patient had disease progression prior to six months. Of these 13 responding patients:
- Monotherapy Arm (n=7 responding patients). Five patients, all of whom were treated with a second FT596 single-dose cycle with the consent of the U.S. Food and Drug Administration (FDA), continued in ongoing response at a median follow-up of 4.1 months, including one patient in ongoing complete response at 8.1 months; one patient, who was treated with only one FT596 single-dose cycle, reached six months in complete response and subsequently had disease progression at 6.5 months; and one patient, who was treated with only one FT596 single-dose cycle, had disease progression at 1.7 months.
- Combination Arm (n=6 responding patients). Five patients, all of whom were treated with a second FT596 single-dose cycle with the consent of the FDA, continued in ongoing response at a median follow-up of 4.6 months, including two patients in ongoing complete response at 6.0 and 10.8 months; and one patient, who was treated with a second FT596 single-dose cycle with the consent of the FDA, reached six months in complete response and subsequently had disease progression at 6.7 months.
|Table 1. FT596 Interim Phase 1 Data – Day 29 Response Assessment 1|
|1 Dose x 1 Cycle||Monotherapy
|Single-dose Level Cohorts (Cells)||OR||CR||OR||CR|
|30M||1/3 (33%)||0||0/3 (0%)||0|
|90M||3/4 (75%)||2||2/4 (50%)||2|
|300M 2||4/5 (80%)||1||4/6 (67%)||3|
|900M 2||0/1 (0%)||0||5/6 (83%)||4|
|aCD19 History (≥90M Cells)||n=10||n=16|
|Naïve||7/9 (78%)||3||5/8 (63%)||4|
|Prior||0/1 (0%)||0||6/8 (75%)||5|
|Disease Histology (≥90M Cells)||n=10||n=16|
|Aggressive||1/3 (33%)||0||6/11 (55%)||4|
|Mantle cell||0/1 (0%)||0||2/2 (100%)||2|
|Indolent||6/6 (100%)||3||3/3 (100%)||3|
aCD19 = autologous CD19-targeted CAR T-cell therapy; Aggressive = diffuse large B-cell lymphoma, Grade 3b follicular lymphoma, Richter's transformation, and high-grade B-cell lymphoma; CR = complete response; Indolent = splenic diffuse red pulp small B-cell lymphoma, non-Grade 3b follicular lymphoma, Waldenstrom's macroglobulinemia, and small lymphocytic lymphoma; M = million; OR = objective response
1 As of data cutoff date of October 11, 2021, unless otherwise noted. Objective response and complete response are based on Cycle 1 Day 29 protocol-defined response assessment per Lugano 2014 criteria. Data subject to source document verification.
2 Cycle 1 Day 29 protocol-defined response assessment completed subsequent to data cutoff date for one patient in the third single-dose cohort of 300 million cells in the Combination Arm and seven patients in the fourth single-dose cohort of 900 million cells (n=1 in Monotherapy Arm; n=6 in Combination Arm).
The FT596 treatment regimens were well tolerated, including in those patients treated with a second, single-dose cycle. No dose-limiting toxicities, and no treatment-emergent adverse events (TEAEs) of any grade of immune effector cell-associated neurotoxicity syndrome (ICANS) or graft-versus-host disease (GvHD) were observed. Three low-grade adverse events (two Grade 1, one Grade 2) of cytokine release syndrome (CRS) were reported, which were of limited duration and resolved without intensive care treatment (see Table 2).
The Company has initiated enrollment of a two-dose treatment schedule in the Combination Arm, with FT596 administered on Day 1 and Day 15 at 900 million cells per dose. Patients with clinical benefit following administration of the first two-dose cycle are eligible for re-treatment with a second two-dose cycle. Additionally, patients with clinical response are eligible for re-treatment following disease progression.
|Table 2. FT596 Interim Phase 1 Data – TEAEs of Interest|
|All Grade||Grade 3+||All Grade||Grade 3+|
|CRS||1 (8%)||—||2 (11%)||—|
|Infections||6 (46%)||3 (23%)||6 (32%)||3 (16%)|
|FT596-related SAEs||—||—||1 (5%) a||—|
CRS = Cytokine Release Syndrome; GvHD = Graft vs. Host Disease; ICANS = Immune Cell-Associated Neurotoxicity Syndrome; TEAE = Treatment-Emergent Adverse Event; SAE = Severe Adverse Events
a Grade 2 CRS