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. |
