Efficacy, safety, and immune priming effect of tazemetostat in patients with epithelioid sarcoma.
Abstract No : 11564
Abstract Type : Poster session
Indication : Epithelioid sarcoma
Intervention : Tazemetostat
Company : Epizyme
Technology : Small molecule
As of July 31 2019, 44 pts were enrolled into Cohort 6 and treated with TAZ 800 mg BID. The objective response rate (ORR) was 11.4%; 4 pts (9.1%) had a partial response and 1 pt (2.3%) had a complete response (Table). Another 17 pts (38.6%) had stable disease (SD). 18 pts had progressive disease; 13 of these pts remained on study beyond progression. Progression-free survival (PFS) and overall survival (OS) at 56 weeks were 19.4% and 59.4%, respectively. In a pooled posthoc analysis of 106 ES pts from Cohorts 5 (n = 62), and 6, ORR was 13.2%. Grade 34 adverse events (AEs) were reported in 16 pts (36.4%), most commonly anemia (6.8%; n = 3) and tumor pain (6.8%; n = 3). 3 pts (6.8%) experienced grade 34 treatment-related AEs. One pt discontinued study drug and there were no treatment-emergent dose reductions or treatment-related deaths. These safety data from Cohort 6 are consistent with previously reported data from Cohort 5. 19 paired biopsies were included for translational endpoint analyses. Preliminary RNA seq and pathway analyses are currently ongoing and updated data, including additional biomarker data will be presented.
Consistent with previously reported data from the completed Cohort 5, TAZ demonstrated clinically meaningful, durable, single agent activity in ES pts. Efficacy data from Cohort 6 continue to mature with 8 patients still on treatment. TAZ was well tolerated with a low incidence of treatment related AEs.
Consistent with previously reported data from the completed Cohort 5, Tazemetostat demonstrated clinically meaningful, durable, single agent activity in Epithelioid Sarcoma patients. Efficacy data from Cohort 6 continue to mature with 8 patients still on treatment. An additional 25 patients will be added to this cohort and primary end point will be changed to ORR for post marketing surveillance.