Syros Pharmaceuticals announced that the enrollment of 190 patients has been completed in the SELECT-MDS-1 Phase 3 clinical trial evaluating tamibarotene in newly diagnosed higher-risk myelodysplastic syndrome (HR-MDS) patients with RARA gene overexpression. This initial cohort of 190 patients is necessary to support the complete response (CR) primary endpoint analysis. Syros expects to report these pivotal data by the middle of the fourth quarter of 2024.

The Phase 3 SELECT-MDS-1 clinical trial is a double-blind, placebo-controlled study evaluating tamibarotene In newly diagnosed HR-MDS patients with RARA overexpression randomized 2:1 to receive tamibarotene in combination with azacitidine or azacitidine alone. The primary endpoint is CR rate in the first 190 patients enrolled in the trial which, together with supporting durability data, can serve as the basis for accelerated approval or full approval; the key secondary endpoint in SELECT-MDS-1 is overall survival (OS) in a total of 550 patients. Syros is also evaluating tamibarotenein combination with venetoclax and azacitidine in the SELECT-AML-1 Phase 2 clinical trial in newly diagnosed acute myeloid leukemia patients with Rara gene overexpression.

Syros previously reported initial data from the study, observing a 100% CR/CRi (complete response/complete response with incomplete hematologic recovery) rate in response-evaluable patients treated with the triplet regimen of tamibarotene, venetoclax and azACitidine without increased toxicity, as compared to 70% among patients treated with venetoclax andazacitidine alone. Syros expects to report additional data from SELECT-AML-1 in 2024.