Syros Presents New Data From Phase 2 Clinical Trial of SY-1425 and Announces Plans to Initiate Registration-Enabling Trial in MDS and Randomized Phase 2 Trial in AML - Seite 3

Data in Relapsed or Refractory AML
As of October 1^st, 28 RARA-positive R/R AML patients were eligible for safety analysis and 21 were evaluable for clinical response. In those patients, the data showed:

• ORR was 19% (4/21), consisting of one CRc, two CRi and one MLFS.
  • In HMA and venetoclax naïve patients, the ORR was 43% (3/7 patients).
• Median OS was 5.9 months.
• 30% (6/20) achieved or maintained transfusion independence, including 27% (3/11) of patients who were transfusion dependent at baseline.
• SY-1425 in combination with azacitidine was also generally well-tolerated in this patient population.

Advancing SY-1425 in Newly Diagnosed HR-MDS and Unfit AML
Based on the encouraging clinical activity and favorable safety and tolerability profile of SY-1425 in combination with azacitidine as well as an assessment of ongoing areas of high unmet need within the evolving treatment landscape, Syros plans to advance SY-1425 in combination with azacitidine into a registration-enabling Phase 3 trial in RARA-positive newly diagnosed higher-risk myelodysplastic syndrome (HR-MDS) patients. HR-MDS is a hematologic malignancy that is closely related to AML, and as in AML, about 30 percent of HR-MDS patients are RARA-positive.

Based on feedback from the U.S. Food and Drug Administration, Syros plans to enroll approximately 190 RARA-positive newly diagnosed HR-MDS patients in the double-blind placebo-controlled trial, randomized 2:1 to receive SY-1425 in combination with azacitidine or placebo with azacitidine, respectively. The primary endpoint of the trial will be the CR rate, which, depending on the data outcome, could support accelerated or full approval in this patient population. Syros expects to initiate the Phase 3 trial in the first quarter of 2021.

In addition, Syros plans to advance SY-1425 in combination with venetoclax and azacitidine in RARA-positive newly diagnosed unfit AML patients. The trial is designed with a single-arm safety lead-in to confirm the dosing regimen of the triplet to be used in the randomized portion of the Phase 2 trial, which will evaluate the safety and efficacy of SY-1425 in combination with venetoclax and azacitidine compared to venetoclax and azacitidine in approximately 80 patients randomized 1:1. The trial will also evaluate the triplet as a salvage therapy in patients who don’t respond to venetoclax and azacitidine. Syros expects to initiate the Phase 2 trial in the second half of 2021.