Syros Pharmaceuticals announced that the United States Food and Drug Administration (FDA) has granted Fast Track Designation to tamibarotene in combination with azacitidine and venetoclax for the treatment of newly diagnosed acute myeloid leukemia (AML) with RARA overexpression as detected by an FDA approved test in adults who are over age 75 years or who have comorbidities that preclude the use of intensive induction chemotherapy. Tamibarotene, an oral first-in-class selective retinoic acid receptor alpha (RARa) agonist, is currently being evaluated in combination with venetoclax and azacitidine for the treatment of newly diagnosed AML patients with RARA gene overexpression. Fast Track is a process designed by the FDA to facilitate the development and expedite the review of drug candidates intended to treat serious conditions and for which nonclinical or clinical data demonstrate the potential to address unmet medical need.

The purpose is to facilitate development and expedite review of drugs to treat serious and life-threatening conditions, to bring the approved products to patients earlier. A therapeutic candidate that receives Fast Track designation may be eligible for more frequent interactions with the FDA to discuss the therapeutic candidate?s development plan. Therapeutic candidates with Fast Track designation may also be eligible for priority review and accelerated approval if supported by clinical data.

Syros is evaluating tamibarotene in combination with venetoclax and azacitidine in newly diagnosed, unfit AML patients with RARA overexpression in the ongoing SELECT-AML-1 Phase 2 trial. In December 2023, Syros announced initial randomized data from SELECT-AML-1, demonstrating a 100% CR/CRi (complete response/complete response with incomplete hematologic recovery) rate in response-evaluable patients (nine of nine) treated with the triplet regimen of tamibarotene, venetoclax and azacitidine, as compared to 70% among patients (seven of ten) treated with venetoclax and azacitidine alone, with corresponding CR rates of 78% vs 30%, respectively. The median time to CR/CRi response was rapid; all patients treated with the triplet regimen achieved a CR/CRi by the end of cycle one.

Consistent with prior clinical experience, tamibarotene in combination with approved doses of venetoclax and azacitidine was generally well tolerated, and the overall safety profile demonstrated no additive toxicities or new safety signals, and no evidence of increased myelosuppression compared to treatment with the doublet combination of venetoclax and azacitidine. Syros expects to report additional data from SELECT-AML-1 in 2024. Syros is also evaluating tamibarotene in combination with azacitidine in newly diagnosed higher-risk myelodysplastic syndrome (MDS) patients with RARA overexpression in the SELECT-MDS-1 Phase 3 trial.

As recently announced, enrollment to support the pivotal primary efficacy analysis was completed in the first quarter of 2024, and pivotal complete response data is expected by the middle of the fourth quarter of 2024. In January 2023, the FDA granted Fast Track Designation to tamibarotene for the treatment of HR-MDS patients with RARA overexpression.