SELLAS Life Sciences Group, a late-stage clinical biopharmaceutical company focused on the development of novel therapies for a broad range of cancer indications, has been granted Orphan Drug Designation (ODD) by the U.S. Food and Drug Administration (FDA) for SLS009, a novel and highly selective CDK9 inhibitor, for the treatment of acute myeloid leukemia (AML).
“We are honored to receive the ODD from the FDA. This designation underscores the potential of SLS009 to address a significant unmet medical need for patients with AML,” said Angelos Stergiou, MD, ScD h.c., President and Chief Executive Officer of SELLAS. “SLS009 is a novel and highly selective CDK9 inhibitor that has already shown a favorable safety profile, strong initial efficacy signals, and evidence of anti-tumor activity. With the support of this ODD, we look forward to accelerating SLS009 clinical development and bringing new hope to those suffering from this devastating disease.”
SLS009 is a highly selective CDK9 inhibitor, currently being evaluated in an open-label, single-arm, multi-center Phase 2a study in patients with relapsed or refractory AML. The primary objectives of the trial are to evaluate safety, tolerability, and efficacy at two dose levels of SLS009 (once weekly at 45 mg and at the recommended Phase 2 dose, 60 mg) in combination with azacitidine and venetoclax (aza/ven). Top-line data are expected by the end of this year.
The ODD designation was supported by data from the Phase 1 study of SLS009 which met all key study objectives: anti-tumor activity (cell killing) of up to 77.3% bone marrow blast reduction, durable complete remission (CR) with no minimal residual disease (MRD), desired 24 hours > IC90 peripheral blood concentrations after the first infusion, with IC90 concentrations resulting in up to 97% cancer cell killed, achievement of desired levels of MCL1 and MYC suppression in peripheral blood with decrease in MCL1 or MYC observed in 97% (66/68) of analyzed patients; and, with regard to safety, no dose limiting toxicities, no higher grade non-hematologic toxicities of any kind and some hematologic toxicities difficult to determine in patients with hematologic cancers but short in duration and reversible.
The FDA’s Office of Orphan Products Development grants ODD status to drugs and biologics intended for the safe and effective treatment, diagnosis or prevention of rare diseases or conditions affecting fewer than 200,000 people in the United States. ODD provides benefits to drug developers designed to support the development of drugs and biologics for small patient populations with unmet medical needs. These benefits include assistance in the drug development process, tax credits for qualified clinical costs, exemptions from certain FDA fees and seven years of marketing exclusivity.