SELLAS Life Sciences Group, Inc. announced that the European Commission, based on a positive opinion issued by the European Medicines Agency (EMA), has granted Orphan Drug Designation (ODD) for SLS009, a novel, and highly selective CDK9 inhibitor, for the treatment of acute myeloid leukemia (AML). Orphan drug designation in the European Union (EU) is granted by the European Commission based on a positive opinion issued by the European Medical Association (EMA) Committee for Orphan Medicinal Products. The EMA?s orphan designation is available to companies developing treatments for life-threatening or chronically debilitating conditions that affect fewer than five in 10,000 persons in the EU.

Medicines that meet the EMA?s orphan designation criteria qualify for financial and regulatory incentives that include a 10-year period of marketing exclusivity in the EU after product approval, protocol assistance from the EMA at reduced fees during the product development phase, and access to centralized marketing authorization. The treatment must also provide significant benefit to those affected by the condition. The Phase 2a clinical trial of SLS009 is an open-label, single-arm, multi-center study designed to evaluate the safety, tolerability, and efficacy of SLS009 in combination with aza/ven at two dose levels, 45 and 60 mg.

In the 60 mg dose cohort patients were randomized into either a 60 mg dose once per week or a 30 mg dose two times per week. The target response rate at the optimal dose level is 20% with a target median survival over 3 months. ASXL1 mutation has been identified as the most promising target mutation based on biology of the mutation and the SLS009 mechanism of action that has been confirmed by the clinical results to date.

The trial continues enrollment in two cohorts, both enrolling patients with myelodysplasia-related mutations, one with ASXL1 mutations and the other with myelodysplasia-related mutations other than ASXL1.