Sellas Life Sciences announces preliminary data from Phase 2a t rial of SLS009

SELLAS Life Sciences Group announces the preliminary data from Phase 2a trial of SLS009, a highly selective CDK9 inhibitor, in relapsed/refractory acute myeloid leukemia and successful filing of a provisional patent application around the ASXL1 mutation and SLS009, including all CDK9 inhibitor drugs. ASXL1 mutations are associated with poor prognosis in all myeloid diseases, owing to the reduced response to the current treatment options. Study highlights: As of April 19, 2024 data cutoff, a 57% overall response rate has been achieved thus far, in the selected optimal dose regimen of 30 mg BIW, far surpassing the targeted 20% rate. 4/4 r/r AML patients with ASXL1 truncating mutations at the selected dose level achieved an overall response and are alive. 5/8 of r/r AML patients, across all dose levels, with ASXL1 truncating mutations treated with SLS009 achieved an overall response. A review of the mutational status of the patient in the Phase 1 trial with SLS009 monotherapy, who achieved a CR lasting 8+ months, revealed that the patient also harbored an ASXL1 mutation. The ASXL1 mutation is found in both hematological malignancies as well as solid tumors. All patients in the study are diagnosed with AML refractory to or relapsed after venetoclax-containing regimens. Enrollment and treatment will be focused on the participants in the expansion cohort receiving 30 mg BIW dose and diagnosed with the ASXL1 mutation.