SELLAS Announces Positive Phase 2 Preliminary Data of SLS009 in r/r AML Achieving a 100% Response Rate in Patients with ASXL1 Mutation At the Optimal Dose Level - Seite 2

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 (100%) r/r AML patients with ASXL1 truncating mutations at the selected dose level achieved an overall response (CR/CRi/MLFS) and are alive.
• 5/8 (63%) 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.

“The remarkable responses achieved in patients with the ASXL1 mutation underscores the transformative potential of SLS009 in addressing the unmet medical needs of AML but also targeting colorectal cancer, and other tumor types with this alteration,” said Angelos Stergiou, MD, ScD h.c., President and Chief Executive Officer of SELLAS. “This is evidenced by strong enthusiasm from the participating investigators reflected in robust enrollment from the clinical sites. These compelling results from the Phase 2a study further reinforce our belief that SLS009 represents a potential breakthrough for relapsed and/or refractory AML patients, and could pave the way for a potential accelerated approval in this defined patient population.”

SELLAS intends to initiate discussions with the U.S. Food and Drug Administration (FDA) about the potential for an accelerated approval pathway with SLS009 in the ASXL1 molecularly defined r/r AML population as well as in patients harboring this mutation in other indications.

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. In addition, the study aims to identify biomarkers for the target patient population and enrichment for further trials. For more information on the study, visit clinicaltrial.gov identifier NCT04588922.