SELLAS Life Sciences Group, Inc. announced that the target patient enrollment outside of mainland China in the ongoing Phase 3 REGAL trial of galinpepimut-S (GPS) in patients with acute myeloid leukemia (AML) who have achieved complete remission following second-line salvage therapy has been reached. The Phase 3 open-label REGAL trial was designed with formal input from the United States Food and Drug Administration. Over 100 patients have been enrolled in the United States, Europe and Asia in the study which compares GPS monotherapy in the maintenance setting to investigators?

choice of best available treatment in AML patients who have achieved hematologic complete remission, with or without thrombocytopenia (CR2/CR2p), after second-line antileukemic therapy and who are deemed ineligible for or unable to undergo allogeneic stem-cell transplantation. The primary endpoint is overall survival (OS) from the time of study entry. Secondary endpoints include leukemia-free survival, antigen-specific T-cell immune response dynamics, measurable residual disease by multigene array, and assessments of AML clonal evolution and inflammasome molecular signatures in the tumor microenvironment in bone marrow biopsy samples.

Based upon the Company?s statistical assumptions, the interim analysis (after 60 events) is expected to occur in late 2023 or early 2024 and the final analysis (after 80 events) is on track to occur by the end of 2024. Because these analyses are event driven, they may occur at a different time than currently expected.