SELLAS Life Sciences Group, Inc. provided an update on its Phase 3 open-label registrational clinical trial (the REGAL study) for galinpepimut-S (GPS) in patients with acute myeloid leukemia (AML) who have achieved complete remission following second-line salvage therapy (CR2 patients). The Company expects to complete enrollment in the REGAL study, other than the 20-25 patients anticipated to be enrolled in China, in November 2023. The number of patients needed for the pre-specified interim and final analyses have already been enrolled.

The interim analysis (after 60 events) is on track 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. The Company anticipates that 3D Medicines Inc. (3D Medicines), its commercialization partner for GPS in Greater China, will begin enrolling patients in China in the REGAL study in the fourth quarter of 2023 which will trigger two development milestone payments totaling $13.0 million.

The Company and 3D Medicines had previously projected that enrollment in China would commence in the third quarter of 2023, however, unforeseen supply-chain delays in China impacted the projected timeline. 3D Medicines has successfully obtained all regulatory permits, recruited investigators, and set up an expansive network of 11 treatment centers across China for participation in the REGAL study. The next meeting of the Independent Data Monitoring Committee for the REGAL study is scheduled for the end of November 2023.