SELLAS Life Sciences Issues Update On Pivotal Phase 3 REGAL Trial Evaluating Galinpepimut-S (GPS) For Acute Myeloid Leukemia

SELLAS Life Sciences Group, Inc., a late-stage clinical biopharmaceutical company developing innovative therapies for a broad range of cancers, provided an update on its ongoing Phase 3 REGAL trial. This study is evaluating GPS as a potential maintenance therapy in patients with acute myeloid leukemia (AML) following their second complete remission (CR2).

In August 2025, the Independent Data Monitoring Committee recommended that the REGAL trial continue without any modifications. According to the trial’s statistical analysis plan, the final analysis of overall survival will be triggered once 80 events (deaths) have occurred. It was initially expected that this 80th event would occur before the end of 2025. 

As of December 26, 2025, SELLAS was informed by its contract research organization managing the trial that 72 events had been recorded. The company remains blinded to all efficacy and survival outcomes, and no analyses have been conducted; therefore, this one-time update does not impact future statistical analyses or the integrity of the trial. SELLAS will announce the occurrence of the 80th event when it happens.

Angelos Stergiou, President and Chief Executive Officer of SELLAS, stated that the company appreciates the dedication of patients, families, and investigators participating in the REGAL trial. He noted that survival times appear to be longer than initially expected, which could potentially increase the likelihood of a successful study. Stergiou emphasized that conclusive results will be available following the unblinding and analysis of the trial data and reaffirmed the company’s commitment to advancing therapies like GPS, which have the potential to improve outcomes for patients with AML.

Dr. Yair Levy, Director of Hematologic Malignancies Research at Texas Oncology Baylor University Medical Center and a member of the REGAL Steering Committee, highlighted the importance of the study. He explained that patients who are not candidates for transplant, as in this trial, typically receive treatments such as hypomethylating agents or BCL-2 inhibitors, with an expected median overall survival of about eight months. Dr. Levy expressed hope that GPS could provide an extended survival benefit while maintaining a tolerable safety profile, consistent with observations from previous GPS studies.