SELLAS Life Sciences Stock Is Surging Higher: What's Going On?

SELLAS Life Sciences Group Inc (NASDAQ:SLS) shares are trading higher on Monday after initially dropping in premarket trading, reversing course as investors seem to react to new trial‑related updates. Here's what you should know.

What To Know: The company shared a new update on its Phase 3 REGAL trial, which is testing GPS as a potential maintenance therapy for patients with acute myeloid leukemia who have achieved a second complete remission.

SELLAS said its contract research organization overseeing the REGAL study reported that 72 events had occurred as of Dec. 26, 2025. Since the trial measures overall survival, the final analysis is set to begin once 80 events, or deaths, have taken place, according to the study's statistical plan.

Back in August 2025, the Independent Data Monitoring Committee recommended that the trial continue as planned with no changes. At that time, SELLAS expected the 80th event, being the trigger for the final analysis, to occur before the end of the year.

“We appreciate the continued dedication of the patients, families, and investigators participating in the pivotal Phase 3 REGAL trial where survival times, fortunately for patients and caregivers, appear longer than expected,” said Angelos Stergiou, president and CEO of SELLAS. “While the 80th event has not yet occurred, and we remain fully blinded, every passing month may increase the probability of a successful study as highlighted by key opinion leaders in our recent R&D event.”

“We hope to see an extended survival benefit, with a tolerable safety profile, as observed in previous GPS studies,” said Dr. Yair Levy, director of Hematologic Malignancies Research at Texas Oncology Baylor University Medical Center and a member of the REGAL Steering Committee.

SLS Price Action: SELLAS Life Sciences shares were up 16.72% at $3.35 at the time of publication on Monday. The stock is trading at a new 52-week high, according to Benzinga Pro.

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