SELLAS Life Sciences Group Inc. (Nasdaq: SLS) has started the final analysis of its Phase 3 REGAL trial after the study reached its prespecified 80th event, defined as a patient death.
The October 28, 2026, announcement represents an important procedural milestone for the event-driven trial of galinpepimut-S, or GPS, in acute myeloid leukemia. It does not reveal whether the investigational therapy improved survival.
Reaching the required number of events allows SELLAS to begin locking the clinical database, unblinding the treatment assignments and conducting the primary statistical analysis. The company expects to report preliminary topline results during the fourth quarter of 2026.
“Reaching the 80th event represents a critical milestone in the REGAL trial,” President and CEO Angelos Stergiou said.
REGAL is a randomized, open-label study evaluating GPS as maintenance therapy for patients with AML who have achieved a second complete remission following additional antileukemic treatment. Participants received either GPS or the investigator’s choice of best available treatment.
The trial’s primary endpoint is overall survival. Secondary measures include leukemia-free survival, safety and other clinical outcomes. Enrollment was completed in March 2024, and the study was designed to include approximately 125 to 140 patients across about 95 clinical sites in North America, Europe and Asia.
GPS is a peptide-based cancer immunotherapy targeting Wilms Tumor-1, a protein found at elevated levels in many leukemias and other cancers. SELLAS licensed the technology from Memorial Sloan Kettering Cancer Center.
The trial reached an interim milestone of 60 deaths in December 2024. After reviewing the unblinded study data, an independent monitoring committee recommended in January 2025 that REGAL continue without modifications. That recommendation addressed whether the trial should proceed and did not establish that GPS was effective.
The upcoming analysis will determine whether the overall-survival results meet the study’s statistical requirements. If the trial is positive, SELLAS could use the results to support discussions with the U.S. Food and Drug Administration about a potential Biologics License Application. A positive regulatory outcome is not assured.
SELLAS reported $138.3 million in cash and cash equivalents as of June 30, 2026. Its second-quarter net loss increased to $9.6 million from $6.6 million one year earlier, while operating cash use totaled $16.4 million during the first six months of 2026. The company expects continued operating losses as it advances GPS and its separate SLS009 program.
Upcoming Catalysts
- Completion of the REGAL database lock and statistical analysis
- Preliminary topline overall-survival results expected in the fourth quarter
- Subsequent leukemia-free survival and safety findings
- Potential FDA discussions if REGAL meets its primary endpoint
- Further regulatory and commercial planning for GPS
- Separate SLS009 clinical data expected during the fourth quarter
Sources
- SELLAS reaches the 80th event in the Phase 3 REGAL trial — October 28, 2026
- REGAL trial record, NCT04229979 — ClinicalTrials.gov
- SELLAS Form 10-Q for the quarter ended June 30, 2026
- SELLAS second-quarter 2026 financial and corporate update
Editorial Disclosure
This article is based entirely on publicly available information, including company announcements, SEC filings and the federal clinical-trial registry. Securities discussed or referenced include SELLAS Life Sciences Group Inc. (Nasdaq: SLS). Biotech Stocks Daily has not received compensation from SELLAS, its management, investor relations representatives or any third party for this specific article. Biotech Stocks Daily may have current or past paid business relationships with other companies, which do not influence the content or conclusions of this article. No staff member or principal of Biotech Stocks Daily holds a position in any security mentioned at the time of publication.
Sources include SELLAS’ October 28, 2026 REGAL announcement, its Form 10-Q for the quarter ended June 30, 2026, its August 11 financial update and the ClinicalTrials.gov study record. Information about GPS, its mechanism and its potential regulatory pathway originated primarily from SELLAS and has not been independently validated by Biotech Stocks Daily.
GPS remains investigational and has not been approved by the FDA or any other regulatory authority. Reaching the 80th event is a trial-administration milestone and is not evidence that the study succeeded. REGAL remains subject to data-quality, statistical, clinical and regulatory risks. The monitoring committee’s earlier recommendation to continue the trial did not establish safety or efficacy. There is no assurance that the results will meet the primary endpoint or support a regulatory submission or approval.
Financial information reflects SELLAS’ position as of June 30, 2026 and may have changed. The company remains dependent on external financing and expects continued operating losses. Equity offerings, warrant exercises or other financing transactions may dilute existing shareholders.
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