Shares of SELLAS Life Sciences surged in after-hours trading on Tuesday following the company's announcement that its pivotal Phase 3 REGAL trial in acute myeloid leukemia (AML) has now recorded 78 out of the 80 patient deaths required for the final survival analysis. The stock jumped 16.76% to $6.095 in extended trading after closing regular trading at $5.22, down 0.57% on the day.
The REGAL trial is evaluating galinpepimut-S (GPS), a cancer vaccine, in AML patients who have achieved remission after second-line salvage therapy. The 80th event will trigger a database lock, followed by a blinded review, statistical analysis, and unblinding before the company reports topline results. SELLAS emphasized that it has not yet seen any trial outcomes.
Financially, SELLAS reported a first-quarter net loss of $8.4 million, or 5 cents per share, compared to a net loss of $5.8 million, or 7 cents per share, in the same period last year. The narrower per-share loss was due to a sharp increase in the weighted average share count, which nearly doubled to 172.5 million. Research and development expenses rose to $5.1 million from $3.2 million, driven by higher manufacturing, clinical, and regulatory costs as the company prepares for a potential biologics license application if REGAL yields positive results.
As of March 31, SELLAS held $107.1 million in cash and cash equivalents, with an additional $7.5 million raised from warrant exercises after the quarter ended. Management expects this cash to fund operations for at least 12 months. CEO Angelos Stergiou described the quarter as an “important period,” highlighting the upcoming REGAL readout as a key milestone.
In addition to REGAL, SELLAS is developing SLS009 (tambiciclib) in an 80-patient Phase 2 trial for newly diagnosed first-line AML. This mid-stage study aims to assess safety and early efficacy, with topline results expected in the fourth quarter of 2026. The program positions SELLAS close to the azacitidine plus venetoclax (AZA/VEN) segment. Venetoclax, marketed as Venclexta by AbbVie and Roche, is approved for use with azacitidine, decitabine, or low-dose cytarabine in certain newly diagnosed AML patients who are older or ineligible for intensive chemotherapy.
Despite the positive trial update, the outcome remains binary. In its latest quarterly filing, SELLAS flagged uncertainty in its financing outlook and noted that additional fundraising could dilute existing shareholders. If needed capital is not obtained in time, research programs may be delayed, scaled back, or discontinued. The company is also locked in arbitration with 3D Medicines over GPS milestone payments and development obligations in Greater China, with a hearing held in Hong Kong in January and a final decision pending.
For now, the market is focused on the 80th event in the REGAL trial. The immediate questions are whether the data review will be favorable and whether the survival readout will provide the leverage SELLAS needs to pursue a regulatory submission for GPS. Until the results are unblinded, traders are positioning based on expectation rather than outcome.
