Shares of SELLAS Life Sciences (SLS) skyrocketed 20.4% during after-hours trading Tuesday following the biotechnology company’s announcement of first quarter financial results that exceeded Wall Street projections and a crucial update indicating its Phase 3 oncology study is approaching a pivotal data milestone.
SELLAS Life Sciences Group, Inc., SLS
Market data showed the stock maintained approximately 15% gains during the subsequent regular trading session.
In the first quarter of 2026, SELLAS delivered an adjusted loss of $0.05 per share, outperforming the Street consensus estimate of $0.07. The earnings surprise provided sufficient momentum to capture investor enthusiasm.
The company’s net loss expanded to $8.4 million for the quarter, compared with $5.8 million during the corresponding period in 2025.
Research and development costs increased substantially to $5.1 million from $3.2 million on a year-over-year basis. Management explained the uptick resulted from manufacturing activities and clinical study costs associated with preparing for a potential Biologics License Application submission.
General and administrative costs similarly rose, reaching $4.1 million versus $2.9 million in the year-ago quarter.
Perhaps more significant than the earnings beat is the advancement of the REGAL trial. The pivotal Phase 3 investigation evaluating Galinpepimut-S in patients with acute myeloid leukemia has now documented 78 events as of May 11, 2026. The protocol stipulates that 80 events must occur before the final statistical analysis can commence.
SELLAS continues operating under blinded conditions, indicating management has no visibility into the actual trial outcomes at this stage.
Beyond the REGAL program, SELLAS is making headway with its second therapeutic candidate, SLS009. Preclinical data unveiled at the American Association for Cancer Research conference demonstrated anti-leukemic activity in AML models by inhibiting critical survival signaling pathways, including effectiveness in challenging genetic profiles such as TP53 and ASXL1 mutations.
The company has also initiated patient enrollment in a Phase 2 clinical study evaluating SLS009 in treatment-naïve, first-line AML cases. This trial focuses on patient populations with limited likelihood of responding to conventional treatment options, including venetoclax-based regimens.
The financial runway appears robust as these catalysts approach. SELLAS disclosed $107.1 million in cash and cash equivalents on its balance sheet as of March 31, 2026.
An additional $7.5 million was generated during the second quarter through the exercise of outstanding warrants.
Furthermore, the company maintains an at-the-market equity distribution agreement with TD Cowen, providing the ability to raise up to $150 million in additional capital. To date, no shares have been issued under this facility.
With the REGAL trial requiring only two additional events to initiate the final efficacy analysis, the upcoming corporate communication from SELLAS represents the key catalyst that market participants are closely monitoring.
The post SELLAS Life Sciences (SLS) Stock Surges 20% on Earnings Beat and Pivotal Trial Milestone appeared first on Blockonomi.

