SELLAS Life Sciences (NASDAQ:SLS) surges 18.79% on renewed investor optimism from clinical updates and strategic developments.

SELLAS Life Sciences (NASDAQ:SLS) surged 18.7861% in pre-market trading on January 13, 2026, driven by renewed investor optimism amid recent clinical updates and strategic developments. The sharp rebound follows a volatile week marked by mixed signals from the company’s pipeline and partnerships.

On January 12, the stock had plunged 10.36% after the suspension of a late-stage immuno-oncology trial due to suboptimal interim data. This led to concerns over the drug’s commercial viability and regulatory hurdles. Revised partnership terms with a key biotech firm also reduced future milestone payments, raising questions about SELLAS’ ability to fund R&D without external capital. A delayed FDA advisory panel meeting for a companion diagnostic further exacerbated uncertainty.

The pre-market rally suggests investors are recalibrating expectations as the company navigates its revised strategy. Recent updates, including positive preclinical data for SLS009 in AML and increased options volume, indicate lingering retail and institutional interest. However, the path to value restoration remains contingent on successful trial outcomes and partnership stability.

With limited short-term catalysts, SELLAS’ stock continues to reflect heightened risk premiums. Investors are closely monitoring regulatory timelines and clinical progress to gauge the company’s long-term prospects in the competitive oncology space.