SELLAS Life Sciences shares fell after traders reduced risk ahead of two binary clinical milestones, including REGAL’s Phase 3 data readout for galinpepimut-S (GPS) maintenance in AML patients in second complete remission. The company remains blinded and has not publicly confirmed topline timing tied to the final 80th event. The same update points to SLS009 (tambiciclib) in newly diagnosed first-line AML, with ongoing enrollment and continued expectations for a Q4 topline readout. The article emphasizes the uncertainty created by public-event timing gaps rather than new clinical failure disclosures. For investors, the headline issue is schedule risk around blinded trials and the market’s sensitivity to when event-count thresholds are reached.