Why Is SELLAS LIFE SCIENCES (SLS) Stock Down Today?

Sellas Life Sciences shares fell 19.04% to close at $9.85. The primary driver was the announcement that the company reached the pre-specified 80th event in its pivotal Phase 3 REGAL trial for galinpepimut-S in acute myeloid leukemia. This milestone triggers the final analysis of the trial, with topline primary endpoint results expected to be reported this quarter.

What Happened

Sellas Life Sciences disclosed that its Phase 3 REGAL study of galinpepimut-S in acute myeloid leukemia participants surpassed the pre-specified 80th event. Reaching this threshold initiates the final analysis of the pivotal trial. The company stated it will report topline primary endpoint results during the current quarter. The news followed a period of significant price appreciation, with the stock gaining 15.7% over the previous eight sessions.

What The Data Shows

The stock opened at $12.18 and hit a session high of $12.97 at 8:50 AM ET before sliding to a session low of $9.81 at 9:50 AM ET. Trading volume stood at 4.7 million shares, which is 0.6 times the three-month daily average. Sellas Life Sciences has a market capitalization of $2.3 billion and remains unprofitable, with a trailing twelve-month earnings per share of negative $0.21. The stock carries a beta of 2.57 and trades within a 52-week range of $1.39 to $15.88. On October 28, 2026, the stock printed one fresh 52-week high and 13 fresh 52-week lows. Retail traders on r/pennystocks are discussing the stock's volatility, with one user asking if another ticker is the next SLS.

What To Watch

Investors will monitor the upcoming release of topline primary endpoint results from the REGAL trial, which the company expects to report this quarter.