SELLAS Life Sciences (SLS) Surges 8.3% on Positive Phase 2 Trial Data and FDA Support

SELLAS Life Sciences (SLS) surged to its highest level so far this month on Dec. 27, rallying 8.30% intraday as a five-day winning streak pushed its shares up 34.60%. The biotech stock has regained ground after a period of volatility, fueled by recent clinical and regulatory progress in its leukemia program.

The rally followed positive data from Phase 2 trials of its CDK9 inhibitor, SLS009, which showed a 46% response rate in treating relapsed or refractory acute myeloid leukemia.

The therapy’s favorable safety profile and combination with existing drugs like azacitidine and venetoclax have drawn investor attention. Regulatory support from the FDA, though unspecified in detail, has further reinforced optimism about accelerated development timelines. These developments have positioned SELLAS as a focal point for oncology-focused capital amid a broader sector rally.

Despite a robust financial position—including a low debt-to-equity ratio and $43 million in working capital—the stock trades at a price-to-book ratio of 8.9x, far exceeding the biotech industry average. Analysts note that the valuation reflects aggressive expectations for SLS009’s commercial potential, though risks remain tied to Phase 3 trial execution and regulatory outcomes. Investors are advised to monitor upcoming trial milestones and partnership developments to gauge whether the current re-rating can be sustained.