A prediction market focused on clinical trial outcomes is giving an 83 percent probability that Sellas Life Sciences’ experimental leukemia therapy will succeed in a pivotal Phase 3 study, with results expected by the end of November. The forecast comes as the company’s stock experienced its worst single-day drop in over a month, falling 10 percent to close at $13.27, though shares were poised to end the week higher.
The market, run by the platform Endpoint Area, is tracking the Regal trial of galinpepimut-S (GPS), an immunotherapy designed as maintenance treatment for patients with acute myeloid leukemia (AML) who are in remission. The market asks whether GPS will show a positive overall survival benefit compared with best available therapy. Prices on the platform reflect an 83 percent chance of success, with “YES” shares trading at $0.83 and “NO” shares at $0.17. The expected catalyst date is listed as Nov. 30.
The trial has reached 78 of the 80 events needed for final analysis. Sellas has said the study would be considered successful if GPS extends median overall survival to 12.6 months, compared with 8 months for standard treatment. CEO Angelos Stergiou has described the delay in reaching the 80th event as “a profoundly positive signal,” suggesting patients are living longer than projected and that GPS could become “the true standard of care in AML maintenance.”
Retail investors appear to share the prediction market’s confidence. On the social trading platform Stocktwits, sentiment around the stock has been “extremely bullish” over the past week, with message volume up 101 percent. In a recent poll, 47 percent of traders said they were holding their shares, while 35 percent said they were buying or adding to positions. Only 9 percent reported selling or trimming. Another poll showed that 72 percent of respondents expected the stock to reach $25 or higher within 12 months.
Beyond the Regal trial, investors are also watching SLS009, the company’s second AML candidate, with topline frontline data expected later this year. Sellas ended the first quarter with $107.1 million in cash and raised an additional $28.7 million through warrant exercises. Shareholders recently approved a 20 million-share increase to the company’s equity incentive plan.
With the final trial events imminent and a prediction market pointing to a high probability of success, the coming weeks could determine whether GPS becomes a new standard in AML maintenance care. If the data confirm the optimistic outlook, the treatment could offer patients a meaningful extension of life after remission.