Sellas Life Sciences, a prominent biopharmaceutical company in the U.S. focused on late-stage clinical developments, has recently announced encouraging results from its Phase I study (NCT02737787) involving galinpepimut-S in combination with Bristol-Myers Squibb’s Opdivo (nivolumab) for treating mesothelioma patients. The study notably surpassed its primary goal by significantly extending overall survival in individuals with malignant pleural mesothelioma (MPM) that was either refractory or had relapsed.
In the clinical trial, which was investigator-sponsored, the blend of Sellas’ galinpepimut-S (GPS) with the checkpoint inhibitor Opdivo led to a median overall survival of 70.3 weeks. This is a stark contrast to the median survival of 28 weeks typically observed with standard therapies for relapsed or refractory mesothelioma.
Further results highlighted a striking finding: the median overall survival leaped from nine months to 27.8 months in patients who exhibited a GPS-specific immune response—an increase of over 200%. The trial, enrolling ten patients, saw nine receiving at least three doses of GPS, with the third dose administered alongside nivolumab. Additionally, nine patients provided sufficient samples for analyzing GPS-specific immune responses.
A Closer Look at the Study Results
Dr. Angelos Stergiou, President of Sellas, expressed enthusiasm over the outcomes, stating, “We’re heartened to see strong GPS-specific immune responses correlating with significant survival benefits in such a challenging disease environment. This study reiterates the potential of our immunotherapy combination to elicit long-term, immunity-mediated antitumor effects, as previously observed in other studies with GPS.” He emphasized the safety profile of the combination therapy, noting it was comparable to that of the checkpoint inhibitor used alone.
These findings build upon earlier positive results released in June 2023 from another Phase I study (NCT03761914) that also tested galinpepimut-S with Opdivo. “The survival benefits observed in these studies underscore the potent biological effect of GPS, even against highly aggressive cancers, reinforcing its value as a viable component in combination therapies,” Stergiou added.
