Sellas Life announces publication of GPS clinical data in ovarian cancer

SELLAS Life Sciences announced that the previously reported results from the final analysis of a Phase 1 clinical trial of the combination of galinpepimut-S with the anti-PD-1 antibody nivolumab in patients with relapsed WT1-expressing ovarian cancers have been published in the peer-reviewed journal Cancers. The article entitled "Phase I Study of a Multivalent WT1 Peptide Vaccine in Combination with Nivolumab in Patients with WT1-Expressing Ovarian Cancer in Second or Third Remission" was published February 25, 2023 in "Advances in the Treatment of Ovarian Cancer," a special issue of the journal Cancers. Key Takeaways of Published Study Data: Broader than expected GPS immunologic responses encompassed both T-cells and antibodies. 91% of patients treated had definite WT1-specific T-cell responses post-therapy, while in 88% of evaluable patients there was emergence of immunoglobulins against both a pool of the GPS constituent WT1 peptides and full-length WT1 protein. Cellular and humoral robust antigen-specific immune responses translated into clear clinical benefit with 70% one-year progression-free survival demonstrated in patients who received two or more treatments of GPS and nivolumab as maintenance immunotherapy after salvage chemotherapy, compared to historic rates of up to 55% in comparable patient populations in the absence of any maintenance treatment. Data suggest that durable responses to maintenance GPS immunotherapy can be attained in patients with WT1-expressing ovarian cancer, thus delaying measurable disease relapse. These results also corroborate previously announced findings from the final analysis of data from a Phase 1/2 study.