Sellas' Ovarian Cancer Candidate Shows Clinical Benefit In Pretreated Patients - Merck & Co (NYSE:MRK), SELLAS Life Sciences Gr (NASDAQ:SLS)

SELLAS Life Sciences Group Inc SLS announced topline data from its Phase 1/2 trial of galinpepimut-S (GPS) in WT1(+) relapsed or refractory platinum-resistant advanced metastatic ovarian cancer.
The trial evaluated SELLAS' peptide immunotherapeutic combined with Merck & Co Inc's MRK Keytruda (pembrolizumab).
Data from 15 patients enrolled in the study has been preliminarily analyzed. Final data for all 17 patients is expected by the end of 2022.
Related: Sellas Life Sciences Reports Encouraging Immune Response From GPS Combo Trial In Ovarian Cancer.
The overall response rate is 7.7%, similar to the response to checkpoint inhibitors, with a disease control rate (DCR) of 53.9% at a median follow-up of 43.1 weeks.
In a checkpoint inhibitor single-agent study in a similar platinum-resistant ovarian cancer patient population, the observed DCR was 37.2%, consistent with a DCR rate increase of 45% in the GPS/Keytruda combo over that seen for checkpoint inhibitors alone.
Median progression-free survival (PFS) was 12 weeks compared to 8.4 weeks for checkpoint inhibitors alone.
Patients with two or fewer previous lines of therapy treated with GPS combo had a median PFS of 24 weeks.
With 43.1 weeks of follow-up, the median overall survival has not been reached.
Price Action: SLS shares are down 6.92% at $2.96 during the market session on the last check Thursday.