On June 8, 2022 SELLAS Life Sciences Group, Inc. (NASDAQ: SLS) ("SELLAS" or the "Company"), a late-stage clinical biopharmaceutical company focused on developing novel therapies for a broad range of cancer indications, reported encouraging updated clinical data from a Phase 1 investigator-sponsored clinical trial of its lead clinical candidate, galinpepimut-S (GPS), combined with the checkpoint inhibitor nivolumab (Opdivo) in patients with malignant pleural mesothelioma (MPM) who were either refractory to or relapsed after at least one line of the standard of care therapy (Press release, Sellas Life Sciences, JUN 8, 2022, View Source [SID1234615751]).
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
Data from eight patients enrolled in the study have been analyzed, with final data in the clinical trial expected by the end of 2022. Of the eight patients, seven received at least three doses of GPS, the last of which was given in combination with nivolumab. All enrolled patients have received and progressed with, or were refractory to, frontline pemetrexed-based chemotherapy.
The study details are as follows:
Of the eight evaluable patients, six were male and two were female, with the median age of 66. 75 percent of the patients entered the study as Stage III or IV patients, with 50 percent of patients entering as Stage IV. Initial tumor stages were II (two patients), III and IIIB (two patients) and IV (four patients).
All patients had the MPM epithelioid and/or sarcomatoid variant, a tumor which is universally expressing Wilms Tumor 1 (WT1), one of the most widely expressed cancer antigens, ranked by the National Cancer Institute as the top priority among cancer antigens for immunotherapy.
Median overall survival (OS) calculated as the time from the cessation of the most recent previous therapy until confirmed death or most recent data update for patients who are still alive (50 percent of patients) was 40.9 weeks (9.4 months) for all eight patients and 45.7 weeks (10.5 months) in patients who received the combination therapy (seven out of eight patients). The median progression-free survival (PFS) was 11.1 weeks for all eight patients and 11.9 weeks in patients who received the combination therapy.
The safety profile of the GPS-nivolumab combination was similar to that seen with nivolumab alone, with the addition of only low-grade, temporary local reactions at the GPS injection site, consistent with previously performed clinical studies with GPS. No Grade 3/4 toxicities were observed for GPS and there were no dose-limiting toxicities.
"This updated data is very encouraging, as it not only confirms our data reported in June 2021, but now reflects an increased survival benefit even though almost all additionally enrolled patients had Grade III and IV malignant mesothelioma," said Angelos Stergiou, M.D., Sc.D. h.c., President and CEO, SELLAS. "This increase in survival appears to be consistent with long term immunity-mediated antitumor effect with this immunotherapy combination and it reinforces the data we unveiled earlier this year from the Phase 1/2 clinical trial of GPS in combination with another checkpoint inhibitor, pembrolizumab, in relapsed and refractory ovarian cancer patients, in which GPS showed a superior disease control rate compared to that seen with checkpoint inhibitors alone."
"Of additional importance is the fact that both trials addressed patients with bulky active disease, the setting in which other cancer vaccines have historically had very little effect. We believe that the results of both studies demonstrate the potential effectiveness of GPS as a combination therapy," concluded Dr. Stergiou.
About MPM
With approximately 3,300 cases in the United States each year, accompanied by a rising incidence in developing countries, MPM is notoriously difficult to treat and can lead to poor clinical outcomes with respect to both OS and PFS, especially for those patients with the sarcomatoid variant who show a median OS of approximately 4.0 to 5.0 months. In relapsed and refractory patients who progressed after the first line standard of care pemetrexed, a similar patient population to that in the GPS nivolumab combination trial, the common treatment regimen is vinorelbine and OS in those patients is reported to be between 4.5 and 6.2 months. In patients treated with other chemotherapy regimens, such as carboplatin and irinotecan, median OS is reported to be approximately 7.0 months.