SELLAS Life Sciences Group, Inc. is a US-based biopharmaceutical company, primarily focused on developing novel immunotherapy treatments for various cancers. The company has two lead product candidates, galinpepimut-S and nelipepimut-S, which are in Phase III and Phase 2b clinical trials respectively, for the treatment of different types of cancer. SELLAS also has a strategic partnership with Merck & Co. to evaluate the potential of GPS in combination with pembrolizumab for various types of hematologic malignancies and solid tumors.