SELLAS Life Sciences Group, Inc., a late-stage clinical biopharmaceutical company, focuses on the development of novel cancer immunotherapies for various cancer indications in the United States.

The company's lead product candidate is galinpepimut-S (GPS), a cancer immunotherapeutic agent that targets Wilms tumor 1, which is in Phase 3 clinical trials for the treatment of acute myeloid leukemia; and in Phase 1/2 clinical trials for the treatment for ovarian cancer.

It has a strategic collaboration with Merck & Co., Inc. to evaluate GPS as it is administered in combination with PD1 blocker pembrolizumab in a Phase 1/2 clinical trial enrolling patients in up to five cancer indications, including hematologic malignancies and solid tumors; and GenFleet Therapeutics (Shanghai), Inc. for the development and commercialization of GFH009, a highly selective small molecule CDK9 inhibitor, currently under Phase 1 clinical trials.

The company is headquartered in New York, New York.