SELLAS Life Sciences Group, Inc. is a late stage clinical biopharmaceutical company focused on the development of novel therapeutics for a broad range of cancer indications.
Its lead product candidates are galinpepimut S, a peptide immunotherapy that targets the Wilms tumor 1 antigen, and SLS009, a highly selective small molecule inhibitor of cyclin dependent kinase 9.
The company operates in the oncology biopharmaceutical sector aiming to bring these candidates through clinical development to potential marketing approval in the United States and other major markets.

SELLAS currently generates revenue principally through milestone and royalty payments received under its licensing and collaboration agreements as it has not yet commercialized any product.
The company has received an upfront cash payment of $7.5 million and has earned additional milestone payments under its agreement with 3D Medicines for the development and commercialization of GPS in Greater China.
As of December 31, 2025 the aggregate amount received from this agreement totaled $10.5 million.
SELLAS may also receive royalties on net sales of GPS in Greater China if commercialization is achieved.

SELLAS positions itself as a developer of innovative immuno oncology and targeted small molecule therapies for acute myeloid leukemia and other hematologic and solid tumor indications.
Its lead candidate GPS is distinguished by orphan drug designations from the FDA and the European Medicines Agency for acute myeloid leukemia malignant pleural mesothelioma and multiple myeloma as well as Fast Track designations for those indications.
SLS009 has received orphan drug designation for acute myeloid leukemia and peripheral T cell lymphoma and Fast Track designation for relapsed or refractory acute myeloid leukemia and relapsed or refractory peripheral T cell lymphoma.
Key competitors in the acute myeloid leukemia space include AbbVie and Genentech with venetoclax, Pfizer with gemtuzumab ozogamicin, Daiichi Sankyo with gilteritinib, Rigel Pharmaceuticals with vadastuximab talirine, Syndax Pharmaceuticals with entospletinib and Bristol Myers Squibb with azacitidine and decitabine.
For SLS009 the competitive landscape includes other selective cyclin dependent kinase 9 inhibitors such as TP 1287 from Sumitomo Dainippon Pharma, zotiraciclib from Cothera Bioscience and PRT2527 from Prelude Therapeutics.
SELLAS believes its competitive advantages lie in the novel mechanisms of action of its product candidates, the breadth of potential indications across more than twenty cancer types and the regulatory incentives that support faster development pathways.

SELLAS collaborates with several biopharmaceutical partners that provide funding, milestones or clinical trial support.
Specific partners include 3D Medicines which licenses GPS for Greater China, Merck which co develops GPS in combination with pembrolizumab, Bristol Myers Squibb which provides nivolumab for combination studies in mesothelioma and GenFleet which licenses SLS009 for development outside Greater China.