SELLAS Life Sciences Group Inc. said Gene Mack resigned as the company's CFO and treasurer Dec. 17.

The company has engaged Aleksey Krylov as a consultant to provide financial services to the company for an initial term of three months. Krylov was the company's CFO from Oct. 24, 2017, through April 20, 2018.

The company also appointed John Burns, its vice president of finance and corporate controller, as the company's interim principal accounting officer.

New York-based SELLAS Life Sciences Group is a clinical-stage biopharmaceutical company that focuses on the development of novel cancer immunotherapies for various cancer indications.