Synthetic Biologics Inc. said Joseph Sliman is looking to terminate his employment as chief medical officer.

Sliman alleges a material reduction in his duties, authorities and responsibilities as a company executive. His employment was due to expire in December.

Synthetic Biologics is reviewing its options to dispute Sliman's attempt to terminate his employment agreement.

The Rockville, Md.-based biotechnology company named Michael Kaleko, who serves as senior vice president of research and development, to take over Sliman's responsibilities on an interim basis.

Synthetic Biologics develops therapeutics designed to preserve the human gut microbiome.