Acceleron Pharma (NASDAQ: XLRN) announced Thursday that John Quisel, the company’s executive vice president and chief business officer, is leaving to become CEO of a venture-backed biotechnology startup. The startup’s name was not disclosed. Quisel was involved in numerous deals struck by Cambridge, MA-based Acceleron, including a development and commercialization agreement with Celgene (now part of Bristol-Myers Squibb (NYSE: BMY)). Last fall, the partners were awarded FDA approval for luspatercept (Rebloyzl), a treatment for anemia in patients who have the rare blood disorder beta thalassemia. Quisel’s last day at Acceleron will be Feb. 24.