** Shares of drug developer Cocrystal Pharma COCP.O rise 5.1% to $1.10 premarket

** Co appoints James Sapirstein as chief executive officer, effective immediately

** It also plans to appoint Sapirstein to the company's board as director

** Sapirstein replaces Sam Lee and Jim Martin, who served as co-CEOs

** Sam Lee will continue as president and transition to chief scientific officer, and Jim Martin will continue as CFO

** Up to last close, stock is down 37.5% YTD