The antitumor efficacy of OSI-027 was evaluated in PIK3CA mutant SKOV-3 ... human ovarian cancer xenograft models. In the SKOV-3 model, OSI-027 at 50 mg/kg once daily for 14 days resulted in significant TGI (100% median TGI) with 15% regression. In addition, twice daily dosing at 25 mg/kg twice daily corresponding to a total daily dose of 50 mg/kg resulted in comparable TGI (100% median TGI with 12% regression; Fig. 5A).