A Study to Evaluate the Potential Benefit of the Addition of BYL719 to Paclitaxel in the Treatment of Breast Cancer and Head-and-neck Cancer

BYL719 will be administered orally once daily on a continuous dosing schedule and dosed on a flat-fixed dose and not adjusted by body weight or body surface area, starting on Day 2 in the dose escalation part and Day 1 in the dose expansion part. In the dose escalation part, the BYL719 starting dose will be 300mg, with anticipated dose escalation to 350mg. In the dose expansion part, BYL719 will be administered at the recommended dose determined in the dose escalation part.

Paclitaxel will be administered once weekly at a dose of 80 mg/m2 i.v. (days 1, 8, 15 and 22) in a 28 day cycle in both dose escalation and expansion.