Study of Safety & Efficacy of the Combination of LJM716 & BYL719 in Patients With Previously Treated Esophageal Squamous Cell Carcinoma (ESCC)

LJM716 (10-40 mg/kg) will be given as a once weekly infusion beginning on cycle 1 day 1. The doses of LJM716 will be increased as dose escalation proceeds until a maximum tolerated dose (MTD) and/or recommended phase II dose (RP2D) is established.

BYL719 (200-400 mg) will be administered orally on a once daily schedule starting cycle 1 day 1. The doses of BYL719 will be increased as dose escalation proceeds until a maximum tolerated dose (MTD) and/or recommended phase II dose (RP2D) is established.

In the Phase II portion of the study Paclitaxel is one of the 3 physician's choice drug which allows single-agent paclitaxel to be used per manufacturer's label.

In the Phase II portion of the study Docetaxel is one of the 3 physician's choice drug which allows single-agent docetaxel to be used per manufacturer's label.

In the Phase II portion of the study Irinotecan is one of the 3 physician's choice drug which allows single-agent irinotecan to be used per manufacturer's label