Impact Of Treatment Breaks On Vismodegib Patient Outcomes: Exploratory Analysis Of The Stevie Study.

9024 Background: Vismodegib (VISMO) is the first Hh pathway inhibitor approved for use in adults with advanced BCC (aBCC) that is inappropriate for surgery or radiotherapy. While most VISMO-related adverse events (AEs) are mild to moderate, the presence of multiple chronic AEs may lead to treatment interruption or discontinuation. Treatment breaks are allowed in the STEVIE study (NCT01367665) for the management of toxicity, among other reasons. Herein we present an exploratory analysis assessing the safety and efficacy profile in patients (pts) with treatment breaks on study. Methods: STEVIE is an ongoing study focusing on safety of VISMO in pts with aBCC. Pts receive VISMO 150 mg once daily until progressive disease, unacceptable toxicity, or withdrawal. The primary objective is safety; efficacy is a secondary end point. Tumor response assessments are performed using RECIST 1.1 as assessed by the investigator. Exploratory analyses were performed using data from a planned interim analysis (data cutoff Nov...