Association of progression-free survival, overall survival, and patient-reported outcomes by skin toxicity and KRAS status in patients receiving panitumumab monotherapy

Abstract

BACKGROUND: The authors explored the association of skin toxicity (ST) severity as measured by patient- reported ST and Common Terminology Criteria for Adverse Events (CTCAE) grading with efficacy of pani- tumumab, a fully human antiepidermal growth factor receptor antibody, from a phase 3 metastatic colorec- tal cancer (CRC) trial. METHODS: Patients were randomized to panitumumab plus best supportive care (BSC) vs BSC alone. ST by modified National Cancer Institute CTCAE v3.0 and modified Dermatology Life Quality Index (mDLQI), health-related quality of life (HRQOL), and CRC symptoms were measured. ST was analyzed using a landmark approach. Associations by KRAS mutational status were also assessed. RESULTS: Of 463 patients, 208 of 231 (90%) panitumumab patients and 184 of 232 (79%) BSC patients had ≥1 postbaseline patient-reported outcome (PRO) assessment. Panitumumab patients with more severe ST had significantly longer overall survival (OS) (grade 2-4:grade 1; hazard ratio, 0.60; P =.0033). Lower mDLQI scores (<67; more bothersome ST) were associated with longer OS (Cox model, P