Safety and efficacy of pazopanib (PAZ) in advanced soft tissue carcinoma (aSTS) by prior lines of therapy, age, and dose modifications: PALETTE subgroup analyses

Abstract

Background: PALETTE was a randomized phase 3 trial (NCT00753688) that demonstrated single-agent activity of PAZ in advanced STS (aSTS). We evaluated the relationship between age, prior lines of therapy, and dose modifications on the safety and efficacy of PAZ in aSTS. Methods: Median progression-free survival (mPFS) was evaluated in subgroups of prior lines of therapy (1 prior line; 2+ prior lines), age (<65 y; >=65 y), and dose reductions and interruptions (no dose reduction/interruption; >=1 dose reduction/interruption). Adverse events (AEs) were also compared in subgroups of prior lines of therapy and age. All analyses were descriptive and exploratory and require cautious interpretation. Results: A total of 246 patients received pazopanib in the PALETTE study. Median PFS and median overall survival (OS) were longer in patients receiving PAZ who had only 1 prior line of therapy vs 2+ prior lines of therapy (mPFS, 24.7 vs 18.9 weeks [Table]; OS, 13.7 vs 11.3 months). In patients receiving PAZ, mPFS was similar in ages<65 and>=65 y (20.0 and 20.1 weeks, respectively). In patients receiving PAZ, mPFS was maintained in patients requiring dose reductions or dose interruptions to manage toxicities (Table). Regardless of number of prior lines of therapy, patients receiving PAZ had similar AE rates. The AEs leading to study discontinuation in patients receiving PAZ were higher in>=65 vs<65 y group (30% vs 17%, respectively). Rates of dose reductions, dose interruptions, and serious AEs leading to study discontinuation were similar between the 2 age groups. Conclusions: Longer mPFS was observed in patients receiving PAZ following only 1 line of therapy. Additionally, mPFS with PAZ was maintained regardless of patient age or if dose modification was required to manage toxicity. (Table Presented).