Randomized phase III trial of gemcitabine plus docetaxel plus bevacizumab or placebo as first-line treatment for metastatic uterine leiomyosarcoma: an NRG Oncology/Gynecologic Oncology Group study

Abstract

PURPOSE: Fixed-dose rate gemcitabine plus docetaxel achieves objective response in 35% of patients with uterine leiomyosarcoma (uLMS). This study aimed to determine whether the addition of bevacizumab to gemcitabine-docetaxel increases progression-free survival (PFS) in uLMS. PATIENTS AND METHODS: In this phase III, double-blind, placebo-controlled trial, patients with chemotherapy-naive, metastatic, unresectable uLMS were randomly assigned to gemcitabine-docetaxel plus bevacizumab or gemcitabine-docetaxel plus placebo. PFS, overall survival (OS), and objective response rates (ORRs) were compared to determine superiority. Target accrual was 130 patients to detect an increase in median PFS from 4 months (gemcitabine-docetaxel plus placebo) to 6.7 months (gemcitabine-docetaxel plus bevacizumab). Treatment effects on PFS and OS were described by hazard ratios (HRs), median times to event, and 95% CIs. RESULTS: In all, 107 patients were accrued: gemcitabine-docetaxel plus placebo (n = 54) and gemcitabine-docetaxel plus bevacizumab (n = 53). Accrual was stopped early for futility. No statistically significant differences in grade 3 to 4 toxicities were observed. Median PFS was 6.2 months for gemcitabine-docetaxel plus placebo versus 4.2 months for gemcitabine-docetaxel plus bevacizumab (HR, 1.12; P = .58). Median OS was 26.9 months for gemcitabine-docetaxel plus placebo and 23.3 months for gemcitabine-docetaxel plus bevacizumab (HR, 1.07; P = .81). Objective responses were observed in 17 (31.5%) of 54 patients randomly assigned to gemcitabine-docetaxel plus placebo and 19 (35.8%) of 53 patients randomly assigned to gemcitabine-docetaxel plus bevacizumab. Mean duration of response was 8.6 months for gemcitabine-docetaxel plus placebo versus 8.8 months for gemcitabine-docetaxel plus bevacizumab. CONCLUSION: The addition of bevacizumab to gemcitabine-docetaxel for first-line treatment of metastatic uLMS failed to improve PFS, OS, or ORR. Gemcitabine-docetaxel remains a standard first-line treatment for uLMS.