A randomized, double-blind, placebo-controlled phase 2 study of tigatuzumab (CS-1008) in combination with carboplatin/paclitaxel in patients with chemotherapy-naïve metastatic/unresectable non-small cell lung cancer.

INTRODUCTION: Tigatuzumab, a humanized monoclonal DR5 agonist antibody induces apoptosis in human cancer cell lines. The objective of this study was to investigate the antitumor effects of tigatuzumab combined with carboplatin/paclitaxel in chemotherapy-naïve patients with metastatic/unresectable non-small cell lung cancer (NSCLC).
METHODS: Patients with histologically or cytologically confirmed NSCLC stage IIIB/IV disease by RECIST (version 1.0) and ECOG-PS 0-1 were enrolled at 15 European sites. Patients received tigatuzumab or placebo intravenously with carboplatin/paclitaxel every 3 weeks (1 cycle) for up to 6 cycles. The primary end point was progression-free survival (PFS). Secondary end points were overall survival (OS), objective response rate and safety.
RESULTS: 97 patients were analyzed for efficacy (49 tigatuzumab; 48 placebo). Median PFS (95% CI) was 5.4 months (3.3, 6.6) for tigatuzumab compared with 4.3 months (4.1, 5.8) for placebo. Median OS (95% CI) was 8.4 months (6.9, 16.3) for tigatuzumab versus 9.0 months (7.6, 14.5) for placebo. 12 patients (24.5%) in the tigatuzumab arm and 11 patients (22.9%) in the placebo arm had partial response. No patient had complete response. In a prospectively-defined Fc gamma receptor genotype subset (n=25), there was a non-significant trend toward increased PFS with tigatuzumab versus placebo (HR=0.47; 95% CI: 0.16, 1.35) but no difference in OS. Tigatuzumab was well tolerated. However, grade 3/4 neutropenia was reported in 10 patients (20.4%) receiving tigatuzumab compared with 4 patients (8.3%) receiving placebo.
CONCLUSIONS: Tigatuzumab was well tolerated but did not improve efficacy of carboplatin/paclitaxel in systemic therapy-naïve, unselected advanced NSCLC patients.

RCT Entities:   Population Interventions Outcomes