ABSTRACT
INTRODUCTION: Tobacco-related NSCLC is associated with reduced survival and greater genomic instability. Veliparib, a potent poly(adenosine diphosphate-ribose) polymerase inhibitor, augments platinum-induced DNA damage. A phase 2 trial of untreated advanced NSCLC showed a trend for improved outcomes (hazard ratio [HR] = 0.80, 95% confidence interval: 0.54-1.18, p = 0.27 for overall survival and HR = 0.72, 95% CI: 0.45-1.15, p = 0.17 for progression-free survival) when veliparib was added to carboplatin/paclitaxel. Here we report an exploratory analysis by smoking history. METHODS: Patients were randomized 2:1 to receive carboplatin/paclitaxel with veliparib, 120 mg (n = 105), or placebo (n = 53). Patients were stratified by histologic subtype and smoking history (recent smokers [n = 95], former smokers [n = 42], and never-smokers [n = 21]). Plasma cotinine level was measured as a chemical index of smoking. Mutation status was assessed by whole exome sequencing (n = 38). RESULTS: Smoking history, histologic subtype, age, Eastern Cooperative Oncology Group performance status, sex, and geographic region predicted veliparib benefit in univariate analyses. In multivariate analysis, history of recent smoking was most predictive for veliparib benefit. Recent smokers treated with veliparib derived significantly greater progression-free survival and overall survival benefits (HR = 0.38 [p < 0.01] and HR = 0.43 [p < 0.01]) than former smokers (HR = 2.098 [p = 0 0208] and HR = 1.62 [p = 0.236]) and never-smokers (HR = 1.025 [p = 0.971] and HR = 1.33 [p = 0.638]). Sequencing data revealed that mutational burden was not associated with veliparib benefit. The rate of grade 3 or 4 adverse events was higher in recent smokers with veliparib treatment; all-grade and serious adverse events were similar in both treatment arms. CONCLUSIONS: Smoking history predicted for efficacy with a veliparib-chemotherapy combination; toxicity was acceptable regardless of smoking history. A prespecified analysis of recent smokers is planned for ongoing phase 3 studies of veliparib in NSCLC.
Subject(s)
Benzimidazoles/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Smoking/adverse effects , Aged , Benzimidazoles/pharmacology , Carcinoma, Non-Small-Cell Lung/pathology , Double-Blind Method , Female , Humans , Lung Neoplasms/pathology , Male , Middle Aged , Poly(ADP-ribose) Polymerase Inhibitors/pharmacologyABSTRACT
Purpose: PARP plays an important role in DNA repair. Veliparib, a PARP inhibitor, enhances the efficacy of platinum compounds and has been safely combined with carboplatin and paclitaxel. The primary endpoint of this phase II trial determined whether addition of veliparib to carboplatin and paclitaxel improved progression-free survival (PFS) in previously untreated patients with advanced/metastatic non-small cell lung cancer.Experimental Design: Patients were randomized 2:1 to carboplatin and paclitaxel with either veliparib or placebo. Veliparib (120 mg) or placebo was given on days 1 to 7 of each 3-week cycle, with carboplatin (AUC = 6 mg/mL/min) and paclitaxel (200 mg/m2) administered on day 3, for a maximum of 6 cycles.Results: Overall, 158 were included (median age, 63 years; male 68%, squamous histology 48%). Median PFS was 5.8 months in the veliparib group versus 4.2 months in the placebo group [HR, 0.72; 95% confidence interval (CI), 0.45-1.15; P = 0.17)]. Median overall survival (OS) was 11.7 and 9.1 months in the veliparib and placebo groups, respectively (HR, 0.80; 95% CI, 0.54-1.18; P = 0.27). In patients with squamous histology, median PFS (HR, 0.54; 95% CI, 0.26-1.12; P = 0.098) and OS (HR, 0.73; 95% CI, 0.43-1.24; P = 0.24) favored veliparib treatment. Objective response rate was similar between groups (veliparib: 32.4%; placebo: 32.1%), but duration of response favored veliparib treatment (HR, 0.47; 95% CI, 0.16-1.42; P = 0.18). Grade III/IV neutropenia, thrombocytopenia, and anemia were comparable between groups.Conclusions: Veliparib combination with carboplatin and paclitaxel was well-tolerated and demonstrated a favorable trend in PFS and OS versus chemotherapy alone. Patients with squamous histology had the best outcomes with veliparib combination. Clin Cancer Res; 23(8); 1937-44. ©2016 AACR.
