Background: This open-label Phase III trial (NCT02264990) evaluated the PARP inhibitor, veliparib, combined with carboplatin/paclitaxel versus chemotherapy alone for first-line treatment of patients with advanced non-squamous non-small cell lung cancers (NSCLC). A 52-gene expression classifier (LP52) previously shown to identify patients more likely to respond to veliparib was evaluated as a planned correlative analysis.
Materials and methods: Adult current or former smokers with advanced non-squamous NSCLC were randomized 1:1 to veliparib (120 mg daily for 7 days/cycle) with carboplatin and paclitaxel or to investigators' choice of platinum doublet chemotherapy (up to 6, 21-day cycles), with optional pemetrexed maintenance. Prospective analysis of the LP52 signature was conducted using a clinical Qiagen/HTG assay. The primary endpoint was overall survival (OS) in LP52+ patients.
Results: Overall, 595 patients received veliparib + carboplatin/paclitaxel (n = 298) or chemotherapy alone (n = 297); 13% (n = 40) in each arm were LP52+. The primary endpoint was not met; median OS was 11.2 months with veliparib + carboplatin/paclitaxel versus 9.2 months with chemotherapy alone in the LP52+ subgroup (hazard ratio [HR] 0.644, 95% confidence interval [CI]: 0.396-1.048; P = .113). In the overall population, median OS was 12.1 months in both arms (HR 0.986, 95% CI: 0.827-1.176; P = .846). No new safety signals were observed.
Conclusion: In patients with non-squamous NSCLC, there was no significant improvement in OS with veliparib + carboplatin/paclitaxel versus chemotherapy alone, although a trend toward improved OS in the LP52+ population suggests this subgroup may benefit from veliparib. Statistical power was limited due to the small sample size.
Keywords: Biomarkers; Combination therapy; NSCLC; Overall survival; PARP inhibitor.
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