Exploratory Subset Analysis of African Americans From the PointBreak Study: Pemetrexed-Carboplatin-Bevacizumab Followed by Maintenance Pemetrexed-Bevacizumab Versus Paclitaxel-Carboplatin-Bevacizumab Followed by Maintenance Bevacizumab in Patients With Stage IIIB/IV Nonsquamous Non-Small-Cell Lung Cancer

Abstract

Introduction: African Americans have a greater incidence of lung cancer than whites and have been underrepresented in clinical trials. In the PointBreak trial (pemetrexed-carboplatin-bevacizumab and maintenance pemetrexed-bevacizumab [PemCBev] vs. paclitaxel-carboplatin-bevacizumab and maintenance bevacizumab [PacCBev]), 10% of the patients were African American. PointBreak had negative findings; PemCBev did not demonstrate superior overall survival (OS).

Materials and methods: PointBreak subgroup efficacy and safety data were retrospectively analyzed: African Americans versus whites for PemCBev; PemCBev versus PacCBev in African Americans; and academic versus community settings for African Americans. Hazard ratios (HRs) and P values were derived from a multivariate Cox proportional hazards model after adjusting for covariates.

Results: Of 939 intent-to-treat (ITT) patients, 94 were African American and 805 were white. African-American enrollment was uniform across the study sites (median, 1 African American per site). In the PemCBev arm, OS (HR, 1.125; P = .525), progression-free survival (PFS) (HR, 1.229; P = .251), response (P = .607), and toxicity profiles were similar in African Americans versus whites. For African Americans, OS (HR, 1.375; P = .209), PFS (HR, 0.902; P = .670), response (P = 1.000), and toxicity profiles were similar in the PemCBev versus PacCBev arm. For African Americans, no significant differences were seen in OS (HR, 0.661; P = .191) or PFS (HR, 0.969; P = .915) in academic versus community practice settings.

Conclusion: In the PemCBev arm, this exploratory analysis showed no significant differences between African Americans and whites for the efficacy outcomes or toxicity profiles. Consistent with the ITT population negative trial result, for African Americans, the median OS was not superior for either arm. For African Americans, PFS and OS were similar in the academic and community settings. Additional outcomes data for African Americans should be collected in lung cancer studies.

Trial registration: ClinicalTrials.gov NCT00762034.

Keywords: Alimta; Avastin; Minority groups.