Author of

• 10743

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  P1.10 - Poster Session 1 - Chemotherapy (ID 204)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10747

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    P1.10-004 - Exploratory Subset Analysis in African Americans from the PointBreak Study (Randomized Phase 3 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) (ID 249)

    09:30 - 09:30  |  Author(s): C. Reynolds
    • Abstract

    Background
    African Americans (AA) have a higher rate of lung cancer than Caucasians per 100,000 population (74.7 versus 64.4) but are underrepresented in randomized clinical trials. In the PointBreak study, AAs were enrolled at the same rate as the US incidence of non-small cell lung cancer (NSCLC) for AAs in 2011 (13%; now 15% in 2013). Post-hoc analyses of the AA subgroup were conducted from this study to evaluate efficacy and safety, as well as these outcomes by treatment center.

    Methods
    All patients (N=939) were chemonaive with an ECOG performance status (PS) of 0/1. AAs were analyzed against Caucasians for efficacy/safety in the pemetrexed (Pem) arm only. Subgroup analyses of AAs alone were conducted for efficacy/safety (between arm comparisons) as well as academic versus community settings (pooled two treatment arms). Hazard ratios and p-values were derived from a multivariate Cox-PH model, adjusting for disease stage, gender, PS and measurable/nonmeasurable disease. Response rates and adverse events (AEs) were compared using the exact test.

    Results
    Patients had stage IIIb (with pleural effusion)/IV nonsquamous NSCLC, according to AJCC edition 6. There were 94 AAs (42 = Pem arm; 52 = Paclitaxel [Pac] arm) and 805 Caucasians in the treated population. Demographics were statistically comparable between AAs and Caucasians in the Pem Arm, respectively: 62%/53% male, 71%/53% ≤65 years, 98%/89% ever smokers, 81%/90% Stage IV disease, with ECOG PS of 0/1, 33%/67%, versus 44%/56%. Median OS was similar between AAs and Caucasians in the Pem arm at 12.4 versus 12.3 months. Median PFS for AAs and Caucasians was 4.6 months versus 6.0 months (HR 1.229 (0.864 – 1.749; p=0.251). Overall response rate (ORR) for AAs was higher, though not statistically, at 38.1% versus 33.3% (p=0.607). Efficacy among AAs was fairly similar with median OS for Pem arm at 12.4 versus 13.7 months for Pac arm (p=0.1208). Median PFS by arm was 4.6 versus 5.1 months (p=0.6699). ORR among AAs was 38% in both arms. AAs showed a heavy trend (80%) for enrollment in community centers (n=74) versus academic center (n=20). Efficacy among AAs by setting showed a higher median OS at academic sites at 16.5 months versus 11.4 months, p=0.1906 (HR=0.6605; 95% CI: 0.355 – 1.229). Median PFS was also higher at academic sites at 6.9 months versus 4.6 months, p=0.9149 (HR =0.9690; 95% CI: 0.544 – 1.726). Drug-related grade 3/4 AEs in the Pem arm showed higher percentages for Caucasians with the exception of neutropenia, as follows: anemia (7.3%/15.9%), thrombocytopenia (9.8%/25.5%), fatigue (4.9%/11.5%), neutropenia (31.7%/25.3%), febrile neutropenia (0%/1.6%). Among AAs in the Pem/Pac Arm respectively, drug-related grade 3/4 AEs were: anemia (7.3%/0%), thrombocytopenia (9.8%/4.0%), fatigue (4.9%/4.0%), neutropenia (31.7%/44.0%), and febrile neutropenia (0%/4.0%).

    Conclusion
    There were no significant differences between AAs and Caucasians for OS, PFS, and ORR. Among AAs, median OS was not superior for either arm. PFS and OS were similar for academic and community settings among AAs. Caucasians had a significantly higher incidence of Grade 3/4 thrombocytopenia (p=0.0217), but this should be interpreted with caution due to the sample size for the AAs.