Objective: Pemetrexed plus carboplatin (PCb) is a frequently used first-line treatment in advanced non-small cell lung cancer (NSCLC). This study examined the characteristics and safety profile of a NSCLC population treated with PCb area under the concentration-time curve 5 (PCb5) or 6 mg/mL•min (PCb6) under real-world conditions.
Research design and methods: A retrospective, observational, cohort study was conducted, utilizing data from the IMS Oncology US clinic-based, longitudinal, patient-level electronic medical records (EMR), including patients with NSCLC on PCb5 or PCb6 regimens initiated concomitantly on or after the diagnosis of lung cancer during 2004-2014. Patient characteristics and incidence of adverse events (AEs) were described for each cohort. Propensity scores were calculated based on baseline demographic and clinical factors. Propensity score stratification was used to further adjust for cohort differences.
Results: In total, 636 NSCLC patients receiving PCb5 (37% aged ≥70 years) and 184 patients receiving PCb6 (34% aged ≥70 years) who met the inclusion criteria were identified in the EMR. Patients with more comorbidities were more likely to have received PCb5. Overall incidence rates (IRs) per 100 person-years were similar for neutropenia in both cohorts, were numerically higher for anemia (IR = 43.6 vs 101.0) and thrombocytopenia (IR = 1.5 vs 17.9), and were numerically lower for nausea (IR = 14.4 vs 9.9) in the PCb6 vs PCb5 cohort. Within the PCb6 cohort, the IR per 100 person-years was higher for neutropenia for ≥70 year-old patients (IR = 41.1) compared to <70 year-old patients (IR = 14.5). After propensity score stratification, adjusted IRs showed similar patterns.
Limitations: Limitations included lack of power for AEs other than anemia, given the nature of EMR.
Conclusions: Results from this real-world analysis add to existing evidence from randomized clinical trials about PCb safety profiles in the overall NSCLC population and in elderly patients. These results may guide physicians when making treatment decisions.
Keywords: Pemetrexed; carboplatin; non-small cell lung cancer; observational study; safety.