Pemetrexed and carboplatin combination therapy followed by pemetrexed maintenance in Japanese patients with non-squamous non-small cell lung cancer: A subgroup analysis of elderly patients.

Background: The combination of pemetrexed and carboplatin is commonly used for the treatment of advanced non-squamous non-small cell lung cancer (NSCLC), mainly because it is comparatively effective and less toxic than other platinum-doublet therapies. Using the JMII (JACAL) study, we report the efficacy and safety of this treatment followed by pemetrexed maintenance in the elderly population (≥70 years of age).

Methods: The JMII study was a multicenter, post-marketing study that assessed the efficacy and safety of carboplatin (AUC6) and pemetrexed (500 mg/m, given on Day 1 of a 21-day cycle, 4 cycles) followed by pemetrexed (500 mg/m) maintenance in advanced non-squamous NSCLC patients (n = 109). Retrospective subgroup analyses were performed in elderly patients aged ≥70.

Results: The study includes younger (<70 years, n = 84) and elderly (≥70 years, n = 25) patients who received induction therapy. Median progression-free survival and overall survival from the start of the induction phase were 5.2 (95% CI: 3.5, 8.2) and 16.8 (95% CI: 10.3, NC) months for the elderly patients compared with 5.8 (95% CI: 4.3, 7.4) and 20.5 (95% CI: 16.7, NC) months for the younger patients, respectively. Grade 3/4 hematologic toxicities were more frequent in the elderly patients. Non-hematologic toxicities in the elderly patients were comparable to those in younger patients. Dose reduction was more common in the elderly (44% vs 23%), due to hematologic toxicities.

Conclusions: There was no difference in efficacy (evaluated by progression-free survival) between elderly and younger patients. Although grade 3/4 hematologic toxicities were frequently observed in the elderly patients, they were easily managed with dose adjustment.