Efficacy of pemetrexed combined with erlotinib/gefitinib in advanced non-small cell lung cancer patients during tyrosine kinase inhibitor treatment

Objective We aimed to evaluate the efficacy and safety of pemetrexed combined with erlotinib/gefitinib in advanced non-small cell lung cancer（NSCLC） patients during tyrosine kinase inhibitor（TKI） treatment. Methods Thirty-two patients with advanced NSCLC were divided into two groups. Patients in the control group received continuous daily epidermal growth factor receptor tyrosine kinase inhibitor（EGFRTKI） treatment, and patients in the experimental group received continuous daily EGFR-TKI along with pemetrexed treatment, which was administered on day 1 at 500 mg/m2. Erlotinib（150 mg） or gefitinib（250 mg） was administered daily from day 1 to day 21, with a cycle of every 21 days. Dexamethasone, folic acid, and vitamin B12 were also administered during the treatment. The endpoint of the primary study was the disease control rate. Results The objective response rate was 21.9%（95% CI： 7.6% to 36.3%） in the control group, whereas the disease control rate was 84.4%（95% CI： 71.8% to 97.0%） in the experimental group. The median progression-free survival was 6.2（95% CI： 2.4 to 10.0）. Grades 3 or 4 adverse effects of leucopenia（15.6%）, neutropenia（12.5%）, anemia（3.1%）, and nausea or vomiting（3.1%） were found in the experimental group.Conclusion The administration of pemetrexed combined with erlotinib or gefitinib showed a higher efficacy in TKI-resistant NSCLC patients. Further, the adverse effects of this drug combination were well tolerated by the patients. Pemetrexed combined with TKI treatment might provide a satisfactory therapeutic strategy for advanced NSCLC patients after TKI treatment.