For patients with EGFR-mutated, advanced non–small cell lung cancer (NSCLC), adding pemetrexed and carboplatin to standard gefitinib therapy markedly extends progression free survival, but at the cost of twice as many serious toxicities, in a recent phase 3 trial.
Two previous phase 2 trials (J Clin Oncol. 2016 Sep 20;34[27]:3258-66 and Ann Oncol. 2015 Feb 10;26[5]:888-94) suggested that adding chemotherapy could improve outcomes over gefitinib alone, but this is the first study to clearly demonstrate better overall survival, reported lead author Vanita Noronha, MD, of Tata Memorial Hospital in Mumbai, India, and colleagues. They noted that this is the second regimen to demonstrate better overall survival than standard gefitinib for EGFR-mutated lung cancer, with dacomitinib being the first, as shown by the ARCHER 1050 trial.
The present study involved 350 patients with advanced, EGFR-mutated NSCLC who had an Eastern Cooperative Oncology (ECOG) performance status of 0-2 and were candidates for first-line palliative therapy. Approximately one-fifth of patients (21%) had a performance status of 2, and almost as many (18%) had brain metastases. After stratification for performance status and mutation type, patients were randomized in a 1:1 ratio to receive either gefitinib monotherapy (250 mg once daily) or gefitinib plus a chemotherapy combination of pemetrexed (500 mg/m2) and carboplatin (area under the curve of 5 with Calvert formula) on day 1 of four 21-day cycles. Subsequently, nonprogressing patients in the chemotherapy group received maintenance therapy with pemetrexed at the same dose and frequency. Treatment was continued until progression, toxicity, or withdrawal of consent. The primary endpoint was progression-free survival (PFS). Secondary outcomes included overall survival (OS), response rate, quality of life, and toxicity.
After a median follow-up of 17 months, the investigators found that adding chemotherapy to gefitinib resulted in a clear benefit, with estimated median PFS increasing from 8 months to 16 months (P less than .001). Estimated median overall survival also increased, with a figure not reached in the chemotherapy/gefitinib group, compared with 17 months among those who received gefitinib alone. Response rates echoed these findings, with more patients in the chemotherapy/gefitinib group achieving complete (2.9% vs. 0.6%) and partial remission (72.4% vs. 61.9%).
“[T]he PFS attained in our study is noteworthy, considering that 21% of our study patients had a [performance status] of 2, whereas the FLAURA study, [which demonstrated a PFS of 18.9 months with osimertinib], only included patients with a [performance status] of 1 or lower,” the investigators wrote. Their report is in Journal of Clinical Oncology.
Still, introducing chemotherapy was not without negative consequences. Compared with the gefitinib monotherapy group, patients who also received chemotherapy more often had grade 3 or higher adverse events (75% vs. 49.4%), and twice as many had clinically significant, serious toxicities (50.6% vs. 25.3%). The additional toxicities were predominantly due to myelosuppression and nephrotoxicity.
Despite these drawbacks, the investigators concluded that combination therapy was superior to gefitinib alone. “The combination of gefitinib, pemetrexed, and carboplatin represents a new standard first-line therapy for EGFR-mutant NSCLC,” the investigators concluded.
The study was funded by Tata Memorial Center Research Administration Council, Fresenius Kabi India, Lung Cancer Consortium India, and others. The investigators reported relationships with Roche, Biocon, Amgen, and others.
SOURCE: Noronha et al. Journal of Clinical Oncology. 2019 Aug 14. doi: 10.1200/JCO.19.01154.