Pemetrexed-based chemo boosts survival in NSCLC

As an add-on to gefitinib monotherapy, pemetrexed-based chemotherapy improves survival outcomes in nonsmall cell lung cancer (NSCLC) patients harbouring EGFR mutations, a recent study has found.

Drawing from the databases of PubMed, Web of Science, Cochrane, and Embase, the researchers retrieved eight studies within five randomized clinical trials for pooled analysis. The outcomes of interest were overall (OS) and progression-free (PFS) survival; objective response rate (ORR), disease control rate (DCR), and discontinuation rate (DR) were also assessed.

Compared with monotherapy, the combination approach significantly improved OS (hazard ratio [HR], 0.57, 95 percent confidence interval [CI], 0.37–0.89; p=0.0125) and PFS (HR, 0.52, 95 percent CI, 0.39–0.79; p<0.0001).

The PFS benefit was pronounced in patients harbouring the EGFR exon 19 deletion (HR, 0.50, 95 percent CI, 0.34–0.75; p=0.0008) and the exon 21 L858R substitution (HR, 0.46, 95 percent CI, 0.26–0.82; p=0.0079). These mutations had no significant impact on OS.

Add-on pemetrexed-based chemotherapy likewise improved ORR (odds ratio [OR], 1.91, 95 percent CI, 1.44–2.55; p<0.0001) but had no effect on DCR (OR, 1.46, 95 percent CI, 0.94–2.26; p=0.0952) or DR (OR, 2.80, 95 percent CI, 0.69–11.44; p=0.1509).

“The addition of pemetrexed-based chemotherapy to gefitinib could be administered as the first-line therapy for advanced EGFR-mutant NSCLC patients,” the researchers said. “Future studies may lead to explore more subtypes of EGFR mutations suitable for receiving a TKI plus pemetrexed-based chemotherapy.”