Gefitinib Plus Chemo Improves PFS2 Over Gefitinib Alone in EGFR-Mutant NSCLC

Combining gefitinib with chemotherapy can improve second progression-free survival (PFS2) in patients with EGFR-mutant non-small cell lung cancer (NSCLC), according to updated data published in the Journal of Clinical Oncology.

Patients who received gefitinib plus platinum chemotherapy had significantly longer PFS2 than patients who received gefitinib alone. However, the combination did not improve overall survival (OS) vs monotherapy.

These findings come from an update of the phase 3 NEJ009 study. The updated analysis included 342 patients with EGFR-mutant NSCLC treated at 47 institutions in Japan. 

Roughly half of patients (n=172) were assigned to receive gefitinib alone (250 mg orally, once daily). The other half (n=170) were assigned to receive gefitinib plus carboplatin and pemetrexed (GCP) in a 3-week cycle for 6 cycles, followed by concurrent gefitinib and pemetrexed maintenance.

At baseline, the mean age was 65 years in the combination arm and 64 years in the monotherapy arm. Most patients (81.8% and 79.7%, respectively) had stage IV disease, and most were women (67.1% and 62.8%, respectively).

Patients in both arms received at least 1 subsequent therapy. A similar proportion of patients in the monotherapy (23.3%) and combination (21.8%) arms received osimertinib. In the monotherapy arm, 26.7% of patients did not receive platinum-based chemotherapy in any treatment line.

Initially, the researchers defined PFS2 as the period from randomization until both chemotherapy and gefitinib were ineffective. However, the team decided this was inappropriate and calculated “corrected PFS2,” which was a comparison of PFS1 in the combination arm and PFS2 (after recommended GCP) in the gefitinib arm. 

At a median follow-up of 84 months, the median corrected PFS2 was 18.0 months in the monotherapy arm and 20.9 months in the combination arm (hazard ratio [HR], 0.77; 95% CI, 0.62-0.97; P =.027).

The researchers also calculated updated median PFS2, which was the actual time to progression or death after second-line therapy in each arm. The updated median PFS2 was 20.7 months in the monotherapy arm and 32.5 months in the combination arm (HR, 0.58; 95% CI, 0.46-0.73; P <.001).

The median OS was 38.5 months in the monotherapy arm and 49.0 months in the combination arm (HR, 0.82; 95% CI, 0.64-1.06; P =.127).

There were no new severe adverse events reported in the current analysis.

“This updated analysis revealed that the GCP regimen improved PFS and PFS2 with an acceptable safety profile compared with gefitinib alone,” the researchers wrote. 

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.  

Reference

Miyauchi E, Morita S, Nakamura A, et al. Updated analysis of NEJ009: Gefitinib-alone versus gefitinib plus chemotherapy for non-small-cell lung cancer with mutated EGFR. J Clin Oncol. Published online August 12, 2022. doi:10.1200/JCO.21.02911

This article originally appeared on Cancer Therapy Advisor