Neoadjuvant erlotinib benefits selected epidermal growth factor receptor (EGFR)-mutated patients who undergo complete resection of stage IIIA-N2 stage non-small cell lung cancer(NSCLC), shows a randomized study comparing erlotinib with gemcitabine plus cisplatin as neoadjuvant treatment, presented at the ESMO 2018 Congress in Munich.
"Our results suggest promise for the use of biomarker-guided neoadjuvant EGFR-tyrosine kinase inhibitor (TKI) treatment strategies in stage IIIA-N2 non-small cell lung cancer,' said Dr Yi-Long Wu, Tenured Professor of Guangdong Lung Cancer Institute, Guangzhou, China who is the principal investigator of the CTONG 1103 study.
"This is the first study to demonstrate progression-free survival (PFS) superiority for erlotinib over gemcitabine plus cisplatin chemotherapy in the neoadjuvant/adjuvant setting of stage IIIA-N2 EGFR mutated NSCLC," added Wu.
Results showed that a total of 386 patients from 17 centers in China were screened, and 72 were randomized 1:1 to therapy and included in the intention-to-treat population. The objective response rate (ORR) for neoadjuvant erlotinib versus gemcitabine plus cisplatin chemotherapy was 54.1% (95% CI: 37.2% to 70.9%) versus 34.3% (95% CI: 17.7% to 50.8%) with an odds ratio of 2.26 (95% CI: 0.87-5.84;p=0.092). After neoadjuvant therapy, 83.8% of patients in the erlotinib group and 68·6% in the gemcitabine plus cisplatin group underwent surgery.
Median progression-free survival (PFS) was significantly longer with erlotinib at 21·5 months (95% CI: 19.3-23.6) versus gemcitabine plus cisplatin chemotherapy at 11.9 months (95% CI: 9.1-14.7) with a hazard ratio of 0.42 (95% CI: 0.23-0.76; p=00003). Overall survival is too immature to report, said Dr Wu.
Current treatment strategies for resected stage IIIA-N2 EGFR mutated NSCLC is controversial, explained Dr Wu, but he added that EGFR-TKIs have been shown to improve the prognosis of patients with advanced EGFR-mutant NSCLC.
"Cisplatin-based doublet chemotherapy as neoadjuvant treatment for stage IIIA-N2 NSCLC only gives patients 5% five-year overall survival benefit," said Dr Wu, explaining the unmet medical need in this patient population. "Recently, the CTONG 1104 trial (2) showed for the first time that adjuvant EGFR-TKI gefitinib could improve disease free survival (DFS) by 10 months compared to adjuvant chemotherapy (28.7 months vs 18.0 months) in N1N2 resected NSCLC. This raises the possibility that EGFR-TKIs may play a beneficial role in the neoadjuvant setting for this subgroup."
Grade 3 and 4 toxicities were fewer in the erlotinib arm (0%) compared to the gemcitabine plus cisplatin arm (29.4%).
Commenting on the study for ESMO, Tony Mok, Professor of Clinical Oncology, the Chinese University of Hong Kong, said that this was a long-awaited study on patients with EGFR mutation positive stage IIIA NSCLC. "It has always been tempting to offer neo-adjuvant EGFR TKI to downstage the patient for surgery, but the action stops short in absence of supporting evidence."
"This randomized study is the first to demonstrate improvement in multiple parameters including tumor response rate, resection rate, major pathologic response and PFS with the use of neoadjuvant EGFR TKI followed by adjuvant TKI," he pointed out. He added that, "While the difference between EGFR TKI and chemotherapy is significant, the impact of neoadjuvant EGFR TKI is relatively disappointing. Response rate of 54% is lower than what is expected of TKI in stage IV disease (about 70%), and only 13% of patients had attained major pathologic response. The reason for this is unclear, but one may have to query if duration of neoadjuvant EGFR TKI for 42 days is sufficient. Overall, this important study offers us the rationale to consider neo-adjuvant EGFR TKI. "