Concurrent use of anlotinib overcomes acquired resistance to EGFR-TKI in patients with advanced EGFR-mutant non-small cell lung cancer.

Background Acquired resistance development is a major challenge in the epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment of non-small cell lung cancer (NSCLC). Here, we investigated the potential effects of the concurrent use of anlotinib and EGFR-TKI to overcome acquired resistance. Methods We conducted a preclinical study to evaluate the antitumor effects of gefitinib + anlotinib in gefitinib-resistant lung adenocarcinoma models in vitro and in vivo. We then investigated the treatment effect of EGFR-TKI + anlotinib therapy in 24 advanced EGFR-mutant NSCLC patients after EGFR-TKI acquired resistance between January 2018 and August 2020. Results Anlotinib reversed gefitinib resistance in gefitinib-resistant lung adenocarcinoma models by enhancing the antiproliferative and proapoptotic effects of gefitinib. The gefitinib + anlotinib treatment exerted a synergistic antitumor effect by downregulating the activation of VEGFR2 and downstream effectors, Akt and ERK. The EGFR-TKI + anlotinib therapy exhibited an objective response rate of 20.8% and a disease control rate of 95.8%. Median progression-free survival (PFS) was 11.53 ± 2.41 months, but median overall survival was not reached. The median PFS was longer in patients experiencing gradual progression (13.30 ± 1.69 months) than in patients with dramatic progression (6.80 ± 1.75 months, p = 0.017). One grade 3 adverse event was noted (diarrhea, n = 2, 8.3%), and grade 4 or 5 adverse events were absent. Conclusions EGFR-TKI combined with anlotinib demonstrated powerful antitumor activity in vitro and in vivo. Concurrent use of anlotinib overcomes acquired resistance to EGFR-TKI in advanced EGFR-mutant NSCLC patients.