Dual blockade of EGFR and VEGFR pathways: Results from a pilot study evaluating apatinib plus gefitinib as a first-line treatment for advanced EGFR-mutant non-small cell lung cancer.

Background Dual blockade of both EGFR and VEGFR pathways in EGFR-mutant NSCLC have shown enhanced antitumor efficacy versus EGFR-TKIs alone. Apatinib is an orally effective VEGFR-2 tyrosine kinase inhibitor (TKI). This pilot study aims to evaluate the tolerability, pharmacokinetic profile, and antitumor activity of apatinib plus gefitinib as a therapy for EGFR-mutant advanced NSCLC. Methods Advanced non-squamous NSCLC participants harbored with the EGFR 19 deletion or the 21 L858R point mutation were included. There were two cohorts: Cohort A: apatinib 500 mg + gefitinib 250 mg. Cohort B: apatinib 250 mg + gefitinib 250 mg. The primary endpoint was safety profile. Other endpoints consisted of PK analysis, objective response rate (ORR), and progression-free survival (PFS). Exploratory analysis was conducted using next-generation sequencing of plasma circulating-tumor DNA. Results Between July 2016 and April 2017, 13 of NSCLC patients were recruited. Six patients were pooled in Cohort A, while seven patients were in Cohort B. Adverse events (AEs) were tolerable (mostly grade 1-2) and the treatment-related AEs were similar in both cohorts: rash (100% vs 71.4%), diarrhea (66.7% vs 71.4%), hypertension (66.7% vs 71.4%), proteinuria (66.7% vs 42.9%), and hand-foot skin reaction (33.3% vs 28.6%). The area under plasma concentration-time curve for the steady state of apatinib was 2864.73 +/- 2605.54 ng mL(-1 )h(-1) in Cohort A and 2445.09 +/- 1550.89 ng mL(-1 )h(-1) in Cohort B. Of the 11 patients evaluable for efficacy, Cohort A achieved an ORR of 80.0% and reached a median PFS of 19.2 months, while it was 83.3% and 13.4 months in Cohort B. Patients without a concomitant mutation at baseline had a prolonged PFS tendency (20.99 months v 13.21 months, P = .0624). The EGFR-T790M mutation remained the dominant resistance mechanism. Conclusion Apatinib (500 mg) plus gefitinib (250 mg) showed a tolerable safety profile and encouraging antitumor activity for advanced EGFR-mutant NSCLC in the first-line setting. Phase III trials of apatinib (500 mg) plus gefitinib (250 mg) are warranted. Trial registration Clinicaltrials.gov, NCT02824458, date of registration June 23, 2016.