Rezivertinib versus gefitinib as first-line therapy for patients with EGFR-mutated locally advanced or metastatic non-small-cell lung cancer (REZOR): a multicentre, double-blind, randomised, phase 3 study.

Background: This study aimed to compare the efficacy and safety of rezivertinib (BPI-7711) and gefitinib as first-line therapies in patients with EGFR-mutated locally advanced or metastatic non-small-cell lung cancer (NSCLC).

Methods: This multicentre, double-blind, randomised, phase 3 study (REZOR) included eligible patients from 50 hospitals across China. Those who had been histologically or cytologically confirmed as having NSCLC with EGFR exon 19 deletion or exon 21 Leu858Arg mutation by central laboratory were randomly assigned (1:1) to receive once daily either rezivertinib 180 mg or gefitinib 250 mg, until unacceptable toxicity occurred, disease progression, or other treatment discontinuation criteria were met. Each cycle lasted for 21 days. The primary endpoint was progression-free survival evaluated by masked independent central review (MICR) in the intention-to-treat set. This trial is registered with ClinicalTrials.gov, NCT03866499 and follow-up is ongoing.

Findings: Between July 15, 2019, and Feb 14, 2022, 695 patients were screened. Among them, 369 eligible patients were randomly assigned to receive either rezivertinib 180 mg/day plus placebo (n=184) or gefitinib 250 mg/day plus placebo (n=185) in a 1:1 ratio; all of eligible participants were included in the intention-to-treat set. Median MICR-assessed progression-free survival was 19·3 months (95% CI 13·8-22·1) in the rezivertinib group and 9·6 months (8·4-11·3) in the gefitinib group (hazard ratio [HR] 0·48, 95% CI 0·36-0·63; p<0·0001) and the prespecified subgroup efficacy analysis showed consistent results. Median duration of exposure was 16·0 months (95% CI 0·0-29·7) in the rezivertinib group and 11·0 months (0·0-28·9) in the gefitinib group. Grade 3 or higher treatment-emergent adverse events (82 [45%] of 184 in the rezivertinib group; 80 [43%] of 185 in the gefitinib group) and treatment-related adverse events (TRAEs; 43 [23%] of 184 in the rezivertinib group; 43 [23%] of 185 in the gefitinib group) were similar in both groups. One patient died from a TRAE in the rezivertinib group, due to pneumonia and interstitial lung disease.

Interpretation: Our findings suggested that rezivertinib is a potential choice for patients with EGFR-mutated locally advanced or metastatic NSCLC as first-line therapy, owing to the superior overall efficacy and subgroup progression-free survival compared with gefitinib in targeted patients. No new safety signals were identified.

Funding: Beta Pharma (Shanghai) and the China National Science and Technology Major Project for Key New Drug Development.