Befotertinib for Patients with Pretreated EGFR T790M Mutated Locally Advanced or Metastatic NSCLC: Final Overall Survival Results from a Phase 2 Trial

Background In the initial analysis of a pivotal phase 2 single-arm study (NCT03861156), befotertinib (D-0316) showed clinical benefit with a manageable safety profile in pretreated patients with EGFR T790M mutated non-small cell lung cancer (NSCLC), including those with brain metastases. Methods Eligible patients received oral befotertinib of 50 mg (cohort A) or 75–100 mg (cohort B) once daily until disease progression, withdrawal of informed consent, or death. The primary endpoint for the initial analysis was objective response rate (ORR) assessed by an independent review committee. OS and safety were secondary endpoints. Herein, we present the final OS and safety data. Results A total of 176 patients in cohort A and 290 patients in cohort B were finally enrolled. At data cutoff (May 31, 2023), the median duration of follow-up was 47.9 months (95 % CI: 47.1–48.3) in cohort A and 36.7 months (35.9–37.9) in cohort B. The median OS was 23.9 months (95 % CI: 21.1–27.2) in cohort A and 31.5 months (26.8–35.3) in cohort B. The median OS for patients with and without brain metastasis in cohort A was 18.6 months (95 % CI: 14.9–26.3) and 26.4 months (95 % CI: 23.0–29.0), respectively. In cohort B, these data was 23.0 months (95 % CI: 18.6–29.1) and 35.5 months (95 % CI: 29.3–NE), respectively. The safety profile of befotertinib remained consistent with previous data. Grade 3 or higher treatment-emergent adverse events were 38.1 % in the cohort A and 50.3 % in the cohort B, in which 22.2 % and 31.7 % were related to the study drug. Conclusion Befotertinib demonstrated a more profound OS benefit compared to other 3rd-generation EGFR TKI, despite that cross trial data comparison should be interpreted with caution. The safety profile was manageable and consistent with previously report data in pretreated patients with confirmed T790M mutation-positive NSCLC.