First-line lenvatinib plus pembrolizumab versus chemotherapy for advanced endometrial cancer: 1-Year follow-up after final analysis of the ENGOT-en9/LEAP-001 phase 3 trial.

OBJECTIVE

The phase 3 ENGOT-en9/LEAP-001 trial (NCT03884101) comparing first-line lenvatinib+pembrolizumab with carboplatin+paclitaxel did not meet pre-specified statistical criteria for overall survival or progression-free survival in participants with advanced/recurrent endometrial cancer. We report results after an additional year of follow-up (overall median 54.5 [range; 46.5-69.0] months).

METHODS

Eligible participants were adult females with stage III to IV or recurrent, histologically confirmed endometrial cancer. Measurable or non-measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and radiographically apparent disease per blinded independent central review was required. Participants were randomly allocated 1:1 to lenvatinib+pembrolizumab or chemotherapy (paclitaxel+carboplatin). The primary end points were overall survival and progression-free survival per RECIST version 1.1 by blinded independent central review. Secondary end points included objective response rate per RECIST version 1.1 by blinded independent central review and safety.

RESULTS

The median overall survival (95% confidence interval [CI]) was 30.9 (range; 25.4-37.6) months with lenvatinib+pembrolizumab versus 29.4 (range; 26.2-34.8) months with chemotherapy in mismatch repair-proficient endometrial cancer (hazard ratio [HR] 0.99, 95% CI 0.82 to 1.21), 37.9 (range; 32.2-43.0) versus 32.3 (range; 27.2-35.7) months in all-comers (HR 0.91, 95% CI 0.77 to 1.09), and not reached in either treatment group in mismatch repair-deficient endometrial cancer (HR 0.60, 95% CI 0.39 to 0.93]). Corresponding results for progression-free survival were 9.6 (range; 8.2-11.9) versus 10.2 (range; 8.4-10.5) months (HR 1.01, 95% CI 0.83 to 1.22), 12.5 (range; 10.3-15.1) versus 10.2 (range; 8.4-10.4) months (HR 0.92, 95% CI 0.77 to 1.10]), and 31.8 (22.5 to not reached) versus 9.0 (range; 8.2-17.1) months (HR 0.62, 95% CI 0.41-0.93). Objective response rates were 50.6% versus 54.7%, 55.7% versus 55.5%, and 72.0% versus 58.0%, respectively. No new safety signals were identified. The results were consistent with those at the final analysis.

CONCLUSIONS

The mismatch repair-proficient, all-comer, and mismatch repair-deficient populations continued to demonstrate antitumor activity for lenvatinib+pembrolizumab after an additional year of follow-up. These results should be interpreted with caution due to the exploratory nature of the analysis.

TRIAL REGISTRATION: ClinicalTrials.gov No. NCT03884101.