305P - A real-world multicenter cohort study of lenvatinib (LEN) plus pembrolizumab (PEM) in Japanese patients with endometrial cancer: Interim analysis of GOGO-EM4 study

Background

LEN+PEM is an effective treatment option for advanced endometrial cancer (EC), however the prior clinical trial enrolled only a limited number of Japanese patients (pts), and further evaluation of efficacy and safety in Japanese pts is warranted.

Methods

This is the first multicenter, retrospective and prospective cohort study with the largest sample size of LEN+PEM for EC in Japan, with a planned enrollment of 100 pts. We performed an interim analysis when 56 pts were enrolled. Pts with EC who had progressed after at least one platinum-containing chemotherapy and received LEN+PEM after January 2022 were enrolled. The primary endpoint was progression-free survival (PFS). The major secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety.

Results

Of 56 pts, mismatch repair (MMR) status of tumor was MMR-deficient in 5 (8.9%), MMR-proficient in 34 (60.7%), and unknown in 17 (30.4%). 24 pts (42.9%) had one prior chemotherapy regimen and 32 pts (57.1%) had ≥2 regimens before LEN+PEM. At data cutoff (May 31, 2023), median follow-up period was 184.5 days. Median PFS was 224 days (95% confidence interval [CI]: 108-280) and median OS was 371 days (95% CI: 254-not reached). ORR was 32.6% (95% CI: 20.9-47.0) and DCR was 78.3% (95% CI: 64.4-87.7). Common adverse events (AEs) (incidence rate ≥30%) were hypertension (67.9%), hypothyroidism (64.3%), fatigue (58.9%), thrombocytopenia (53.6%), proteinuria (50.0%), decreased appetite (44.6%), hand-foot syndrome (39.3%), aspartate/alanine aminotransferase increased (30.4%/35.7%), and diarrhea (32.1%). AEs of grade ≥3 (incidence rate ≥10%) were hypertension (21.4%), hand-foot syndrome (14.3%), thrombocytopenia (10.7%), proteinuria (10.7%), and fatigue (10.7%). AEs with a delay of ≥2 weeks from first onset to most severe grade onset were anemia, proteinuria, hand-foot syndrome, hypothyroidism, decreased appetite, and weight decreased.

Conclusions

The therapeutic effect of LEN+PEM was consistent with that of the prior trial. The degree and frequency of AEs in Japanese pts tended to be higher than in the prior trial, and further research in real-world settings is warranted.

Clinical trial identification

UMIN000049997; 10/1/2023.

Editorial acknowledgement

Legal entity responsible for the study

Gynecologic Oncology Group of Osaka.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.