This is a Phase 3, multicenter, randomized, open-label trial to evaluate whether EG-007 plus Len+Pem is superior to Len+Pem alone in patients with advanced endometrial cancer (Stage III or IV). This trial will be preceded by a safety lead-in study with up to 28 patients (the safety lead-in is a separate, free-standing protocol).
Approximately 450 patients will be randomized equally (1:1) to receive EG-007 plus Len+Pem or Len+Pem alone. The randomization will be stratified by the following stratification factors:
* Diagnosis Classification (advanced Stage III/IV vs. recurrent endometrial cancer) * ECOG score at baseline (0 vs 1) * Geographic region (Asia vs ROW)
Female, 18 years and older at the time of informed consent, who has a histologically confirmed diagnosis of endometrial carcinoma, endometroid histology, that is not MSI-H or dMMR.
Documented evidence of advanced (Stage III or IV), or recurrent EC.
Must have a recurrence or progressed on a platinum containing chemotherapy regimen and are not candidates for curative surgery or radiation
Has historical or fresh tumor biopsy specimen for confirmation of mismatch repair (MMR) status as not MSI-H or dMMR.
Brain metastasis: Brain metastases must be asymptomatic, fully treated and stable and not requiring steroids within 4 weeks prior to study treatment initiation.
Has carcinosarcoma (malignant mixed mullerian tumor), serous carcinoma, endometrial leiomyosarcoma and endometrial stromal sarcomas.
Has failed treatment of lenvatinib + pembrolizumab in prior lines of therapy.
Prior anticancer treatment within 28 days (or 5 times the half-life time, whichever is shorter) or any investigational agent within 30 days prior to the first dose of study drugs. All acute toxicities related to prior treatments must be resolved to Grade less than or equal to 1.