Adding Tecentriq to chemo resulted in survival outcomes comparable to placebo plus chemo in patients with advanced or recurrent endometrial cancer, according to results from the phase 3 AtTEnd/ENGOT-EN7 trial presented at the 2025 ESMO Congress.
Adding Tecentriq (atezolizumab) to chemotherapy resulted in survival outcomes comparable to placebo plus chemotherapy in patients with advanced or recurrent endometrial cancer, according to results from the phase 3 AtTEnd/ENGOT-EN7 trial presented at the 2025 ESMO Congress.
After a median follow-up of 48.9 months, overall survival (OS) did not significantly differ between patients treated with Tecentriq versus placebo, with a median of 36 months versus 30.5 months, respectively. The respective 12- and 24-month OS rates were 80.1% versus 73.8% and 61.1% versus 58.4%. Additionally, 12.1% of patients in the Tecentriq arm versus 29.2% in the placebo arm received subsequent immunotherapy.
In a planned subgroup analysis based on mismatch repair deficient (dMMR) status, patients with dMMR disease experienced significantly improved OS with Tecentriq. Median OS was not evaluable in the Tecentriq arm versus 31.8 months with placebo; 12- and 24-month rates were 86.8% versus 66.8% and 74.8% versus 54.8%. Subsequent immunotherapy was received by 7.4% versus 45.5% of patients in each respective arm.
Among patients with non-dMMR status, survival outcomes did not significantly differ. Median OS was 30 months with Tecentriq versus 30.2 months with placebo; 12- and 24-month rates were 77.8% versus 75.8% and 55.9% versus 58.8%. Subsequent immunotherapy was received by 13.8% versus 24.3% of patients, respectively.
Progression-free survival (PFS) outcomes numerically favored Tecentriq across all patients. Median PFS was 9.9 months versus 8.9 months, with 12- and 24-month rates of 44.7% versus 28.9% and 28.7% versus 16.8%. Among patients with dMMR disease, median PFS was not evaluable versus 6.9 months, with 12- and 24-month rates of 62.7% versus 23.3% and 52.1% versus 16.3%. In non-dMMR patients, median PFS was 9.5 months versus 9.2 months, with 12- and 24-month rates of 39.1% versus 30.2% and 21.7% versus 16.0%.
Glossary
Overall survival (OS): The length of time patients are still alive after starting treatment.
Progression-free survival (PFS): The length of time patients live without cancer getting worse.
Mismatch repair deficient (dMMR): A genetic feature of some cancers where cells cannot fix DNA errors properly, making tumors more responsive to immunotherapy.
Objective response rate (ORR): The percentage of patients whose tumors shrink or disappear after treatment.
Complete response (CR): The disappearance of all signs of cancer.
Partial response (PR): A significant reduction in tumor size but not complete disappearance.
Duration of response (DOR): How long a patient’s tumor remains reduced or gone after treatment.
ECOG performance status: A scale (0-5) that measures a patient’s daily functioning and ability to care for themselves.
Objective response rate (ORR) and duration of response (DOR) in dMMR patients numerically favored Tecentriq. ORR was 82.4% with a complete response (CR) rate of 26.5% and a partial response (PR) rate of 55.9%, versus 75.7% with a CR rate of 18.9% and a PR rate of 56.8% with placebo. Median DOR was not evaluable versus 4.9 months, with 12- and 24-month rates of 66.9% versus 22.3% and 57.6% versus 14.8%. In non-dMMR patients, ORR was 75.6% versus 74.6%, with CR and PR rates of 15.1% and 60.5% versus 10.5% and 64.0%. Median DOR was 7.8 months versus 7 months, with 12- and 24-month rates of 35.1% versus 29.8% and 19.9% versus 15.0%.
“The addition of Tecentriq to chemotherapy did not demonstrate a statistically significant survival benefit in patients with advanced or recurrent endometrial carcinoma,” said Dr. Maria Pilar Barretina Ginesta. “In the pre-planned subgroup analysis based on mismatch repair status, substantial survival improvement was observed in patients with dMMR carcinomas.”
The study enrolled patients with advanced newly diagnosed or recurrent endometrial carcinoma or carcinosarcoma and randomly assigned them to receive paclitaxel and carboplatin area with Tecentriq or matching placebo. Following chemotherapy, patients received Tecentriq as maintenance or matching placebo.
Patients were stratified by country, histology, recurrent status, and dMMR status. Dual primary end points were PFS and OS.
Among all patients in the Tecentriq (360) and placebo (189) arms, 22.5% versus 23.3% had dMMR status. Recurrent disease status was 67.5% versus 66.7%, and 70.6% versus 68.2% had not received prior chemotherapy. In newly diagnosed disease, 75.2% versus 85.7% had measurable disease. Median age was 67 versus 65 years, and most patients were Caucasian (80.3% versus 75.7%), PD-L1–negative (68.6% versus 68.2%), and had intact ARID1A expression (68.9% versus 69.3%).
Any-grade side effects occurred in 98.6% versus 100%, with 75.8% versus 63.8% related to Tecentriq versus placebo. Grade 3 or higher side effects were observed in 26.4% versus 14.1%, with fatal side effects in 0.3% versus 0.5%. The most common side effects in the Tecentriq versus placebo arms were anemia (41.3% versus 35.1%), fatigue (39% versus 41.1%), neutropenia (40.7% versus 39.5%), peripheral sensory neuropathy (38.8% versus 39.5%), nausea (34% versus 37.3%), and hair loss (31.5% versus 36.2%).
Reference
- "Final overall survival (OS) results from the randomized double-blind phase III AtTEnd/ENGOT-EN7 trial evaluating atezolizumab in combination with paclitaxel and carboplatin in women with advanced/recurrent endometrial cancer," by Dr. Maria Pilar Barretina Ginesta. Presented at the European Society for Medical Oncology (ESMO) Congress 2025; October 17-21, 2025; Berlin, Germany. Abstract LBA39.
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