A trial of an immunotherapy combination of nivolumab and ipilimumab was successful in treating patients with advanced gynecological clear cell cancers, including endometrial cancer (EC), according to a study published recently in JAMA Oncology.
In this nonrandomized clinical trial involving 28 patients, researchers found that over half experienced meaningful tumor shrinkage and more than half remained free of disease progression at six months, suggesting this combination could be a valuable treatment option for a population with few choices.
“In this nonrandomized clinical trial, immunotherapy using combined anti–PD-1/CTLA-4 blockade demonstrated encouraging activity with a high rate of durable responses in patients with advanced gynecological CCCs [clear cell carcinomas],” the study authors wrote.
Patients enrolled in the study had advanced clear cell ovarian or endometrial cancers, both known for resisting traditional chemotherapy. Participants were treated across 17 sites in Australia and New Zealand between August 2021 and February 2024. They received four doses of nivolumab and ipilimumab together, followed by ongoing nivolumab alone every four weeks for nearly two years or until the disease worsened or side effects became too severe.
Read more about therapies for EC
The results were striking. The overall objective response rate was 54%, with 12 patients showing partial responses and three achieving complete responses. Importantly, all responses remained ongoing at the time of analysis. The 6-month progression-free survival rate was 58%, giving patients meaningful time without their cancer growing. While the median overall survival has not yet been reached, these early signs are encouraging and suggest that many may live significantly longer than expected.
Patients in the study had a median age of 55, ranging from 34 to 77, with most having had at least one prior course of therapy. Outcomes were similar between those with clear cell ovarian cancer and those with clear cell EC, with response rates of 55% and 50%, respectively. This consistency suggests the treatment could work broadly in clear cell cancers of the gynecological tract.
However, the treatment is not without risks. About 35% of patients experienced severe immune-related side effects, including one fatal case of myocarditis. These findings underscore the need for careful monitoring and management of side effects, balancing the potential benefits with the risks.
For patients facing limited and often ineffective treatment options, these results may offer hope that harnessing the immune system to fight cancer could lead to longer-lasting control of disease. The study’s promising results support further research so more patients can access effective therapies for these challenging cancers.
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