Ipilimumab plus nivolumab shows clinical activity in advanced rare gynecological tumors

A combination of ipilimumab and nivolumab showed significant clinical activity and a favorable safety profile in the treatment of a range of advanced rare gynecological malignancies, according to a study.

There are limited treatment options for patients with rare gynecological malignancies, and poor survival outcomes are common.

Due to the success of the anti-programmed cell death protein 1 (anti-PD-1) antibody nivolumab and the anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA-4) antibody ipilimumab in common cancers, researchers evaluated the combination in rare gynecological cancers.

In this multicenter phase II study, 43 patients with advanced rare gynecological cancers were treated with nivolumab (3 mg/kg) and ipilimumab (1 mg/kg), every 3 weeks for 4 doses. Nivolumab (3 mg/kg) monotherapy was continued every 2 weeks until disease progression or for a maximum of 2 years.

In the radiologically evaluable population, the objective response rate was 36% (12/33 patients); in the intention-to-treat population, it was 28% (12/43 patients). An additional 7 patients obtained stable disease, resulting in disease control rates of 58% in the radiologically evaluable population and 44% in the intention-to-treat population.

Durable responses were seen across multiple tumor histologies.

An immune-related adverse event was reported in 72% of patients, with 16% reporting grade 3/4. Patients that had baseline PD-L1 expression (≥1% on tumor cells) had a higher response rate; this was independent of tumor mutational burden.

Reference
Klein O, Kee D, Gao B, et al. Combination immunotherapy with nivolumab and ipilimumab in patients with rare gynecological malignancies: results of the CA209-538 clinical trial. J Immunother Cancer. 2021;9(11):e003156. doi: 10.1136/jitc-2021-003156. PMID: 34782426; PMCID: PMC8593709.