The checkpoint inhibitor nivolumab may hold some promise for treating women with metastatic gynecologic cancers, especially cervical disease, according to cohort results from the phase 1/2 CheckMate 358 trial.
Of twenty-four patients enrolled in the recurrent/metastatic cervical and vaginal/vulvar carcinoma cohorts, 26.3% of patients with cervical cancer and 20% with vaginal/vulvar cancers experienced an objective response, R. Wendel Naumann, MD, and colleagues reported in the Journal of Clinical Oncology.
Median overall survival was 21.9 months (95% confidence interval, 15.1 months to not reached) among patients with cervical cancer. Because of the small size of the vaginal/vulvar cohort, median overall survival was not calculated.
“Given the lack of effective therapy and low survival rates for patients with metastatic disease in these gynecologic cancers, the results reported here are of strong clinical interest and underscore the growing role of immune checkpoint inhibitors in this patient population,” the investigators wrote.
Checkmate 358 is investigating nivolumab in patients with virus-associated cancers. Patients receive nivolumab monotherapy (240 mg intravenously every 2 weeks for 2 years) until disease progression, unacceptable side effects, or withdrawal of consent.
The median age was 51 years in the cervical cohort (n = 19) and 59 in the vaginal/vulvar cohort (n = 5). HPV status was positive in 83.3% of those with cervical disease and 40% of those with vaginal/vulvar disease. Ten cervical tumors and four vaginal/vulvar tumors expressed PD-L1.
The median duration of nivolumab treatment was 5.6 months in the cervical cohort and 6.7 months in the vaginal/vulvar cohort. Median follow-up was 19 months and 10 months, respectively.
At 12 months and 18 months, 40.0% of the cervical cohort and 20% of the vaginal/vulvar cohort were still alive.
The most common treatment-related adverse effects were diarrhea and decreased appetite. One patient in the cervical cohort discontinued treatment because of pneumonitis, which was considered treatment related.
Bristol-Myers Squibb funded the study. Several of Dr. Naumann’s associates reported relationships with the company and four others are employed by Bristol-Myers Squibb.
SOURCE: Naumann RW et al. J Clin Oncol. 2019 Sep 5. doi: 10.1200JCP.19.00739.