Nivolumab–Ipilimumab Yields Greater Response in Ovarian Cancer Than Nivolumab Alone

Combining nivolumab with ipilimumab led to a greater response rate and longer progression-free survival (PFS) than nivolumab alone in patients with epithelial ovarian cancer (J Clin Oncol. 2020 Apr 10. Epub ahead of print).

“Single-agent PD-1 blockade exhibits limited efficacy in epithelial ovarian cancer,” explained Dmitriy Zamarin, MD, PhD, Memorial Sloan Kettering Cancer Center, New York, and colleagues, who sought to compare the use of ipilimumab plus nivolumab with nivolumab alone in patients with persistent or recurrent disease.

A total of 100 patients with measurable epithelial ovarian cancer and a platinum-free interval (PFI) <12 months who had previously received 1 to 3 regimens were include in the study by Dr Zamarin et al. These patients were randomized to receive nivolumab every 2 weeks (n = 49) or nivolumab plus ipilimumab for 4 doses every 3 weeks followed by maintenance nivolumab every 2 weeks for a maximum of 42 doses (n = 51). Approximately 60% had a PFI <6 months.

According to the investigators, the primary null hypothesis was an equal probability of objective response within 6 months of being allocated to one of the treatment arms.

Findings showed that within 6 months, 6 (12.2%) and 16 (31.4%) responses occurred in the nivolumab monotherapy and nivolumab plus ipilimumab arms, respectively (odds ratio, 3.28; 85% CI, 1.54 to infinity; P = .034).

Furthermore, Dr Zamarin and co-investigators reported that the median PFS was 2 months and 3.9 months, respectively (PFI-stratified hazard ratio, 0.53; 95% CI, 0.34-0.82 and hazard ratio for death, 0.79; 95% CI, 0.44-1.42).

Approximately 30% and 50% of patients in the monotherapy and combination regimen arms, respectively, had grade ≥3 related adverse events, and no treatment-related deaths were documented.

Of note, PD-L1 expression was not found to be significantly tied to response in recipients of either treatment regimen.

“Compared with nivolumab alone, the combination of nivolumab and ipilimumab in [epithelial ovarian cancer] resulted in superior response rate and longer, albeit limited, PFS, with toxicity of the combination regimen comparable to prior reports,” Dr Zamarin and colleagues said.

“Additional combination studies to enhance durability of the dual regimen are warranted,” they concluded.—Hina M. Porcelli