A pilot study of nivolumab in combination with neoadjuvant and post-surgical chemotherapy in newly diagnosed ovarian cancer.

OBJECTIVE: To evaluate whether the addition of nivolumab to standard neoadjuvant chemotherapy (NACT) in previously untreated advanced-stage epithelial ovarian cancer (EOC) is safe and feasible. METHODS: In this single-institution pilot study (NCT03245892), patients with advanced EOC for whom NACT was considered the most appropriate initial therapy option were treated with intravenous nivolumab 360 mg with standard carboplatin and dose-dense paclitaxel NACT every 3 weeks for 3-6 cycles. Patients then underwent interval cytoreductive surgery (ICS) followed by another 3 cycles of post-operative treatment. RESULTS: Safety results were consistent with the known profile of the study drugs for the 21 patients treated. Seven (33 %) patients had grade 3/4 adverse events attributed to nivolumab, with one case of grade 3 infusion reaction making that patient unevaluable. Fifteen of the 20 (75 % [95 % CI, 50.9-91.3 %]) evaluable patients had complete gross resection at ICS, and 7 of 20 (35 % [95 % CI, 15.4-59.2 %]) achieved an optimal pathologic chemotherapy response score (CRS) of 3. Median progression-free survival was 15.6 months (95 % CI, 11.6-26.4 months), with a 2-year rate of 32.5 % (95 % CI, 12.8-54.1 %). Median overall survival was 50.7 months (95 % CI, 26.5 months-not evaluable), with a 2-year rate of 85 % (95 % CI, 60.4-94.9 %). CONCLUSIONS: The combination of nivolumab with carboplatin and paclitaxel was safe and tolerable. Most patients achieved a complete gross resection and one-third had an optimal CRS at ICS. Further studies are needed to identify patients with ovarian cancer most likely to benefit from upfront immune checkpoint blockade.