Objectives: Immune checkpoint inhibitors (ICIs) have modest activity in ovarian cancer (OC), yet little is known about their effects on subsequent treatment. Preclinical studies suggest immunotherapy may enhance response to chemotherapy. We sought to evaluate the impact of ICIs on subsequent therapies and survival in recurrent OC.
Methods: A retrospective review was conducted to identify women with recurrent OC who received ICI from 01/2013 to 5/2017 and ≥1 subsequent treatment. Treatment duration after ICI was calculated using time-to-event analysis. Kaplan-Meier survival analysis and Cox proportional hazards models were used to calculate overall survival (OS) from first treatment after ICI and to assess survival differences by clinical benefit from ICI, defined by long (≥24 weeks) versus short (<24 weeks) ICI treatment duration.
Results: Of 79 evaluable women identified, 66 (84%) had platinum-resistant OC. Median age at diagnosis was 57 years. Median time from diagnosis to ICI was 39.7 months, with median of 4 prior treatments (range, 1-12). Median number of treatments after ICI was 2 (range, 1-8). Median duration of first-line treatment after ICI was 3.7 months (95% CI, 2.9-6.0) and declined with each subsequent line. The most common therapies after ICI were taxanes, platinum-based regimens, and pegylated liposomal doxorubicin. Bevacizumab was used in 47 women (59%). Median OS after ICI was 18.3 months (95% CI, 11.8-22.7) and did not differ between long versus short ICI.
Conclusions: In this heavily pretreated population of patients with recurrent OC, therapies after ICI resulted in promising survival, suggesting that ICI may improve efficacy of subsequent chemotherapy.
Keywords: Checkpoint inhibition; Immunotherapy; Ovarian cancer; Platinum resistance; Survival.
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