Rechallenge with Anti-PD-1 Inhibitors in Patients with Recurrent Gynecologic Malignancies

PURPOSEWe investigated the treatment outcomes of immune checkpoint inhibitor (ICI) rechallenge in patients with recurrent gynecologic cancers. MATERIALS AND METHODSWe retrospectively reviewed the medical records of 20 patients who underwent rechallenge with PD-1 inhibitors for recurrent gynecologic cancers at two tertiary centers between January 2018 and September 2022. RESULTSThe median age of the patients was 56 years (range, 35-79). Seven (35%), 1 (5%), 11 (55%), and 1 (5%) patients presented with cervical, vulvar, ovarian, and endometrial cancers, respectively. Sixteen (80%) patients received pembrolizumab and 4 (20%) received nivolumab at first treatment. Eight (40%) and 12 (60%) patients received pembrolizumab and nivolumab, respectively, at second treatment. At initial ICI treatment, 1 (5%) and 4 (20%) cases of a complete response (CR) and a partial response (PR) were observed, respectively, with a median progression-free survival (PFS) of 2.8 months (range, 1.4-49.6). Reasons for first ICI discontinuation were disease progression (n=16), severe adverse events (AEs) (n=2), and treatment withdrawal (n=2). During second ICI treatment, 1 (5%) patient achieved CR, 2 (10%) showed PR, and 5 (25%) experienced stable disease. The median PFS to second ICI was 1.8 months (range, 0.4-10.4). The median overall survival was 21.3 months (range, 10.1-52.7). Neither patient who discontinued ICI treatment due to AEs experienced AE relapse during second ICI treatment. CONCLUSIONThese results suggest that responses to ICI rechallenge are not as intolerable as responses to previous ICI. Clinicians should carefully consider rechallenge with PD-1 inhibitors outside of clinical trials until there are sufficient data to routinely support this practice.