Adjuvant PD-1 antibody in recurrent, previously irradiated oral cavity cancer treated with salvage surgery

Abstract

ObjectivesThe role of re-irradiation after salvage surgery for recurrent oral cavity cancer (OCC) is controversial. We evaluated the efficacy and safety of adjuvant toripalimab (PD-1 antibody) in this patient setting. Materials and methodsIn this phase II study, patients after salvage surgery with OCC occurring in an area of previously irradiated were enrolled. Patients received toripalimab 240 mg once every 3 weeks for 12 months, or combined with S-1 orally for 4–6 cycles. The primary endpoint was 1-year progression-free survival (PFS). ResultsBetween April 2019 and May 2021, 20 patients were enrolled. Sixty percent patients had ENE or positive margins, 80% were restaged as stage IV, and 80% were previously treated with chemotherapy. The 1-year PFS and overall survival (OS) were 58.2%, and 93.8%, respectively, for patients with CPS ≥ 1, which was significantly better than those of the real-world reference cohort (p = 0.001 and 0.019). No grade 4–5 toxicities were reported, and only one patient experienced grade 3 immune related adrenal insufficiency and discontinued treatment. The 1-year PFS and OS were significantly different for patients with CPS < 1, CPS 1–19 and CPS ≥ 20 (p = 0.011 and 0.017, respectively). The peripheral blood B cell proportion was also correlated with PD in 6 months (p = 0.044). ConclusionAdjuvant toripalimab or combine with S-1 after salvage surgery showed improved PFS compared with a real-world reference cohort in recurrent, previously irradiated OCC, and favorable PFS were observed in patients with a higher CPS and peripheral B cell proportion. Further randomized trials are warranted.