Complete response to immunotherapy combined with an antiangiogenic agent in multiple hepatic metastases after radical surgery for advanced gallbladder cancer: a case report.

Most advanced gallbladder cancers (GBCa) are unresectable or metastatic once diagnosed, and even patients who undergo surgery have a high risk of recurrence and metastasis. Immunotherapy, especially immune checkpoint inhibitors (ICIs), combined with an antiangiogenic agent, is an emerging prospective treatment for GBCa. However, the efficacy and safety of this combination therapy have not yet been investigated. We report the case of a 70-year-old female patient with recurrent metastatic GBCa (stage IVB) after radical surgery. Immunohistochemical examination revealed that 10% of the tumor cells expressed programmed cell death protein-1 (PD-1) and programmed cell death receptor ligand 1 (PD-L1). Whole-exome sequencing showed cancer tissues with a low tumor mutational burden (TMB) and microsatellite stability (MSS). The patient received Camrelizumab (200 mg, every three weeks) and Apatinib (40 mg/d). The clinical and immunological responses were observed, and the patient achieved a complete response after five cycles. This is the first case describing the efficacy and safety of Camrelizumab plus Apatinib in a GBCa patient with weak PD-1 and PD-L1 expression, and low TMB and MSS. The treatment had a tolerable safety profile and a complete response in the patient. Also, we found that the cluster of differentiation (CD)16+CD56+natural killer (NK) cell ratio in peripheral blood was increased after the combined treatment. Immunotherapy with antiangiogenic drugs may be a potential treatment option for patients with recurrent GBC or GBCa.