Dramatic Response in a Patient with Metastatic Gastric Cancer Using Trifluridine/Tipiracil after Rapid Disease Progression while on Nivolumab.

The introduction of immune checkpoint inhibitors has redefined the treatment strategy and changed the way tumor assessments are made because of its response pattern. Studies have suggested that initiating chemotherapy after checkpoint inhibitors may have high anti-tumor activity in some cancer types. This response pattern has not been reported in patients with gastric cancer, and particularly for the combination of trifluridine/tipiracil. A 69-year-old man presented at follow-up for metastatic gastric cancer being treated with nivolumab, an anti-PD-1 antibody. Computed tomography of the liver showed a rapid 4-fold growth of the metastasis compared with baseline measurements taken while receiving paclitaxel and ramucirumab. It met the definition of a phenomenon called hyperprogressive disease. Nivolumab was discontinued, and he was switched to trifluridine/tipiracil. The liver metastasis was shrunk markedly after 2 months with improvement in his performance status and laboratory data. Sequential therapy starting with immune checkpoint inhibitors followed by cytotoxic agents such as trifluridine/tipiracil may have an apparent efficacy in gastric cancer even though prior immunotherapy demonstrates hyperprogressive disease.