Excellent response to chemotherapy post immunotherapy

INTRODUCTION: Immunotherapy in the form of immune checkpoint inhibitors has changed the landscape of cancer treatment. Newer monoclonal antibodies are coming up and are being tested in various cancers during different stages of treatment. With the increasing use of immune checkpoint inhibitors in the management of various types of cancers, the question is raised as to what next can be offered to a patient who has progressed on this newer treatment. Does Sequence matter? There have been reports of improved responses to chemotherapy after immunotherapy in the form of vaccines. Here we present a case series of 6 patients who progressed on immunotherapy with immune checkpoint inhibitors after initial modality of treatment (chemotherapy/radiation), subsequently received chemotherapy with excellent response. METHODS: We have a cohort of six patients who had disease progression on second line Immunotherapy for solid or hematological malignancies and had ECOG < 2. All these patients received third line salvage chemotherapy. Three patients had metastatic head and neck cancer, 2 had non-small cell lung cancer (NSCLC), and one had T -cell rich B- cell lymphoma. Prior review and approval were obtained from our institutional review board. RESULTS: All patients had an excellent response to chemotherapy in third line setting, after immune checkpoint inhibitors and most of them achieved a complete response. CONCLUSION: Targeting cancer with chemotherapy after failure of immunotherapy is a valid option and can lead to better response rates and PFS which may lead to OS. This effect may be secondary to immunotherapy removing the inhibition exerted by tumor cells or other immune cells initially followed by cytotoxic chemotherapy mediated killing of tumor cells.