Hyperprogressive disease rarely occurs during checkpoint inhibitor treatment for advanced melanoma

INTRODUCTION: Hyperprogression, characterized by a rapid acceleration in tumor growth, is a novel pattern of progression recently described in patients treated with immune checkpoint inhibitors. This study aims to assess the incidence of hyperprogression in patients with advanced melanoma treated with checkpoint inhibitors. METHODS: Clinical and radiological findings of all advanced melanoma patients who started checkpoint inhibitors between January 2013 and March 2019 in a tertiary academic center in the Netherlands were analyzed. Change in tumor burden was calculated by assessing volumetric tumor growth using the criteria as defined by immune Response Evaluation Criteria in Solid Tumors version 1.1. Hyperprogression was defined as a time to treatment failure less than 2 months with doubling of tumor burden and a twofold increase in tumor growth rate during treatment. Possible hyperprogression was defined as the presence of the first two criteria in the absence of a pre-baseline scan. RESULTS: Out of 206 treatment episodes in 168 patients, 75 were evaluable for hyperprogression and 87 for possible hyperprogression. Hyperprogression was observed in one patient (1.3%) and possible hyperprogression was observed in one patient (1.1%). CONCLUSION: Hyperprogression is rare in melanoma patients treated with immune checkpoint inhibitors. Our data question if hyperprogression really is a biological entity in metastatic melanoma.