Tre-P-16 - Phase II trial evaluating resminostat for maintenance treatment of patients with advanced stage (stage IIB–IVB) mycosis fungoides (MF) or Sézary syndrome (SS): RESMAIN study

Abstract

<h3>Background:</h3> Patients with advanced CTCL disease ((stage IIB–IVB) mycosis fungoides (MF) or Sézary syndrome (SS)) have a poor prognosis and suffer from profound symptom burden. These patients require systemic treatment. However, it is still a key challenge to achieve durable remissions with the available treatment options. CTCL is characterized by the presence of malignant clonal T-cells in the skin and/or blood, lymph nodes or visceral organs. Epigenetic alterations in malignant T cells are known to play a key role in the pathogenesis of the disease. Resminostat is an orally available HDAC-inhibitor, which induces changes in gene expression resulting in growth inhibition, modified cell differentiation and enhanced tumor immunogenicity. The purpose of the RESMAIN study is to investigate resminostat as maintenance treatment for patients with advanced stage mycosis fungoides (MF) or Sézary syndrome (SS) that have achieved disease control with systemic therapy. <h3>Methods:</h3> The RESMAIN study is a multicenter, double blind randomized, placebo controlled, prospective efficacy trial. Patients are randomized 1:1 to the resminostat and the placebo arm. Furthermore, patients are stratified according to their remission status and their disease stage immediately prior to the last systemic therapy. Patients will be treated until disease progression. Patients of the placebo arm have the option to receive resminostat treatment. In addition, exploratory biomarker analyses will be performed. <h3>Results:</h3> The study is conducted in 11 European countries at 51 sites and at 5 sites in Japan. The first patient was enrolled in January 2017. Recruitment was impacted by the COVID-19 pandemic but continued slowly in 2020 and is now in its final stage. The independent data safety monitoring committee (DSMB) recommended continuation of the ongoing RESMAIN study without modification after a pre-specified review of cumulative safety data of the first 50, 100, ,150 and 175 patients which had completed at least one treatment cycle. The poster will present an actual status update of the RESMAIN study. <h3>Conclusion and objectives:</h3> The primary objective is to determine if maintenance treatment with resminostat increases progression free survival (PFS) compared to placebo. As a key secondary end point the effect of resminostat on time to symptom worsening (TTSW) of pruritus compared to placebo will be assessed. Further secondary endpoints are TTP, TTNT, ORR, OS and HrQoL among others. To our knowledge, this is the first randomized study that investigates the potential of an HDAC inhibitor as maintenance therapy in advanced CTCL.