Autologous Dendritic Cell Vaccination in Mesothelioma

In this multicenter phase I/II trial, dendritic cells (DCs) loaded with the mesothelioma-associated tumor antigen WT1 will be used in conjunction with conventional chemotherapy for the frontline treatment of malignant pleural mesothelioma (MPM). The general objective is to provide the first-in-human experimental demonstration that the combination of platinum/pemetrexed-based chemotherapy with WT1-targeted DC vaccination is feasible and safe and enables the induction of both systemic and in situ mesothelioma-specific immune responses in patients with MPM.

Malignant pleural mesothelioma (MPM) is a highly aggressive and in virtually all cases fatal cancer that is tightly associated with prior asbestos exposure. Despite some improvement over time, the prognosis of patient diagnosed with MPM remains dismal with a median overall survival from diagnosis of only 12 months. In this single arm phase I/II trial the investigators want to demonstrate the feasibility and safety of WT1-targeted dendritic cell vaccination in MPM patients as frontline treatment in conjunction with first line platinum/pemetrexed-based chemotherapy and the induction of both systemic and in situ mesothelioma-specific immune responses. During three years of recruitment the investigators aim at including 20 patients diagnosed with histologically proven epithelial MPM (WHO grade 0-1) who are able to undergo leukapheresis, chemotherapy, immunotherapy and pleurectomy/decortication (P/D; in case of resectable disease). Patients who underwent prior treatment for MPM or with a history of another malignancy within the last five years will be excluded. The intention of this study is to administer four vaccine doses in combination with standard of care of four 3-weekly cytoreductive platinum/pemetrexed-based chemotherapy cycles to each participant and prior to surgery (P/D) in the case of resectable MPM. Patients will receive four 3-weekly intradermal vaccinations with autologous WT1 messenger (m)RNA-loaded dendritic cells (V1-4), at day 14 after the start of each chemotherapy cycle (CT1-4). The dendritic cell therapy product will be generated and administered in the Antwerp University Hospital, more specifically the Center for Cell Therapy and Regenerative Medicine (CCRG) and the Division of Hematology, both headed by Prof. Zwi Berneman. The DC vaccines will be under embargo from release until the safety and quality control test results have become available and all release criteria have been met. A detailed overview of all applicable release criteria is provided in the investigational medicinal product dossier. The embargo period generally lasts 3 weeks counting from the day of cryopreservation (i.e. 8 days after leukapheresis). Recruitment started in August 2017. Study-related follow-up of the included patients is intended to be until 90 days after final DC vaccine administration or 22 months after diagnosis, whichever occurs later. In addition to feasibility and safety of the chemoimmunotherapy schedule, the investigators will look for the time to progression (TTP), progression-free survival (PFS), overall survival (OS), systemic immunogenicity and local immunogenicity.