Re-directed T cells for the treatment of fibroblast activation protein (FAP)-positive malignant pleural mesothelioma (FAPME-1)

Abstract

BackgroundAsbestos is the main cause of MPM in industrialized countries. Even since asbestos is banned in most developed countries, the peak wave of MPM incidence is anticipated for the next years due to the long latency of asbestos induced MPM. MPM patients not eligible for surgical procedures like decortication or pleuro-pneumectomie have a median survival of 12 months with palliative chemotherapy. Therefore, new therapeutic approaches are of crucial need in this clinical situation.Methods/designThis is a phase I trial for patients with malignant pleural mesothelioma with pleural effusion testing the safety of a fixed single dose of 1x106 adoptively transferred FAP-specific re-directed T cells given directly in the pleural effusion. Lymphocytes will be taken 21 days before transfer from peripheral blood. CD8 positive T cells will be isolated and re-programmed by retroviral transfer of a chimeric antigen receptor recognizing FAP which serves as target structure in MPM. At day 0 of the protocol, re-directed T cells will be injected in the pleural effusion and patients will be monitored for 48h under intermediate care conditions. AE, SAE, SADR and SUSAR will be monitored for 35 days and evaluated by an independent safety board to define any dose limiting toxicity (DLT). No further patient can be treated before the previous patient passed day 14 after T cell transfer. The protocol will be judged as save when no DLT occurred in the first 3 patients, or 1 DLT in 6 patients. Secondary objectives are feasibility and immune monitoring.DiscussionAdoptive T cell transfer is a new and rapidly expanding branch of immunotherapies focusing on cancer treatment. Recently, objective responses could be observed in patients with chronic lymphatic leukemia treated with adoptively transferred CD19-specific re-directed T cells. The choice of the target antigen determines the possible on-target off-tissue toxicity of such approaches. There are reports of severe toxicity in patients who received T cells intravenously due to unexpected expression of the target antigen (on-target) in other tissues than the tumor (off-tissue). To minimize the risk of on-target off-tissue toxicity and to maximize the on-target anti-tumor effect we propose a clinical protocol with loco-regional administration of re-directed T cells. FAP-specific T cells will be directly injected in the pleural effusion of patients with MPM.Trial registrationClinicalTrials.gov (NCT01722149)

Chimeric antigen receptor T cells: a novel therapy for solid tumors

“…At present, a phase I clinical trial of anti-CD133 CAR-T cells in patients with relapsed and/or chemotherapy refractory advanced malignancies is ongoing (NCT02541370). In addition to above antigens, fibroblast activation protein (FAP) [139, 140], NY-ESO-1 [141], MUC1 [142], foliate receptor [143, 144], and IL13Rα2 [145, 146] are also potential target antigens for immunotherapy.…”

Can Targeting Stroma Pave the Way to Enhanced Antitumor Immunity and Immunotherapy of Solid Tumors?

“…Finally, several groups have used adoptive transfer of FAP-specific redirected T cells to deplete FAP + stromal cells in a variety of tumor models (25,28,103–106). The majority of these studies utilized adoptive transfer of FAP-specific chimeric antigen receptor expressing (FAP-CAR) T cells.…”

Mesenchymal Stromal Cells Can Regulate the Immune Response in the Tumor Microenvironment

“…In this context, it is conceivable that surface markers expressed mainly, if not exclusively, by MSC should be considered to regulate the TME. Indeed, FAP, CD73, and CD105 can be considered as suitable markers to target MSC [11,13,14,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150]. In hematological malignancies, but also in solid tumors, the administration of immunomodulatory drugs (IMiDs) derived from their prototype Thalidomide to CC-122 has given very attractive results because these compounds can hit MSC besides tumor cells [151,152,153].…”

“…Several kinds, compositions, and modes of administration of anti-tumor vaccines have been used with different results [160,161,162,163,164,165,166,167]. More recently, the focus of anti-tumor vaccines has been moved from tumor cells to TME too [7,9,10,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175]. Indeed, the possibility of targeting tumor endothelial cells or the VEGF signaling axis with specific vaccines has been assessed in preclinical studies, and clinical trials are ongoing [168].…”