• Inger S Nijhof, Richard W J Groen, Willy A Noort, Berris van Kessel, Regina de Jong-Korlaar, Joost Bakker, Jeroen J L van Bueren, Paul W H I Parren, Henk M Lokhorst, Niels W C J van de Donk, Anton C M Martens, and Tuna Mutis.
• Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, the Netherlands. Department of Hematology, University Medical Center Utrecht, Utrecht, the Netherlands. Department of Hematology, VU University Medical Center, Amsterdam, the Netherlands.
• Clin Cancer Res. 2015 Jun 15; 21 (12): 2802-10.

PurposeNovel therapeutic agents have significantly improved the survival of patients with multiple myeloma. Nonetheless, the prognosis of patients with multiple myeloma who become refractory to the novel agents lenalidomide and bortezomib is very poor, indicating the urgent need for new therapeutic options for these patients. The human CD38 monoclonal antibody daratumumab is being evaluated as a novel therapy for multiple myeloma. Prompted with the encouraging results of ongoing clinical phase I/II trials, we now addressed the potential value of daratumumab alone or in combination with lenalidomide or bortezomib for the treatment of lenalidomide- and bortezomib-refractory patients.Experimental DesignIn ex vivo assays, mainly evaluating antibody-dependent cell-mediated cytotoxicity, and in an in vivo xenograft mouse model, we evaluated daratumumab alone or in combination with lenalidomide or bortezomib as a potential therapy for lenalidomide- and bortezomib-refractory multiple myeloma patients.ResultsDaratumumab induced significant lysis of lenalidomide/bortezomib-resistant multiple myeloma cell lines and of primary multiple myeloma cells in the bone marrow mononuclear cells derived from lenalidomide- and/or bortezomib-refractory patients. In these assays, lenalidomide but not bortezomib, synergistically enhanced daratumumab-mediated multiple myeloma lysis through activation of natural killer cells. Finally, in an in vivo xenograft model, only the combination of daratumumab with lenalidomide effectively reduced the tumorigenic growth of primary multiple myeloma cells from a lenalidomide- and bortezomib-refractory patient.ConclusionsOur results provide the first preclinical evidence for the benefit of daratumumab plus lenalidomide combination for lenalidomide- and bortezomib-refractory patients.©2014 American Association for Cancer Research.

56 keywords...

hide…