Overdijk MB, Verploegen S, Bögels M, van Egmond M, van Bueren JJL, Mutis T, Groen RWJ, Breij E, Martens ACM, Bleeker WK, Parren PWHI. Antibody-mediated phagocytosis contributes to the anti-tumor activity of the therapeutic antibody daratumumab in lymphoma and multiple myeloma.
MAbs 2015;
7:311-21. [PMID:
25760767 PMCID:
PMC4622648 DOI:
10.1080/19420862.2015.1007813]
[Citation(s) in RCA: 374] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/14/2014] [Accepted: 12/01/2014] [Indexed: 01/14/2023] Open
Abstract
Daratumumab (DARA) is a human CD38-specific IgG1 antibody that is in clinical development for the treatment of multiple myeloma (MM). The potential for IgG1 antibodies to induce macrophage-mediated phagocytosis, in combination with the known presence of macrophages in the tumor microenvironment in MM and other hematological tumors, led us to investigate the contribution of antibody-dependent, macrophage-mediated phagocytosis to DARA's mechanism of action. Live cell imaging revealed that DARA efficiently induced macrophage-mediated phagocytosis, in which individual macrophages rapidly and sequentially engulfed multiple tumor cells. DARA-dependent phagocytosis by mouse and human macrophages was also observed in an in vitro flow cytometry assay, using a range of MM and Burkitt's lymphoma cell lines. Phagocytosis contributed to DARA's anti-tumor activity in vivo, in both a subcutaneous and an intravenous leukemic xenograft mouse model. Finally, DARA was shown to induce macrophage-mediated phagocytosis of MM cells isolated from 11 of 12 MM patients that showed variable levels of CD38 expression. In summary, we demonstrate that phagocytosis is a fast, potent and clinically relevant mechanism of action that may contribute to the therapeutic activity of DARA in multiple myeloma and potentially other hematological tumors.
Collapse