Poster: MM-324 Effects of Soluble and Microvesicle-Bound Therapeutic Anti-CD38 Antibodies on Immune Effector Cells in Multiple Myeloma

The results of this work indicate that MVs obtained from Dara-treated MM cells may be a particulate system to modulate the immune response, either locally in the bone marrow niche or at distance. Moreover, these observations provide evidence that Dara enhances NK degranulation and activation while paradoxically decreasing their proliferation. These phenomena were observed with both the soluble and insolubilized forms of the antibody. Our data may describe a mechanism underlying Dara effectiveness and may also partially explain the onset of Dara resistance. In conclusion, our results may pave the way for new strategies to improve treatment efficacy and avoid the onset of resistance.