Graft-Versus-Host Disease in Multiple Myeloma Patients Treated With Daratumumab After Allogeneic Transplantation

IntroductionAllogeneic hematopoietic cell transplantation (allo-HCT) represents an adoptive immunotherapy strategy for eliciting a graft-versus-myeloma, the effect for high-risk or relapsed multiple myeloma (MM). Allo-HCT recipients are at risk for graft-versus-host disease (GVHD) as well as associated increases in morbidity and mortality. Daratumumab, an anti-CD38 human immunoglobulin G1 kappa humanized monoclonal antibody, is used for treatment of MM. Daratumumab also affects CD38⁺ nonmyeloma cells, including T cells, which mediate GVHD. The use of daratumumab after allo-HCT has not been well described, and its potential impact on GVHD is unknown.Patients and MethodsIn a multicenter retrospective study, we evaluated incidence of GVHD in 34 patients with relapsed MM treated with daratumumab after allo-HCT.ResultsOverall response to daratumumab (partial response or better) was 41% (95% confidence interval, 24-59). Five patients (15%) developed acute GVHD after daratumumab therapy; no chronic GVHD events were observed after daratumumab therapy. One of these 5 patients had a history of chronic GVHD and developed a flare of acute GVHD during daratumumab therapy. The remaining 4 patients did not have a history of GVHD before daratumumab.ConclusionThe incidence of GVHD after daratumumab was low and did not result in increased exacerbation of GVHD in patients with a history of GVHD.