Immune recruitment by bispecific antibodies for the treatment of Hodgkin disease

For the treatment of Hodgkin lymphoma, bispecific monoclonal antibodies (bi-mAbs) were established which recognize the Hodgkin-associated CD30 antigen with one arm and the CD3 or CD28 antigen on T lymphocytes or the CD16 antigen on natural killer (NK) cells with the second arm. The NK cell-activating α-CD16/CD30 antibody was able to retarget human NK cells toward CD30+ target cells and induce their lysis. Sixty percent of Hodgkin tumor-bearing severe combined immunodeficient mice responded to a combined treatment with bi-mAb and human NK cells, leading to a final cure rate of 20%. T cell-activating bi-mAbs were more effective, resulting in the cure of all mice treated. The in vivo administration of both α-CD3/CD30 and α-CD28/CD30 antibodies resulted in the specific activation of resting human T cells infiltrating the CD30+ Hodgkin tumors. Tumor-infiltrating lymphocytes in the group of mice treated with both T cell-activating bi-mAbs expressed high levels of cytokines and cytotoxic molecules such as perforin and the cytotoxic serine esterases granzyme A and B. More importantly, activated T cells did not home to CD30− tissue and did not enter the circulation. Encouraged by these preclinical data, 15 patients with treatment-refractory Hodgkin lymphoma were included in a phase I/II dose-escalation study and treated four times every 3 or 4 days with increasing doses of the α-CD16/CD30 bi-mAb ranging from 1 mg/m2 to 128 mg/m2. No dose-limiting toxicity occurred even at the highest doses. Of these 15 patients, one had a complete response, one a partial response, three a mixed response, two stable disease, and eight patients had progressive disease. Treatment with immunological effector cell-recruiting bi-mAbs is a promising new approach to the treatment of Hodgkin disease refractory to standard therapy.