INDUCTION IMMUNOTHERAPY IN HEART-TRANSPLANTATION WITH T101B9.1A-31 - A PHASE-I STUDY

Cytolytic induction therapy of heart transplantation with OKT3 (immuno globulin G2a isotype, anti CD3 idiotype) or T10B9.1A-31 (immunoglobuli n MK isotype: anti-T-cell receptor clp idiotype) was done in an open-l abel trial to determine the safety and efficacy of the latter monoclon al antibody. A total of nine patients undergoing orthotopic heart tran splantation received a 10-day course of either T10B9.1A-31 (T10B9) (n = 4) 18 mg on bypass and 6 mg intravenously every 12 hours or OKT3 (n = 5) 10 mg on cardiopulmonary bypass and 5 mg intravenously daily. End omyocardial biopsy surveillance revealed no rejection during induction therapy with T10B9, and one OKT3 induction failure was successfully t reated with T10B9, all without significant side effects. T10B9 effecti vely prevented the onset of early acute rejection in heart transplanta tion with minimal side effects. T10B9 reversed rejection in one patien t whose OKT3 induction failed. Results are encouraging and warrant fur ther investigation.