HUMAN MOUSE CHIMERIC CD7 MONOCLONAL-ANTIBODY (SDZCHH380) FOR THE PROPHYLAXIS OF KIDNEY-TRANSPLANT REJECTION

mAb directed against CD7 have been shown to inhibit T cell proliferati on in the allogeneic mixed lymphocyte reaction suggesting that CD7 may be an appropriate target for in vivo immunotherapy. We performed a pr ospective randomized clinical trial with a human-mouse chimeric CD7 mA b (SDZCHH380) and compared it with murine OKT3 for the prophylaxis of kidney transplant rejection. Twenty recipients of first cadaveric rena l allografts were randomized to receive either SDZCHH380 or OKT3. SDZC HH380 was well tolerated. Rejection was delayed to day 35. No patients were sensitized to SDZCHH380. In contrast 7/10 OKT3 patients made ant i-OKT3 antibodies. SDZCHH380 coated peripheral blood and lymph node T cells and, in contrast to OKT3, induced minimal release of IL-2, IL-6, TNF-alpha, and IFN-gamma. In addition, we showed that CD7-negative T cells mediated rejection in one of the SDZCHH380-treated patients. We conclude that the human-mouse chimeric CD7 mAb SDZCHH380 is well toler ated, is not immunogenic, and merits further study in the prophylaxis of transplant rejection.