A DOSE-SEARCHING TRIAL OF AN ANTI-LFA1 MONOCLONAL-ANTIBODY IN FIRST KIDNEY-TRANSPLANT RECIPIENTS

25.3, a mouse IgG1 monoclonal antibody (MoAb), directed at the oc chai n of the LFA1 molecule (CD11a) has been used in prophylaxis of rejecti on in recipients of cadaveric kidney graft. Promising clinical results have been obtained for both tolerance and efficacy [1]. The aim of th is trial was to determine the optimal dosage, based on a pharmacokinet ic-pharmacodynamic analysis of the data obtained from the 15 patients included in this dose-searching study. Biological parameters, such as circulating levels and functional inhibition (as detected in an adhesi on assay of patient lymphocytes), were measured during and after treat ment. A Hill relation was calculated between the effect and the concen tration measured and led us to select a 15 mg/day dose for further cli nical trials, with a loading dose of 30 mg. An additional group receiv ing this protocol was submitted to the same calculation, and the resul ts from this last group were in agreement with this previous analysis.