Giant Cell Arteritis: Comparison Between Two Standardized Corticosteroids Tapering

Corticosteroid therapy has always been the standard treatment for giant cell arteritis (GCA), with very good initial clinical efficacy but a high relapse rate when it declines. The target population of this condition, often elderly, is particularly exposed to the numerous undesirable effects of corticosteroid therapy, and this especially as its duration lengthens with the re-increases of doses according to relapses: metabolic complications, osteo-muscular , infectious or neuropsychiatric. Investigators propose to compare prospectively the results of a "conventional" corticosteroid regimen as recommended by European societies, to those of a "lighter and / or shorter" scheme, inspired by recent North American trials. , including the largest prospective global study in the field. Investigators hypothesize non-inferiority of the lightened regimen for relapse rate without relapse at S52, but with a decrease in treatment-related adverse events whose cumulative doses should be lower. Investigators therefore plan to include prospectively over 3 years 150 patients, 75 for each of the two arms, with a newly diagnosed ACG. A randomization of the treatment arm will be performed and a predefined pattern of cortisone adapted to body weight will be given to the patient. Relapse rates, maintenance of remission, cumulative doses of cortisone and adverse effects of treatment will be analyzed at the 52nd week of the introduction of corticosteroid therapy. An interim analysis is planned at S28.