[Clinical development of OCT].

OCT was first synthesized in the late 1980s, and clinical development was started in July 1991 with entry into Phase I. By the time the application for manufacturing approval was submitted, in February 1998, 15 clinical studies had been carried out, including 2 double-blind comparative studies and 5 long-term administration studies. The efficacy and safety of OCT were evaluated on the basis of clinical data obtained from totally 977 participants. OCT was found to be effective against secondary hyperparathyroidism in long-term dialysis patients, as it markedly decreased the PTH level, and showed ameliorative effects in bone tissue showing high bone turnover, and on bone metabolic markers. Adding to above clinical effects, because safety data demonstrated that there was no significant drawback except for an increase of serum calcium level, manufacturing approval was finally achieved in July 2000, under the commercial name "Oxarol injection".