Clinical effectiveness of nemifitide, a novel pentapeptide antidepressant, in depressed outpatients: comparison of follow-up re-treatment with initial treatment.

Data from two Phase 2 clinical studies with nemifitide, a novel pentapeptide antidepressant, were evaluated. The initial double-blind, placebo-controlled study was performed on outpatients with DSM-IV criteria for major depressive disorder. An open-label extension study enrolled subjects either completing or having been discontinued due to lack of efficacy during the follow-up period of the initial study. In the extension study, both the investigator and the subjects were blinded to the previous treatment in the initial study. No clinically significant side-effects were observed in either study. Twenty-seven subjects have been entered and evaluated in the extension study. Eighteen of these 27 subjects (66.7%) responded to re-treatment in the extension study. Mean duration of effect between re-treatments was 3.3 months. The results of the extension study support investigating a range of doses of nemifitide from 18 to 72 mg/d in future clinical trials. Further studies are planned to determine the most effective nemifitide clinical treatment regimen.