Clinical effect of nemifitide, a novel pentapeptide antidepressant, in the treatment of severely depressed refractory patients

Clinical data were evaluated from an open-label, single-center, pilot study in patients with chronic refractory depression. The primary efficacy criterion was the change from baseline using the Montgomery-Asberg Depression Rating Scale. The secondary efficacy criteria were the 17-item Hamilton Depression Rating Scale and the Clinical Global Impression-Improvement scale. Response to treatment (40-240 mg once per day by subcutaneous injection for 10-20 doses) was defined as more than 50% improvement in the Montgomery-Asberg Depression Rating Scale from baseline or Clinical Global Impression-Improvement < or =2 and lasting for at least two sequential weeks. Patients with a sustained response at the end point in the acute main treatment phase were enrolled for up to 2 years in a maintenance phase of the study to determine duration of response and to initiate retreatments upon relapse. Of the 25 patients with chronic refractory depression, 11 patients showed a response for Montgomery-Asberg Depression Rating Scale and one responded according to the secondary criterion Hamilton Depression Rating Scale. In seven of the 11 responders to Montgomery-Asberg Depression Rating Scale the effects were sustained for the remainder of the acute phase. Two additional sustained responders identified according to secondary criteria (Hamilton Depression Rating Scale or Clinical Global Impression-Improvement) were also enrolled in the maintenance phase. All nine sustained responders were retreated, as needed, in the maintenance phase of the study, ranging from 71 to 660 days. Mean duration of response following initial treatment and between retreatments was around 2 months. Pharmacokinetic data indicated dose-proportional systemic exposure to the drug.