A Study in Relapse Prevention of Treatment-resistant Depression

This is a multicenter, randomized, double-blind, active comparator-controlled, parallel
study of patients with Treatment Resistant Depression (TRD), comparing the efficacy and
safety of olanzapine and fluoxetine Combination (OFC) versus fluoxetine in relapse
prevention of stabilized patients with TRD. The study will consist of 4 phases: a screening
phase; a 6- to 8-week open-label acute treatment phase; a 10- to 12-week open-label
stabilization phase; and a 27- to 29-week double-blind relapse prevention treatment phase.
Patients who demonstrate response to open-label OFC during the acute treatment phase will
continue into the stabilization phase. Patients who remain stable while receiving open-label
OFC during this phase will be randomized to receive either OFC or fluoxetine during the
double-blind relapse prevention phase. Investigators and patients will be blinded to the
precise duration of the stabilization period, the definition of remission, and the criteria
for entry into the relapse prevention phase; this information is described in a supplement
given to Ethical Review Boards (ERBs) and regulatory authorities.