Study design
This was a multicenter, open-label, flexible-dose, 52-week extension study of study participants who had completed one of two previous acute double-blind efficacy and safety trials that were conducted at 88 sites in Asia, Australia, Europe (NCT00735709) (Henigsberg et al., 2012), and the USA (NCT00672620) (Mahableshwarkar et al., 2013). In the US study, study participants were originally randomized to receive vortioxetine 2.5 mg, vortioxetine 5 mg, duloxetine 60 mg, or placebo once daily; those in the non-US study were randomized to receive vortioxetine 1 mg, vortioxetine 5 mg, vortioxetine 10 mg, or placebo once daily. Study participants completing one of these acute double-blind studies were eligible to continue treatment for 52 weeks in this open-label extension study, irrespective of their response to treatment at the end of week 8 of the acute efficacy studies if they were considered by the investigator to benefit from 52 weeks of treatment with vortioxetine. After baseline screening, all study participants were switched to vortioxetine 5 mg/day for the first week of the extension study, irrespective of their treatment assignment at the completion of the acute double-blind trials. Thereafter, the vortioxetine dose could be maintained at 5 mg/day, increased to a maximum of 10 mg/day, or decreased to 2.5 mg/day, on the basis of patient response and tolerability as determined by the investigator.
The study was approved by the ethics committee of each site and was carried out in accordance with the ethical principles outlined in the Declaration of Helsinki and International Conference on Harmonisation Good Clinical Practice Guidelines. All enrolled study participants provided written informed consent before undergoing any study procedures.