Study is second flexible-dose trial to miss primary endpoint.

A second Phase III study evaluating AstraZeneca and Targacept’s TC-5214 as an adjunct to antidepressants in patients with major depressive disorder (MDD) has failed to meet its primary endpoint. The Renaissance 2 study involved 710 patients who didn’t initially respond to antidepressant therapy using one of seven SSRIs or SNRIs.

Results from this trial showed that in comparison with placebo, adding TC-5214 to antidepressant therapy failed to result in significant changes in depression scores (measured on the Montgomery-Asberg Depression Rating Scale) after eight weeks.

The Renaissance 2 trial data follow on from recently reported results from the Renaissance 3 study, which also failed to meet its primary endpoint.  However, Targacept and AstraZeneca stress that both these trials were flexible-dose trials and the two remaining efficacy studies in the Renaissance program for TC-5214 are fixed-dose trials. Topline results from these ongoing studies and from a long-term safety evaluation are due to report in the first half of 2012.

The firms say they don’t plant to review regulatory filing targets until the remaining Renaissance trial results are evaluated. A potential NDA filing for TC-5214 in the U.S. is planned for the second half of 2012, with a potential EU MAA projected for filing in 2015.

AstraZeneca and Targacept inked a global development and commercialization deal for the latter’s TC-5214 at the end of 2009. The initial development program is focused on the drug as an adjunct therapy for patients with inadequate response to therapy with SSRI or SNRI therapy. TC-5214 is also undergoing a Phase IIb switch monotherapy study in SSRI/SNRI-unresponsive MDD patients.