Allergan Endures Another R&D Setback With Rapastinel Failing Three Pivotal Studies

Clinical development failures in major depressive disorder (MDD) are nothing new, but Allergan PLC’s trio of unsuccessful Phase III studies with NMDA receptor modulator rapastinel might be more damaging because of the company’s recent litany of R&D setbacks, along with Johnson & Johnson’s US approval in the same class with Spravato on March 5.

Allergan announced top-line results late in the day March 6 showing that rapastinel – a driver of its $560m purchase of Naurex Inc. in 2015 – failed to meet the primary and secondary endpoints as adjunctive MDD therapy in three Phase III studies enrolling 1,500 patients. The candidate appeared unlikely to meet endpoints in an ongoing, open-label relapse-prevention study as well. Allergan spoke optimistically about rapastinel during the J.P. Morgan Healthcare Conference in January and had named it one of the six “stars” of its pipeline. (Also see "J.P