Otsuka Pharmaceuticals has said its OPC-34712 drug has shown efficacy when used as an adjunctive therapy in adults with major depressive disorder.

In Phase II multicentre, double-blind, placebo-controlled study involving 429 adult major depressive disorder patients, it found that, used alongside antidepressant therapy, OPC-34712 demonstrated an improvement in the Montgomery Asberg Depression Rating Scale.

The adverse events associated with OPC-34712 included upper respiratory tract infection, akathisia, weight gain and nasopharyngitis.

OPC-34712, a D2 dopamine partial agonist psychotherapeutic compound, provides improved efficacy and tolerability over established adjunctive treatments for major depressive disorder.

The drug candidate is now under Phase III testing for schizophrenia and adjunctive treatment of major depressive disorder, and is also in Phase II testing for adjunctive treatment of adult ADHD.