Otsuka Pharmaceutical and H. Lundbeck have announced results from the Phase 3 clinical trial demonstrating the efficacy, safety and tolerability of once-monthly aripiprazole intramuscular (IM) depot formulation, used for the treatment of adults with schizophrenia.

Aripiprazole IM depot formulation is a sterile lyophilised cake that, when reconstituted with sterile water for injection, forms an injectable suspension.

In a 52-week, double-blind, randomised, placebo-controlled study conducted by Otsuka Pharmaceutical Development & Commercialization (OPDC), there were four phases: oral conversion, oral stabilisation, IM depot formulation stabilisation and maintenance treatment.

The trial’s primary efficacy endpoint was time to impending relapse, while the secondary efficacy endpoint was the percentage of subjects who met the impending relapse criteria at the endpoint of the double-blind, placebo-controlled phase, as well as mean changes from baseline.

"A once-monthly injection of aripiprazole IM depot formulation is effective in delaying the time to relapse for patients with schizophrenia."

The data demonstrated that aripiprazole IM depot formulation considerably delayed time-to-impending relapse compared to a placebo in 710 adult patients with schizophrenia who required chronic treatment with an antipsychotic agent.

Patients treated with aripiprazole IM depot formulation also showed improvements in the symptoms as measured by the Positive and Negative Syndrome Scale (PANSS) total score and were sustained throughout the study.

At week 52, the mean change from baseline was 1.4 for the aripiprazole IM depot formulation compared to 11.6 for the placebo.

During the maintenance treatment phase, the PANSS subscale scores showed both positive and negative symptom stability with aripiprazole IM depot formulation, but showed significant worsening for patients who received the placebo.

The study also reported that the incidence of injection site pain was 3% for aripiprazole IM depot formulation and 3.7% for the placebo. The incidence of clinically relevant weight gain was 6.4% for aripiprazole IM depot formulation versus 5.2% for the placebo.

North Shore-LIJ Health System, US, Behavioral Health Services vice president and The Zucker Hillside Hospital, US, psychiatry chairman John Kane said the study results demonstrate that a once-monthly injection of aripiprazole IM depot formulation is effective in delaying the time to relapse for patients with schizophrenia.