Hungarian drug company Gedeon Richter and US partner Forest Laboratories announced on Monday that they may conduct further Phase II dose-response testing on the antipsychotic agent Cariprazine (RGH-188) in the treatment of major depressive disorder.
While preliminary results of an eight-week Phase II clinical trial indicated no statistical difference between drug-treated and placebo-treated groups of patients, they did show evidence of a treatment effect in the high-dose arm of the study compared to the placebo.
The companies are currently engaged in Phase III trials on the Richter-developed drug for the treatment of schizophrenia and bipolar mania after Phase II trials demonstrated a reduction in symptoms for these disorders.
Richter and Forest Laboratories said that tolerability results for Cariprazine support further investigation. The reported that approximately 3% of patients suffering from major depressive disorder discontinued the Phase II clinical trial of Cariprazine early due to adverse events in both the high-dose and placebo arm of the study, while 1% did so in the low-dose arm.
The trials were conducted using patients diagnosed with major depressive disorder who had failed to respond to at least two anti-depressive therapies.
Forest Laboratories licensed the drug in the United States and Canada in 2004.