Allergan and Gedeon Richter said they will continue to develop the marketed bipolar I disorder and schizophrenia drug cariprazine despite the failure of the drug in a Phase III trial for a new indication.
Cariprazine missed its primary endpoint in the MD-72 trial of showing significant improvement as an adjunctive treatment to antidepressant therapy in adults with major depressive disorder (MDD) who failed to respond adequately to antidepressant monotherapy, the companies acknowledged.
MD-72 was a prospective, randomized, double-blind, placebo-controlled, parallel-group study evaluating flexible doses of cariprazine (1.5–4.5 mg) conducted at numerous U.S. sites.
Cariprazine is an oral, once-daily, atypical antipsychotic marketed in the U.S. as Vraylar™ for the treatment of manic or mixed episodes of bipolar I disorder and schizophrenia in adults, having won FDA approval in September 2015.
Allergan and Richter said they remain committed to developing cariprazine as a potential treatment option for patients suffering from MDD, adding that they will continue to work on another Phase III trial.
The companies have started enrolling patients for a pivotal study assessing cariprazine as a treatment for bipolar depression, an indication for which positive data was published from a Phase IIb trial last year in the Journal of American Psychiatry. Two parallel studies will be conducted at approximately 85 sites across the U.S. and Europe.
Also last year, the companies announced positive Phase III trial results for cariprazine in the prevention of relapse of schizophrenia symptoms in adults, and Richter separately disclosed positive results from a Phase III study evaluating cariprazine for predominant negative symptoms of schizophrenia.
MD-72 was one of more than 20 trials conducted over the past decade to evaluate the efficacy and safety of cariprazine on thousands of patients in a broad range of mental health illnesses, Allergan and Richter said.
“We are disappointed with the results of this trial,” Allergan Chief R&D Officer David Nicholson said of MD-72 in a statement. “However, we believe that our plan to move forward with another Phase III study in adjunctive MDD coupled with our previous positive clinical trial would provide the two studies needed for submission.”