US regulators have extended their review of Allergan/Gedeon Richter’s investigational antipsychotic cariprazine by three months.

Cariprazine is a potent dopamine D3/D2 receptor partial agonist atypical antipsychotic, which the firms are seeking to market as a treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder.

But the drug’s regulatory path met a key obstacle in 2013 when the US Food and Drug Administration turned down its marketing application calling for more trial data, even though the Agency noted at the time that it ‘clearly demonstrated effectiveness’.

Now, the extended review comes after a response to an FDA query was deemed to be a “major amendment”, requiring extra time to process. 

Further details were not revealed, but the firm said they “remain committed to pursuing this important treatment option for patients and physicians”.