* Gedeon Richter’s shares jump more than 10 pct
* Forest shares rise nearly 3 percent
* Clinical trial focused on bipolar mania
* Cariprazine could have sales of $500 mln-$1 bln-analyst
By Toni Clarke
Oct 5 (Reuters) - Hungarian drugmaker Gedeon Richter (GDRB.BU) and U.S. partner Forest Laboratories Inc FRX.N reported positive results on Wednesday from a late-stage clinical trial of their experimental drug to treat mania associated with bipolar disorder.
The news sent shares of Gedeon Richter up more than 10 percent. Forest’s shares rose nearly 3 percent.
Data from a Phase III trial of 312 patients with bipolar I disorder showed that patients treated with cariprazine experienced a significant improvement in symptoms compared with those treated with a placebo.
Symptoms of bipolar mania include an unusually elevated mood, excess energy, sleeplessness and irritability.
Cariprazine is an oral antipsychotic that modulates levels in the brain of the chemical messenger dopamine. Dopamine helps regulate movement and emotional responses. The drug is also under development for the treatment of schizophrenia, bipolar depression, and as an add-on treatment for patients with major depressive disorder.
The companies said patients in the bipolar mania trial found the drug to be reasonably well tolerated. The overall discontinuation rate was 32 percent in the cariprazine group and 31 percent for patients in the placebo group. The most common side effects included restless leg syndrome, movement disturbances, tremor, upset stomach and vomiting.
Discontinuations due to adverse events were 10 percent in the cariprazine group and 7 percent in the placebo group.
“The positive Phase III data underscore that Forest’s pipeline is underappreciated,” Louise Chen, an analyst with Collins Stewart, said in a research note. She predicted sales of the drug could eventually reach $500 million to $1 billion a year.
Chen said she expects Forest to file for approval of the drug in bipolar mania and schizophrenia in 2012.
In August, Forest, which makes the antidepressants Celexa and Lexapro, won a showdown with activist investor Carl Icahn, who had sought to place four nominees on the company’s board. Icahn’s loss came after the U.S. government dropped plans to bar Forest’s chief executive, Howard Solomon, from doing business with federal healthcare programs.
Forest’s revenue is expected to drop by about one-fourth after Lexapro loses patent protection early next year. Its Alzheimer’s drug Namenda will lose patent protection in 2015.
The bipolar trial results represent a significant boon for Gedeon Richter, which earlier this year warned its profit would decline in 2011 due to higher marketing and research costs associated with two acquisitions. (Additional reporting by Marton Dunai in Budapest, editing by Maureen Bavdek)