NEW YORK -- Pfizer Inc. said Tuesday a clinical trial showed its anti-smoking treatment Chantix was safe and effective in patients with depression.
Pfizer said patients who took Chantix twice a day had a higher likelihood of quitting smoking after 12 weeks of treatment than patients who took a placebo. It said there were no differences between patients on Chantix and patients who took a placebo on psychiatric health scales. The trial included 525 patients with a current or past diagnosis of depression without psychotic features.
The trial excluded patients who had conditions like dementia, schizophrenia, bipolar disorder, who were considered suicide or homicide risks, had histories of substance abuse, or who were using certain antidepressants.
The study was done at the request of European Union regulators, Pfizer said. EU regulators and the U.S. Food and Drug Administration both approved Chantix in 2006. Sales approached $900 million in 2007 but have slipped because of concerns about the drug's side effects. In October 2011 the FDA said Chantix did not increase psychiatric problems like depression and suicidal thoughts in two studies that were based on hospitalizations.
Pfizer is facing around 2,400 lawsuits related to the neuropsychiatric side effects of Chantix.
Pfizer said the label on Chantix notes that the drug's safety and effectiveness in patients with psychiatric illnesses like schizophrenia, bipolar disorder, and depression have not been established.
The company reported $720 million in revenue from Chantix in 2011, down 5 percent from 2010. In the six months of 2012 sales fell 10 percent to $350 million.
Shares of Pfizer rose 23 cents to $25.80 on Tuesday.