The drug: Abilify
The companies: Bristol-Myers Squibb/Otsuka Holdings
Estimated worldwide sales for 2012: $5.38 billion

Otsuka and Bristol-Myers have had to fight to retain patent protection on the schizophrenia drug Abilify. But they've succeeded in holding of cheap copycats until the spring of 2015. That stay of execution means billions in annual revenue for the two pharma companies.

Of course, Bristol-Myers Squibb ($BMY) did run into some trouble with the drug 5 years ago --$515 million worth of trouble. FDA approved Abilify for adult schizophrenia and bipolar disorder, but not for children and adolescents or geriatric patients suffering from dementia. Yet the Justice Department claims the company homed in on child psychiatrists, pediatric specialists and nursing homes to market to those demographics. Despite the bad behavior of the past, the company anticipates a bright future with the drug. An injectable version of Abilify is expected to hit $500 million in peak sales.

Generics have delivered a wallop to the antidepressants market. But longer-acting add-on drugs such as Abilify provide a silver lining. Decision Resources recently reported these drugs are "modestly" increasing their share of patients, helping to stabilize the antidepressants market.

For more:
Report: Schizophrenia drug sales are shrinking, but growth will return
Is the antidepressant glass half-empty or half-full?
AZ's Nexium tops Q2 sales ranks, with BMS' Abilify on its heels
Bristol-Myers' Q4 shows growth in newer products