CAMBRIDGE, Mass. (AP) -- Specialty drugmaker Vertex Pharmaceuticals Inc. swung to a loss in the fourth quarter as doctors turned away from the company's best-selling drug for treating hepatitis C.
Vertex said revenue for quarter ended Dec. 31 fell 41 percent to $334 million. Most of the decline was due to lower sales of the company's hepatitis C pill, Incivek, which contributed $223 million, down from $457 million.
Incivek is taken in combination with interferon drugs, which can cause nausea, diarrhea and other unpleasant side effects. Late last year, the FDA added a boxed warning to the drug about several cases of a fatal skin rash among patients taking the drug. Since a number of other hepatitis drugs are now in development, doctors may be advising patients to wait until future treatments become available before beginning treatment.
The company posted a loss of $76 million, or 35 cents per share, down from $158.6 million, or 74 cents per share, in the same quarter last year. The company's other approved product, the cystic fibrosis drug Kalydeco, posted sales of $58.5 million.
Excluding one-time charges and events the company would have earned $9 million, or 4 cents per share.
Analysts polled by FactSet expected a loss of 6 cents per share on revenue of $320 million.
The company ramped up research and development costs during the quarter to $213.1 million to fund testing on new hepatitis and cystic fibrosis drug.
Looking ahead to 2013 the company expects revenue in the range of $1.1 billion to $1.25 billion. Analysts expect $1.15 billion.
The company said it expects full-year research and development costs to increase to between $750 million and $790 million in 2013. Those expenses were $719 million last year.
Company shares rose 47 cents to close at $46.39 before the earnings report. They were unchanged in aftermarket trading.