NEW YORK — The Swiss drugmaker Roche agreed on Sunday to buy InterMune — which sells a drug to treat a deadly lung disease — for $8.3 billion, as pharmaceutical companies continue to seek products to bolster their offerings.
The price, $74 a share, represents a 38 percent premium to InterMune’s closing price on Friday and a 63 percent premium to the price on Aug.12, before news reports that InterMune might be acquired.
The acquisition was announced amid a flurry of pharmaceutical deals and attempted deals. About $87 billion in pharmaceutical acquisitions were made in the first half of this year, eclipsing the total for all of 2013, according to Evaluate, a research company. The total for the first half does not include the $54 billion acquisition of Shire by AbbVie, which was announced in July.
InterMune, based in Brisbane, Calif., has one product on the market: a drug called pirfenidone to treat idiopathic pulmonary fibrosis, a fatal scarring of the lungs.
InterMune, which is still not profitable, sells pirfenidone under the name Esbriet in Europe and Canada, where it received regulatory approval in 2011 and 2012. The drug could receive approval in the United States by Nov. 23.
Sales of Esbriet were $35.7 million in the second quarter, but some analysts expect annual revenues to eventually exceed $1 billion.
“We are obviously focused on high unmet medical needs and looking for medicines that make a significant difference clinically, and this clearly fits that bill,’’ Daniel O’Day, who runs Roche’s pharmaceutical business, said in an interview Sunday.
He said the acquisition would strengthen its portfolio of drugs for respiratory diseases. That has not been a major business for a company mainly known for its cancer treatments.
Roche sells Xolair, a drug for asthma, and Pulmozyme for cystic fibrosis. But it has another drug, lebrikizumab, that is in late-stage clinical trials to treat severe asthma and is also being evaluated as a possible treatment for idiopathic pulmonary fibrosis.
Roche, however, has historically not relied much on acquisitions for its pharmaceutical business, though it has in its diagnostics business. The big exception was its acquisition of the part of biotechnology pioneer Genentech that it did not already own for $46.8 billion in 2009.
In the last couple of months, Roche has announced smaller acquisitions, agreeing to pay at least $725 million for privately held Seragon Pharmaceuticals, and at least $250 million for privately held Santaris Pharma.