The successful U.S. launches of breast-cancer treatment Ibrance and pneumonia vaccine Prevnar for adults helped Pfizer Inc. to boost Tuesday its profit expectations for 2015 as the pharmaceutical giant released its second-quarter results.

Ian Read, Pfizer’s chairman and chief executive, credited the company's second-quarter results to a variety of factors, including continued growth of blood-clot medicine Eliquis and rheumatoid arthritis pill Xeljanz, the latter of which was developed at the company's Groton laboratories.

“Our second-quarter and year-to-date financial performance is the result of continued business momentum,” Read said in a statement.

During the second half of the year, Read said, Pfizer is looking toward completing its deal to buy Hospira Inc. for $16 billion. The merger will enhance Pfizer’s move into injectable and biosimilar drugs.

Despite the boost in profit expectations, Pfizer’s second-quarter results were down compared with last year. Profits of $2.63 billion were down about $300 million from a year ago, while its earnings of 42 cents a share were off by 3 cents.

Excluding one-time profit hits, however, earnings were 56 cents a share, which was higher than Wall Street expectations of 52 cents a share.

The stock market reacted positively to Pfizer's second-quarter results, with the shares finishing the day at $35.35, up nearly 3 percent.

Revenue of $11.9 billion reflected a 7 percent decline from the second quarter last year. But Pfizer said revenue would have increased slightly were it not for losses tied to currency impacts related to a higher U.S. dollar.

Read said in a conference call with financial analysts that the company is still considering a possible split of Pfizer into three different companies, as was announced two years ago. The company began recording results for divisions focusing on generic medicines, innovative drugs and vaccines, oncology and consumer drugs separately starting last year.

"We would be in a position, if we so took the decision, to effectuate or start the split in 2017, which probably means we would have to take the decision in the latter part of 2016," Read said, according to a transcript provided by Thomas Reuters.

Pfizer has been fighting a wave of patent expirations, the most recent of which was for painkiller Celebrex. The company’s biggest gains were seen in its oncology division, which saw revenues rise 25 percent in the second quarter.

l.howard@theday.com

Twitter: @KingstonLeeHow