Glaxo cuts year's outlook as Advair sales tumble

London-based drugmaker GlaxoSmithKline cut its forecast for the year, as sales of its best-selling asthma drug, Advair, continue to fall. Glaxo shares on the London Stock Exchange dropped the most in almost six years.

Full-year earnings per share will be similar to last year and sales are unlikely to increase, the company said Wednesday.

Glaxo has operations at the Philadelphia Navy Yard and in other locations in Pennsylvania and New Jersey.

Profits excluding certain items fell to $2.39 billion, from $3.2 billion for the same period in 2013. Sales for the quarter fell 4 percent at constant currency exchange rates, to $9.8 billion.

The British pound reached $1.71 in the second quarter, the highest level since 2008, reducing the profit from U.S. revenue. Pharmaceutical and vaccine sales in the U.S. fell 10 percent.

Market share for Advair fell after the drug lost patent protection and the largest U.S. pharmacy-benefits manager stopped reimbursing prescriptions. Efforts to introduce two new lung drugs, Breo and Anoro, to help replace Advair revenue have taken longer to bear fruit than the company anticipated. The marketing costs of new products also hurt profit.

"Our strategy to transition and diversify our respiratory portfolio is underway," chief executive officer Andrew Witty said in the statement. "We expect the transition of this portfolio to continue over the next two to three years and remain confident that GSK will maintain its leadership position in respiratory well into the next decade."

Advair sales declined 12 percent. Generic competition for Lovaza, a heart medicine, "has been more substantive and began earlier than we expected," Glaxo said.

China began a probe last year into the company's sales practices in the country, detaining some of its employees there. In May, Chinese police handed the bribery case to prosecutors, accusing a British executive of ordering workers to illegally pay doctors, hospitals, and medical associations to boost sales. Revenue in the country fell 25 percent, to 129 million pounds, in the second quarter.

Glaxo said it is cooperating with Chinese officials and is conducting an internal investigation. The U.K. Serious Fraud Office has also opened a probe.

The company is selling some of its established products, which are expected to have $1.7 billion in revenue this year. Potential purchasers include private-equity firms and mid-tier pharmaceutical companies, Witty told journalists on a conference call Wednesday. Glaxo expects to complete the sale by the end of the year.