Pharmaceutical company SkyePharma PLC (SKP.LN) said Tuesday its asthma treatment Flutiform was unlikely to receive approved in the U.S. before the second half of 2011 after U.S. regulators asked for more research.

London-based SkyePharma received a letter from the U.S. Food and Drug Administration in June, following its submission of Flutiform for marketing approval. The firm said the letter suggested further work might be required for Flutiform before the FDA approves it for sale.

SkyePharma said Tuesday that a meeting has now been held with the FDA and additional clinical work will be required to provide more data on dosing.

"The board believes that it is unlikely that Flutiform will, therefore, be approved in the U.S. before the second half of 2011."

The firm had held talks about a submission in 2007 but had to perform an additional Phase III trial after the FDA asked for more data.

The additional research is not expected to have an impact on the Flutiform development in Europe or Japan, it said.

Asthma and other respiratory diseases are big business. Products similar to Flutiform generate sales of about $29 billion a year.

Marketing partner Abbott Laboratories (ABT) is responsible for paying for additional clinical or other trials required by the FDA, and is entitled to recoup such costs once approval is granted.

Company Web site: www.SkyePharma.com

-By Michael Carolan, Dow Jones Newswires; 44-20-7842-9278; michael.carolan@dowjones.com