SkyePharma shares have been hit by the news that regulators in the USA want more information on its asthma product Flutiform.

The UK drug delivery specialist says it has received a 74-day letter from the US Food and Drug Administration concerning a regulatory submission for Flutiform (fluticasone and formoterol). The letter states that “further clarification is required” of some potential review issues and “steps are being taken to seek discussions with the FDA with a view to agreeing how they may be addressed”.

The company added that although the requirements “cannot be precisely assessed” prior to discussion with the agency, “based on a preliminary assessment, it appears likely that some additional clinical work may be required to provide more data on dosing”. Also reviews for asthma treatments take typically longer than the standard 10-month Prescription Drug User Fee Act timeline, SkyePharma noted.

Flutiform is vital to the future prospects of SkyePharma, which has Abbott Laboratories as its partner in the USA. In Europe, a filing by partner Mundipharma is expected by the first quarter of 2010.

Last month, SkyePharma revealed that headcount has been reduced by over 10% at its R&D facility in Muttenz, Switzerland, while the 120-strong workforce at its manufacturing facility in Lyon, France will be cut by one-third. The cuts are expected to save operating costs at the rate of £1.5 million per year and SkyePharma will take a £2 million charge which will be included in its accounts for the first half of 2009.