Generic drug firm Barr Pharmaceuticals is seeking FDA approval to market thalidomide, a generic version of Thalomid, a skin defect drug manufactured by Celgene, Barr announced Dec. 26.

Barr amended an abbreviated new drug application sent to the FDA earlier in December seeking approval to market a generic version of the drug in 200-mg capsules. It now wants to market the drug in 50- and 100-mg capsules, the company said.

Celgene had immediately moved to file a patent infringement lawsuit against the generic company banking on the seven patents it holds covering key areas such as the administration of the drug and how it is used in certain treatment areas.

Barr could not be reached for comment.

Thalomid is widely used for the treatment of skin defects. Barr, as a first-filer, may be looking to tap into the multiple myeloma market, according to one Merrill Lynch analyst.

Thalomid capsules in 50-, 100- and 200-mg doses had annual sales of about $424 million for the 12 months ending October 2006, according to IMS Health sales data.