Denmark’s Novo Nordisk said yesterday it believes Sanofi-Aventis has infringed one of its US patents covering its disposable insulin pen product NovoPen 4 and has filed a complaint in a New Jersey court.

According to reports Novo Nordisk is awaiting a court date, but told the media that it could be a long process. The complaint concerns Sanofi’s SoloStar, which won approval in the USA for use with its big-selling once-daily diabetes therapy Lantus (insulin glargine) in April and is expected to be launched there shortly.

Sanofi-Aventis says it will 'vigorously' defend its patent, but acknowledged to reporters that its understanding of the complaint was ‘preliminary’. Lantus SoloStar, says the firm, is the only disposable insulin pen that allows patients to administer doses from 1 up to 80 units in one injection.