Danish diabetes drugmaker Novo Nordisk is taking France’s Sanofi-Aventis to court in the USA over its OptiClik pen system which, it claims, infringes its patents relating to the FlexPen insulin delivery device.

The complaint, filed against Sanofi and certain of its US, German and Swiss affiliates earlier this month in the US District Court for the District of Delaware, accuses the French group of “willful and deliberate patent infringement.” Novo Nordisk is seeking an injunction against use of Sanofi’s OptiClik pen system, which represents the firm’s only US Food and Drug Administration-approved insulin delivery device and is used with all its insulin products in the USA.

Martin Soeters, president of Novo Nordisk said, “Novo Nordisk is an

innovator and leader in insulin delivery technology, changing diabetes by providing people with access to the best diabetes care and quality insulin delivery devices. We developed the world’s first insulin pen in 1985, and today our advanced devices offer precise dosing and may help people better comply with their insulin regimens.” He added: “As a pioneer in diabetes treatment for 80 years, we have amassed a large patent portfolio that we are committed to defending.”

The US market for insulin is worth around $2 billion a year, and around 20% of patients in the country taking insulin use pen-like devices, James Shehan, Novo Nordisk’s general counsel, told Reuters.