Sanofi files patent infringement lawsuit against Merck

Sanofi has launched a new patent infringement suit against US pharma company Merck & Co in the USA.

The suit alleges infringement of two patents relating to Lantus (insulin glargine), Sanofi’s flagship diabetes drug.

Sanofi’s legal action was triggered by a notification received in late June this year, in which Merck stated that it had filed a New Drug Application (NDA) with the US Food and Drug Administration for an insulin glargine vial drug product.

Merck stated that its NDA included a paragraph IV certification challenging all of the Sanofi patents then listed in the FDA Orange Book for the Lantus and Lantus SoloStar products.

Sanofi also filed a suit against Merck in Delaware less than a year ago, which alleged the infringement of 10 patents relating to Lantus.

Sales of Lantus fell 19% to 1.2 billion euros ($1.4 billion) in the latest quarter compared to a year ago due to competition from biosimilars and other biologics. Despite this, Lantus was the French drugmaker’s biggest selling product, generating sales of around $6.6 billion in 2016.