Sanofi has announced that it filed a patent infringement suit against Merck Sharp & Dohme Corp. (Merck) on August 8, 2017 in the United States District Court for the District of New Jersey. In its suit Sanofi alleges infringement of two patents.

The suit was triggered by a notification received from Merck in late June, in which Merck stated that it had filed an NDA (505(b)(2) New Drug Application) with FDA for an insulin glargine vial drug product. Merck also stated that its NDA included a paragraph IV certification challenging all of the Sanofi patents then listed in the FDA Orange Book for Sanofi's Lantus and Lantus SoloStar products.