Sanofi files US lawsuit against Eli Lilly over Lantus patents

Sanofi announced the filing of a US patent infringement suit against Eli Lilly related to the former's diabetes therapy Lantus (insulin glargine). The case, filed in District Court in Delaware, alleges that Eli Lilly's marketing submission to the FDA for the insulin glargine product LY2963016, which was co-developed with Boehringer Ingelheim, infringes four of Sanofi's patents.

Analysts estimate that US sales of Lantus grew by 22 percent in 2013 to 3.8 billion euros ($5.1 billion), although the therapy is set to lose patent protection in the country in February 2015. According to Sanofi, Eli Lilly indicated that it will not launch its product before the expiry of the drug's US patent on the active ingredient. Sanofi added that in its marketing application, Eli Lilly challenged six of the seven patents for Lantus and Lantus SoloStar products. Eli Lilly general patent counsel Doug Norman said that the drugmaker "respects the intellectual property of others and does not believe the application for approval of its new insulin glargine product infringes any valid claim of the asserted patents."

Deutsche Bank analyst Mark Clark said the legal process started by Sanofi would probably delay the launch of Eli Lilly's insulin glargine product until at least 2016. Deutsche Bank analysts added that the suit also raised the possibility of a further extension of exclusivity for Lantus if a court ultimately finds that Sanofi's patents have been infringed. An Eli Lilly spokesman remarked that the drugmaker was studying the complaint. In July last year, the company announced that the filing for LY2963016 had been accepted for review by the European Medicines Agency.

Sanofi's lawsuit triggers an automatic 30-month stay of approval by the FDA on Eli Lilly's insulin glargine product, which Sanford Bernstein analyst Tim Anderson said would raise the French company's earnings by about 6 percent from 2015 through 2020. He added that it would reduce Eli Lilly's earnings for the period by about 3 percent. According to Deutsche Bank analysts, the delay would likely increase Sanofi's forecast earnings by close to 10 percent in 2016.

Sanofi is also developing a long-acting follow-up product to Lantus, called U300, which is expected to receive FDA approval in 2015. "Time is important in any switching strategy, so any delay would be supportive to the franchise's long-term growth," Jefferies analysts said. For related analysis, see Physician Views Poll Results – Usage of Sanofi's U300 will not be limited to 'high-risk' Lantus patients, infer endocrinologists and In Focus: Can Eli Lilly's biosimilar Lantus shake-up Sanofi and Novo Nordisk's 'cosy duopoly' in the long-acting insulin market.

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