Novo Nordisk, Sanofi and Eli Lilly are all facing patent expiry for their blockbuster insulin analogs (Novolog, Lantus and Humalog, respectively) this and next yearin 2013 and 2014, and will suffer erosion to biosimilars from around 2015, when presumably all the regulations for biosimilar insulin production will be in place. The companies are undertaking different strategies, whereby they either go on the offense or defense, to address this problem. Eli Lilly already has a Lantus biosimilar in late-stage development, which will be a strong competitor to Sanofi's Lantus, while Sanofi is developing a superior version of its own product Lantus and also a fixed-dose combination of Lantus and Lyxumia in order to protect its own franchise.