Sanofi's rivals in the insulin field are nipping at its heels – Lantus sales dipped 5 per cent in the first half of 2015, and analysts don't expect Toujeo to make up for its decline.

Sanofi’s Toujeo – a follow-up to its long-acting insulin drug Lantus – has underperformed commercially since launch but the company hopes new data could help it gather momentum. The French ...