Reinforcing its interest in immuno-oncology, Sanofi has agreed to acquire US biotech, Synthorx, for US$2.5 B. Synthorx’s lead candidate THOR-707, a variant of IL-2, is in Phase I/II studies for the treatment of solid tumours as a single agent and in combination with immune checkpoint inhibitors. The announcement comes just six months after Sanofi announced an R&D reorganisation to focus its efforts in the key therapy areas of oncology, immunology, rare diseases and vaccines.