Sanofi is to make a huge $2.18 billion investment in the collaboration with Regeneron, buying into the US firm's PD-1 inhibitor candidate, currently in phase I.

Earlier in 2019 Sanofi also paid Regeneron $462 million to exit from an immuno-oncology alliance formed in 2015, and in 2017 said they would end discovery research in new antibody drugs.

Regeneron Pharmaceuticals (REGN) and Sanofi (SNY) presented positive results from the pivotal ADEPT Phase 2/3 trial evaluating the ...