Sanofi and Regeneron have expanded their long-running immunology alliance with four next-generation antibody programmes in a deal worth up to $8 billion.

The approval provides adults with fibrodysplasia ossificans progressiva with a new treatment option designed to reduce abnormal bone formation and disease flare-ups in an ultra-rare genetic disorder.

The deal gives Regeneron access to Helicon peptide technology as pharma companies race to unlock previously “undruggable” intracellular targets.