Swedish pharmaceutical company Medivir AB (STO:MVIR) announced on Thursday that its selective cathepsin K inhibitor, MIV-711, has received Orphan Drug Designation (ODD) from the US Food and Drug Administration (FDA) for the treatment of osteogenesis imperfecta (OI).

This designation provides development support, tax credits, FDA fee exemptions and seven years of marketing exclusivity for rare diseases that affect fewer than 200,000 people in the United States.

MIV-711 has demonstrated significant, dose-dependent improvements in bone strength, quality and morphology in an OI-specific animal model, supporting its potential clinical benefit.

Clinical data in osteoarthritis further indicate that MIV-711 can prevent bone degradation, highlighting its potential to address OI's key pathological mechanisms.

By inhibiting cathepsin K, MIV-711 reduces bone resorption and promotes bone formation, targeting the underlying collagen defects that cause bone fragility in OI. The disease ranges from mild to severe, with severe subtypes often incompatible with life and no approved treatment options currently available.

Medivir's ODD designation strengthens the evidence base for MIV-711 as a potential therapy to improve bone remodelling and mitigate long-term complications in patients with OI.