STOCKHOLM, April 25, 2024 /PRNewswire/ -- Medivir AB (NASDAQ: MVIR) (STO: MVIR), a pharmaceutical company focused on developing innovative treatments for cancer in areas of high unmet medical need, announced today that its selective cathepsin K inhibitor, MIV-711, has been granted Rare Pediatric Disease Designation (RPDD) as well as Orphan Drug Designation (ODD) for the treatment of Legg-Calvé-Perthes Disease (LCPD).

The FDA defines a rare pediatric disease as a serious or life-threatening disease in which the disease manifestations primarily affect individuals aged from birth to 18 years of age. Pediatric diseases recognized as "rare", affect fewer than 200,000 people in the United States. With a RPDD, MIV-711 qualifies to receive fast track review and upon marketing approval in LCPD, the Company may be eligible to receive a Priority Review Voucher from the FDA. The voucher can be redeemed to receive priority review for any subsequent marketing application or may be sold to another company for their use.

- "LCPD is a disease, with a significant impact on daily life as well as risk for long-term sequalae, for which there are no available effective treatments. Children with LCPD are more likely to suffer from obesity and depression due to the forced immobility as a consequence of the disease. In more than half of the children, the affected leg becomes shorter than the healthy leg and about 50% end up with a deformed hip joint where ultimately osteoarthritis develops. We are delighted that MIV-711 has been granted RPDD by the FDA with the potential to become the first approved treatment option. We see partnership as an attractive way to move forward with MIV-711 to ensure speed of development," said Jens Lindberg, CEO of Medivir.

To gain RPDD, there must be supportive data suggesting that the drug may be effective in the disease. MIV-711 has shown, in an LCPD-specific animal model, the ability to prevent femoral head deformity and positive impact on biomarker of bone degradation without negatively impacting normal bone formation. Similarly, clinical studies have shown that MIV-711 prevents bone degradation in patients with osteoarthritis, further supporting the potential clinical benefit in LCDP.

Cathepsin K is the main cysteine protease involved in bone resorption and cartilage degradation by osteoclasts, through the breakdown of key bone matrix proteins. Cathepsin K inhibition protects the damaged bone by reducing bone resorption and promoting bone formation, thereby addressing the key mechanisms causing pathological changes in LCPD, with potential to minimize long-term negative effects. Selective inhibition of cathepsin K has the potential to provide clinical benefit in diseases characterized by excessive bone resorption, including additional pediatric bone disorders.