Potential Treatment for Osteogenesis Imperfecta Receives FDA’s “Rare Pediatric Disease Designation”

By T. Chakraborty, Ph.D.

Osteogenesis Imperfecta (OI) is a rare disorder that affects the connective tissues in the body. It is characterized by extremely fragile bones that break easily, reduced bone mass, loose joints, and weakened teeth. Studies have identified four main types of OI, of which type I is the most common and the mildest form, while type II is the most severe form of the disorder. Approximately 20,000 – 50,000 individuals have OI in the US [1].

In most cases, the various forms of OI are inherited and caused by a dominant mutation in a gene coding for type I collagen, which is a key ingredient to having healthy bones. Current treatments of OI focus on reducing fractures and increasing mobility, but to date, there have been no approved US Food and Drug Administration (FDA) or EU treatments.

Mereo Biopharma, a clinical-stage biopharmaceutical company, headquartered in the UK, announced on September 24th that the FDA had granted the designation of “Rare Pediatric Disease” to Setrusumab, their proprietary treatment therapy for OI. The designation of “Rare Pediatric Disease” is usually granted for severe and life-threatening diseases that affect children aged below 18 years and less than 200,000 people in the US.

If Setrusumab can get a Biologics License Application (BLA) in the US approved, Mereo Biopharma can receive a priority review voucher from the FDA, which in the future is redeemable for a priority review. Additionally, they may be eligible for other marketing applications or sold/transferred to other companies for their proprietary programs [2].

Dr. Denise Scots-Knight, Chief Executive Officer of Mereo, said, “Receiving Rare Pediatric Disease Designation from the FDA highlights the significant unmet medical need facing children with OI and underscores the potential of Setrusumab to become the first approved treatment option specifically for these patients. Following the completion of our Phase 2b ASTEROID study, we are pleased that both the FDA and EMA have agreed on the principles of design of a single Phase 3 pivotal pediatric study in OI. We believe there is a clear path forward for Setrusumab in OI and are continuing discussions with potential partners prior to the initiation of a Phase 3 study consistent with our Company strategy.” [2]

Setrusumab

Sclerostin is a protein expressed in bone cells and is involved in bone remodeling. Setrusumab is a humanized monoclonal antibody inhibiting this protein. Inhibition of sclerostin with Setrusumab could be the first approved treatment for OI by improving the quality of life. Setrusumab has already obtained the status of orphan drug for OI in the US and EU. ASTEROID clinical trial, a phase 2b study with Setrusumab, demonstrated that the drug reduced fractures and was safe in adults with OI. The success of the Phase 2 study was the backbone of the FDA approving a phase III trial in pediatric patients. Currently, the company is looking for partners before venturing into a trial with severe OI pediatric patients.

Editor: Rajaneesh K. Gopinath, Ph.D.

Related Article: Sarepta and Codiak Biosciences Join Hands to Tackle Rare Diseases Using Exosome-Based Therapeutics

References

1. https://rarediseases.org/rare-diseases/osteogenesis-imperfecta/#:~:text=Affected%20Populations&text=OI%20type%20II%20is%20estimated,the%20United%20States%20have%20OI
2. https://www.mereobiopharma.com/news-and-events/press-releases/2020/setrusumab-fda-rare-pediatric-disease-designation/setrusumab-fda-rare-pediatric-disease-designation/

Author

Tulip Chakraborty