Burosumab Treatment for Autosomal Recessive Hypophosphatemic Rickets Type 1 (ARHR1).

Area of Science:

• Endocrinology
• Genetics
• Bone Metabolism

Background:

• Autosomal recessive hypophosphatemic rickets (ARHR) are rare genetic disorders caused by fibroblast growth factor 23 (FGF23) overexpression, leading to impaired bone mineralization.
• ARHR type 1 (ARHR1) specifically results from inactivating mutations in Dentin matrix protein 1 (DMP1).
• Current treatments with phosphate and calcitriol have limited efficacy and potential side effects.

Purpose of the Study:

• To evaluate the safety and efficacy of burosumab, an anti-FGF23 monoclonal antibody, in patients with ARHR1.
• To explore a novel therapeutic approach for ARHR1 beyond traditional treatments.

Main Methods:

• Monthly administration of burosumab to two brothers diagnosed with ARHR1.
• Clinical and biochemical assessments were performed to monitor treatment response.

Main Results:

• Burosumab treatment led to normalized serum phosphate levels.
• Healing of pseudofractures, reduced bone pain, fatigue, and incapacity were observed.
• No adverse effects were reported during the study period.

Conclusions:

• Burosumab demonstrates significant biochemical and clinical benefits in patients with ARHR1.
• This suggests burosumab is a safe and effective therapeutic option for ARHR1.
• Further research may establish burosumab as a standard of care for ARHR1.