FDA Approves Expended Indication for Procysbi to Include Children with Nephropathic Cystinosis

Rare Daily Staff

The U.S. Food and Drug Administration approved an expansion to the indication for Horizon Pharma’s Procysbi to include children one year of age and older living with nephropathic cystinosis.  

Nephropathic cystinosis is a rare, life-threatening metabolic lysosomal storage disorder that causes toxic accumulation of cystine in all cells, tissues, and organs in the body.  If untreated, elevated cystine accumulation leads to progressive, irreversible tissue damage and multi-organ failure, including kidney failure, blindness, muscle wasting and premature death.  It is estimated that only about 2,000 people worldwide are currently diagnosed with nephropathic cystinosis. Procysbi was previously FDA-approved for adults and children as young as two years of age.

The company said with the update to the indication, the Procysbi prescribing information now includes revised guidance for physicians administering the medicine to pediatric patients, including new clinical evidence and dosing information for very young children. 

The Procysbi labeling was updated based on a long-term, prospective, open-label study that enrolled 17 people living with nephropathic cystinosis, including 15 children between the ages of 1 and 5 years old, who had not previously been treated with cysteamine therapy. Children enrolled in the study experienced lowering of white blood cell cystine levels from poor controlled to well controlled at 12- and 18-month measurements.  White blood cell levels are the biomarker for disease control. 

Additionally, they experienced measured improvements in growth milestones including weight and height.  The most common adverse reactions in patients treated in clinical trials reflected in the FDA approved product labeling were vomiting, gastroenteritis/viral gastroenteritis, diarrhea, breath odor, nausea, electrolyte imbalance and headache. 

December 27, 2017