Cystinosis is a rare inherited metabolic disorder that impacts approximately 500 to 600 people in the United States.1 It is classified as a lysosomal storage disorder (LSD), leading to the accumulation of cystine within the lysosomes of almost every cell.2
Lysosomal storage disorders include more than 60 different inherited diseases, each caused by a deficiency of specific proteins, that can lead to multisystemic complications that afflict multiple organs across the body.3
Hypothyroidism
Impaired growth
Rickets
Fanconi syndrome and renal failure
Ophthalmic complications
Deterioration of the central nervous system
Nephropathic (or infantile) cystinosis is the most prevalent and severe form of cystinosis
Intermediate cystinosis (or juvenile) is characterized by slower disease progression
Nonnephropathic (or ocular) cystinosis affects the eyes but does not present in other body systems
Cystinosis symptoms commonly present in otherwise healthy infants within the first year of life. Parents primarily note frequent wet diapers (polyuria) and persistent thirst (polydipsia, resulting in dehydration) when first describing their child’s symptoms.5,6
Initial cystinosis symptoms are commonly the result of cystine accumulation in the kidney tubules, which results in Fanconi syndrome. Fanconi syndrome involves cellular atrophy of the proximal renal tubules, giving “swan neck” like deformities. Cystinosis is the most common identifiable cause of renal Fanconi syndrome in children.4 If untreated, this will lead to end-stage renal disease, requiring a kidney transplant by age 10 years.5,6
Within infants’ first 6-12 months, the eyes are commonly affected and become photosensitive, and the bones can develop rickets.
Cystine accumulation can harm nearly every cell in the body and can lead to widespread organ damage if left untreated.2,6
*Cystinosis has not been shown to cause infertility in women.
While cystinosis can affect several organs, the kidneys are typically affected first. Preserving kidney function is an important treatment goal.2,7
PROCYSBI (cysteamine bitartrate) delayed-release capsules and delayed-release oral granules is a cystine-depleting agent indicated for the treatment of nephropathic cystinosis in adults and pediatric patients 1 year of age and older.
The most common adverse reactions reported in PROCYSBI clinical trials (≥ 5%): were:
Please see Full Prescribing Information.
1. Nesterova G, Gahl WA. Infantile nephropathic cystinosis standards of care. Cystinosis Research Network. June 2012. Accessed June 18, 2019. https://www.cystinosis.org/publications/infantile-nephropathic-cystinosis-standards-of-care/ 2. Elmonem MA, Veys KR, Soliman NA, van Dyck M, van den Heuvel LP, Levtchenko E. Cystinosis: a review. Orphanet J Rare Dis. 2016;11(47):1-17. 3. Veys KR, Besouw MT, Pinxten AM, van Dyck M, Casteels I, Levtchenko EN. Cystinosis: a new perspective. Acta Clin Belg. 2016;71(3):131-137. 4. Nesterova G, Gahl W. Nephropathic cystinosis: late complications of a multisystemic disease. Pediatr Nephrol. 2008;23(6):863-878. 5. Gahl WA, Thoene JG, Schneider JA. Cystinosis. N Engl J Med. 2002;347(2):111-121. 6. Gahl WA, Balog JZ, Kleta R. Nephropathic cystinosis in adults: natural history and effects of oral cysteamine therapy. Ann Intern Med. 2007;147(4):242-250. 7. Langman CB, Barshop BA, Deschênes G, et al. Controversies and research agenda in nephropathic cystinosis: conclusions from a “Kidney Disease: Improving Global Outcomes” (KDIGO) Controversies Conference. Kidney Int. 2016;89(6):1192-1203.