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What is the rationale for developing Cystadrops®?
Cystinosis is a severe life-threatening autosomal recessive lysosomal storage disease, with an estimated incidence of 1:100,000 to 1;200,000 live births [1-4]. Mutations in the CTNS gene prevent the production of cystinosin, which is the lysosomal membrane transporter responsible for moving free cystine from the lysosome to the cytoplasm. This, in turn, leads to the accumulation of intralysosomal cystine, followed by the formation of cystine crystals and finally by progressive damage to all organs and tissues, especially the kidney (leading to end-stage renal disease and the need for transplantation) and the eye (leading to photophobia, pain, keratopathy, loss of vision and potentially blindness) [1-4].
Cystinosis may result from many different CTNS mutations, leading to different phenotypes based on age at onset and severity of symptoms [3]. Infantile nephropathic cystinosis, which is the most severe type of the disease, accounts for &95% of cases and is associated with an average life-expectancy of & 10 years without treatment with cystine-depleting and renal-replacement therapy [3]. Early diagnosis of the disease may be made via ophthalmological examination for corneal deposits before signs of nephropathy become evident [1].
In patients with cystinosis, life-long systemic treatment with oral cysteamine bitartrate (e.g. Cystagon® immediaterelease capsules [5] and Procysbi® gastro-resistant prolonged-release capsules [6]) is necessary, with treatment being initiated early in the course of the disease [3, 7]. Following oral administration of cysteamine bitartrate, free-base cysteamine interacts with lysosomal cystine to form cysteine and cysteine-cysteamine mixed disulphide, neither of which require...