A potential new prodrug for the treatment of cystinosis:Design, synthesis and in-vitro evaluation

Nephropathic cystinosis is a rare autosomal recessive disease characterised by raised lysosomal levels of cystine in thecells of most organs. The disorder is treated by regular administration of the aminothiol, cysteamine, an odiferous and unpleasanttasting compound that along with its metabolites is excreted in breath and sweat, leading to poor patient compliance. In an attemptto improve patient compliance a series of novel prodrugs has been designed and evaluated as a potential new treatment for nephropathiccystinosis. The first of the prodrugs tested, 3a, was found to decrease the levels of intracellular cystine in cystinotic fibroblasts.This is the first report of a potential new therapeutic treatment for nephropathic cystinosis since the advent of cysteaminebitartrate.