A systematic literature review of cysteamine bitartrate in the treatment of nephropathic cystinosis

<p><b>Objectives:</b> To summarize available clinical evidence for cysteamine bitartrate preparations in the treatment of nephropathic cystinosis as identified through a systematic literature review (SLR).</p> <p><b>Methods:</b> We searched MEDLINE, MEDLINE In-Process and Embase using Ovid with a predefined search strategy through 19 January 2016. All publicly available clinical reports on the use of delayed-release (DR) cysteamine bitartrate (Procysbi<a href="#FN0001" target="_blank">¹</a>) or immediate-release (IR) cysteamine bitartrate (Cystagon<a href="#FN0002" target="_blank">²</a>) in patients with cystinosis were included.</p> <p><b>Results:</b> We identified a total of 103 publications and 10 trial records. Of these, 9 studies describe DR cysteamine bitartrate (<i>n</i> = 267 patients), 42 describe IR cysteamine bitartrate (<i>n</i> = 1,427 patients) and in 53 studies the exact preparation was not specified (<i>n</i> = 906 patients). The vast majority of the studies used a non-randomized study design, with randomized clinical trials (RCTs) being scarce (1 study comparing DR and IR formulation) and case reports (<i>n</i> = 49) being the most common study design representing 47% of the total.</p> <p><b>Conclusion:</b> A substantial evidence base for cysteamine bitartrate in the treatment of nephropathic cystinosis was identified. However, the majority of the evidence was of relatively low quality, with evidence levels of 3 or 4.</p