Critical appraisal of observational studies on enzyme replacement therapy for Gaucher’s Disease

Abstract

Objective: The objective of this study was to critically appraise the validity of observational studies on enzyme replacement therapy for Gaucher’s disease. Methods: A literature search was performed in electronic databases without limits of date and for patients with confirmed Gaucher’s Disease, regardless of age, receiving enzyme replacement therapy (alglucerase, imiglucerase, velaglucerase, or taliglucerase). Outcomes of interest were haemoglobin, platelet count, liver and spleen volume, plasma chitotriosidase, bone parameters, and antibodies production. The Newcastle-Ottawa tool was used for quality assessment, and the Oxford Centre for Evidence-based Medicine guidelines were used to assess the level of evidence. Results: Nineteen studies were selected. Studies with more comprehensive and recent data from the International Collaborative Gaucher Group (ICGG) Gaucher Registry were analyzed. Fifteen studies were from patients who used alglucerase or imiglucerase, including data of 757 patients after 10 years of use. Data on velagucerase treatment were restricted to four studies with 24 children and 8 adults after 2 and 7 years of follow-up, respectively. Only the French Gaucher’s disease registry presented results for one patient using taliglucerase. The level of evidence was 2C for fourteen studies, 2B for one study, and 4 for four studies. Conclusion: Critical appraisal of observational studies revealed important and good quality data on imiglucerase treatment effectiveness and long- -term safety. Although there are other treatment options (velaglucerase and taliglucerase), the lack of long-term observational data does not enable comparisons of the results in real world settings.