Eliglustat: A Review in Gaucher Disease Type 1.

Oral eliglustat (Cerdelga®) is approved in several countries for the long-term treatment of adults with Gaucher disease type 1 (GD1) who are cytochrome P450 (CYP) 2D6 extensive metabolizers (EMs), intermediate metabolizer (IMs) or poor metabolizers (PMs) [these three CYP categories encompass >90 % of individuals]. Eliglustat is a potent, selective inhibitor of glucosylceramide synthase, the rate-limiting enzyme in the synthesis of certain glycosphingolipids, and thus, reduces the rate of biosynthesis of glycosphingolipids to counteract the catabolic defect (i.e. substrate reduction therapy). In the 9-month phase 3 ENGAGE trial, eliglustat significantly improved haematological endpoints and reduced organomegaly compared with placebo in treatment-naive adults with GD1, with the bone marrow burden score (a marker of Gaucher cell infiltration) and GD1 biomarkers also improving from baseline in eliglustat recipients. After 12 months in the phase 3 ENCORE trial, oral eliglustat was noninferior to intravenous imiglucerase [an enzyme replacement therapy (ERT)] in maintaining disease stability in adults who had stable disease after receiving ERT for ≥3 years. During long-term treatment with eliglustat (≤4 years) in the extension period of each of these pivotal trials and a phase 2 trial, patients experienced sustained improvements in visceral, haematological and skeletal endpoints, with no new safety concerns identified. Further clinical experience will help to more definitively establish the position of eliglustat treatment in adults with GD1. In the meantime, with its convenient oral regimen, eliglustat is an emerging alternative therapy to ERT for the long-term treatment of adults with GD1 who are CYP2D6 EMs, IMs or PMs.