Effect of sebelipase alfa after 90 weeks in adults with lysosomal acid lipase deficiency

Wolman's disease and cholesteryl ester storage disorder: the phenotypic spectrum of lysosomal acid lipase deficiency

Lysosomal acid lipase deficiency is a rare, autosomal recessive condition caused by mutations in the gene encoding lysosomal acid lipase (LIPA) that result in reduced or absent activity of this essential enzyme. The severity of the resulting disease depends on the nature of the underlying mutation and magnitude of its effect on enzymatic function. Wolman's disease is a severe disorder that presents during infancy, resulting in failure to thrive, hepatomegaly, and hepatic failure, and an average life expectancy of less than 4 months. Cholesteryl ester storage disorder arises later in life and is less severe, although the two diseases share many common features, including dyslipidaemia and transaminitis. The prevalence of these diseases has been estimated at one in 40 000 to 300 000, but many cases are undiagnosed and unreported, and awareness among clinicians is low. Lysosomal acid lipase deficiency-which can be diagnosed using dry blood spot testing-is often misdiagnosed as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), hereditary dyslipidaemia, or cryptogenic cirrhosis. There are no formal guidelines for treatment of these patients, and treatment options are limited. In this Review we appraise the existing literature on Wolman's disease and cholesteryl ester storage disease, and discuss available treatments, including enzyme replacement therapy, oral lipid-lowering therapy, stem-cell transplantation, and liver transplantation.

Sebelipase Alfa: A Review in Lysosomal Acid Lipase Deficiency

Sebelipase alfa (Kanuma®, Kanuma™), the first commercially available recombinant human lysosomal acid lipase (LAL), is approved in various countries worldwide, including those of the EU, the USA and Japan, as a long-term enzyme replacement therapy for patients diagnosed with LAL deficiency (LAL-D), an ultra-rare, autosomal recessive, progressive metabolic liver disease. In an ongoing study in nine infants presenting with early-onset LAL-D (Wolman disease), open-label treatment with sebelipase alfa significantly improved 1-year survival compared with historical controls. A substantial mortality benefit was maintained at 2 years of age, as was a reduction in disease-related activity. In an ongoing study of 66 children and adults with late-onset LAL-D (cholesteryl ester storage disease), 20 weeks' double-blind treatment with sebelipase alfa significantly reduced multiple disease-related hepatic and lipid abnormalities compared with placebo. Sustained improvements in markers of liver damage and dyslipidaemia were seen after 76 weeks' open-label treatment in an extension of this trial and, similarly, after 2 years' open-label treatment in an extension of another study in nine adults with late-onset LAL-D. Sebelipase alfa therapy has thus far been generally well tolerated, with signs and symptoms consistent with anaphylaxis being the most serious adverse reactions experienced by patients receiving the drug in clinical trials. Due to the rarity of the disease, these studies have enrolled a limited number of patients. Nonetheless, the available data indicate that sebelipase alfa is an effective disease-specific therapy for individuals with LAL-D who have historically been managed using supportive therapies (e.g. cholesterol reduction, hematopoietic stem cell transplantation, and liver transplantation).