Extension Study to Evaluate the Long-Term Safety, Tolerability, and Efficacy of SBC-102 (Sebelipase Alfa) in Adult Subjects With Lysosomal Acid Lipase Deficiency

Extension Study to Evaluate the Long-Term Safety, Tolerability, and Efficacy of SBC-102 (Sebelipase Alfa) in Adult Subjects With Lysosomal Acid Lipase Deficiency

An Open Label Multicenter Extension Study to Evaluate the Long-Term Safety, Tolerability, and Efficacy of SBC-102 in Adult Subjects With Liver Dysfunction Due to Lysosomal Acid Lipase Deficiency Who Previously Received Treatment in Study LAL-CL01

This was an extension study to Study LAL-CL01 (NCT01307098). The primary objective of the study was to evaluate the long-term safety and tolerability of sebelipase alfa in participants with liver dysfunction due to lysosomal acid lipase (LAL) deficiency.

Participants who successfully received all 4 doses of sebelipase alfa in Study LAL-CL01 and opted to continue treatment in the extension study underwent screening assessments to determine study eligibility. Eligible participants initiated treatment in the extension study at least 4 weeks after their last dose of sebelipase alfa in Study LAL-CL01. This extension study consisted of a treatment period of up to 5 years, and a follow-up period of approximately 30 days after the last dose of sebelipase alfa. Cholesteryl ester storage disease (CESD) is the late onset phenotype for LAL deficiency, a lysosomal storage disorder, which also has an early onset phenotype that primarily affects infants. CESD can present in childhood but often goes unrecognized until adulthood when the underlying pathology is advanced. Many of the signs and symptoms are common to patients with other liver conditions. CESD is an autosomal recessive genetic condition and is characterized by hepatomegaly, persistently abnormal liver function tests (LFTs) and type II hyperlipidemia. Splenomegaly and evidence of mild hypersplenism may affect some patients. Untreated, CESD may lead to fibrosis, cirrhosis, liver failure and death.

Enzyme replacement therapy (ERT), Lysosomal storage disease, Late onset lysosomal acid lipase (LAL) deficiency, Acid cholesteryl ester hydrolase deficiency, type 2, Acid lipase disease, Cholesterol ester hydrolase deficiency, LAL deficiency, LIPA enzyme deficiency

Participants were administered sebelipase alfa once weekly (qw) as an intravenous (IV) infusion at the same dose received in Study LAL-CL01 (0.35, 1, or 3 milligrams per kilogram [mg/kg]) for 4 weeks. After the initial 4 qw doses, participants transitioned to dosing every other week (qow) at either 1 mg/kg (participants who initiated treatment at 0.35 or 1 mg/kg qw) or 3 mg/kg (participants who initiated dosing at 3 mg/kg qw). Subsequent modifications to the dose and dosing frequency were permitted for individual participants based on observed safety, tolerability, and clinical response to treatment. Participants could continue to receive treatment with sebelipase alfa for up to 5 years.

Safety and tolerability of sebelipase alfa was primarily assessed by monitoring the number of participants reporting treatment-emergent adverse events (TEAEs), including serious adverse events, and infusion-associated reactions (IARs). The number of participants who discontinued from the study due to a TEAE is also presented. An IAR was defined as any adverse event that occurred during the 2-hour infusion or within 4 hours after the end of the infusion and was assessed by the investigator as at least possibly related to study drug. A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module. TEAEs that occurred after the first dose administration at Week 1 through the End of Study (EOS) are presented. End of study was 30 days (+ 7 days) after the last dose of study drug (at Week 260).

Changes from Baseline to Week 12, Week 24, Week 52, Week 104, Week 156, Week 208, Week 260, and EOS for alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Baseline values were defined as the last measurement prior to the first infusion of sebelipase alfa in Study LAL-CL04.

Changes in liver volume from Baseline to Week 10 or 12, Week 24, Week 52, Week 104, Week 156, Week 208, Week 260, and EOS was assessed by magnetic resonance imaging (MRI). Baseline values were defined as the last measurement prior to the first infusion of sebelipase alfa in Study LAL-CL04. Liver volume was expressed as multiples of normal (MN), where normal is defined as 2.5% of body weight.

Changes in liver fat content from Baseline to Week 10 or 12, Week 24, Week 52, Week 104, Week 156, Week 208, and Week 260, as assessed by multi-echo gradient-echo MRI. Baseline values were defined as the last measurement prior to the first infusion of sebelipase alfa in Study LAL-CL04.

Changes from Baseline to Week 12, Week 24, Week 52, Week 104, Week 156, Week 208, Week 260, and EOS for gamma glutamyltransferase (GGT) and alkaline phosphatase (ALP). Baseline values were defined as the last measurement prior to the first infusion of sebelipase alfa in Study LAL-CL04.

Lipid changes from Baseline to Week 10 or 12, Week 24, Week 52, Week 104, Week 156, Week 208, Week 260, and EOS were measured in serum for total cholesterol (Total-C), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and triglycerides (TG). Baseline values were defined as the last measurement prior to the first infusion of sebelipase alfa in Study LAL-CL04.

Changes from Baseline to Week 12, Week 24, Week 52, Week 104, Week 156, Week 208, Week 260, and EOS for serum ferritin. Baseline values were defined as the last measurement prior to the first infusion of sebelipase alfa in Study LAL-CL04.

Changes from Baseline to Week 12, Week 24, Week 52, Week 104, Week 156, Week 208, Week 260, and EOS for high sensitivity C-reactive protein (hs-CRP). Baseline values were defined as the last measurement prior to the first infusion of sebelipase alfa in Study LAL-CL04.

Inclusion Criteria: Participant received all 4 scheduled doses of sebelipase alfa in Study LAL-CL01 with no life-threatening or unmanageable study drug toxicity. Exclusion Criteria: Clinically significant concurrent disease, serious inter-current illness, concomitant medications or other extenuating circumstances Clinically significant abnormal values on laboratory screening tests, other than LFTs or lipid panel tests

Balwani M, Breen C, Enns GM, Deegan PB, Honzik T, Jones S, Kane JP, Malinova V, Sharma R, Stock EO, Valayannopoulos V, Wraith JE, Burg J, Eckert S, Schneider E, Quinn AG. Clinical effect and safety profile of recombinant human lysosomal acid lipase in patients with cholesteryl ester storage disease. Hepatology. 2013 Sep;58(3):950-7. doi: 10.1002/hep.26289. Epub 2013 Mar 28.

Malinova V, Balwani M, Sharma R, Arnoux JB, Kane J, Whitley CB, Marulkar S, Abel F. Sebelipase alfa for lysosomal acid lipase deficiency: 5-year treatment experience from a phase 2 open-label extension study. Liver Int. 2020 Sep;40(9):2203-2214. doi: 10.1111/liv.14603. Epub 2020 Aug 9.