A randomized, placebo-controlled clinical trial evaluating olipudase alfa enzyme replacement therapy for chronic acid sphingomyelinase deficiency (ASMD) in adults : one-year results

Purpose: This trial aimed to assess the efficacy and safety of olipudase alfa enzyme replacement therapy for non–central nervous system manifestations of acid sphingomyelinase deficiency (ASMD) in adults. Methods: A phase 2/3, 52 week, international, double-blind, placebo-controlled trial (ASCEND; NCT02004691/EudraCT 2015-000371-26) enrolled 36 adults with ASMD randomized 1:1 to receive olipudase alfa or placebo intravenously every 2 weeks with intrapatient dose escalation to 3 mg/kg. Primary efficacy endpoints were percent change from baseline to week 52 in percent predicted diffusing capacity of the lung for carbon monoxide and spleen volume (combined with splenomegaly-related score in the United States). Other outcomes included liver volume/function/sphingomyelin content, pulmonary imaging/function, platelet levels, lipid profiles, and pharmacodynamics. Results: Least square mean percent change from baseline to week 52 favored olipudase alfa over placebo for percent predicted diffusing capacity of the lung for carbon monoxide (22% vs 3.0% increases, P = .0004), spleen volume (39% decrease vs 0.5% increase, P < .0001), and liver volume (28% vs 1.5% decreases, P < .0001). Splenomegaly-related score decreased in both groups (P = .64). Other clinical outcomes improved in the olipudase alfa group compared with the placebo group. There were no treatment-related serious adverse events or adverse event–related discontinuations. Most adverse events were mild. Conclusion: Olipudase alfa was well tolerated and associated with significant and comprehensive improvements in disease pathology and clinically relevant endpoints compared with placebo in adults with ASMD

Resolution of cor pulmonale after medical management in a patient with cblC-type methylmalonic aciduria and homocystinuria: a case report

We describe a 3-year-old Hispanic male with cblC-type methylmalonic aciduria and homocystinuria who presented to the emergency department with progressive tachypnea, vomiting, and edema secondary to pulmonary embolism and cor pulmonale. With aggressive medical management, there was complete resolution of right heart failure and pulmonary hypertension after 3 months. Pulmonary embolism is rare in the pediatric population. Children with cblC-type methylmalonic aciduria and homocystinuria may be at increased risk for thrombus formation and pulmonary embolism due to chronic hyperhomocystinemia, a risk factor for thrombus formation in the adult population. Aspirin therapy may be indicated in children with inborn errors of metabolism that predispose to hyperhomocystinemia

Clinical relevance of endpoints in clinical trials for acid sphingomyelinase deficiency enzyme replacement therapy

Background: Acid sphingomyelinase deficiency (ASMD) also known as Niemann-Pick disease, is a rare lysosomal storage disorder with a diverse disease spectrum that includes slowly progressive, chronic visceral (type B) and neurovisceral forms (intermediate type A/B), in addition to infantile, rapidly progressive fatal neurovisceral disease (type A). Purpose and methods: We review the published evidence on the relevance of splenomegaly and reduced lung diffusion capacity to the clinical burden of chronic forms of ASMD. Targeted literature searches were conducted to identify relevant ASMD and non-ASMD studies for associations between diffusing capacity of the lungs for carbon monoxide (DLCO) and splenomegaly, with clinical parameters and outcome measures. Results: Respiratory disease and organomegaly are primary and independent contributors to mortality, disease burden, and morbidity for patients with chronic ASMD. The degree of splenomegaly correlates with short stature, atherogenic lipid profile, and degree of abnormality of hematologic parameters, and thus may be considered a surrogate marker for bleeding risk, abnormal lipid profiles and possibly, liver fibrosis. Progressive lung disease is a prevalent clinical feature of chronic ASMD, contributing to a decreased quality of life (QoL) and an increased disease burden. In addition, respiratory-related complications are a major cause of mortality in ASMD. Conclusions: The reviewed evidence from ASMD natural history and observational studies supports the use of lung function and spleen volume as clinically meaningful endpoints in ASMD trials that translate into important measures of disease burden for patients

Precision Newborn Screening for Lysosomal Disorders

Purpose: The implementation of newborn screening for lysosomal disorders has uncovered overall poor specificity, psychosocial harm experienced by caregivers, and costly follow-up testing of false-positive cases. We report an informatics solution proven to minimize these issues. Methods: The Kentucky Department for Public Health outsourced testing for mucopolysaccharidosis type I (MPS I) and Pompe disease, conditions recently added to the recommended uniform screening panel, plus Krabbe disease, which was added by legislative mandate. A total of 55,161 specimens were collected from infants born over 1 year starting from February 2016. Testing by tandem mass spectrometry was integrated with multivariate pattern recognition software (Collaborative Laboratory Integrated Reports), which is freely available to newborn screening programs for selection of cases for which a biochemical second-tier test is needed. Results: Of five presumptive positive cases, one was affected with infantile Krabbe disease, two with Pompe disease, and one with MPS I. The remaining case was a heterozygote for the latter condition. The false-positive rate was 0.0018% and the positive predictive value was 80%. Conclusion: Postanalytical interpretive tools can drastically reduce false-positive outcomes, with preliminary evidence of no greater risk of false-negative events, still to be verified by long-term surveillance

Maple Syrup Urine Disease: Identification and Carrier-Frequency Determination of a Novel Founder Mutation in the Ashkenazi Jewish Population

Maple syrup urine disease (MSUD) is a rare, autosomal recessive disorder of branched-chain amino acid metabolism. We noted that a large proportion (10 of 34) of families with MSUD that were followed in our clinic were of Ashkenazi Jewish (AJ) descent, leading us to search for a common mutation within this group. On the basis of genotyping data suggestive of a conserved haplotype at tightly linked markers on chromosome 6q14, the BCKDHB gene encoding the E1β subunit was sequenced. Three novel mutations were identified in seven unrelated AJ patients with MSUD. The locations of the affected residues in the crystal structure of the E1β subunit suggested possible mechanisms for the deleterious effects of these mutations. Large-scale population screening of AJ individuals for R183P, the mutation present in six of seven patients, revealed that the carrier frequency of the mutant allele was ∼1/113; the patient not carrying R183P had a previously described homozygous mutation in the gene encoding the E2 subunit. These findings suggested that a limited number of mutations might underlie MSUD in the AJ population, potentially facilitating prenatal diagnosis and carrier detection of MSUD in this group

Olipudase alfa enzyme replacement therapy for acid sphingomyelinase deficiency (ASMD): sustained improvements in clinical outcomes after 6.5 years of treatment in adults

Abstract Background Enzyme replacement therapy with olipudase alfa, a recombinant human acid sphingomyelinase (rhASM), is indicated for non-central nervous system manifestations of acid sphingomyelinase deficiency (ASMD) in children and adults. An ongoing, open-label, long-term study (NCT02004704) assessed the safety and efficacy of olipudase alfa in 5 adults with ASMD. Results: After 6.5 years of treatment, there were no discontinuations, no olipudase-alfa-related serious adverse events, and no new safety signals compared to earlier assessments. Most treatment-emergent adverse events were mild in intensity (1742/1766, 98.6%). Among treatment-related adverse events (n = 657), more than half were considered infusion-associated reactions (n = 403, 61.3%) such as headache, nausea, abdominal pain, arthralgia, pyrexia, and fatigue. No patient developed neutralizing anti-drug antibodies to cellular uptake, and there were no clinically significant adverse changes in vital signs, hematology, or cardiac safety parameters. Improvements (decreases) in spleen and liver volumes progressed through 6.5 years (mean changes from baseline of -59.5% and  -43.7%, respectively). There was a mean increase in diffusing capacity of the lung for carbon monoxide from baseline of 55.3%, accompanied by improvements in interstitial lung disease parameters. Lipid profiles at baseline indicated dyslipidemia. All patients had sustained decreases in pro-atherogenic lipid levels and increases in anti-atherogenic lipid levels following olipudase alfa treatment. Conclusions Olipudase alfa is the first disease-specific treatment for ASMD. This study demonstrates that long-term treatment with olipudase alfa is well-tolerated and is associated with sustained improvements in relevant disease clinical measures. NCT02004704 registered 26 November 2013, https://clinicaltrials.gov/ct2/show/NCT02004704?term=NCT02004704&draw=2&rank=1

Clearance of Hepatic Sphingomyelin by Olipudase Alfa Is Associated With Improvement in Lipid Profiles in Acid Sphingomyelinase Deficiency

Acid sphingomyelinase deficiency (ASMD; Niemann-Pick disease type A and B) is a lysosomal storage disorder characterized by abnormal intracellular sphingomyelin (SM) accumulation. Prominent liver involvement results in hepatomegaly, fibrosis/cirrhosis, abnormal liver chemistries, and a proatherogenic lipid profile. Olipudase alfa (recombinant human ASM) is in clinical development as an investigational enzyme replacement therapy for the non-neurological manifestations of ASMD. In a phase 1b study conducted to evaluate the safety and tolerability of within-patient dose escalation with olipudase alfa, measurement of SM levels in liver biopsies was used as a pharmacodynamic biomarker of substrate burden. Five adult patients with non neuronopathic ASMD received escalating doses of olipudase alfa every 2 weeks for 26 weeks. Liver biopsies obtained at baseline and 26 weeks after treatment were evaluated for SM storage by histomorphometric analysis, biochemistry, and electron microscopy. Biopsies were also assessed for inflammation and fibrosis, and for the association of SM levels with liver volume, liver function tests, and lipid profiles. At baseline, SM storage present in Kupffer cells and hepatocytes ranged from 9.8% to 53.8% of the microscopic field. After 26 weeks of treatment, statistically significant reductions in SM (P<0.0001) measured by morphometry were seen in 4 patients with evaluable liver biopsies. The 26-week biopsy of the fifth patient was insufficient for morphometric quantitation. Posttreatment SM levels ranged from 1.2% to 9.5% of the microscopic field, corresponding to an 84% to 92% relative reduction from baseline. Improvements in liver volume, liver function tests, and lipid profiles were also observed. This study illustrates the utility of SM assessment by liver biopsy as a pharmacodynamic biomarker of disease burden in these patients

Parental Depression and Anxiety Associated with Newborn Bloodspot Screening for Rare and Variable-Onset Disorders

The ability to screen newborns for a larger number of disorders, including many with variable phenotypes, is prompting debate regarding the psychosocial impact of expanded newborn bloodspot screening (NBS) on parents. This study compares psychological outcomes of parents of children with a range of NBS/diagnostic experiences, with a particular focus on lysosomal storage disorders (LSDs) and X-linked adrenoleukodystrophy (X-ALD) as representative disorders with complex presentations. An online cross-sectional survey with six domains was completed in 2019 by a volunteer sample of parents with at least one child born between 2013 and 2018. Parents were classified in the analysis stage into four groups based on their child&rsquo;s rare disorder and means of diagnosis. Stress and depression were estimated using dichotomous measures of the depression subscale of the Hospital Anxiety and Depression Scale and the Parental Stress Scale. Logistic regression models were estimated for the relationship between the parent group and stress/depression, controlling for demographic variables (region of the US, income, education, major life events, relationship to the child, number of children, parent age, and race/ethnicity). One hundred seventy-four parents were included in this analysis. Parents of children with an LSD or X-ALD diagnosis clinically may have higher odds of depression (OR: 6.06, 95% CI: 1.64&ndash;24.96) compared to parents of children with the same disorders identified through NBS, controlling for covariates. Although a similar pattern was observed for parental stress (OR: 2.85, 95% CI: 0.82&ndash;10.37), this did not reach statistical significance. Ethically expanding NBS and genome sequencing require an understanding of the impacts of early detection for complex disorders on families. These initial findings are reassuring, and may have implications as NBS expands. Given our small sample size, it is difficult to generalize these findings to all families. These preliminary trends warrant further investigation in larger and more diverse populations

Recommendations for clinical monitoring of patients with acid sphingomyelinase deficiency (ASMD)

Background: Acid sphingomyelinase deficiency (ASMD), a rare lysosomal storage disease, results from mutations in SMPD1, the gene encoding acid sphingomyelinase (ASM). As a result, sphingomyelin accumulates in multiple organs including spleen, liver, lung, bone marrow, lymph nodes, and in the most severe form, in the CNS and peripheral nerves. Clinical manifestations range from rapidly progressive and fatal infantile neurovisceral disease, to less rapidly progressing chronic neurovisceral and visceral forms that are associated with significant morbidity and shorter life span due to respiratory or liver disease. Objectives: To provide a contemporary guide of clinical assessments for disease monitoring and symptom management across the spectrum of ASMD phenotypes. Methods: An international group of ASMD experts in various research and clinical fields used an evidenceinformed consensus process to identify optimal assessments, interventions, and lifestyle modifications. Results: Clinical assessment strategies for major organ system involvement, including liver, spleen, cardiovascular, pulmonary, and neurological/developmental are described, as well as symptomatic treatments, interventions, and/or life style modifications that may lessen disease impact. Conclusions: There is currently no disease-specific treatment for ASMD, although enzyme replacement therapy with a recombinant human ASM (olipudase alfa) is in clinical development. Current monitoring addresses symptoms and multisystem involvement. Recommended interventions and lifestyle modifications are designed to address morbidity and disease complications and improve patient quality of life. While infantile neurovisceral ASMD is uniformly fatal in early childhood, patients with chronic visceral and chronic neurovisceral ASMD require appropriate management throughout childhood and adulthood by an interdisciplinary clinical team