Improvement in quality of life and general functions in pediatric acid sphingomyelinase deficiency patients after receiving olipudase alfa: A single-center experience in Taiwan

Background: The ultra-rare lysosomal storage disease, Acid sphingomyelinase deficiency (ASMD), is currently managed with olipudase alfa, an enzyme replacement therapy (ERT). Specifically targeting the non-neurological manifestations in chronic ASMD cases, olipudase alfa has demonstrated efficacy in reducing disease burdens through clinical trials and real-world studies. However, data on the impact of olipudase alfa on quality of life and its real-world influences are limited. Materials and methods: By May 2024, two pediatric patients-Patient 1 (P1) and Patient 2 (P2)-diagnosed with chronic neurovisceral ASMD A/B had undergone three years of olipudase alfa treatment in a single tertiary medical center in southern Taiwan. Throughout the treatment course, major outcomes including neurocognitive function and functional capability assessments were measured regularly. The primary caregivers completed the PedsQL™ version 4.0 questionnaire for the evaluation of the quality of life of the patients. Additionally, the progress of major symptoms was independently assessed using a customized questionnaire. Results: Following treatment with olipudase alfa, the six-minute walking distance improved from zero to 127.7 m in P1 and from zero to 340 m in P2. Functional capability, measured by the EDSS and pmRS scales, showed no decline in either patient. Quality of life, evaluated using the PedsQL 4.0 generic scales, which measures the frequency of discomfort caused by the disease, showed improvement for both patients. The total score decreased from 64 to 55 in P1 and from 58 to 39 in P2, with the greatest improvement observed in physical functioning. Among the major symptoms and signs, abdominal fullness and growth failure showed the most notable improvements. However, the caregiver noted increased emotional challenges in P1, particularly due to fear of needle injections following treatment. For P1, the full-scale IQ score fell from the 0.2nd percentile at baseline to below the 0.1st percentile after three years of enzyme replacement therapy (ERT). In P2, Bayley III scores for cognitive, language, and motor domains remained below the 1st percentile compared to age- and gender-matched controls, showing no obvious improvement or deterioration after treatment. Conclusion: ERT improves functional capacity and quality of life in two pediatric patients with chronic neurovisceral ASMD A/B. Further data from larger samples are required to confirm these findings.