Trial of N-Acetyl-l-Leucine in Niemann-Pick Disease Type C

BACKGROUND

Niemann-Pick disease type C is a rare lysosomal storage disorder. We evaluated the safety and efficacy of N-acetyl-l-leucine (NALL), an agent that potentially ameliorates lysosomal and metabolic dysfunction, for the treatment of Niemann-Pick disease type C.

METHODS

In this double-blind, placebo-controlled, crossover trial, we randomly assigned patients 4 years of age or older with genetically confirmed Niemann-Pick disease type C in a 1:1 ratio to receive NALL for 12 weeks, followed by placebo for 12 weeks, or to receive placebo for 12 weeks, followed by NALL for 12 weeks. NALL or matching placebo was administered orally two to three times per day, with patients 4 to 12 years of age receiving weight-based doses (2 to 4 g per day) and those 13 years of age or older receiving a dose of 4 g per day. The primary end point was the total score on the Scale for the Assessment and Rating of Ataxia (SARA; range, 0 to 40, with lower scores indicating better neurologic status). Secondary end points included scores on the Clinical Global Impression of Improvement, the Spinocerebellar Ataxia Functional Index, and the Modified Disability Rating Scale. Crossover data from the two 12-week periods in each group were included in the comparisons of NALL with placebo.

RESULTS

A total of 60 patients 5 to 67 years of age were enrolled. The mean baseline SARA total scores used in the primary analysis were 15.88 before receipt of the first dose of NALL (60 patients) and 15.68 before receipt of the first dose of placebo (59 patients; 1 patient never received placebo). The mean (±SD) change from baseline in the SARA total score was -1.97±2.43 points after 12 weeks of receiving NALL and -0.60±2.39 points after 12 weeks of receiving placebo (least-squares mean difference, -1.28 points; 95% confidence interval, -1.91 to -0.65; P<0.001). The results for the secondary end points were generally supportive of the findings in the primary analysis, but these were not adjusted for multiple comparisons. The incidence of adverse events was similar with NALL and placebo, and no treatment-related serious adverse events occurred.

CONCLUSIONS

Among patients with Niemann-Pick disease type C, treatment with NALL for 12 weeks led to better neurologic status than placebo. A longer period is needed to determine the long-term effects of this agent in patients with Niemann-Pick disease type C. (Funded by IntraBio; ClinicalTrials.gov number, NCT05163288; EudraCT number, 2021-005356-10.).

Long-Term Evaluation of Biomarkers in the Czech Cohort of Gaucher Patients

A personalized treatment decision for Gaucher disease (GD) patients should be based on relevant markers that are specific to GD, play a direct role in GD pathophysiology, exhibit low genetic variation, reflect the therapy, and can be used for all patients. Thirty-four GD patients treated with enzyme replacement therapy (ERT) or substrate reduction therapy (SRT) were analyzed for platelet count, chitotriosidase, and tartrate-resistant acid phosphatase activity in plasma samples, and quantitative measurement of Lyso-Gb1 was performed in dried blood spots. In our ERT and SRT study cohorts, plasma lyso-GL1 correlated significantly with chito-triosidase (ERT: r = 0.55, p < 0.001; SRT: r = 0.83, p < 0.001) and TRAP (ERT: r = 0.34, p < 0.001; SRT: r = 0.88, p < 0.001), irrespective of treatment method. A platelet count increase was associated with a Lyso-Gb1 decrease in both treatment groups (ERT: p = 0.021; SRT: p = 0.028). The association of Lyso-Gb1 with evaluated markers was stronger in the SRT cohort. Our results indicate that ERT and SRT in combination or in a switch manner could offer the potential of individual drug effectiveness for particular GD symptoms. Combination of the key biomarker of GD, Lyso-Gb1, with other biomarkers can offer improved response assessment to long-term therapy.