Natural history and 12-month progression of multiple system atrophy in a Chinese cohort

Background Understanding disease natural history is important for the development of potential treatments for people with MSA. We describe the natural progression of early MSA in a Chinese population. Methods Observational, 12-month study conducted in 8 sites across China . Eligible participants were aged 40–75 years, with possible or probable MSA of the parkinsonian (MSA-P) or cerebellar (MSA-C) subtype, and anticipated survival of ≥ 3 years. Disease progression was analyzed using a linear mixed model of Total UMSARS (Part I + II) progression, including baseline, Month 6 and Month 12 data. Results A total of 89 participants with a mean ± SD time since diagnosis of 0.4 ± 0.6 years were enrolled. Of these 52% had MSA-C and 48% participants had MSA-P. The mean ± SE [95%CI] rate of Total UMSARS progression was 1.27 ± 0.13 [1.01, 1.53] points per month. Participants showed a progression of 0.64 ± 0.06 [0.51, 0.76] points/month on UMSARS Part I and 0.62 ± 0.07 [0.47, 0.77] points/month on UMSARS Part II. Differences in the rates of UMSARS progression between patients with MSA-P and MSA-C were not statistically significant ( p > 0.05). Conclusions This is the first multicenter natural history study of MSA progression conducted in China. While prior studies have indicated a predominance of MSA-C in Asian populations, we found a more even split of MSA-C and MSA-P subtypes. In this early population, patients showed an average progression rate of ~ 15 Total UMSARS points/year; rates of progression were similar between the two subtypes and were in alignment with previous studies that assessed disease progression using UMSARS in Western populations. Trial registration Clinicaltrals.gov, NCT05453058 (registered June 16, 2022).