Multiple system atrophy (MSA) is a sporadic, rapidly progressing neurodegenerative disorder. Most MSA patients are diagnosed between 50 to 60 years of age and the mean survival time is 6 to 10 years from symptom onset, with few surviving more than 15 years from symptom onset. The rapid progression and complexity of the disease, as well as its unresponsiveness to drugs, such as Levodopa for parkinsonian symptoms, makes MSA a challenging disease to treat. Based on the predominant motor features at the time of clinical evaluation, MSA is classified as either MSA with predominant parkinsonism (MSA-P) or MSA with predominant cerebellar ataxia (MSA-C).
MSA is an orphan and rare disease. The prevalence estimate of MSA is 3 to 5 per 100,000 in the general population. The prevalence estimate ranges from 2 to 5 per 100,000 in the United States and European Union (EU) and from 7 to 20 per 100,000 in Japan. MSA-P comprises approximately 70% of cases in the US and EU, whilst MSA-C comprises approximately 70% of cases in Japan.
Blood and MRI biomarkers have been evaluated in MSA patients. NfL (Neurofilament light protein) levels are increased in the cerebrospinal fluid (CSF) and plasma of patients with MSA and correlate with MSA disease severity, as measured by the unified MSA rating scale (UMSARS). An accurate estimate of NfL levels over time could help monitor MSA prognosis and help define the timepoints that could be targeted for effective treatment.
Furthermore, MSA patients with abnormal brain MRI findings have faster clinical progression of MSA, as evaluated with the UMSARS total score and UMSARS Part II (clinical examination). A recent review on the role of MRI in MSA noted that whilst MRI is a promising tool for diagnosing and monitoring disease progression; well-designed, large, prospective studies are needed before MRI biomarkers could be incorporated into a neuroimaging-supported diagnosis of MSA. The knowledge gained from this study should help improve understanding of biomarkers and other disease progression outcomes in MSA. This could allow MSA disease progression to be monitored and therefore treated more effectively. Insights into the natural course of disease in MSA patients in the EU will be combined and compared with data on the natural course of disease in MSA patients in China, as part of a larger global cohort. Specifically, the natural course of MSA will be explored in patients in China (using [Chinese versions of] the same prospective observational assessments as the current prospective protocol in the EU). This will allow for data collected prospectively during routine visits for MSA in China to be combined and compared with data collected prospectively during routine visits for MSA in the EU.
The extension part of Talisman:
The extension of Talisman will describe early MSA disease progression and mortality assessed remotely via telephone call with either the participant or care-partner in 6-month intervals up until 60 months after enrolling in extension study. The long-term extension will generate knowledge on long-term disease progression and survival in MSA.