The primary purpose of this study is to estimate the incidence of progressive multifocal leukoencephalopathy (PML) among patients who switched to Tysabri from disease modifying therapies (DMTs), including newer DMTs (including fingolimod, dimethyl fumarate and teriflunomide) and the established DMTs (interferon beta and glatiramer acetate). Researchers will also look to estimate the incidence of other serious opportunistic infections among patients who switch to Tysabri from newer DMTs (including fingolimod, dimethyl fumarate and teriflunomide) and the established DMTs (interferon beta and glatiramer acetate)
This is an observational cohort study utilising all available data from the Tysabri TOUCH (TYSABRI Outreach: Unified Commitment to Health) prescribing programme (US) supplemented with data from European Union (EU) multiple sclerosis (MS) registries to estimate the risk of PML and other serious opportunistic infections (OIs) among patients on Tysabri who have switched from newer DMTs (including fingolimod, dimethyl fumarate and teriflunomide) and the established DMTs (interferon beta and glatiramer acetate). This study will provide cumulative data from its two components: a retrospective component (data captured prior to 01 January 2016) and a prospective component (data captured, and patients followed up, from 01 January 2016 through 31 December 2023; total prospective study duration of 8 years). All patients who switched to Tysabri from another DMT through 31 December 2020 will be included. The study will continue to follow-up patients until 31 December 2023 to allow for a minimal follow-up of 3 years.
Study Type
OBSERVATIONAL
Enrollment
80,327
Administered as specified in the treatment arm.
Research Site
Cambridge, Massachusetts, United States
Prospective and Retrospective Analyses: Number of Participants with Confirmed Progressive Multifocal Leukoencephalopathy (PML)
Confirmed cases of PML must have one of the following: • Brain biopsy or brain from post mortem examination showing evidence of viral cytopathic changes on hematoxylin and eosin (H \& E) staining associated with either positive immunohistochemistry for SV40 or in-situ hybridization for John Cunningham Virus (JCV) deoxyribonucleic acid (DNA) OR All of the following criteria: • Cerebrospinal fluid (CSF) with evidence of JCV DNA, preferably by ultra-sensitive quantitative polymerase chain reaction (PCR) testing (limit of quantification of ≤ 50 copies/ml), or JCV DNA on brain biopsy by PCR AND detailed description of brain magnetic resonance imaging (MRI) findings that are consistent with PML AND PREFERABLY new or progressive clinical symptoms suggestive of PML
Time frame: Retrospective: from the time of switching to Tysabri to 31 December 2015; Prospective: from the time of switching to Tysabri (on or after 01 January 2016) to 31 December 2023 (up to 8 years)
Prospective and Retrospective Analyses: Number of Participants with Serious Adverse Events of Other Serious Opportunistic Infections (OIs)
An SAE is any untoward medical occurrence at any dose that results in death, immediate risk of death, hospitalization, disability, or congenital anomaly/birth defect. Opportunistic infections (OIs) are infections that occur more frequently and are more severe in individuals with weakened immune systems.
Time frame: Retrospective: from the time of switching to Tysabri to 31 December 2015; Prospective: from the time of switching to Tysabri (on or after 01 January 2016) to 31 December 2023 (up to 8 years)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.