[Progressive Multifocal Leukoencephalopathy: An Overview of Current Topics]

Area of Science:

• Neuroimmunology
• Infectious Neurology
• Drug Safety

Background:

• Progressive multifocal leukoencephalopathy (PML) is a rare, opportunistic demyelinating disease.
• PML is primarily associated with JC virus reactivation.
• Disease-modifying drugs (DMDs) used for multiple sclerosis (MS) have been linked to an increased risk of PML.

Purpose of the Study:

• To provide an overview of PML and its association with DMDs in MS.
• To discuss the current status of PML in MS patients treated with natalizumab, fingolimod, and dimethyl fumarate.
• To evaluate the potential risk of PML with newer MS DMDs like siponimod and ofatumumab.

Main Methods:

• Literature review and analysis of existing data on PML incidence in MS patients.
• Examination of drug labels and post-marketing surveillance data for natalizumab, fingolimod, and dimethyl fumarate.
• Assessment of the pharmacological profiles and proposed mechanisms of action for siponimod and ofatumumab in relation to PML risk.

Main Results:

• PML is a known risk associated with several MS DMDs, including natalizumab, fingolimod, and dimethyl fumarate.
• The risk and incidence of PML vary among different DMDs.
• Emerging DMDs for MS, such as siponimod and ofatumumab, may also carry a risk of PML, requiring careful monitoring.

Conclusions:

• Managing PML risk is crucial in the era of advanced MS therapies.
• There are currently no specific antiviral treatments for JC virus-induced PML.
• Ongoing research is exploring potential therapeutic agents for PML, but none are yet established.