The risk of developing PML while on treatment with TYSABRI is <1% regardless of JCV status1

  • PML is an opportunistic viral infection of the brain caused by the John Cunningham virus (JCV) that usually leads to death or severe disability. JCV infection is required for the development of PML
    • There are no known interventions that can reliably prevent PML or that can adequately treat PML if it occurs
    • PML is not the only factor to consider when assessing the safety profile of TYSABRI
  • Previous immunosuppressant use and treatment duration with TYSABRI are PML risk factors for JCV+ patients
  • Biogen offers free anti-JCV antibody testing (the STRATIFY™ JCV Antibody assay) to support regular monitoring

Early detection of PML is important1

  • MRI findings may be apparent before clinical signs or symptoms suggestive of PML. Periodic monitoring for radiographic signs consistent with PML should be considered to allow for early diagnosis of PML
    • Consider monitoring patients at high risk of PML more frequently
  • Lower PML-related mortality and morbidity have been reported following TYSABRI discontinuation in patients with PML who were initially asymptomatic compared to patients with PML who had characteristic clinical signs and symptoms at diagnosis. It is not known whether these differences are due to early detection and discontinuation of TYSABRI or due to differences in disease in these patients

Continually evaluate treatment response and disease activity as measured by MRI activity, relapse rate, and EDSS progression2

Typical symptoms associated with PML are diverse, progress over days to weeks, and may include1:

  • Progressive weakness on one side of the body or clumsiness of limbs
  • Disturbances of speech or vision
  • Changes in thinking, memory, and orientation leading to confusion and personality changes

Upon initial suspicion of PML, follow these 4 steps1:

To make the diagnosis of PML, various MRI evaluations, including gadolinium-enhanced and T2-weighted scans, as well as PCR analysis of CSF for JC viral DNA, are recommended1

There are no known interventions that can reliably prevent PML or adequately treat it if it occurs.

  • Although PLEX has not been prospectively studied in TYSABRI-treated patients with PML, it has been used in such patients in the postmarketing setting to remove TYSABRI more quickly from the circulation. There is no evidence that PLEX has any benefit in the treatment of opportunistic infections such as PML
  • PML has been reported following discontinuation of TYSABRI in patients who did not have findings suggestive of PML at the time of discontinuation
  • Patients should continue to be monitored for any new signs or symptoms that may be suggestive of PML for approximately 6 months following discontinuation of TYSABRI

This information is provided as an educational resource for healthcare providers. It is not intended to be a substitute for consultation with your patients and review of reference material and medical literature. Healthcare providers should make all treatment decisions based on the context of the situation and their own clinical judgment.

Learn more about monitoring with TOUCH®

Because of the risk of PML, TYSABRI is available only under a restricted distribution program, the TOUCH Prescribing Program.

Only prescribers, pharmacies, and administration sites enrolled in the TOUCH Prescribing Program (REMS program) are able to prescribe, distribute, or infuse TYSABRI.

Learn More About TOUCH®