What Should You Discuss with Your Doctor About Tysabri and PML?

Latest update (2026-07)

Tysabri (natalizumab) PML injury claims continue to be evaluated based on individual monitoring and diagnosis records. [source]

From General Health Awareness to Targeted Risk Communication

If you or a loved one is taking Tysabri for multiple sclerosis, you may have heard about the risk of progressive multifocal leukoencephalopathy (PML). This serious brain infection is a known complication, and understanding the warning signs and risk factors is crucial. The heritage of medical research has long guided our understanding of such adverse effects, and this page provides a clear overview of the PML warning context for Tysabri patients in Texas.

Tysabri and PML: Medical Evidence and Risk Factors

Tysabri (natalizumab) is a biologic therapy approved as monotherapy for relapsing forms of multiple sclerosis and for Crohn's disease. Its use carries a well-documented risk of progressive multifocal leukoencephalopathy (PML), a severe opportunistic brain infection caused by the JC virus. For patients in Texas who have developed PML after Tysabri treatment, understanding the medical evidence linking the drug to this harm, as well as the legal context of settlements and statutes of limitations, is essential. The clinical presentation of PML is characterized by progressive neurological deficits. Symptoms may include weakness, cognitive decline, visual disturbances, ataxia, and personality changes. Diagnosis typically relies on brain MRI showing characteristic white matter lesions and detection of JC virus DNA in cerebrospinal fluid. PML usually leads to death or severe disability (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962). The disease is caused by reactivation of the JC virus in immunocompromised individuals, and Tysabri's mechanism of action—blocking lymphocyte trafficking to the central nervous system—impairs immune surveillance, allowing the virus to replicate unchecked in the brain. The U.S. Food and Drug Administration has issued a boxed warning for Tysabri stating that the drug increases the risk of PML (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962). Three established risk factors for PML in Tysabri-treated patients are: the presence of anti-JCV antibodies, longer treatment duration (especially beyond two years), and prior use of immunosuppressants (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962). These factors should be weighed against expected benefits when initiating or continuing therapy. The label instructs healthcare professionals to monitor patients for any new signs or symptoms suggestive of PML and to withhold Tysabri immediately at the first such indication (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962). Because of the PML risk, Tysabri is only available through a restricted distribution program called the TOUCH Prescribing Program (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962). This program requires prescribers to evaluate patients at specified intervals—three months after the first infusion, six months after the first infusion, every six months thereafter, and for at least six months after discontinuing Tysabri (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962). Prescribers must also submit status reports and reauthorization questionnaires every six months, and report cases of PML, hospitalizations due to opportunistic infections, and deaths to Biogen as soon as possible (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962). Despite these monitoring requirements, PML has occurred in patients receiving Tysabri.

Legal Context: Statute of Limitations and Settlement Considerations in Texas

The adequacy of warnings regarding Tysabri and PML is a central issue in legal claims. The boxed warning clearly states the increased risk, but questions may arise about whether prescribers and patients were fully informed of the magnitude of that risk, especially in the context of individual risk factors. For affected patients in Texas, settlement considerations often involve evaluating the timeline between Tysabri exposure and documented harm. PML can develop months to years after starting treatment, and the latency period may complicate efforts to link the drug to the injury. The statute of limitations for filing a product liability claim in Texas generally requires action within two years from the date the injury was discovered or should have been discovered. Given the progressive nature of PML, the date of diagnosis is typically the trigger for the limitations period. Patients who have developed PML after Tysabri use may be eligible for compensation through settlements or litigation. Settlement amounts depend on factors such as the severity of disability, medical expenses, lost income, and the strength of evidence that inadequate warnings contributed to the harm. The mechanistic pathway linking Tysabri to PML is well-established: the drug inhibits alpha-4 integrin, preventing immune cells from crossing the blood-brain barrier, which reduces central nervous system immune surveillance and allows JC virus reactivation. This biological plausibility supports causation in legal claims. In summary, Tysabri carries a known risk of PML, a devastating disease with high morbidity and mortality. The FDA boxed warning and TOUCH program aim to mitigate this risk, but cases continue to occur. For Texas patients, the statute of limitations for filing a claim is typically two years from discovery of the injury. Settlement considerations involve the adequacy of warnings, the timeline of exposure and harm, and the severity of the patient's condition. Anyone affected should consult with a qualified attorney to understand their legal options. References: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c5fdde91-1989-4dd2-9129-4f3323ea2962

Important Notice

This page is for educational and informational purposes only. It does not provide medical diagnosis, treatment, or legal advice. Consult licensed clinicians and qualified attorneys for case-specific decisions.

Frequently Asked Questions

What is the statute of limitations for Tysabri-related PML claims in Texas?

In Texas, the statute of limitations for product liability claims, including those related to Tysabri and PML, is generally two years from the date the injury was discovered or should have been discovered. For PML, the date of diagnosis typically triggers the limitations period.

What factors influence Tysabri PML settlement amounts?

Settlement amounts depend on the severity of disability, medical expenses, lost income, and the strength of evidence that inadequate warnings contributed to the harm. The well-established mechanistic link between Tysabri and PML supports causation in legal claims.

Does submitting information create an attorney-client relationship?

No. Submission requests an initial records screening only and does not create an attorney-client relationship.

Information Registry: individuals with documented Tysabri exposure and a confirmed Progressive Multifocal Leukoencephalopathy diagnosis may request an independent eligibility review. [Begin Assessment]

References

DailyMed - Tysabri Label

Request a Free Case Review

This page is for educational and informational purposes only and is not medical or legal advice. Consult a licensed professional for case-specific guidance.