"Introduction to drugs for the treatment of multiple sclerosis
Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system that leads to the degeneration of nerves in the brain and spinal cord. The immune "...
Progressive Multifocal Leukoencephalopathy
Progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the brain caused by the JC virus (JCV) that typically only occurs in patients who are immunocompromised, and that usually leads to death or severe disability, has occurred in patients who have received TYSABRI.
Three factors that are known to increase the risk of PML in TYSABRI-treated patients have been identified:
- Longer treatment duration, especially beyond 2 years. There is limited experience in patients who have received more than 6 years of TYSABRI treatment.
- Prior treatment with an immunosuppressant (e.g., mitoxantrone, azathioprine, methotrexate, cyclophosphamide, mycophenolate mofetil).
- The presence of anti-JCV antibodies. Patients who are anti-JCV antibody positive have a higher risk for developing PML.
These factors should be considered in the context of expected benefit when initiating and continuing treatment with TYSABRI.
Table 1: Estimated United States Incidence of PML
Stratified by Risk Factor
|Anti-JCV Antibody Negative||TYSABRI Exposure†||Anti-JCV Antibody Positive|
|No Prior Immunosuppressant Use||Prior Immunosuppressant Use|
|< 1/1,000||1-24 months||< 1/1,000||1/1,000|
|Notes: The risk estimates are
based on postmarketing data in the United States from approximately 69,000
TYSABRI exposed patients.
†Data beyond 6 years of treatment are limited. The anti-JCV antibody status was determined using an anti-JCV antibody test (ELISA) that has been analytically and clinically validated and is configured with detection and inhibition steps to confirm the presence of JCV-specific antibodies with an analytical false negative rate of 3%.
Infection by the JC virus is required for the development of PML. Anti-JCV antibody testing should not be used to diagnose PML. Anti-JCV antibody negative status indicates that exposure to the JC virus has not been detected. Patients who are anti-JCV antibody negative have a lower risk of PML than those who are positive. Patients who are anti-JCV antibody negative are still at risk for the development of PML due to the potential for a new JCV infection or a false negative test result. The reported rate of seroconversion in patients with MS (changing from anti-JCV antibody negative to positive and remaining positive in subsequent testing) is 3 to 8 percent annually. In addition, some patients' serostatus may change intermittently. Therefore, patients with a negative anti-JCV antibody test result should be retested periodically. For purposes of risk assessment, a patient with a positive anti-JCV antibody test at any time is considered anti-JCV antibody positive regardless of the results of any prior or subsequent anti-JCV antibody testing. When assessed, anti-JCV antibody status should be determined using an analytically and clinically validated immunoassay. Anti-JCV antibody testing should not be performed for at least two weeks following plasma exchange due to the removal of antibodies from the serum.
There are no known interventions that can reliably prevent PML or that can adequately treat PML if it occurs. It is not known whether early detection of PML and discontinuation of TYSABRI will mitigate the disease. 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 at least six months following discontinuation of TYSABRI.
Ordinarily, patients receiving chronic immunosuppressant or immunomodulatory therapy or who have systemic medical conditions resulting in significantly compromised immune system function should not be treated with TYSABRI.
Because of the risk of PML, TYSABRI is available only under a restricted distribution program, the TOUCH® Prescribing Program.
In Crohn's disease patients, a baseline brain MRI may also be helpful to distinguish pre-existent lesions from newly developed lesions, but brain lesions at baseline that could cause diagnostic difficulty while on TYSABRI therapy are uncommon.
Healthcare professionals should monitor patients on TYSABRI for any new sign or symptom suggestive of PML. Typical symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes. The progression of deficits usually leads to death or severe disability over weeks or months. Withhold TYSABRI dosing immediately at the first sign or symptom suggestive of PML.
For diagnosis of PML, an evaluation including a gadolinium-enhanced MRI scan of the brain and, when indicated, cerebrospinal fluid analysis for JC viral DNA are recommended. If the initial evaluations for PML are negative but clinical suspicion for PML remains, continue to withhold TYSABRI dosing, and repeat the evaluations.
There are no known interventions that can adequately treat PML if it occurs. Three sessions of plasma exchange over 5 to 8 days were shown to accelerate TYSABRI clearance in a study of 12 patients with MS who did not have PML, although in the majority of patients, alpha-4 integrin receptor binding remained high. Adverse events which may occur during plasma exchange include clearance of other medications and volume shifts, which have the potential to lead to hypotension or pulmonary edema. Although plasma exchange has not been 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. Anti-JCV antibody testing should not be performed during or for at least two weeks following plasma exchange because of the removal of antibodies from the serum.
Immune reconstitution inflammatory syndrome (IRIS) has been reported in the majority of TYSABRI treated patients who developed PML and subsequently discontinued TYSABRI. In almost all cases, IRIS occurred after plasma exchange was used to eliminate circulating TYSABRI. It presents as a clinical decline in the patient's condition after TYSABRI removal (and in some cases after apparent clinical improvement) that may be rapid, can lead to serious neurological complications or death, and is often associated with characteristic changes in the MRI. TYSABRI has not been associated with IRIS in patients discontinuing treatment with TYSABRI for reasons unrelated to PML. In TYSABRI treated patients with PML, IRIS has been reported within days to several weeks after plasma exchange. Monitoring for development of IRIS and appropriate treatment of the associated inflammation should be undertaken.
TYSABRI TOUCH Prescribing Program
For prescribers and patients, the TOUCH® Prescribing Program has two components: MS TOUCH® (for patients with multiple sclerosis) and CD TOUCH® (for patients with Crohn's disease).
Selected requirements of the TOUCH® Prescribing Program include the following:
- Prescribers must be certified and comply with the
- Review the TOUCH Prescribing Program prescriber educational materials, including the full prescribing information.
- Educate patients on the benefits and risks of treatment with TYSABRI, ensure that patients receive the Medication Guide, and encourage them to ask questions.
- Review, complete, and sign the Patient-Prescriber Enrollment Form.
- Evaluate patients 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.
- Determine every six months whether patients should continue on treatment and, if so, authorize treatment for another six months.
- Submit to Biogen Idec the “TYSABRI Patient Status Report and Reauthorization Questionnaire” six months after initiating treatment and every six months thereafter.
- Complete an “Initial Discontinuation Questionnaire” when TYSABRI is discontinued, and a “6-Month Discontinuation Questionnaire” following discontinuation of TYSABRI.
- Report cases of PML, hospitalizations due to opportunistic infections, and deaths to Biogen Idec at 1-800-456-2255 as soon as possible.
- Patients must be enrolled in the TOUCH Prescribing Program, read the Medication Guide, understand the risks associated with TYSABRI, and complete and sign the Patient-Prescriber Enrollment Form.
- Pharmacies and infusion centers must be specially certified to dispense or infuse TYSABRI.
Herpes Encephalitis And Meningitis
TYSABRI increases the risk of developing encephalitis and meningitis caused by herpes simplex and varicella zoster viruses. Serious, life-threatening, and sometimes fatal cases have been reported in the postmarketing setting in multiple sclerosis patients receiving TYSABRI. Laboratory confirmation in those cases was based on positive PCR for viral DNA in the cerebrospinal fluid. The duration of treatment with TYSABRI prior to onset ranged from a few months to several years. Monitor patients receiving TYSABRI for signs and symptoms of meningitis and encephalitis. If herpes encephalitis or meningitis occurs, TYSBARI should be discontinued, and appropriate treatment for herpes encephalitis/meningitis should be administered.
Clinically significant liver injury, including acute liver failure requiring transplant, has been reported in patients treated with TYSABRI in the postmarketing setting. Signs of liver injury, including markedly elevated serum hepatic enzymes and elevated total bilirubin, occurred as early as six days after the first dose; signs of liver injury have also been reported for the first time after multiple doses. In some patients, liver injury recurred upon rechallenge, providing evidence that TYSABRI caused the injury. The combination of transaminase elevations and elevated bilirubin without evidence of obstruction is generally recognized as an important predictor of severe liver injury that may lead to death or the need for a liver transplant in some patients.
TYSABRI should be discontinued in patients with jaundice or other evidence of significant liver injury (e.g., laboratory evidence).
Hypersensitivity reactions have occurred in patients receiving TYSABRI, including serious systemic reactions (e.g., anaphylaxis), which occurred at an incidence of < 1%. These reactions usually occur within two hours of the start of the infusion. Symptoms associated with these reactions can include urticaria, dizziness, fever, rash, rigors, pruritus, nausea, flushing, hypotension, dyspnea, and chest pain. Generally, these reactions are associated with antibodies to TYSABRI.
If a hypersensitivity reaction occurs, discontinue administration of TYSABRI, and initiate appropriate therapy. Patients who experience a hypersensitivity reaction should not be re-treated with TYSABRI. Hypersensitivity reactions were more frequent in patients with antibodies to TYSABRI compared to patients who did not develop antibodies to TYSABRI in both MS and CD studies. Therefore, the possibility of antibodies to TYSABRI should be considered in patients who have hypersensitivity reactions [see ADVERSE REACTIONS].
Antibody testing: If the presence of persistent antibodies is suspected, antibody testing should be performed. Antibodies may be detected and confirmed with sequential serum antibody tests. Antibodies detected early in the treatment course (e.g., within the first six months) may be transient and may disappear with continued dosing. It is recommended that testing be repeated three months after an initial positive resultto confirm that antibodies are persistent. Prescribers should consider the overall benefits and risks of TYSABRI in a patient with persistent antibodies.
Experience with monoclonal antibodies, including TYSABRI, suggests that patients who receive therapeutic monoclonal antibodies after an extended period without treatment may be at higher risk of hypersensitivity reactions than patients who received regularly scheduled treatment. Given that patients with persistent antibodies to TYSABRI experience reduced efficacy, and that hypersensitivity reactions are more common in such patients, consideration should be given to testing for the presence of antibodies in patients who wish to recommence therapy following a dose interruption. Following a period of dose interruption, patients testing negative for antibodies prior to re-dosing have a risk of antibody development with re-treatment that is similar to TYSABRI na´ve patients [see ADVERSE REACTIONS].
The immune system effects of TYSABRI may increase the risk for infections. In Study MS1 [see Clinical Studies], certain types of infections, including pneumonias and urinary tract infections (including serious cases), gastroenteritis, vaginal infections, tooth infections, tonsillitis, and herpes infections, occurred more often in TYSABRI-treated patients than in placebo-treated patients [see Progressive Multifocal Leukoencephalopathy, ADVERSE REACTIONS]. One opportunistic infection, a cryptosporidial gastroenteritis with a prolonged course, was observed in a patient who received TYSABRI in Study MS1.
In Studies MS1 and MS2, an increase in infections was seen in patients concurrently receiving short courses of corticosteroids. However, the increase in infections in TYSABRI-treated patients who received steroids was similar to the increase in placebo-treated patients who received steroids.
In CD clinical studies, opportunistic infections (pneumocystis carinii pneumonia, pulmonary mycobacterium avium intracellulare, bronchopulmonary aspergillosis, and burkholderia cepacia) have been observed in < 1% of TYSABRI-treated patients; some of these patients were receiving concurrent immunosuppressants [see Progressive Multifocal Leukoencephalopathy, ADVERSE REACTIONS].
In Studies CD1 and CD2, an increase in infections was seen in patients concurrently receiving corticosteroids. However, the increase in infections was similar in placebo-treated and TYSABRI-treated patients who received steroids.
Concurrent use of antineoplastic, immunosuppressant, or immunomodulating agents may further increase the risk of infections, including PML and other opportunistic infections, over the risk observed with use of TYSABRI alone [see Progressive Multifocal Leukoencephalopathy, ADVERSE REACTIONS]. The safety and efficacy of TYSABRI in combination with antineoplastic, immunosuppressant, or immunomodulating agents have not been established. Patients receiving chronic immunosuppressant or immunomodulatory therapy or who have systemic medical conditions resulting in significantly compromised immune system function should not ordinarily be treated with TYSABRI. The risk of PML is also increased in patients who have been treated with an immunosuppressant prior to receiving TYSABRI [see Progressive Multifocal Leukoencephalopathy].
For patients with Crohn's disease who start TYSABRI while on chronic corticosteroids, commence steroid withdrawal as soon as a therapeutic benefit has occurred. If the patient cannot discontinue systemic corticosteroids within six months, discontinue TYSABRI.
Laboratory Test Abnormalities
In clinical trials, TYSABRI was observed to induce increases in circulating lymphocytes, monocytes, eosinophils, basophils, and nucleated red blood cells. Observed changes persisted during TYSABRI exposure, but were reversible, returning to baseline levels usually within 16 weeks after the last dose. Elevations of neutrophils were not observed. TYSABRI induces mild decreases in hemoglobin levels that are frequently transient.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (Medication Guide).
General Counseling Information
Counsel patients to understand the risks and benefits of TYSABRI before an initial prescription is written. The patient may be educated by either the enrolled prescriber or a healthcare provider under that prescriber's direction. INSTRUCT PATIENTS USING TYSABRI TO:
- Read the Medication Guide before starting TYSABRI and before each TYSABRI infusion.
- Promptly report any new or continuously worsening symptoms that persist over several days to their prescriber [see WARNINGS AND PRECAUTIONS].
- Inform all of their physicians that they are receiving TYSABRI.
- Plan to see their prescriber 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.
Progressive Multifocal Leukoencephalopathy
Inform patients that Progressive Multifocal Leukoencephalopathy (PML) has occurred in patients who received TYSABRI. Instruct the patient of the importance of contacting their doctor if they develop any symptoms suggestive of PML. Instruct the patient that typical symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes. Instruct the patient that the progression of deficits usually leads to death or severe disability over weeks or months.
Instruct patients to continue to look for new signs and symptoms suggestive of PML for approximately 6 months following discontinuation of TYSABRI [see WARNINGS AND PRECAUTIONS].
TYSABRI TOUCH Prescribing Program
Advise the patient that TYSABRI is only available through a restricted program called the TOUCH Prescribing Program. Inform the patient of the following requirements:
Patients must read the Medication Guide and sign the Patient Prescriber Enrollment Form. Advise patients that TYSABRI is available only from certified pharmacies and infusion centers participating in the program [see WARNINGS AND PRECAUTIONS].
Inform patients that TYSABRI increases the risk of developing encephalitis and meningitis caused by herpes simplex and varicella zoster viruses. Instruct patients to report immediately if they experience symptoms such as fever, headache and confusion [see WARNINGS AND PRECAUTIONS].
Inform patients that TYSABRI may cause liver injury. Instruct patients treated with TYSABRI to report promptly any symptoms that may indicate liver injury, including fatigue, anorexia, right upper abdominal discomfort, dark urine, or jaundice. [see WARNINGS AND PRECAUTIONS].
Instruct patients to report immediately if they experience symptoms consistent with a hypersensitivity reaction (e.g., urticaria with or without associated symptoms) during or following an infusion of TYSABRI [see WARNINGS AND PRECAUTIONS].
Inform patients that TYSABRI may lower the ability of their immune system to fight infections. Instruct the patient of the importance of contacting their doctor if they develop any symptoms of infection [see WARNINGS AND PRECAUTIONS].
Carcinogenesis, Mutagenesis, Impairment Of Fertility
No clastogenic or mutagenic effects of natalizumab were observed in the Ames test or in vitro chromosomal aberration assay in human lymphocytes. Natalizumab showed no effects in in vitro assays of α4-integrin positive human tumor line proliferation/cytotoxicity. Xenograft transplantation models in SCID and nude mice with two α4-integrin positive human tumor lines (leukemia, melanoma) demonstrated no increase in tumor growth rates or metastasis resulting from natalizumab treatment.
Reductions in female guinea pig fertility were observed in one study at dose levels of 30 mg/kg, but not at the 10 mg/kg dose level (2.3-fold the clinical dose). A 47% reduction in pregnancy rate was observed in guinea pigs receiving 30 mg/kg relative to control. Implantations were seen in only 36% of animals having corpora lutea in the 30 mg/kg group versus 66 to 72% in the other groups. Natalizumab did not affect male fertility at doses up to 7-fold the clinical dose.
Use In Specific Populations
Pregnancy Category C. TYSABRI has been shown to reduce pup survival in guinea pigs when given in doses 7 times the human dose, and has been shown to have hematologic effects on the fetus in monkeys when given in doses 2.3 times the human dose [see Nonclinical Toxicology]. There are no adequate and well-controlled studies in pregnant women. TYSABRI should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. If a woman becomes pregnant while taking TYSABRI, consider enrolling her in the TYSABRI Pregnancy Exposure Registry by calling 1-800-456-2255.
TYSABRI has been detected in human milk. The effects of this exposure on infants are unknown.
Safety and effectiveness of TYSABRI in pediatric patients with multiple sclerosis or Crohn's disease below the age of 18 years have not been established. TYSABRI is not indicated for use in pediatric patients.
Clinical studies of TYSABRI did not include sufficient numbers of patients aged 65 years and over to determine whether they respond differently than younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients.
Last reviewed on RxList: 5/29/2015
This monograph has been modified to include the generic and brand name in many instances.
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