Progressive Multifocal Leukoencephalopathy (PML)
Progressive multifocal leukoencephalopathy, an opportunistic infection caused
by the JC virus that typically only occurs in patients who are immunocompromised,
developed in three patients who received TYSABRI in clinical trials [see Boxed
Warning]. Two cases of PML were observed among 1869 patients with multiple
sclerosis treated for a median of 120 weeks. The third case occurred among 1043
patients with Crohn's disease after the patient received eight doses. Both multiple
sclerosis patients were receiving concomitant immunomodulatory therapy and the
Crohn's disease patient had been treated in the past with immunosuppressive
therapy. In the postmarketing setting, additional cases of PML have been reported
in multiple sclerosis patients who were receiving no concomitant immunomodulatory
therapy. The absolute risk for PML in patients treated with TYSABRI cannot be
precisely estimated, and factors that might increase an individual patient's
risk for PML have not been identified. There are no known interventions that
can reliably prevent PML or adequately treat PML if it occurs. It is not known
whether early detection of PML and discontinuation of TYSABRI will mitigate
the disease. There is limited experience beyond two years of treatment. The
relationship between the risk of PML and the duration of treatment is unknown,
but most cases of PML were in patients who received more than one year of treatment.
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. The incidence of
PML appears to be lower in patients receiving TYSABRI as monotherapy; however,
the number of cases is too few and the number of patients treated too small
to reliably conclude that the true risk of PML is lower in patients treated
with TYSABRI alone than in patients who are receiving other drugs that decrease immune function or who are otherwise immunocompromised.
Because of the risk of PML, TYSABRI is available only under a special restricted distribution program, the TOUCH™ Prescribing Program.
In multiple sclerosis patients, an MRI scan should be obtained prior to initiating therapy with TYSABRI. This MRI may be helpful in differentiating subsequent multiple sclerosis symptoms from PML.
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, an evaluation including a gadolinium-enhanced MRI scan of the brain and, when indicated, cerebrospinal fluid analysis for JC viral DNA are recommended. 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, 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. There is no evidence that plasma exchange has any benefit in the treatment of opportunistic infections such as PML.
Distribution Program for TYSABRI
TYSABRI is available only under a special restricted distribution program called
the TOUCH™ Prescribing Program. Under the TOUCH™ Prescribing Program,
only prescribers, infusion centers, and pharmacies associated with infusion
centers registered with the program are able to prescribe, distribute, or infuse
the product. 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). TYSABRI must be administered
only to patients who are enrolled in and meet all the conditions of the MS or
CD TOUCH™ Prescribing Program. Contact the TOUCH™ Prescribing Program
at 1-800-456-2255 [see Boxed Warning].
To enroll in the TOUCH™ Prescribing Program, prescribers and patients are required to understand the risks of treatment with TYSABRI, including PML and other opportunistic infections. Prescribers are required to understand the information in the Prescribing Information and to be able to:
- Educate patients on the benefits and risks of treatment with TYSABRI, ensure
that the patient receives the Medication Guide, instruct them to read it,
and encourage them to ask questions when considering TYSABRI. Patients may
be educated by the enrolled prescriber or a healthcare provider under that
prescriber's direction.
- Review the TOUCH™ Prescriber/Patient Enrollment form for TYSABRI
with the patient and answer all questions.
- As part of the initial prescription process for TYSABRI, obtain the patient's signature and initials on the TOUCH™ program enrollment form, sign it,
place the original signed form in the patient's medical record, send a copy
to Biogen Idec, and give a copy to the patient.
- Report serious opportunistic and atypical infections with TYSABRI to Biogen
Idec or Elan at 1-800-456-2255 and to the Food and Drug Administration's MedWatch
Program at 1-800-FDA-1088.
- Evaluate the patient three months after the first infusion, six months
after the first infusion, and every six months thereafter.
- Determine every six months whether patients should continue on treatment
and if so reauthorize treatment every six months.
- Submit to Biogen Idec the TYSABRI Patient Status Report and Reauthorization
Questionnaire six months after initiating treatment and every six months thereafter.
Hypersensitivity/Antibody Formation
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 disappear with continued dosing. Repeat testing at three months after the initial positive result is recommended in patients in whom antibodies are detected to 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 naïve patients [see ADVERSE
REACTIONS].
Immunosuppression/Infections
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 WARNINGS AND PRECAUTIONS, 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 Boxed
Warning, WARNINGS AND PRECAUTIONS, 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 Boxed
Warning, WARNINGS AND PRECAUTIONS, 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.
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.
Hepatotoxicity
Clinically significant liver injury 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).
Laboratory Test Abnormalities
TYSABRI induces increases in circulating lymphocytes, monocytes, eosinophils, basophils, and nucleated red blood cells. Observed changes persist during TYSABRI exposure, but are reversible, returning to baseline levels usually within 16 weeks after the last dose. Elevations of neutrophils are not observed. TYSABRI induces mild decreases in hemoglobin levels that are frequently transient.
Immunizations
No data are available on the effects of vaccination in patients receiving TYSABRI. No data are available on the secondary transmission of infection by live vaccines in patients receiving TYSABRI.
Patient Counseling Information
See 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 Boxed Warning,
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, and at least as frequently as every six months
thereafter.
Progressive Multifocal Leukoencephalopathy
Inform patients that Progressive Multifocal Leukoencephalopathy (PML) has occurred
in patients who received TYSABRI, some who have received concomitant immunomodulatory
therapy and some who have not. 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 [see WARNINGS AND PRECAUTIONS].
Hypersensitivity Reactions
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].
Immunosuppression/Infections
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].
Hepatotoxicity
Inform patients that TYSABRI may cause liver injury. Instruct the patient to
contact their doctor if they develop symptoms of hepatoxicity [see WARNINGS
AND PRECAUTIONS].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, and 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
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.
Nursing Mothers
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from TYSABRI, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Pediatric Use
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.
Geriatric Use
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 updated on RxList: 8/31/2009