Natalizumab
/api/v1/drug/natalizumabBoxed warning
PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY TYSABRI increases the risk of progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the brain that usually leads to death or severe disability. Risk factors for the development of PML include the presence of anti-JCV antibodies, duration of therapy, and prior use of immunosuppressants. These factors should be considered in the context of expected benefit when initiating and continuing treatment with TYSABRI [ see Warnings and Precautions ( 5.1 ) ]. Healthcare professionals should monitor patients on TYSABRI for any new sign or symptom that may be suggestive of PML. TYSABRI dosing should be withheld immediately at the first sign or symptom suggestive of PML. For diagnosis, an evaluation that includes a gadolinium-enhanced magnetic resonance imaging (MRI) scan of the brain and, when indicated, cerebrospinal fluid analysis for JC viral DNA are recommended [ see Contraindications ( 4 ), Warnings and Precautions ( 5.1 ) ]. Because of the risk of PML, TYSABRI is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the TOUCH ® Prescribing Program [ see Warnings and Precautions ( 5.2 ) ].
Mechanism of action
Sourced from openFDANatalizumab binds to the α4-subunit of α4β1 and α4β7 integrins expressed on the surface of all leukocytes except neutrophils, and inhibits the α4-mediated adhesion of leukocytes to their counter-receptor(s). The receptors for the α4 family of integrins include vascular cell adhesion molecule-1 (VCAM-1), which is expressed on activated vascular endothelium, and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) present on vascular endothelial cells of the gastrointestinal tract.
Indications
Sourced from openFDA- TYSABRI is an integrin receptor antagonist indicated for treatment of: Multiple Sclerosis (MS) TYSABRI is indicated as monotherapy for the treatment of relapsing forms of multiple sclerosis, to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. TYSABRI increases the risk of PML [See Warnings and Precautions ( 5.1 ) ].ICD-10: G35
Contraindications
Sourced from openFDA- TYSABRI is contraindicated in patients who have or have had progressive multifocal leukoencephalopathy (PML) [ see Warnings and Precautions ( 5.1 ) ]. TYSABRI is contraindicated in patients who have had a hypersensitivity reaction to TYSABRI.contraindicated
Dosage & administration
Sourced from openFDA300 mg infused intravenously over one hour, every four weeks. Do not give as an intravenous push or bolus ( 2.1 , 2.2 ) TYSABRI solution must be administered within 48 hours of preparation ( 2.3 ) Observe patients during all infusions. Post-infusion, for the first 12 infusions, observe patients for one hour after the infusion is complete. For patients who have received 12 infusions without evidence of a hypersensitivity reaction, observe patients post-infusion for the 13th and subsequent infusions according to clinical judgment. ( 2.4 ) In CD, discontinue in patients that have not experienced therapeutic benefit by 12 weeks of induction therapy, and in patients that cannot discontinue chronic concomitant steroids within six months of starting therapy ( 2.2 ) 2.1 Multiple Sclerosis (MS) Only prescribers registered in the MS TOUCH ® Prescribing Program may prescribe TYSABRI for multiple sclerosis [ see Warnings and Precautions ( 5.2 ) ]. The recommended dose of TYSABRI for multiple sclerosis is 300 mg intravenous infusion over one hour every four weeks. 2.2 Crohn's Disease (CD) Only prescribers registered in the CD TOUCH ® Prescribing Program may prescribe TYSABRI for Crohn's disease [ see Warnings and Precautions ( 5.2 ) ]. The recommended dose of TYSABRI for Crohn's disease is 300 mg intravenous infusion over one hour every four weeks. TYSABRI should not be used with concomitant immunosuppressants (e.g., 6-mercaptopurine, azathioprine, cyclosporine, or methotrexate) or concomitant inhibitors of TNF-α. Aminosalicylates may be continued during treatment with TYSABRI.
Warnings & precautions
Sourced from openFDAHerpes infections: Life-threatening and fatal cases have occurred with herpes encephalitis and meningitis infections. Blindness has occurred in patients developing acute retinal necrosis. Discontinue TYSABRI if these infections occur and treat appropriately ( 5.3 ) Hepatotoxicity: Significant liver injury, including liver failure requiring transplant, has occurred. Discontinue TYSABRI in patients with evidence of liver injury ( 5.4 ) Hypersensitivity reactions: Serious hypersensitivity reactions (e.g., anaphylaxis) have occurred. Permanently discontinue TYSABRI if such a reaction occurs ( 5.5 ) Immunosuppression/Infections: TYSABRI may increase the risk for certain infections. Monitor patients for development of infections due to increased risk with use of TYSABRI ( 5.6 ) Hematological Abnormalities: TYSABRI may cause thrombocytopenia. Monitor patients for bleeding abnormalities. Discontinue TYSABRI in patients with thrombocytopenia. Neonatal thrombocytopenia and anemia have also occurred. Obtain a complete blood count in neonates exposed to TYSABRI in utero. ( 5.8 ) 5.1 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: The presence of anti-JCV antibodies.
Adverse reactions
Sourced from openFDAThe following serious adverse reactions are described below and elsewhere in the labeling: Progressive Multifocal Leukoencephalopathy (PML) [see Warnings and Precautions ( 5.1 )] Herpes Infections [see Warnings and Precautions ( 5.3 )] Hepatotoxicity [see Warnings and Precautions ( 5.4 )] Hypersensitivity/Antibody Formation [see Warnings and Precautions ( 5.5 )] Immunosuppression/Infections [see Warnings and Precautions ( 5.6 )] Hematological Abnormalities [see Warnings and Precautions ( 5.8 )] Most common adverse reactions (incidence ≥ 10%): MS - headache, fatigue, arthralgia, urinary tract infection, lower respiratory tract infection, gastroenteritis, vaginitis, depression, pain in extremity, abdominal discomfort, diarrhea NOS, and rash ( 6.1 ) CD - headache, upper respiratory tract infections, nausea, and fatigue ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Biogen at 1-800-456-2255 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The most common adverse reactions (incidence ≥ 10%) were headache and fatigue in both the multiple sclerosis (MS) and Crohn's disease (CD) studies.
Use in specific populations
Sourced from openFDAPregnancy: Can cause fetal harm. ( 5.8 , 8.1 ) 8.1 Pregnancy Risk Summary There are no adequate data on the risk of major birth defects, miscarriage, or other adverse maternal outcomes associated with the use of TYSABRI in pregnant women. Adverse fetal outcomes of neonatal thrombocytopenia and anemia have been reported (see Clinical Considerations ) . In animal studies, administration of natalizumab during pregnancy produced fetal immunologic and hematologic effects in monkeys at doses similar to the human dose and reduced offspring survival in guinea pigs at doses greater than the human dose. These doses were not maternally toxic but produced the expected pharmacological effects in maternal animals [ see Data ]. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown. Clinical Considerations Fetal/Neonatal Adverse Reactions Cases of neonatal thrombocytopenia and anemia in infants born to women exposed to TYSABRI during pregnancy were reported in the post-marketing setting [see Warnings and Precautions ( 5.8 )] . Therefore, a CBC should be obtained in neonates who were exposed to TYSABRI in utero .
Pharmacokinetics
Sourced from openFDA- Metabolism
- Multiple Sclerosis (MS) Patients: In patients with MS, following the repeat intravenous administration of a 300 mg dose of TYSABRI, the mean ± SD maximum observed serum concentration was 110 ± 52 mcg/mL. Mean average steady-state trough concentrations ranged from 23 mcg/mL to 29 mcg/mL.
Overdosage
Sourced from openFDASafety of doses higher than 300 mg has not been adequately evaluated. The maximum amount of TYSABRI that can be safely administered has not been determined.
Approval history
Sourced from openFDA- Nov 23, 2004BLABLA125104Biogen Idec
- Aug 24, 2023BLABLA761322Sandoz Inc
FAERS reports
- 1Fatigue19,54511%
- 2Multiple Sclerosis Relapse16,8589.4%
- 3Headache9,9725.5%
- 4Multiple Sclerosis9,7365.4%
- 5Gait Disturbance9,4955.3%
- 6Fall8,0324.5%
- 7Asthenia8,0044.4%
- 8Memory Impairment7,9454.4%
- 9Malaise7,3644.1%
- 10Drug Ineffective6,8983.8%
- 11Urinary Tract Infection6,2963.5%
- 12Pain5,9563.3%
- 13Balance Disorder5,6933.2%
- 14Hypoaesthesia5,4183.0%
- 15Pain In Extremity4,9262.7%
Literature
Recent PubMed references pinned to Natalizumab as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.
- Clinical implications of natalizumab Fab-arm exchange in patients with multiple sclerosis.Frontiers in immunology · 2026 · Gelissen LMY, van den Berg SPH, Toorop AA, et al.PMID 42183264DOI 10.3389/fimmu.2026.1796273
- Validation of a new diagnostic ELISA to detect anti-JCV antibodies in serum of patients with multiple sclerosis considering or receiving treatment with natalizumab.Multiple sclerosis and related disorders · 2026 · Adler F, Andersen M, Bartl T, et al.PMID 42134893DOI 10.1016/j.msard.2026.107150
- Do apelin and ghrelin play a role in multiple sclerosis? The analysis of patients treated with immunomodulatory therapies.Frontiers in immunology · 2026 · Adamczyk B, Morawiec N, Rakoca M, et al.PMID 42131351DOI 10.3389/fimmu.2026.1701657
- Real-world transition from uncontrolled disease to stability: Three-year Pre-post natalizumab comparison in relapsing multiple sclerosis.Multiple sclerosis and related disorders · 2026 · Ozakbas S, Mammadov O, Alizada S, et al.PMID 41985260DOI 10.1016/j.msard.2026.107195
- Real-world cost of disease-modifying treatments administered by intravenous infusion in relapsing-remitting multiple sclerosis patients from Argentina.Multiple sclerosis and related disorders · 2026 · Silva BA, Federico MB, Lázaro L, et al.PMID 41962304DOI 10.1016/j.msard.2026.107173
- EDSS and disease duration associate with progression independent of relapse and MRI activity in natalizumab-treated multiple sclerosis patients.Multiple sclerosis and related disorders · 2026 · Puthenparampil M, Passamonti M, Rozzi M, et al.PMID 41916082DOI 10.1016/j.msard.2026.107148
- No association between the wearing-off effect and α4-integrin receptor saturation in natalizumab treated patients with relapsing-remitting multiple sclerosis.Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics · 2026 · Freeman SA, Rual C, Biotti D, et al.PMID 41864122DOI 10.1016/j.neurot.2026.e00888
- Safety and patient experiences with the natalizumab biosimilar in multiple sclerosis treatment.Multiple sclerosis and related disorders · 2026 · Gelissen LMY, Strijbis EMM, van Oosten BW, et al.PMID 41861706DOI 10.1016/j.msard.2026.107147
Clinical trials
The 10 most recently updated of 149 ClinicalTrials.gov registrations naming Natalizumab as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.
- A Study to Learn More About The Safety of Diroximel Fumarate (VUMERITY®) in Participants Who Took it During Pregnancy And About the Health of Their BabiesActive not recruiting · Observational · 1,178 enrolled · BiogenNCT05688436updated 2026-06-04
- A Study Utilising Data From European Union (EU) National Multiple Sclerosis (MS) Registries to Assess the Incidence of Anti-Natalizumab Antibody Among Participants Who Receive Subcutaneous Administration of Natalizumab for Treatment of Relapsing-remitting Multiple Sclerosis (RRMS)Active not recruiting · Observational · 400 enrolled · BiogenNCT05925049updated 2026-05-13
- Comparing the Safety and Benefit of Natalizumab (Tysabri®) At-home Infusion vs At-hospital Infusion in Multiple SclerosisCompleted · Observational · 295 enrolled · Nantes University HospitalNCT04777539updated 2026-04-30
- Evaluation of Early Changes Visible to the Diffusion MRI in Response to Two Years of Treatment With Tysabri in Patients With Multiple SclerosisTerminated · Phase 4 · Interventional · 70 enrolled · University Hospital, Strasbourg, FranceNCT02904876updated 2026-03-16
- Study of the Mechanisms of Action of Cladribine in Multiple SclerosisCompleted · Interventional · 77 enrolled · University Hospital, RouenNCT04821596updated 2026-02-18
- Natalizumab for the Treatment of People With Inflammatory Demyelination Suggestive of Multiple Sclerosis, or Definite Multiple Sclerosis, at First Presentation (AttackMS)Recruiting · Phase 2 · Interventional · 40 enrolled · Queen Mary University of LondonNCT05418010updated 2026-01-07
- Best Available Therapy Versus Autologous Hematopoietic Stem Cell Transplant for Multiple Sclerosis (BEAT-MS)Recruiting · Phase 3 · Interventional · 156 enrolled · National Institute of Allergy and Infectious Diseases (NIAID)NCT04047628updated 2026-01-06
- Implication of 5-HT7 Receptor in Inflammatory Mechanisms in Multiple SclerosisCompleted · Observational · 100 enrolled · Centre Hospitalier Régional d'OrléansNCT05746845updated 2025-12-23
- Cladribine Tablets After Treatment With Natalizumab (CLADRINA)Active not recruiting · Phase 4 · Interventional · 40 enrolled · University of Texas Southwestern Medical CenterNCT04178005updated 2025-12-08
- A Study to Evaluate Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Multiple Doses of Natalizumab (BG00002) Administered Subcutaneously to Japanese Participants With Relapsing-Remitting Multiple SclerosisTerminated · Phase 3 · Interventional · 21 enrolled · BiogenNCT05265728updated 2025-11-25
Frequently asked questions
- How does Natalizumab work?
- Natalizumab binds to the α4-subunit of α4β1 and α4β7 integrins expressed on the surface of all leukocytes except neutrophils, and inhibits the α4-mediated adhesion of leukocytes to their counter-receptor(s). The receptors for the α4 family of integrins include vascular cell adhesion molecule-1 (VCAM-1), which is expressed on activated vascular endothelium, and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) present on vascular endothelial cells of the gastrointestinal tract.
- What is Natalizumab used for?
- According to FDA labeling, Natalizumab carries indications including: TYSABRI is an integrin receptor antagonist indicated for treatment of: Multiple Sclerosis (MS) TYSABRI is indicated as monotherapy for the treatment of relapsing forms of multiple sclerosis, to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. TYSABRI increases the risk of PML [See Warnings and Precautions ( 5.1 ) ].. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
- What class of drug is Natalizumab?
- Natalizumab is classified as Monoclonal antibodies, Integrin Receptor Antagonist, Integrin Receptor Antagonists, Decreased Adhesion Factor Activity.
- What are the brand names for Natalizumab?
- Natalizumab is marketed under brand names including Tyruko, Tysabri.
- What are the contraindications for Natalizumab?
- Natalizumab labeling lists contraindications including: TYSABRI is contraindicated in patients who have or have had progressive multifocal leukoencephalopathy (PML) [ see Warnings and Precautions ( 5.1 ) ]. TYSABRI is contraindicated in patients who have had a hypersensitivity reaction to TYSABRI.. Always consult the full prescribing information and a clinician.
natalizumab is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.