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Natalizumab · Tyruko, Tysabri

Monoclonal antibody · Antagonist of integrin alpha-4 (α4 subunit of α4β1 and α4β7 integrins) (ITGA4) · developed by Biogen Idec

Approved FDA, Nov 2004

BIIB Developer

2 Registered trials

What is Natalizumab?

Natalizumab is an antibody that binds the α4 subunit of α4β1 and α4β7 integrins on leukocytes, blocking their adhesion to VCAM-1 and MAdCAM-1 and preventing their migration across the endothelium into inflamed tissue.

Summary written with AI from the sources listed at the end of this page.

At a glance

Also known as: Tyruko, Tysabri, BG00002, AN100226M
Drug type: Monoclonal antibody
Targets: integrin alpha-4 (α4 subunit of α4β1 and α4β7 integrins) (ITGA4), VCAM-1 (binding partner it blocks), MAdCAM-1 (binding partner it blocks)
Mechanism: Antagonist of integrin alpha-4 (α4 subunit of α4β1 and α4β7 integrins) (ITGA4)
Pathways: leukocyte adhesion and transmigration across endothelium, inhibition of leukocyte recruitment into inflamed tissue
Therapy area: Immunology, Neurology
Developer: Biogen Idec (BIIB)
FDA status: Approved as Tyruko, Tysabri (November 23, 2004), BLA125104 · FDA label
UNII: 3JB47N2Q2P

✅ FDA-approved uses

Multiple Sclerosis (Tysabri)
Crohn's Disease (Tysabri)
Multiple Sclerosis (Tyruko)
Crohn's Disease (Tyruko)

From the indications section of the FDA label (version of Mar 21, 2025). Read the full label for the exact wording, limitations and safety information.

🧪 Clinical trials

Trial	Phase	Condition	Status	Sponsor
NCT05658497	N/A	Multiple Sclerosis	Recruiting	BIIB
NCT05688436	N/A	Multiple Sclerosis	Active not recruiting	BIIB

Trials of the companies BioRadar tracks, from ClinicalTrials.gov, most advanced phase first.

Conditions studied

Multiple Sclerosis

More from Biogen Idec

Dimethyl Fumarate FDA approved Diroximel Fumarate FDA approved Interferon Beta-1A FDA approved Nusinersen FDA approved Omaveloxolone FDA approved Tofersen FDA approved Zuranolone FDA approved BIIB115 Phase 1 BIIB122 Phase 3 BIIB144 Phase 1 BIIB147 Phase 1/2 Diranersen Phase 2

Sources

Updated Oct 11, 2026. Something wrong or missing? Report it on the BIIB page.

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Data: FDA (Drugs@FDA, Purple Book, DailyMed), NIH (NCI Thesaurus, GSRS, RxNorm), ClinicalTrials.gov • Informational purposes only, not medical or investment advice. • All drugs A–Z