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FDA Approves Tyruko®, Biosimilar to Tysabri®, for Relapsing Forms of MS 

August 24, 2023

The U.S. Food and Drug Administration recently approved Tyruko® (natalizumab-sztn, Sandoz), making it the first biosimilar disease-modifying therapy for adults living with relapsing forms of MS. Tyruko, which is similar to Tysabri, is expected to be made available during the first half of 2024. Its price has not yet been released.  

“Access to affordable, high-quality healthcare is essential for people with multiple sclerosis to live their best lives. The approval of Tyruko, the first FDA-approved biosimilar disease-modifying treatment for people with relapsing forms of MS, is a milestone,” said Bari Talente, Executive Vice President, Advocacy and Healthcare Access at the National MS Society. “Biosimilars are an important treatment option because they have no clinically meaningful differences from their reference medicines. Prescribing them can increase accessibility to affordable medications, improve adherence and help contain healthcare costs.”  

  • Relapsing forms of MS include  clinically isolated syndrome (an initial neurological episode),  relapsing-remitting MS and active secondary progressive MS. People with active secondary progressive MS have had progression of disability but still experience acute relapses or new MRI activity. 

  • Like Tysabri, Tyruko is a monoclonal antibody that binds to an α4-integrin, inhibiting the migration of active inflammatory immune cells, called lymphocytes, from crossing the blood-brain barrier into the central nervous system (CNS). Preventing the entry of these cells into the CNS reduces damage to nerve cells. 

  • Tyruko is administered by intravenous infusion over one hour, every four weeks.  

  • Tyruko was approved as having no clinically meaningful differences from Tysabri.  

    • Tyruko has the same strength, dosage form and route of administration (infusion) as Tysabri (natalizumab). 

    • Tyruko has been shown to work in the body the same as Tysabri. It has a similar safety, efficacy and side effect profile as Tysabri. 

  • The FDA’s approval was based on results from the randomized, double-blind phase 3 Antelope trial. This trial assessed the comparative efficacy, safety and immunogenicity between Tyruko and Tysabri in participants with relapsing-remitting MS. There were no significant differences in effectiveness, safety and other factors between those on Tyruko and those on Tysabri.  

  • Side Effects: The most common adverse reactions reported were headache, feeling tired, urinary tract infections, joint pain, lung infection, depression, pain in your arms or legs, diarrhea, vaginitis, rash, nose and throat infections, nausea and stomach area pain. Like Tysabri, Tyruko may also cause serious side effects (see below under Potential Risks). 

  • Support Programs: For people who qualify, Sandoz has announced its intent to offer patient support services for Tyruko once the product becomes commercially available.

  • Price: The price has not been announced. The actual cost to an individual will depend on the provisions of their insurance coverage and the degree to which that individual will be eligible for programs designed to assist with out-of-pocket costs.  

More information about Tyruko is available from Sandoz: 1-800-525-8747 


Potential Risks: Tyruko, like Tysabri, has a “black box” warning for risk of progressive multifocal leukoencephalopathy (PML). PML is a viral infection of the brain that can result in death or severe disability. Risk factors for the development of PML include the presence of anti-John Cunningham Virus (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 Tyruko therapy. Because of the risk of PML, Tyruko is available only through a restricted distribution program called the MS TYRUKO REMS Prescribing Program (Sandoz, 2023).  

Testing and Observation:  Testing for anti‐JCV antibody status should be considered prior to treatment and throughout treatment with Tyruko. Individuals should tell their healthcare providers right away if experiencing any new or worsening neurological symptoms such as weakness on one side of the body, loss of coordination in arms and legs, vision problems, changes in thinking and memory, or confusion and personality changes. Individuals undergo a post-infusion, one hour observation period for the first 12 infusions and for future infusions if evidence of hypersensitivity exists. 

-Read the press release from the FDA  

-Download the Prescribing Information and Medication Guide for Tyruko

-Read the Phase 3 Antelope study: “Efficacy and Safety of Proposed Biosimilar Natalizumab (PB006) in Patients With Relapsing-Remitting Multiple Sclerosis: The Antelope Phase 3 Randomized Clinical Trial” in JAMA Neurology. 
-Read more about biosimilars: 


Tysabri is a registered trademark of Biogen 

Tyruko is a registered trademark of Sandoz 


About Multiple Sclerosis

Multiple sclerosis is an unpredictable disease of the central nervous system. Currently there is no cure. Symptoms vary from person to person and may include disabling fatigue, mobility challenges, cognitive changes, and vision issues. An estimated 1 million people live with MS in the United States. Early diagnosis and treatment are critical to minimize disability. Significant progress is being made to achieve a world free of MS.

About the National Multiple Sclerosis Society

The National MS Society, founded in 1946, is the global leader of a growing movement dedicated to creating a world free of MS. The Society funds cutting-edge research for a cure, drives change through advocacy and provides programs and services to help people affected by MS live their best lives. Connect to learn more and get involved:, Facebook, X, formerly known as Twitter, Instagram, YouTube or 1-800-344-4867.


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