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A biosimilar is a biological product that is highly similar to and has no clinically meaningful differences from an FDA-approved reference product.
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FDA Approves First Biosimilar to Treat Multiple Sclerosis

Tyruko® has been shown to safely mitigate and manage inflammation in autoimmune conditions like Crohn’s disease

U.S. Food and Drug Administration
Published:Aug 25, 2023
|3 min read
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The U.S. Food and Drug Administration recently approved Tyruko® (natalizumab-sztn), the first biosimilar to Tysabri® (natalizumab) injection for the treatment of adults with relapsing forms of multiple sclerosis (MS). The FDA granted approval of Tyruko to Sandoz Inc.

Tyruko, like Tysabri, is also indicated for inducing and maintaining clinical response and remission in adult patients with moderately to severely active Crohn’s disease (CD) with evidence of inflammation who have had an inadequate response to, or are unable to tolerate, conventional CD therapies and inhibitors of TNF-α.

“Biosimilar medications offer additional effective treatment options that have the potential to increase access for people living with relapsing forms of multiple sclerosis,” said Paul R. Lee, MD, PhD, director of the Division of Neurology II in the FDA’s Center for Drug Evaluation and Research. “Today’s approval could have a meaningful impact for patients managing their disease.” 

Tyruko is approved to treat the following relapsing forms of MS:

  • Clinically isolated syndrome: A single, first occurrence of MS symptoms.

  • Relapsing-remitting disease: A type of MS that occurs when patients have episodes of new neurological symptoms followed by periods of stability.

  • Active secondary progressive disease: A type of MS when patients experience gradual disability worsening with continued relapses following a relapsing-remitting course.

What is a biosimilar?

Biological products include medications for treating many serious illnesses and chronic health conditions, including MS. A biosimilar is a biological product that is highly similar to—and has no clinically meaningful differences from—a biological product already approved by the FDA (also called the reference product). 

This means patients can expect the same safety and effectiveness from the biosimilar as they would the reference product. All biological products are approved only after they meet the FDA’s rigorous approval standards. 

The approval of Tyruko, a biosimilar to Tysabri (natalizumab), is based on evidence that showed there are no clinically meaningful differences between the two products in terms of safety, purity, and potency (i.e., safety and effectiveness).

“Today’s approval of the first biosimilar product indicated to treat relapsing forms of multiple sclerosis furthers the FDA’s longstanding commitment to support a competitive marketplace for biological products and ultimately empowers patients by helping to increase access to safe, effective, and high-quality medications at potentially lower cost,” said Sarah Yim, MD, director of the Office of Therapeutic Biologics and Biosimilars in the FDA’s Center for Drug Evaluation and Research.

What happens in multiple sclerosis? 

MS is a chronic, inflammatory, autoimmune disease of the central nervous system that disrupts communication between the brain and other parts of the body. It is among the most common causes of acquired neurological disability in young adults and occurs more frequently in women than men.

For most people with MS, episodes of worsening function and the appearance of new symptoms, called relapses, are initially followed by recovery periods (remissions). Over time, recovery may be incomplete, leading to progressive decline in function and increased disability. 

The prescribing information for natalizumab products (including Tyruko and Tysabri) contains a boxed warning to inform healthcare professionals and patients about the increased risk of progressive multifocal leukoencephalopathy (PML), a viral infection of the brain that usually leads to death or severe disability. 

How does PML risk affect multiple sclerosis treatment?

Risk factors for the development of PML include the presence of anti-JCV antibodies (antibodies to the John Cunningham or JC virus), longer 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 natalizumab products: Healthcare providers should monitor patients and withhold treatment immediately at the first sign or symptom suggestive of PML.

Because of the risks of PML, natalizumab products are available only through a restricted drug distribution program, under a risk evaluation and mitigation strategy (REMS). The REMS requires healthcare professionals who prescribe and pharmacies that dispense natalizumab products to be specially certified in the REMS, and that patients be enrolled in the REMS. 

As part of the REMS requirements, prescribers must evaluate patients three and six months after the first infusion, every six months thereafter, as well as immediately and six months after discontinuing treatment.

Risks associated with natalizumab treatment

Additional warnings in the prescribing information include risks regarding

  • herpes infections,

  • thrombocytopenia,

  • Immunosuppression, and

  • serious hypersensitivity reactions such as anaphylaxis and hepatotoxicity.

The most common side effects associated with natalizumab products are headache and fatigue. Other common side effects are arthralgia (pain in a joint), UTI, lower respiratory tract infection, gastroenteritis, vaginitis, depression, pain in extremities, abdominal discomfort, diarrhea, and rash.

- This press release was originally published on the U.S. Food and Drug Administration website