FDA Okays First Biosimilar for Multiple Sclerosis

Megan Brooks

August 25, 2023

The US Food and Drug Administration (FDA) has approved natalizumab-sztn injection (Tyruko, Sandoz), the first biosimilar to Biogen's Tysabri (natalizumab), to treat adults with relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome (CIS), relapsing-remitting MS, and active secondary progressive disease.

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

The natalizumab biosimilar is given using the same dosing and administration schedule. Like the reference product, it is indicated for adults with moderately to severely active Crohn's disease that is unresponsive to other medications.

The approval of the natalizumab biosimilar is based on results of the phase 3 Antelope trial, which showed no clinically meaningful differences between it and the reference product.

As reported previously by Medscape Medical News, the trial included 264 adults (mean age, 36 years; 61% women) with relapsing-remitting MS from 48 centers in seven Eastern European countries.

All were randomly assigned to receive intravenous infusions every 4 weeks of 300 mg of the natalizumab biosimilar or the reference product for a total of 12 infusions.

At 24 and 48 weeks, there were no between-group differences in annualized relapse rates or Expanded Disability Status Scale scores, which were similar between treatment groups at baseline. There were also no significant differences in safety, tolerability, or immunogenicity.

The prescribing information for both natalizumab products includes a boxed warning about the increased risk of progressive multifocal leukoencephalopathy (PML), a viral infection of the brain that usually leads to death or severe disability.

Risk factors for the development of PML include the presence of antibodies to the 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, and health care providers should monitor patients and withhold treatment immediately at the first sign or symptom suggestive of PML," the FDA advises.

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).

In a statement, Sandoz said it's committed to having the product available in the US "as soon as possible."

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