Natalizumab Biosimilar Officially Launched in the United States

More than 2 years after its original approval, Sandoz’ natalizumab (Tyruko) biosimilar is officially available to patients with multiple sclerosis (MS) and Chron disease (CD) in the United States, the company announced. The drug, available through a Risk Evaluation and Mitigation Strategy (REMS) program, is to be used as a monotherapy for adults with these conditions.¹

Approved in August 2023 as the first biosimilar for MS, the therapy is indicated for those with clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease. Natalizumab, a humanized IgG4k monoclonal antibody, was first approved by the FDA in 2004, and re-approved in 2006 under post-marketing monitoring requirements for safety concerns related to progressive multifocal leukoencephalopathy (PML).

"As the only biosimilar available to treat multiple sclerosis in the US, TYRUKO® has an important opportunity to help people with MS navigate this disease in a way that is more cost effective," Keren Haruvi, president of Sandoz North America, said in a statement.¹ "We are proud to be expanding the reach of natalizumab, which underscores our commitment to our Purpose of pioneering access for patients."

Natalizumab biosimilar, marketed as Tyruko, is available through a REMS program due to the increased risk of PML, especially in the presence of anti-JCV antibodies. The program advises against using Tyruko with other antineoplastic, immunosuppressive, or immunomodulatory therapies and emphasizes early PML detection and prompt discontinuation in immunocompromised patients. Notably, Sandoz has also partnered with Labcorp to provide a validated anti-JCV antibody test at no cost to eligible patients through the Tyruko JCV Testing Program.

Similar to the original natalizumab formulation, Tyruko is contraindicated in patients who have or have had PML, as well as those who have had a hypersensitivity reaction to natalizumab products. The medication also caries warning labels for herpes infections, blindness, hepatotoxicity, and hypersensitivity reactions. In addition, natalizumab products may cause thrombocytopenia, and thus monitoring for bleeding abnormalities is required.

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The FDA’s decision to approved Tyruko in 2023 was based on data from the phase 3 Antelope trial (NCT04115488), a 264-patient cohort study of individuals with relapsing-remitting MS who were assigned to either natalizumab biosimilar or the reference agent natalizumab for 24 weeks. At the conclusion of the treatment period, the model-based, least-squares mean difference in cumulative number of active new lesions between biosimilar and reference treatment groups was 0.17 (biosimilar, 0.34 [SE, 0.34]; reference, 0.45 [SE, 0.28]; 95% CI, –0.61 to 0.94), indicating noninferiority between the therapies.^2,3

At week 24, those in the reference natalizumab group underwent rerandomization, whereby 30 patients switched for the remainder of the study. Overall, most patients (n = 239; 90.5%) completed the 48-week study. Because the study remained blinded and randomization followed the original strata, data integrity was preserved. A sensitivity analysis using the corrected stratification factors confirmed the primary endpoint in the per-protocol population, showing a model-based mean difference of 0.06 (SE, 0.08) between biosimilar natalizumab and reference natalizumab. The mean cumulative number of new active lesions was 1.5 (SD, 3.72) in the biosimilar group and 2.3 (SD, 5.68) in the reference group.

In Antelope, changes in EDSS scores were minimal and comparable across treatment groups at both 24 and 48 weeks, including in those who switched at week 24 (biosimilar: –0.10, reference: –0.02, reference/biosimilar switch: –0.03). Treatment-emergent adverse event rates were also similar, occurring in 64.9% of patients on the biosimilar, 68.9% on reference natalizumab, and 73.3% in the switch group. The most common TEAEs were nervous system disorders (23.3% to 26.7%) and infections or infestations (29.8% to 50.0%).

"For people living with multiple sclerosis, cost and access to care remain significant barriers," Leslie Ritter, Vice President of Healthcare Access for the National MS Society, said in a statement. "The availability of a biosimilar is an important step forward in making medications more affordable."

Biosimilars play an increasingly important role in neurology, and their impact is especially significant in MS, where long-term treatment with high-cost biologics is the norm. These treatments, while highly similar, equally safe, and therapeutically equivalent, offer a pathway to expand access by reducing costs while maintaining clinical effectiveness.

NeurologyLive^® convened several advanced practice providers to discuss the role of biosimilars in MS care and review emerging clinical data. In the clip below, Amy Perrin Ross, APN; Patricia Melville, NP-C; Aliza Ben-Zacharia, PhD, DNP, ANP-BC; and John Kramer, PA-C, highlight Sandoz’s natalizumab biosimilar and findings from the phase 3 Antelope study.

REFERENCES
1. Sandoz launches TYRUKO® (natalizumab-sztn) in US, as first and only multiple sclerosis biosimilar. News release. Sandoz. November 17, 2025. Accessed November 21, 2025. https://www.sandoz.com/sandoz-launches-tyrukor-natalizumab-sztn-us-first-and-only-multiple-sclerosis-biosimilar/
2. FDA Approves First Biosimilar to Treat Multiple Sclerosis. News release. FDA. August 24, 2023. Accessed November 21, 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-first-biosimilar-treat-multiple-sclerosis
3. Hemmer B, Wiendl H, Roth K, et al. Efficacy and Safety of Proposed Biosimilar Natalizumab (PB006) in Patients With Relapsing-Remitting Multiple Sclerosis: The Antelope Phase 3 Randomized Clinical Trial. JAMA Neurol. 2023;80(3):298–307. doi:10.1001/jamaneurol.2022.5007