First Natalizumab Biosimilar Tyruko Launches, Expanding Access in Multiple Sclerosis

The launch of natalizumab-sztn (Tyruko) marked a milestone for biosimilars in neurology, as it became the first biosimilar approved to treat multiple sclerosis (MS) and the first neurology biosimilar to receive regulatory clearance in the US.¹

Developed by Polpharma Biologics and commercialized by Sandoz, Tyruko entered the market with the potential to expand access to a high-efficacy biologic therapy for people living with MS while introducing long-anticipated price competition in a high-cost therapeutic area.

Natalizumab-sztn (Tyruko) was the first biosimilar approved to treat multiple sclerosis in the US. | Image credit: Matthieu - stock.adobe.com

Regulatory Milestones and Clinical Evidence

Tyruko references Biogen’s Tysabri (natalizumab), which received approval from the FDA in August 2023.² The European Commission followed in September 2023, granting marketing authorization and making Tyruko the first natalizumab biosimilar approved in Europe.³ Regulators approved the biosimilar for all indications held by the reference product, including clinically isolated syndrome, relapsing-remitting MS (RRMS), and active secondary progressive disease, as well as Crohn disease in adults.

The biosimilar shared the same intravenous route of administration, dosage form, dosing schedule, and presentation as the reference product. Regulatory decisions were supported by a comprehensive development program that included analytical, preclinical, and clinical comparisons.

Clinical evidence included 2 randomized, comparative studies: the phase 3 Antelope trial (NCT04115488), which enrolled people with RRMS, and a separate study evaluating pharmacokinetics and pharmacodynamics in healthy participants.⁴ The Antelope study was a multicenter, double-blind, active-controlled, parallel-group trial designed to assess similarity in efficacy, safety, and immunogenicity between the biosimilar and the European Union–approved reference natalizumab.

Investigators found no clinically meaningful differences between products. Immunogenicity profiles were comparable in both healthy participants and people with RRMS, with no safety or efficacy concerns attributed to antidrug antibodies. At week 24, the incidence of overall antidrug antibodies was 79.4% for natalizumab-sztn and 73.7% for the reference product, while neutralizing antibody rates were 68.7% and 66.2%, respectively. Switching from the reference product to the biosimilar did not alter immune response or clinical outcomes.

Stakeholder Response and Safety Oversight

Stakeholders broadly welcomed the approval, citing the high cost burden of MS care and the need for additional high-efficacy treatment options.^1,5 MS is among the most expensive chronic diseases in the US, driven largely by disease-modifying therapy costs.

Keren Haruvi, president of Sandoz North America, said the biosimilar could help expand access to natalizumab for people experiencing disease relapse while introducing competition that may support health care savings.¹ Leslie Ritter, vice president of health care access at the National MS Society, described biosimilar availability as an important step toward addressing affordability and access barriers. Fran Gregory, PharmD, MBA, vice president of emerging therapies at Cardinal Health, characterized the launch as a significant development for neurology, noting its potential to offer additional treatment choices and cost relief.⁵

As with the reference product, natalizumab-sztn carried a boxed warning for progressive multifocal leukoencephalopathy (PML), a rare but potentially fatal viral infection.¹ Tyruko was therefore made available only through a Risk Evaluation and Mitigation Strategy (REMS) program, which educated prescribers and patients on known risk factors, including anti–JC virus antibody status, treatment duration, and prior immunosuppressant use. Post-authorization pharmacovigilance was recommended to monitor PML incidence.

Sandoz partnered with Labcorp to provide no-cost anti-JC virus antibody testing for eligible patients, supporting appropriate risk stratification and ongoing monitoring.

Budget Impact and Market Implications

Economic modeling suggested that the introduction of natalizumab-sztn could meaningfully reduce MS treatment costs.⁶ A budget impact analysis estimated that adding the biosimilar to formulary coverage could generate cumulative savings of approximately $452,611 over 3 years for a hypothetical US commercial health plan, primarily through lower drug acquisition costs. Mean savings per treated member per year were projected to increase annually, reaching $2359 by year 3.

Analysts noted that savings could be greater if price reductions exceeded the 15% discount assumed in base-case modeling. Increased competition was expected to help address long-standing affordability challenges associated with high-efficacy disease-modifying therapies.

In Europe, neurologists reported favorable perceptions of upcoming MS biosimilars, viewing them as tools to expand patient access.⁷ Projections estimated potential savings of €4.5 billion to €5.5 billion across 5 major European markets between 2023 and 2028. Sandoz positioned Tyruko as a key component of its broader growth strategy in MS.

As the first biosimilar to enter the MS treatment landscape, natalizumab-sztn represents a test case for biosimilar adoption in neurology, with implications for access, competition, and sustainability in one of the costliest therapeutic areas in modern medicine.

References

1. Sandoz launches Tyruko (natalizumab-sztn) in US, as first and only multiple sclerosis biosimilar. Sandoz. News release. November 17, 2025. Accessed December 17, 2025. https://www.sandoz.com/sandoz-launches-tyrukor-natalizumab-sztn-us-first-and-only-multiple-sclerosis-biosimilar/
2. Jeremias S. FDA approves first MS biosimilar. The Center for Biosimilars^®. August 25, 2023. Accessed December 17, 2025. https://www.centerforbiosimilars.com/view/fda-approves-first-ms-biosimilar
3. Jeremias S. EC approves first MS biosimilar; Coherus receives CRL for Neulasta Onpro competitor. The Center for Biosimilars. September 27, 2025. Accessed December 17, 2025. https://www.centerforbiosimilars.com/view/ec-approves-first-ms-biosimilar-coherus-receives-crl-for-neulasta-onpro-competitor
4. Santoro C. Biosimilar Natalizumab-sztn Shows Comparable Efficacy and Safety to Tysabri in RRMS. The Center for Biosimilars. March 25, 2025. Accessed December 17, 2025. https://www.centerforbiosimilars.com/view/biosimilar-natalizumab-sztn-shows-comparable-efficacy-and-safety-to-tysabri-in-rrms
5. Jeremias S. Cardinal Health's Dr Fran Gregory reacts to first MS biosimilar approval. The Center for Biosimilars. August 27, 2023. Accessed December 17, 2025. https://www.centerforbiosimilars.com/view/cardinal-health-s-dr-fran-gregory-reacts-to-first-ms-biosimilar-approval
6. Li E, Goh A, Gupta S, et al. Budget impact analysis of biosimilar natalizumab in the US. Am J Manag Care. 2024;30(7):e191-e197. doi:10.37765/ajmc.2024.89558
7. Jeremias S. IQVIA: Neurologists are excited for MS biosimilars in Europe. The Center for Biosimilars. April 5, 2023. Accessed December 17, 2025. https://www.centerforbiosimilars.com/view/iqvia-neurologists-are-excited-for-ms-biosimilars-in-europe