On Thursday, the FDA approved Tyruko (natalizumab-sztn) by Sandoz, the first biosimilar to Biogen’s Tysabri (natalizumab). The approval will provide more treatment options for Americans with multiple sclerosis (MS).
Tyruko is a monotherapy IV infusion given for over one hour every four weeks for individuals with relapsing forms of MS. The drug is also intended for maintaining clinical response and remission in patients battling Crohn’s Disease (CD) with evidence of inflammation, or those unable to show a positive reaction from conventional therapies.
Sandoz is a division of Novartis that focuses on generic pharmaceuticals and biosimilars. The company received approval for Tyruko based on successful Phase I and III clinical studies proving Sandoz’s biosimilar as efficient and safe as Tysabri.
"Biosimilar medications offer additional effective treatment options that have the potential to increase access for people living with relapsing forms of multiple sclerosis."- Paul R. Lee, M.D., Ph.D., director at the FDA’s Center for Drug Evaluation and Research
MS is a long-lasting disease of the central nervous system that is difficult to predict. Unlike other central nervous system diseases, MS does not have a single genetic factor for its cause. Some patients may experience mild symptoms, while others may lose their ability to see, write, speak, or walk when the brain loses connection with other parts of the body.
Myelin is the fatty tissue that encompasses and guards nerve fibers. For MS patients, myelin is destroyed in various areas. Myelin loss forms scar tissue known as sclerosis. When nerves are significantly damaged, they become unable to produce electrical impulses to the brain and back.
According to the National Multiple Sclerosis Society, nearly one million Americans are currently living with MS. Director of the Office of Therapeutic Biologics and Biosimilars in the FDA’s Center for Drug Evaluation and Research, Sarah Yim, M.D., believes Tyruko is a huge win for MS patients.
"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," Yim said.
The FDA says Tyruko is cleared to treat three relapsing forms of MS. The first, clinically isolated syndrome, refers to the initial neurological symptoms caused by inflammation and demyelination in the central nervous system.
Patients with relapsing-remitting MS, a type of MS that occurs with new episodes of neurological symptoms followed by periods of stability, will also be eligible for Tyruko. Individuals experiencing gradual disability worsening in active secondary progressive MS may also ask their doctor about the new biosimilar drug.
Prescribing info for both Tyruko and Tysabri contains a box warning to inform healthcare professionals and patients about the increased risk of progressive multifocal leukoencephalopathy (PML), an infection of the brain that can lead to severe disability or death.
Due to this risk, natalizumab products like Tyruko and Tysabri are only available through the Risk Evaluation and Mitigation Strategy (REMS) program. The REMS requires medical professionals who prescribe natalizumab products, and pharmacies who dispense them to be REMS certified. Patients must also be enrolled in REMS.
The FDA notes additional warnings in the prescribing information for Tyruko and Tysabri feature risk for herpes, thrombocytopenia (low blood platelet count), immunosuppression (increased risk of certain infections), and severe hypersensitivity reactions such as anaphylaxis or hepatotoxicity (significant liver injury). Headaches and fatigue are often the most common side effects of natalizumab products. Other side effects include joint pain, urinary tract infection, lower respiratory tract infection, stomach flu, vaginitis, depression, abdominal pain, diarrhea, or rash.