TYRUKO

What it is

TYRUKO (natalizumab) is a recombinant humanised IgG4 monoclonal antibody produced in Chinese hamster ovary (CHO) cells. TYRUKO (natalizumab) is a biosimilar medicine to Tysabri. Each 15 mL dose contains 300 mg natalizumab. TYRUKO (natalizumab) concentrate for intravenous infusion is supplied as a sterile, colourless, clear to slightly opalescent solution.

Approved indications

— Treatment of patients with relapsing remitting multiple sclerosis (MS) to delay the progression of physical disability and to reduce the frequency of relapse.

Dosing overview

The recommended dose of TYRUKO by intravenous infusion is 300 mg every four weeks. TYRUKO concentrate 300 mg/15 mL should be diluted in 100 mL 0.9% Sodium Chloride and infused over approximately one hour. Patients should be observed during the infusion and for 1 hour after the infusion is complete.

Key safety warnings

TYRUKO is associated with an increased risk of progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the brain that may lead to death or severe disability. There are no known interventions that can reliably prevent PML or adequately treat PML if it occurs. Early diagnosis (from clinical and MRI monitoring), and stopping therapy are important factors in management of PML in patients on natalizumab. The following risk factors are associated with an increased risk of developing PML: the presence of anti-JCV antibodies, treatment duration especially beyond 2 years in patients who are anti-JCV antibody positive, and immunosuppressant use prior to receiving natalizumab. Spontaneous suspect adverse drug reactions of liver injury, including severe liver injury, have been reported from the market. Signs of liver injury, including markedly elevated serum hepatic enzymes and elevated total bilirubin, occurred as early as six days after the first dose. Signs of liver injury have also been reported for the first time after multiple doses, including cases with rechallenge. If liver injury occurs during treatment with natalizumab the drug should be discontinued and investigation of cause undertaken. Natalizumab should be initiated with caution in patients with a history of liver disease and liver function tests should be regularly monitored in these patients. Other opportunistic infections have been reported with the use of natalizumab, primarily in patients with Crohn's disease who were immunocompromised or where significant co-morbidity existed. However increased risk of other opportunistic infections with use of natalizumab in patients without these co-morbidities cannot currently be excluded. Serious, life-threatening and sometimes fatal reports of encephalitis and meningitis caused by herpes simplex or varicella zoster have been seen. Natalizumab has been associated with hypersensitivity reactions, including anaphylactic/anaphylactoid reactions, which occurred at an incidence of <1%. These reactions usually occurred during administration or up to 1 hour after completion of administration, but there have been occasional post-market reports of delays of up to 2 weeks in symptom onset.

Contraindications

TYRUKO should not be administered to patients with known hypersensitivity to natalizumab or any of the excipients, or to patients with known hypersensitivity to Chinese hamster ovary cell products or other recombinant human or humanised antibodies. TYRUKO is contraindicated in patients who have or have had progressive multifocal leukoencephalopathy. TYRUKO should not be administered to patients with increased risk for opportunistic infections, including those immunocompromised due to current or recent immunosuppressive therapies (e.g. azathioprine, mitoxantrone), or systemic medical conditions resulting in significantly compromised immune system function (e.g. human immunodeficiency virus, organ transplant, active malignancy). TYRUKO should not be administered in combination with immunomodulatory agents (e.g. beta interferons or glatiramer acetate).

Regulatory history

TYRUKO received TGA approval as a biosimilar to Tysabri for the treatment of relapsing remitting multiple sclerosis on 2024-09-11. The TGA's evaluation found that Tyruko demonstrated biosimilarity to the reference product Tysabri at the quality level, with comprehensive testing showing similarity in physiochemical and functional attributes. Observed minor differences in glycosylation profiles were deemed not clinically relevant, and the reference products were adequately bridged. TYRUKO natalizumab 300 mg/15 mL concentrate for infusion vial was first listed on the ARTG on 2025-04-04.