Safety advice on particular drugs or classes of drugs
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| European Union: EMA confirms recommendations to minimise risk of brain infection progressive multifocal leukoencephalopathy (PML) with Tysabri |
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The European Medicines Agency (EMA) has completed its review of the known risk of PML with the multiple sclerosis medicine Tysabri (natalizumab), and has confirmed initial recommendations aimed at minimising this risk.
PML is a rare brain infection caused by John Cunningham (JC) virus. This virus is very common in the general population and is normally harmless; however, it can lead to PML in persons whose immune system is weakened. The most common symptoms of PML are progressive weakness, speech and communication difficulties, vision changes, and sometimes changes in mood or behaviour. PML is a very serious condition that may result in severe disability or death.
Recent studies suggest that early detection and treatment of PML when the disease is asymptomatic (is still in the initial stages and shows no symptoms) may improve patients’ outcomes. Asymptomatic cases of PML can be detected on MRI scans, and experts in the field of MRI and multiple sclerosis agree that simplified MRI protocols (which allow for shorter procedures, and also limit the burden for patients undergoing the scans) permit the identification of PML lesions. All patients taking Tysabri should undergo full MRI scans at least once a year, but on the basis of the new data EMA now recommends that for patients at higher risk of PML more frequent MRI scans (e.g. every 3 to 6 months) performed using simplified protocols should be considered. If lesions suggestive of PML are discovered, the MRI protocol should be extended to include ‘contrast-enhanced T1-weighted MRI’, and testing the spinal fluid for the presence of JC virus should be considered.
New data from large clinical studies also suggest that, in patients who have not been treated with immunosuppressants (medicines that reduce the activity of the immune system) before starting Tysabri, the blood level of antibodies against JC virus (‘antibody index’) relates to the level of risk for PML.
Please refer to the following website in EMA for details:
http://www.ema.europa.eu/../news_detail_002476.jsp&mid=WC0b01ac058004d5c1
In Hong Kong, Tysabri Concentrate for Solution for Infusion 300mg (HK-61519) is a pharmaceutical product registered by UCB Pharma (Hong Kong) Limited, and is a prescription only medicine. News on the start of review of Tysabri was previously issued by the EMA, and was posted on the Drug Office website on 12 October 2015 and 13 February 2016. Letters to inform local healthcare professionals was issued on 15 February 2016. The local package insert of the product has already included the warning on PML. So far, the Department of Health has not received any adverse drug reaction case related to the product. In view of the confirmation of the EMA's review with updated recommendations to minimise the risk of PML, the matter will be discussed by the Registration Committee of the Pharmacy and Poisons Board.
Ends/ Saturday, February 27, 2016
Issued at HKT 13:00
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