On 19 October 2026, the MHRA authorised plozasiran, marketed as Redemplo, to reduce triglyceride levels in adults with familial chylomicronaemia syndrome when used alongside a low-fat diet. The marketing authorisation was granted to Arrowhead Pharmaceuticals Ireland Limited, giving the UK market a new licensed option for this rare disorder. (gov.uk)
According to the MHRA, familial chylomicronaemia syndrome is a rare condition in which triglycerides rise to abnormally high levels. Those raised fat levels can lead to pancreatitis, a painful inflammation of the pancreas, which helps explain why even a narrowly targeted medicines decision is significant for a small patient group with serious clinical risk. (gov.uk)
Plozasiran works by reducing production of apolipoprotein C3, a protein made in the liver that slows the breakdown of fats in the blood. In practical terms, the authorised regimen is a 25 mg injection under the skin once every three months, and the MHRA says patients or their carers may give the injection after training. (gov.uk)
The evidence cited by the MHRA comes from a study of 75 adults with FCS, all of whom followed a controlled diet. Fifty received plozasiran and 25 received placebo; after 10 months, the median reduction in triglyceride levels was about 80% in the treatment group, compared with 17% in the placebo group, and fewer episodes of acute pancreatitis were recorded among those given plozasiran. (gov.uk)
Safety monitoring remains part of the authorisation. The MHRA identifies hyperglycaemia, or raised blood sugar, as the most common side effect and says it may affect more than one in 10 people; headache, nausea and injection-site reactions are also listed as common. Suspected adverse effects should be discussed with a doctor, pharmacist or nurse and reported through the Yellow Card scheme or app. (gov.uk)
The decision also shows how the UK’s International Recognition Procedure is being used in practice. The authorisation was granted through IRP Route B, with the European Medicines Agency acting as the reference regulator; MHRA guidance says the IRP has been available since 1 January 2024 and allows the agency to use prior approvals from specified overseas regulators while retaining its own authority to approve or refuse an application. (gov.uk)
Route B is not a formality. MHRA performance guidance says the agency aims to determine 95% of IRP Route B medicines applications within 110 days, and the timetable can be extended if further information is required. For clinicians and patients, the next practical documents are the Summary of Product Characteristics and Patient Information Leaflet, which the MHRA says will be published on its products website in due course. (gov.uk)