Hereditary Angioedema (HAE) is a rare, potentially life-threatening disorder that affects as few as 1 in every 50,000 individuals – with children having a 50% chance of inheriting the disease from a parent who has HAE.
It causes unpredictable swelling attacks that affect the hands, feet, arms, legs, face, abdomen, tongue, and genitals. Abdominal swelling is often associated with severe pain, vomiting and diarrhoea. Although less common, people with HAE may also experience swelling of the throat, which can lead to a potentially life-threatening airway obstruction.
Symptoms usually start in childhood, progress at puberty, and continue throughout life. The rarity of the disease and its similarity to other, more common conditions, mean that the majority of people with HAE don’t receive the correct diagnosis until they are adults.
A major challenge to treating the disease has been that the triggers of HAE were not fully understood – some include stress and increases in oestrogen, but most cases are caused by a genetic deficiency in a protein found in blood plasma (C1 inhibitor).
There have been significant advancements in the treatment of HAE within the last 10 years, both for adults and, now also for children.
A major step forward came in the form of Shire’s Firazyr, which was authorised in 2008 in the EU as an injection that can be administered as soon as a patient recognises symptoms of an HAE attack, after appropriate training from a healthcare professional.
Studies for Firazyr’s paediatric use have been completed recently. The application for use in children has been submitted and is under review currently for approval. Under the provisions of the Paediatric Regulation, the manufacturer will therefore be granted an additional two years of its orphan market exclusivity in exchange for conducting these paediatric and adolescent studies.
The outcomes from these paediatric studies will go a long way in helping clinicians make evidence-based treatments decisions for children with HAE under their care and improving the lives of these patients.
Without the reward provided under the Paediatric Regulation it would not have been financially feasible to proceed with the clinical studies for Firazyr.
Shire has already been able to have another HAE product approved for paediatric use. Cinryze, a plasma-derived C1 esterase inhibitor product, was approved in 2011 in the EU. It not only treats, but also helps to prevent angioedema attacks in both adults and adolescents with HAE. Shire conducted studies for the use of Cinryze in paediatric and adolescent populations, and based on the results, EMA approval has recently been received for children (>2 years) to receive Cinryze.3