The first treatment for the most common cause of dwarfism has been approved in the US but Britain will have to wait until 2023 to see if it will be available on the NHS.
Vosoritide, a once-daily injection, was given the green light by the US Food and Drug Administration (FDA) for use on children over five-years-old with achondroplasia.
US health authorities said 10,000 children are set to benefit from the drug being approved and it’s expected to be available from mid-December.
Achondroplasia is behind eight in 10 cases of dwarfism, affecting one in 25,000 births each year, and can lead to life threatening conditions such as a build-up of fluid in the brain, though the vast majority will have a normal life expectancy.
Children will be given the injection — which costs around £240,000 ($320,000) per patient — over the course of a year.
The drug works by reversing a genetic quirk which causes a gene responsible for bone growth to become overactive and stunt growth.
A clinical trial of vosoritide, the results of which were published in September last year, saw patients who got the drug grow on average half an inch more than the children given a placebo.
Part of the global trial was conducted in Guy’s and St Thomas NHS Trust in London.
Vosoritide is still undergoing a clinical and cost effectiveness appraisal by the NHS’ medical watchdog. An update on the National Institute for Health and Care Excellence (NICE) website said the next stage of the process won’t go ahead until 2023.
MailOnline contacted NICE for more information on why this is the case.
The US Food and Drug Administration has approved a drug that treats the most common form of dwarfism but patients with the condition in the UK may have to wait until 2023 before it could be approved for use on the NHS
There are about 7,000 people with a form dwarfism in the UK, the majority of which is achondroplasia, thought is unknown how many might be eligible for the vosoritide treatment if it was approved in the UK.
Achondroplasia occurs in one in every 25,000 births on average, meaning roughly 28 children are born with the condition in the UK every year.
In an update in November last year, NICE said: ‘Following an update from the company that is developing vosoritide, NICE has agreed that holding a scoping exercise at this time is not appropriate.’
How does vosoritide work?
Vosoritide works by treating the bone inhibition that comes with achondroplasia.
A person who has achondroplasia has an overactive gene regulating the growth of their bones, called fibroblast growth factor receptor 3.
Normally this gene performs its function correctly in stopping bones growing when they have reached the correct shape.
However in a person with achondroplasia this gene is activated too much, reducing the growth of the bones, leading to dwarfism.
Vosoritide essentially counteracts this gene, by binding to it and stopping it from working with the net result being that bone growth is encouraged and a child develops more along normal lines.
‘The scoping exercise will be rescheduled to take place at a later date in 2023.’
NICE did not provide any more details on the nature of the update from the company that makes vosoritide, by American biotechnology BioMarin Pharmaceutical, which had prompted the delay.
The UK’s delay in appraising vosoritide makes it is an outlier compared to its neighbors with the drug was approved for use in the EU in August of this year.
The FDA’s director of general endocrinology Dr Theresa Kehoe said more than 10,000 children in the US stand to benefit from the drug’s approval.
‘With this action, children with short stature due to achondroplasia have a treatment option that targets the underlying cause of their short stature.’
BioMarin Pharmaceutical chief executive Jean-Jacques Bienaimé welcomed the FDA’s approval and said the drug will be available in the US by the middle of next month.
‘We thank the FDA for recognizing its value as the first therapeutic treatment option for children with achondroplasia,’ he said.
The company has also announced it is seeking approval for the drug in Japan, Australia and Brazil but made no mention of any UK plans.
Vosoritide has been controversial in the dwarfism community, with some organisations arguing the focus on treating height and not other health conditions that can occur with achondroplasia is unhelpful.
Health problems associated with achondroplasia such hearing loss, sleep apnea, and life-threatening skeletal and problems with fluid in the brain.
The charity Restricted Growth Association UK has previously said it would not support the drug if the only benefit of the treatment was the extra height it granted participants.
Achondroplasia is estimated to occur in one in every 25,000 births world wide, people who are born with the condition have a normal sized ‘trunk’ or torso but their limbs are proportionally smaller.
They can also have a large head with prominent forehead and flattened bridge of the nose, an increased curvature of the lower spine and, sometimes, exceptionally flexible joints.
The average height of an adult with achondroplasia is approximately four feet with most people with the condition born to average sized parents.
While children with achondroplasia may develop some motor skills and mobility more slowly because of the combination of a heavier head and shorter arms and legs, both life expectancy and intelligence are not affected.
It is the most common cause of dwarfism accounting for between seven to eight out of 10 cases.
WHAT IS DWARFISM?
Dwarfism is general term used to cover a swath of conditions that result in the medical term of restricted growth.
There are two main types of restricted growth:
- Proportionate short stature (PSS) – a general lack of growth, where the length of the trunk and limbs are in proportion
- Disproportionate short stature (DSS) – where the limbs are shorter or out of proportion with other parts of the body
Achondroplasia is a DSS type of dwarfism and is the most common cause of the condition.
As well as having short stature, some people with restricted growth also have other physical problems, such as bowed legs or an unusually curved spine.
However, most people don’t have any other serious problems. They can often live a relatively normal life and have a normal life expectancy.
Source: NHS Choices