The NHS is set to make a drug for the rare, debilitating disorder phenylketonuria (PKU) available to patients of all ages for the first time.

A deal has been struck by the NHS to secure a non-branded ‘generic’ version of the drug, sapropterin dihydrochloride, for patients with the inherited condition, which means patients cannot eat protein.

The health service will roll-out a national genetic testing and responsiveness programme for around 2,300 people with PKU across England in order to identify those patients who stand to benefit from the treatment.

Around 50 people have already shown a positive response to the drug through testing and will be eligible to receive it on the NHS from next week.

Pregnant women who have PKU will also be offered the drug immediately.

The genetic disorder prevents the breakdown of the amino acid phenylalanine and can lead to serious health issues, including brain damage, with patients forced to live on a highly restricted low-protein diet.

Clinical trials suggest that around four in 10 people may benefit from sapropterin, improving their quality of life significantly and reducing restrictions on the food they can eat.

This is the latest in a string of deals agreed by NHS England to make life-changing, innovative treatments more readily available for patients, including risdiplam and Zolgensma for Spinal Muscular Atrophy, a first new treatment for sickle cell disease in two decades, and ‘5 minute’ breast cancer treatment, Phesgo, which has been rolled-out by the NHS in England faster than anywhere else in the World.

NHS Medical Director Professor Stephen Powis said: “This life-changing drug will make a huge difference to hundreds of people with PKU, allowing them to enjoy foods that were previously off limits and significantly improve their quality of life.

“It is fantastic the NHS has been able to use its commercial abilities to reach a deal to supply a non-branded version of sapropterin, to offer it all to all patients who are shown to gain a clinical response from the treatment.

“In the run-up to Christmas, after what I know has been a long and frustrating wait for many people, I am delighted the NHS has been able to reach this agreement with an alternative company that was ready to put patients first”.

The testing process can take between eight to ten weeks and the drug will be offered to every individual where a clinical benefit is observed.

The NHS is rolling out the testing programme to support the implementation of guidance from the National Institute for Health and Care Excellence (NICE).

The original manufacturer of the branded drug had consistently refused to offer the drug at a fair price, meaning that NICE could only recommended its use in a much smaller patient population.

Previously the drug was only available to patients up to age 22 due to a previous branded version not being deemed cost-effective by NICE.

The NHS has now agreed a cost-effective deal with Teva Pharmaceuticals, backed by NICE, to make the first non-branded version of this drug available to all, without the need for any restriction on people aged 22 and older treatment to be withdrawn on a patient’s 22nd birthday, and we will work with suppliers as more generic drugs become available.

Kim Innes, General manager of Teva UK and Ireland, said: “Doing the right thing by giving patients and the NHS access to affordable treatments is at the heart of everything we do at Teva.

“We’re working closely in partnership with NHS England in order to provide a cost-effective treatment for Phenylketonuria (PKU) patients that will give clinicians more options to help treat this rare but potentially serious inherited disorder.”

People living with PKU are required to adhere to a restricted diet with significant limitations on the amount of protein they can have, but those able to take sapropterin can enjoy a more varied range of foods, making the drug life-changing.

The drug works by stimulating a specific enzyme in the blood that helps to improve the breakdown of phenylalanine.

Until now, patients have had limited treatment options, which involved managing the condition through a very strict low-protein diet and avoiding certain substances such as aspartame.