Alexion Pharma and the National Institute for Health and Care Excellence have come to a new arrangement that widens NHS access to Strensiq for people with paediatric-onset hypophosphatasia.

The extremely rare inherited condition, which affects between one and seven babies each year in England, is characterised by defective bone mineralisation that can lead to destruction and deformity of bones, profound muscle weakness, seizures, respiratory failure and premature death.

Strensiq is an enzyme replacement therapy that targets the underlying cause of the disease but, with the cost of the treatment per person hitting an eye-watering £377,000 a year, cost regulators had previously sought to restrict its use by the NHS to those with the most urgent need.

Originally, NICE backed the therapy as an option for treating the bone manifestations of hypophosphatasia (HPP_ in babies with perinatal- and infantile-onset disease, but not in people those with juvenile-onset disease.

While juvenile-onset disease has a much lower mortality rate than cases appearing in infancy, where 100 percent percent of those diagnosed in the first six months of their lives die before they reach one year, later forms are often linked with debilitating and lead to bone deformities that may result in delayed walking, limb weaknesses, skeletal pain and non-traumatic fractures.

However, in new draft guidelines the Institute is recommending Strensiq (asfotase alfa) for all eligible patients paediatric-onset HPP, following an improved deal that includes a five-year managed access agreement reducing the cost of the drug to the NHS. During this time, extra information on the therapy’s use can be collected to help shape future guidelines on its use.

Described as a ‘step-change’ in the management of the condition, the drug offers a ‘lifeline’ for people that could enable them to have a good quality of life but without which they would not survive, NICE said.

“It is a success that patients with HPP in England who meet the criteria of the Managed Access Agreement will have access to Strensiq, which is the only treatment for this severely debilitating and often life-threatening disease,” said Lindsay Weaver, chief executive, Children Living with Inherited Metabolic Diseases (CLIMB).

“We are relieved that NICE, NHS England and Alexion have reached an agreement that benefits patients with paediatric-onset HPP most in need of treatment. We will be following the progress of the agreement, which involves the collection of robust data, to ensure continued access for patients.”