The National Institute for Health and Care Excellence has issued draft guidelines concluding that Biomarin’s Brineura is not a cost-effective treatment option for patients with the ultra rare disorder Batten disease.

Batten disease, which is also referred to as neuronal ceroid lipofuscinosis type 2 (CLN2), affects just one to six babies a year in the UK.

The progressive condition is caused by deficiency of the enzyme tripeptidyl peptidase 1, causing abnormal storage of proteins and lipids in neurons and other cells, preventing their normal function.

Symptoms begin from around the age of two years and can then progress rapidly with the onset of seizures, decline in speech, loss of mobility, involuntary muscle spasms, progressive dementia and visual impairment leading to blindness. Average life expectancy is just 10 years.

Currently there is no cure or life-extending treatment available for the condition, as so clinical management is focused on symptom relief and supportive and palliative care.

Brineura (cerliponase alfa) is an enzyme replacement therapy administered directly into the brain via a surgically implanted permanent access device; a year’s treatment costs more than £500,000 per patient.

NICE’s committee agreed that Bineura is an innovative treatment and effective in the short-term at slowing the rate at which the condition progresses.

“However, in the absence of long term evidence about its effectiveness in stabilising the disease and preventing death, and having taken all the health and non-health-related benefits of cerliponase alfa into account, the committee considered that the drug was not a good use of NHS resources,” said Dr Peter Jackson, chair of the independent Highly Specialised Technology committee, explaining the decision.

The preliminary decision is now out for public consultation until 5 March. In the meantime, the company has confirmed that it plans to negotiate with NHS England terms that might allow the drug to be made available while uncertainties in the evidence of its long-term benefits are addressed.