The National Institute for Health and Care Excellence is not recommending NHS use of Biogen’s Spinraza for the rare genetic disorder spinal muscular atrophy (SMA) at this time.

In draft guidelines, the Institute said evidence showed “a substantial benefit” for the drug, but the appraisal committee felt there were “significant uncertainties, particularly around its long-term benefits,” which, coupled with Spinraza's “extremely high” cost, meant it could not be recommended as a cost-effective treatment option.

However, NICE said it would welcome “further discussions” and noted that it is aware Biogen intends to develop a proposal for a managed access programme that might address uncertainties in the evidence and to reduce the financial risk to the NHS.

It is estimated there are there are between 1,200 and 2,500 children and adults in the UK living with SMA, which results in devastating muscle wasting that can cause patients to lose the ability to move, breathe and swallow.

People with the most severe forms of the condition usually die before the age of two, and there are currently no active treatments targeting its underlying cause.

Spinraza is an antisense oligonucleotide (ASO) designed to treat SMA caused by mutations or deletions in the SMN1 gene located in chromosome 5q that leads to SMN protein deficiency. It is the first to address the cause of motor neurone degeneration in patients with the disease.

The therapy was cleared for use in Europe in following accelerated assessment in May 2017, based on data from two pivotal multicenter, controlled studies which showed clinically meaningful efficacy and a favourable benefit-risk profile, according to the company.

Earlier this year, Biogen said it is “optimistic” that patients in with the rare spinal disorder will get rapid and broad access to Spinraza via the NHS. While access now seems more uncertain for England and Wales, the Scottish Medicines Consortium has already accepted the drug for use on NHS Scotland.