The parents of a boy with a rare genetic condition are "greatly heartened" by their High Court victory in a battle over the NHS's decision to refuse funding for a "life-changing" drug.
The seven-year-old, identified only as S, has severe autism and phenylketonuria (PKU), which inhibits his ability to digest protein.
His autism affects his ability to comply with the dietary restrictions which form the standard treatment for PKU, so his doctors sought funding for a drug called Kuvan.
Mrs Justice Andrews was told by S's lawyers that funding had been repeatedly refused by NHS England for differing reasons, leaving S at risk of the consequences of poorly controlled PKU, including brain damage.
On Tuesday, after she remitted the decision for reconsideration, she warned: "Whilst this judgment is bound to give rise to a degree of optimism, I must caution against raising hopes too high.
"The fact that this claim for judicial review has succeeded does not mean that there will necessarily be a favourable outcome to this IFR (individual funding request) application.
"However much one might hope that on the next occasion the panel will decide that the net additional expenditure of treating S with Kuvan would be justified having regard to the likely clinical benefit of keeping his blood phenylalanine levels consistently within the range that would avoid his suffering any additional neurological impairment, thereby potentially enabling him to realise his maximum functioning potential, they could still lawfully decide to refuse funding.
"It is their decision, and their decision alone; and provided it is taken on the basis of the correct interpretation of the IFR policy, and a proper understanding of the case put before the panel and the supporting evidence, it will not be open to challenge."
S's father had earlier branded the decision "extremely frustrating, unfair and inhumane".
He said: "No family should have to fight with the NHS for over 18 months to ensure that their child is given proper treatment.
"It is clear to me they do not want to fund this life-changing drug."
Peter Todd, of Hodge Jones & Allen, who is representing S's family, said they were "greatly heartened" by the ruling.
"We hope that the panel will now take prompt action and secure the funding to ensure that S's long-term health is no longer endangered."
S's father added: "We are very pleased that the court has ordered that NHS England reconsider their decision not to fund Kuvan for our son
"It's been a very difficult two years for our whole family and we are hoping that the funding will be granted soon, so that our son's quality of life can be improved significantly."
Eric Lange, chairman of the The National Society for Phenylketonuria (NSPKU) said the family had shown "great determination and bravery".
Mr Lange said: "Kuvan is already widely used across Europe.
"We would like to invite the NHS to actively engage with people living with PKU and ensure their needs are met.
"It should not need litigation to make the NHS listen to us."