THE parents of a sick Otley boy have taken their campaign for a new drug to David Cameron’s door, warning that time is running out.

Six-year-old Sam Brown is one of just 88 people across the UK with the ultra-rare genetic condition Morquio, which causes worsening mobility problems.

There have been growing protests over delays before NHS England decides whether to fund the drug Vimizim, which slows the onset of the effects of Morquio.

Now Sam’s parents, Katy and Simon, have been given the “devastating” warning that their son will no longer receive the drug on a temporary basis, from later this year.

The drug company BioMarin says it will not be “economically sustainable” to continue the goodwill arrangement unless NHS England makes up its mind by the end of February.

That looks highly unlikely because the organisation has announced a 90-day consultation which, MPs were told last week, has not yet even started.

The Telegraph & Argus has seen the letter sent by BioMarin, which criticises NHS England for not responding to its offer – made last October – to supply Vimizim for a further five years.

The company says the drug is available to patients in the Czech Republic, Hungary, Russia, Brazil, Canada, Indonesia, the United States and in the Middle East.

And it writes: “We have reluctantly commenced planning to cease supply of free product later in the year, as it is not economically sustainable for us to continue providing free product interminably.

“As an innovative pharmaceutical company dedicated to developing treatments for patients with rare diseases, it is tragic that we find ourselves in this position.”

Yesterday, the Brown family met fellow campaigners outside Parliament, before heading to Downing for Sam to deliver a letter to the prime minister, calling for help.

Mrs Brown told the T&A: “This letter is devastating. It’s an excusable situation – and that’s the message we are taking to David Cameron.

“The problem is the continued inability of the NHS to put in a robust appraisal process and even to respond when there’s a five-year offer on the table to supply this drug.

“The company is saying it won’t provide the drug from later this year unless a decision is taken very quickly – and that would mean Sam’s treatment would stop.”

Otley Liberal Democrat MP Greg Mulholland, who is supporting the family, said: “We cannot wait six months before having a system to decide whether or not fund the drugs Sam needs.”

In a Commons debate last week, health minister George Freeman insisted he could not intervene in what was a matter for NHS England.