And what’s the truth about this experimental drug?

THE ‘fresh evidence’ which has sent the case back to court involves a debate about whether the therapy can successfully reach Charlie’s brain.

Called nucleoside bypass therapy, the treatment involves a drug that replaces deoxynucleosides, which are naturally produced in healthy people, to repair DNA. But for it to work, the drug would need to penetrate a biological membrane known as the ‘blood brain barrier’.

This barrier separates blood circulating the body from the brain’s fluids. For the medication to fix cells in the brain – as well in the rest of the body – it needs to cross the barrier.

The High Court was told there was ‘no evidence’ the therapy could cross the blood brain barrier, and the judge adopted this position in his ruling.

But the new evidence challenges this. In their letter, the seven experts said there was ‘substantial direct and indirect evidence clearly demonstrating’ that the drug can cross the barrier.

If it can, experts believe there is a small chance it could make Charlie better. The US doctor did tell the court in March he believed his experimental drug could cross the blood brain barrier – but his was a lone voice.

If the judge had heard all seven voices saying the same, it raises the question of whether he would have ruled there was ‘no evidence’ the drug would work on someone with Charlie’s condition.