Dr Richard D'Souza, consultant nephrologist at the Royal Devon and Exeter Hospital, described Eculizumab as a "magic bullet".

BBC: Barnstaple kidney patient Elena Lilley's fight for drug

Alexion said the high cost of Eculizumab reflects 15 years of research, difficulty of manufacturing and the fact that few people will be prescribed it.

BBC: Barnstaple kidney patient Elena Lilley's fight for drug

Rachel Bennett from Exeter, whose son Felix was diagnosed with aHUS at six months, said Eculizumab was "incredible" and had given him a normal childhood for the first time at the age of nearly four.

BBC: Barnstaple kidney patient Elena Lilley's fight for drug