Economic modelling will be in the dock in London's High Court this morning, as a groundbreaking legal challenge over access to dementia drugs get under way.

The case centres on treatments for "mild stage" Alzheimer's disease and pits Eisai, the big Japanese drugmaker, together with The Alzheimer's Society and Shire Pharmaceuticals, against the National Institute for Health and Clinical Excellence, which recommends the treatments the National Health Service should adopt.