Biotech firm's shares plummet as cat-allergy trial fails

Circassia Pharmaceuticals loses two-thirds of its value after significant placebo effect halts vaccine for sufferers

An Oxford company hailed as a star of British biotechnology lost almost two-thirds of its stock market value on Monday after it revealed that its experimental cat allergy treatment had failed in a late-stage trial.

Circassia Pharmaceuticals floated on the stock exchange in 2014 and was seen as one of the great hopes of the sector for its research into cat allergies, which affect 24 million people in the US alone.