Ark Therapeutics has dispersed some of the gloom in the biotechnology sector by reporting positive results in a late-stage clinical trial of a treatment for malignant brain tumours, sending the shares up almost 69 per cent.

The results are a relief for a sector that has suffered from plunging share prices and a series of high-profile drug trial failures, including Oxford BioMedica’s Trovax and Alizyme’s Colal-Pred.