Oxford BioMedica, the biotechnology group, received a fillip after the US Food and Drug Administration approved a series of amendments to the clinical trial of Trovax, a drug designed to treat kidney cancer.

Trovax, which is being developed with Oxford's partner Sanofi-Aventis, hit a stumbling block in July when an independent monitoring board recommended that patients in clinical trials stop being given the drug as it appeared to have little effect. The news knocked more than half the value off Oxford's shares.