Sanofi-Aventis and partner Oxford BioMedica say the TroVax vaccine discovered by the latter has failed to reach its targets in a late-stage trial in renal cancer, news which has caused the UK firm’s share price to collapse.

Oxford BioMedica said the independent data safety monitoring board for the 733-patient Phase III TRIST study of TroVax in renal cancer has recommended that the trial should continue but that further vaccinations be discontinued, following its fourth interim review. The DSMB advised that TroVax administered according to the protocol will not meet the predefined primary efficacy endpoint, “but there is important scientific merit and more to be learned by additional follow-up of all patients.”

Oxford BioMedica and Sanofi say they will now evaluate the available data and the implications on the development plan for TroVax, including planned Phase III trials in colorectal cancer. The companies will discuss the proposed TRIST protocol amendments with the regulatory authorities and its focus will now be to explore the number of doses that provide optimal benefit, which most likely will mean less vaccinations.

The firms admitted that it is unlikely that the TRIST study alone will support registration of TroVax in renal cancer, although it may ultimately demonstrate a survival advantage for the jab and the results may form part of a regulatory submission, alongside an additional trial.

Mike McDonald, chief executive of Oxford BioMedica, said the news “is clearly disappointing” but “there is good reason to continue the study and potentially a late survival benefit for TroVax may still be demonstrated”. He added that there is more to the firm than TroVax, saying that in particular, we look forward to reporting initial results from the Phase I/II trial of ProSavin in Parkinson's disease in September.”

However at first glance it appears that investors do not share Mr McDonald’s enthusiasm and its shares at 10am this morning had slumped 56.3% to just over 8 pence. Now all eyes are on Sanofi, whose shares were down 1.3% to 44.87 euros, to see if it will continue with the TroVax project.