US-based biopharmaceutical company GenVec saw its share price plummet after the company said it was scrapping a Phase III clinical trial with its lead compound, the DNA carrier TNFerade, in locally advanced pancreatic cancer.

The decision was taken after a scheduled interim analysis indicated that the PACT (Pancreatic Cancer Clinical Trial) study “would not meet the goal of demonstrating persuasive evidence of clinical effectiveness that could form the basis for regulatory approval in the population chosen for the study”, GenVec announced.

It will continue to analyse the data from PACT “in order to assess the future strategic value of TNFerade to the Company”.

The interim analysis of overall survival in the PACT trial was triggered by the 184th death, representing two-thirds of total expected events, among the 330 patients taking part. The data showed about an 8% lower risk of death in patients given TNFerade in combination with standard of care (SOC) than in those patients given SOC alone. The hazard ratio was 0.921, meaning patients on TNFerade had 0.921 times the chance of dying versus the SOC group.

“Accordingly, these data strongly suggest the trial will not achieve the statistical significance required to form the basis for approval of a biological licence application in the population chose for the study,” GenVec stated. It is in the process of notifying investigators and regulatory agencies about the decision not to continue with PACT.

Data from the first interim analysis of overall survival in the PACT trial were released in November 2008. These showed about a 25% lower risk of death with TNFerade plus SOC than with standard of care alone, although median survival at that stage was
9.9 months in both arms of the trial.

TNFerade is an adenovector containing the gene for an immune system protein, tumour necrosis factor-alpha (TNF-alpha). It is injected directly into tumours, where TNFerade stimulates the production of TNF-alpha.

For the time being, GenVec will focus on its vaccine programmes as well as its recently announced collaboration with Novartis to develop treatments for hearing loss and balance disorders, the company said. All of these programmes rely on GenVec’s proprietary adenovector technology.