Vaccines firm Intercell and partner Merck & Co. have formally terminated a Phase II/III clinical trial evaluating Intercell’s Staphylococcus aureus preventive vaccine V710, on the recommendation of the trial’s independent Data Monitoring Committee (DMC). A review of the study data led the committee to conclude that V710 was unlikely to demonstrate a statistically significant clinical benefit.
However, the firms stress, a prior safety concern regarding overall mortality and multiorgan dysfunction among vaccine recipients has been shown to be statistically insignificant, and will warrant no action beyond routine safety follow-up. Merck had been informed by the DMC back in April that although the V710 study hadn’t formally met futility criteria, it nevertheless recommended suspending further enrollment pending completion of additional analyses on the benefits and risks of vaccination. It is these analyses that have now led to the recommendation to terminate the study on efficacy grounds.
The S. aureus vaccine candidate is based on a conserved protein antigen discovered by Intercell and licensed to Merck 2004 on an exclusive worldwide basis.The firms’ S. aureus partnership has been focused on the development of V710 as well as antibody-based products against nosocomial S. aureus infections. Under terms of the deal, Merck is responsible for clinical development, manufacturing, and marketing of resulting products.
In November 2010 the firms reported positive data from a U.S.-based Phase II V710 vaccine study in hemodialysis patients. The results showed that the vaccine V710 elicited a sustained immune response in this population of patients who are at chronic risk for developing serious S. aureus infections.