The decision is thought to represent a severe blow to GSK’s efforts to become the first company to bring to market a CCR5 inhibitor, a new type of HIV drug that prevents the virus from entering cells.
The setback is expected to put the development program for Aplaviroc further behind its rival Pfizer which already has its own CCR5 inhibitor in late stage development.
Although GSK has been forced to terminate this study in treatment naive patients, it is offering treatment to experienced patients in a separate phase III trial the option to continue taking the drug.
Aplaviroc is part of a new class of drugs that work by binding to one of the chemokine co-receptors, CCR5, on the immune cell surface that is essential for HIV-1 entry and infection.