Trial patient screening: ViroLogic, Schering-Plough in assay deal for HIV drug trial

SOUTH SAN FRANCISCO, Calif.–ViroLogic Inc, announced in early July it signed a three-year $4.8 million service agreement with the Schering-Plough Research Institute. Schering-Plough will use ViroLogic assays during Phase III clinical trails for its drug candidate vicriviroc, a potential new entry inhibitor drug for HIV.

"This assay is used to screen all the patients in the trial," says Bill Young, ViroLogic's chairman and CEO, and will tell researchers whether the patient's virus is likely to respond to vicriviroc, which antagonizes the CCR5 receptor on a cell's surface to prevent the virus from entering. Young says the agreement is important for ViroLogic because "if this plays out in the approval of this drug, our assay could well be required" before use of vicriviroc to ensure that a patient's virus enters at CCR5 instead of another receptor, CXCR4.

Laura Knipmeyer, global project leader at Schering-Plough Research  Institute, says ViroLogic is "the only commercial supplier of a certified test for characterizing viral population in our clinical studies."

ViroLogic's assays will determine which study experienced patients will enter: 500 will be in a pure CCR5 viral population group, and 500 will enroll in a group with mixed CCR5 and CXCR4 viruses. Each study will include three arms. "Studies will be looking at two doses of vicriviroc," says Knipmeyer, "The doses will be 10 mg and 15 mg once a day. And those will be in addition to optimized background therapy." Another group will receive a placebo instead of vicriviroc.

Schering-Plough expects to file a new drug application with the Food and Drug Administration based on 24 weeks of treatment and "we do expect an accelerated approval" thanks to fast track designation, says Knipmeyer. American and western European markets for vicriviroc, which will receive a brand name, are expected to cover about 665,000 people, but Knipmeyer says "it's important to understand that the candidates for this drug are those that are already drug-treated. And of those patients, two-thirds are already on some therapy."

Young says that agreements like the one with Schering-Plough allow ViroLogic "to really plan our resourcing better because we know the companies are committed to use, and it's more than a one-project-at-a-time kind of deal." ViroLogic hopes to expand its HIV model into oncology through a merger with ACLARA BioSciences, whose technologies complement ViroLogic's. Many oncology drugs only perform for small portions of the population, so "it made a lot of sense to put the companies together," says Young. He sees individualized medicine as "the most important trend in medicine now" – perhaps more important than the drugs themselves – though it is currently only practiced with HIV patients. ViroLogic avoids competing with its clients by not undertaking drug discovery or development activity on its own, and Young says about one third of ViroLogic's revenues comes from work with drug companies.