By Karen Pihl-Carey

Agouron Pharmaceuticals Inc. started recruitment for a double-blind, placebo-controlled Phase II trial for AG7088 intranasal spray to treat common colds caused by rhinovirus infection.

It is too early to tell whether data from the trial would support a new drug application or would lead the company into a Phase III trial next year. The large Phase II trial will include about 900 patients at more than 50 sites in the U.S.

"This is a Phase II trial, so it's not, at this point, defined as a registrational one," said Agouron spokeswoman Joy Schmitt. "However, depending on how quickly it accrues and what the data show, it could indeed be a portion of our package."

If a Phase III trial is needed, it would begin sometime next year, Schmitt told BioWorld Today.

The La Jolla, Calif., company said it will reimburse patients who participate in the trial for time and travel, as well as supply them with the medication. Human rhinovirus is the most frequent cause of the common cold, and it is associated with exacerbations in those with certain chronic respiratory diseases, such as asthma, emphysema and chronic bronchitis. It affects more than 30 million Americans.

"We're hoping to accrue within the month because the rhinovirus season is really most acute in the fall," Schmitt said. "It's important that they respond quickly within 36 hours of first experiencing cold symptoms."

AG7088 is a synthetic compound designed to inhibit the rhinovirus 3C protease, an enzyme essential for rhinovirus replication. In preclinical testing, it demonstrated potent antirhinoviral activity. There are no antiviral drugs yet on the market to treat the common cold, Agouron said.

Some of the Phase I studies of the compound, initiated last year, were completed in England to evaluate its safety and pharmacokinetic parameters in healthy volunteers given single and multiple intranasal doses. Those studies showed that AG7088 was an active agent and "that it appeared safe," Schmitt said.