By Karen Pihl-Carey

Agouron Pharmaceuticals Inc. and The Immune Response Corp. (IRC) initiated a pivotal trial of Remune (HIV-1 immunogen) in combination with highly active antiretroviral therapy (HAART) to treat HIV infection.

Clinical studies suggest that when combination antiviral drug therapy is accompanied by injections once every three months of Remune, it results in improvements in immunologic markers and virologic markers of the response to HIV.

"Our corporate partner, Agouron, is enthusiastic about the therapy and its potential," said a spokesman for IRC, of Carlsbad, Calif. "That's why they're carrying it forward. The Immune Response Corp. believes in this product and is encouraged and happy that our partner is going forward. We're encouraged that the trial is taking place as soon as it is."

In the pivotal trial, a randomized, double-blind study, researchers hope to determine whether the addition of Remune to a HAART regimen of Viracept (nelfinavir mesylate) and Combivir delays the time to virologic failure.

"We'll have approximately 700 patients that will accrue in this trial and they will all be on Viracept plus Combivir," said Joy Schmitt, a spokeswoman for Agouron, of La Jolla, Calif. After eight weeks, patients who achieve plasma HIV-1 RNA levels less than or equal to 2,000 copies will then receive injections of either Remune or placebo.

"It's basically going to look at the differences in terms of duration of the response below the level of detection," Schmitt told BioWorld Today.

Remune is an inactivated form of HIV lacking its envelope that is combined with a mineral oil-based adjuvant. It is designed to stimulate a patient's immune defenses to keep the virus in check.

The pivotal trial will last 48 weeks and be conducted at sites in North America Europe and Australia. Eligible HIV-infected patients must have plasma HIV-1 RNA levels of greater than or equal to 10,000 copies and no previous exposure to antiretroviral therapy.

Just four months ago, a Phase III trial of Remune was halted upon recommendation of a data safety monitoring board. The 2,500-patient, placebo-controlled study tracked the ability of Remune to slow disease progression by tracking the clinical endpoints of a diagnosis of AIDS or death. (See BioWorld Today, May 18, 1999, p. 1.)

"The endpoints we were looking at were no longer the standard of which we needed to be judged," the IRC spokesman said. "Now the standard is viral load. Can Remune have an impact, a significant impact, on viral load?"

In January, Warner-Lambert Co., of Morris Plains, N.J., purchased Agouron for $2.1 billion, just six months after Immune Response and Agouron signed a $77 million pact to develop Remune. (See BioWorld Today, Jan. 27, 1999, p. 1; and June 12, 1998, p. 1.)