FDA Panel Recommends Go-Ahead on AIDS Vaccine Tests Despite Critics

A Food and Drug Administration advisory panel, despite much skepticism from its scientist members, has recommended that a Southern California biotechnology company be allowed to go ahead with widespread human clinical tests of the first therapeutic vaccine for AIDS.

The experimental AIDS vaccine being developed by Immune Response Corp., a Carlsbad firm co-founded by polio vaccine pioneer Dr. Jonas Salk, is intended to help people with HIV, the virus believed to cause AIDS, stay healthy longer by stimulating their immune systems.

During a grueling, 13-hour hearing that concluded late Thursday night, the FDA reviewers said clinical trials so far had produced little evidence that the vaccine was effective in combatting HIV. Nevertheless, the panel recommended the company be allowed to proceed with the much-larger trials in the hope that they would yield more encouraging data.

“I am not at all excited about the data I’ve seen,” said the panel’s chairman, Dr. Stanley Lemon of the University of North Carolina. “But I would be thrilled to be proven wrong.”

AIDS activists who attended the hearing strongly urged the FDA panel to approve further trials for the vaccine, called Immunogen.

“We know of no individuals who participated in the (earlier) trials who would not clamor for additional booster vaccines,” Kiyoshi Kuromiya, editor of Critical Paths AIDS Project newsletter in Philadelphia, said Friday.

“We feel that Salk, while he may be a maverick researcher, has over the years been on the right course,” said Kuromiya, who is HIV-positive.

Several of the FDA panelists, however, said during the hearing that, without the Salk name attached to Immunogen, the vaccine would have attracted far less interest.

The panel told the FDA that clinical data indicated the vaccine might inhibit the HIV virus from increasing in patients’ blood, but there was no evidence that it did any more for patients in the long run than a placebo. Immune Response officials said that in small studies, patients receiving the vaccine saw a slightly slower progression of the disease and a slightly slower decrease in vital immune cells.

Salk attended the hearing and pleaded with the panel to give the vaccine more time, saying: “We want desperately to move forward.”

The FDA must authorize the further tests and is working with Immune Response to be sure it can produce enough vaccine for the trials, but no deadline for FDA action has been set. The agency normally abides by the panel’s recommendations.

Despite the go-ahead from the FDA reviewers, Wall Street took its cue from news reports Friday about the skeptical remarks of panelists. Immune Response shares fell 56 cents to $4.56 Friday, a 52-week low.

Edmund A. Debler, drug-industry analyst at Mehta and Isaly in New York, said Immune Response has “fallen out of favor with Wall Street.” Many investors are highly skeptical of the company and of past management statements that they believe exaggerated the effectiveness of Immunogen, he said.

Immune Response’s HIV therapy is a joint project with French drug maker Rhone-Poulenc Rorer, which has invested $27.5 million in Immunogen so far.

The recommended additional tests would cost up to $30 million a year over several years, said Charles Cashion, Immune Response’s chief financial officer.