By Lisa Seachrist

Washington Editor

WASHINGTON — Public Citizen, a Washington-based consumer advocacy group, has filed suit in federal court to compel the FDA to release the protocol for the postmarketing study of Interneuron Pharmaceuticals Inc.'s diet drug, Redux.

In filing the lawsuit, Public Citizen maintains the safety and efficacy data produced from postmarketing or Phase IV studies should be available to the public and not considered confidential proprietary information. In addition, the group holds that the public should be assured those studies are rigorous.

"Postmarketing studies are required because the agency or its advisory committees have lingering questions about a drug's safety or effectiveness," said Larry Sasich, a pharmacist and researcher with Public Citizen. "One of the things that nobody knows is if the trial is valid to answer those lingering questions. It is quite possible to design a trial so badly that a dangerous drug looks safe."

The lawsuit requests that the FDA be required to release the research protocol of the Phase IV trial for Redux (dexfenfluramine) that Wyeth-Ayerst Laboratories, of Philadelphia — marketer of the drug — agreed to perform. The group filed suit after the FDA failed to provide the study protocol under an Aug. 21, 1997, Freedom of Information Act request. The agency claimed the findings were proprietary.

This is the second time Public Citizen has sued the agency over a Phase IV protocol. The group requested and was denied the Phase IV protocol for the diabetes drug Glucophage (metformin), produced by Bristol-Myers Squibb, of Princeton, N.J. The drug is associated with lactic acidosis, which is fatal 50 percent of the time. On Nov. 3, 1997, the U.S. District Court of the District of Columbia found "that no competitive harm will flow from the release of the metformin protocol."

Public Citizen sees the Redux case as the FDA putting the industry's interests before those of the public. Redux was approved on a 6-5 vote by an FDA advisory committee in November 1995. The committee was concerned about the potential neurotoxicity associated with long-term use of the drug.

Postmarketing Study Required By FDA

In April 1996, the FDA cleared Cambridge, Mass.-based Interneuron's Redux for marketing with the stipulation that Wyeth-Ayerst, a division of American Home Products Corp., of Madison, N.J., conduct a Phase IV study to assess the drug's long-term safety.

Redux was withdrawn from the market in September 1997 because of its association with heart valve damage.

"One month before the drug was withdrawn from the market, the company agreed to a protocol to assess long-term safety, but had yet to begin the study while millions were taking Redux," Sasich said. "Companies should be required to perform these studies with due diligence."

Sasich, however, pointed out that the FDA doesn't have the capability to track whether postmarketing studies are completed and won't for at least six months. In addition, Sasich called the agency's enforcement power the equivalent of "dunning letters," or repeated requests for the information.

Because biotechnology companies frequently receive approvals in the accelerated approval environment, they are often required to conduct Phase IV trials as a condition of approval. Changes in the way the FDA manages Phase IV studies are likely to have a significant impact on biotechnology companies.

"We do not think that the safety and efficacy data should be trade secrets," Sasich said. "The public should know the risks and benefits associated with any drug. After all, they are the ones who are taking the pills." *