FDA staffer's departure spurs contrast optimism

Drug manufacturers are hoping that a changing of the guard atthe Food and Drug Administration's medical imaging drugs divisionwill result in the end of a controversial new policy that hastightened evaluation criteria for contrast agents. The policyhas slowed the drug approval process for two MRI contrast agentsby requiring their manufacturers to indicate the diseases forwhich the drugs are intended.

Before the policy change, the FDA allowed manufacturers tosubmit contrast agent applications without indicating the diseasesthe products might be used to diagnose. Several drug makers tailoredtheir applications to adhere to the older policy and were takenaback by the FDA's request for disease-specific data (SCAN 9/16/92).

The new policy was communicated to drug manufacturers lastsummer by Dr. Wiley Chambers, acting director of the Divisionof Medical Imaging, Surgical and Dental Drug Products.

In advisory committee hearings last May for Alliance Pharmaceutical'sImagent GI contrast agent, Chambers pointed out that FDA regulationson labeling require all drug applications to include informationon the type of disease for which a drug is intended. Chambersproposed that the regulations be applied to Imagent, and as aresult Alliance has had to submit additional data to the FDA.

The FDA also refused to accept an application as written forAdvanced Magnetics' gastrointestinal imaging agent, Ferumoxsil,because the application did not include disease-specific criteria.Ferumoxsil's application was delayed while the company gathereddisease-specific data from completed trials, according to a companyspokesperson.

The FDA's shift on contrast agents was an effort to achieveregulatory uniformity when reviewing drug applications, accordingto Chambers.

"I applied things consistent with what I saw elsewherein the Center for Drug Evaluation and Research," Chamberstold SCAN. "In areas where I saw (the disease-specific regulation)wasn't being applied I tried to apply it. The goal was achievinguniformity in the center."

The medical imaging drugs division is one of several withinthe CDER that review drug applications.

But the new interpretation frustrated manufacturers, who feltthey were not given advance warning of the policy shift. Manyclinicians also expressed displeasure with the policy, claimingit ignored the fundamental difference between imaging and therapeuticdrugs.

The FDA announced in December that Chambers had been reassignedto another position in the agency. Dr. Paula Botstein, deputydirector of the Office of Drug Evaluation I, has assumed Chambers'duties as director of the medical imaging drugs division pendingthe selection of a replacement. Chambers has applied for the directorshipon a permanent basis, but the status of his application is questionablein light of the reassignment.

Chambers' exit has given hope to manufacturers that the FDAwill return to its previous policy in reviewing contrast agents.

"We will now be dealing with people who understand medicalimaging and we can have the issue straightened out," saidDuane J. Roth, president and CEO of Alliance.

Chambers, however, is not so sure that his departure will promptany change in the way the medical imaging division reviews contrastagent applications.

"I assume the division will continue to follow the regulations,"he said. "Part of the mission of the center is to maintainconsistency (in drug evaluation). I don't see how they can't continueit."