German agency begins review of dimeric x-ray contrast agents

Agency asks for data from Schering and Nycomed

A German regulatory agency has begun a review of dimeric x-raycontrast agents following reports of delayed allergic reactionsto Schering's Isovist 280 product.

Germany's Federal Institute for Drugs and Medical Devices isreviewing Isovist 280 as well as Visipaque, a dimeric agent developedby Hafslund Nycomed. Both agents have been approved for marketingin Europe and are under regulatory review in the U.S.

Schering pulled Isovist 280 off the market last year afterallergy-like skin reactions were reported in fewer than 1% ofpatients administered with the agent (SCAN 12/13/95). Scheringtook a net write-off of 42 million deutsche marks ($29 million)in 1995 and expects losses of 70 million DM ($48.3 million) in1996 related to the withdrawal.

The agency is reviewing Isovist 280 and Visipaque as part ofa "graduated plan procedure," a regulatory tool to assessthe risk-benefit ratio of products already on the market, accordingto Schering officials. The institute has requested informationon delayed hypersensitive reactions from Schering and Nycomedand is also asking doctors to report delayed reactions relatedto the use of dimeric agents and other x-ray contrast media.

Nycomed representatives said that the rate of allergic reactionsto Visipaque is no higher than the reaction rate for other x-raycontrast media. They characterized the agency's request for informationas normal.

"They asked for some documentation from us as part ofa routine follow-up in investigating other dimeric products onthe market," said Eric Cameron, senior vice president ofcorporate communications for the Oslo company. "There isno singular action looking into Visipaque."

Nycomed continues to sell Visipaque in Europe and believesthat U.S. regulatory clearance should be forthcoming this year.

Schering emphasized that it has voluntarily suspended salesof Isovist 280 and could put the product back on the market ifit chose to. In reality, however, it could take up to two yearsfor the company to complete its clinical trials intended to determinethe cause of the reactions and to investigate whether dimericagents have different pharmacokinetic effects than monomeric agents,according to industry observers.