Slow FDA, patent suit lie in Omniscan's path

Sterling-Winthrop continues its do-si-do with the Food and DrugAdministration over approval of Omniscan, a nonionic gadoliniumcontrast agent for MRI. Sterling has licensed rights to marketOmniscan in the U.S. from Nycomed of Oslo (SCAN 7/15/92).

While waiting for word from the FDA, Sterling is also facinga legal challenge to Omniscan's patents posed by Schering. Aninfringement suit filed by Schering against Sterling and Nycomedin February was quickly followed by a countersuit.

Schering holds patents on gadolinium-based image enhancementtechnology. The suit charges infringement, asks for an injunctionagainst Sterling's distribution of Omniscan, and requests paymentof damages. In its countersuit, Nycomed contends its patent isin order and does not infringe Schering's.

In an interview last month, a Schering representative deniedthe existence of the patent infringement suit. But according toDiane Islen, a corporate communications staffer at Sterling, thecase is in litigation. The ongoing suit bars Sterling officialsfrom commenting on its status, she said.

As with other major developments, however, the company willmake a public announcement about the suit once it is resolved,she said.

It is unlikely that the suit will hinder the FDA's review ofOmniscan, according to Steve Wage, Sterling's Omniscan productmanager.

"I don't think the FDA really looks at those issues,"he said. "It's not part of their requirement for establishingefficacy and reviewing clinical data."

Discussions between FDA and Sterling are frequent, but companyrepresentatives are in the dark as to when Omniscan approval willbe announced.

"I wish I knew," Wage said. "We're moving alongand of course, discussions continue between our regulatory staffand the FDA. But approval will come only after the FDA has answersto all of its questions. We don't know when they will reach thatpoint."

The agency favorably reviewed Omniscan late last year but hasreserved final judgment until after labeling and manufacturingdetails are refined. Prohance, another nonionic MRI agent licensedby Squibb, was similarly reviewed by the FDA at the same meetingand is also pending approval.

Currently, only Magnevist, a Berlex gadolinium agent, is approvedby the FDA for use with MRI. Berlex is Schering's U.S. subsidiary.