Sonus stumbles with EchoGen while MBI’s Optison surges forward

Will FDA’s action provide an edge for Optison?

The ultrasound contrast agent EchoGen from Sonus Pharmaceuticals may be six or more months from entering the U.S. market as the result of a negative review by the Food and Drug Administration last month. The decision came as a surprise to many in the ultrasound community and may prove to be a boost to Sonus' arch-rival, Molecular Biosystems.

As 1997 drew to a close, Sonus of Bothell, WA, appeared to be in a dead heat with San Diego-based MBI for gaining FDA approval for their respective contrast agents. Optison received approval in December (SCAN 1/14/98), but when weeks passed without word from the FDA on EchoGen, questions surfaced about whether the Sonus product had hit a snag. Those questions were answered Feb. 25, when the FDA faxed Sonus a not-approvable letter.

Terry Willard, Sonus vice president of marketing and business development, refused to speculate about whether the FDA action would cause a substantial delay. Willard stated only that the company is examining all aspects of the FDA decision.

One contrast media industry analyst, David Crossen of Nations Bank Montgomery Securities in San Francisco, believes that there could be a delay of up to half a year as Sonus and the FDA sort out the issues in EchoGen's application. Crossen does not believe, however, that EchoGen's application is in long-term danger.

"I believe that it is not serious in any sense that might jeopardize the approvability of the product, but I am now assuming a six-month delay," Crossen said.

Crossen's estimate figures 30 to 60 days for Sonus to answer the FDA's questions and a further 90 days for FDA review. Crossen threw in an extra month as a margin for error.

The FDA's questions on EchoGen will require Sonus and its marketing and manufacturing partner, Abbott Laboratories of Abbott Park, IL, to submit additional information about the agent's manufacturing process, including chemistry and analytic methods validation. Also required will be a re-analysis of some of the animal and clinical data.

For MBI, the news couldn't be better. The company and its marketing partner for Optison, Mallinckrodt of St. Louis, had already won about a two-month head start on EchoGen by the time the FDA decision became public knowledge. The extra six or so months of exclusivity could give MBI and Mallinckrodt enough time to pitch each of the thousand or so hospitals that do most of the echocardiograms in the U.S.

"By then, probably a pretty significant proportion of those hospitals will have tried or become a routine user of the product," said William Ramage, vice president of marketing and business development at MBI. "That means the next company that comes out with an agent will have to displace Optison from the shelves and the minds of major customers."

Mallinckrodt has sold Optison aggressively in U.S. echo labs right from the start. Commercial shipments of the product were being administered just two days after receiving FDA approval on Dec. 31. By mid-March, more than 300 hospitals had bought Optison. According to Ramage, those 300 hospitals do a major portion of the echocardiograms done in the U.S.

"About 20% of the 6000 acute-care hospitals (about 1200 hospitals) do 80% of the echoes in the U.S.," Ramage said. "Those are our targets, so you can see that 300 represents a very significant penetration of our target population."

As important as the number of hospitals initially buying Optison is the number reordering the product, Ramage said. In mid-March, that percentage had risen to a healthy 30%.

MBI got more good news in March from other quarters, as the U.S. Patent and Trademark Office awarded a patent to the company for microbubbles made from an emulsion. Not coincidentally, EchoGen is made from an emulsion.

MBI's patent, entitled "Emulsions as Contrast Agents and Methods of Use," in combination with a related patent, issued earlier, regarding methodology, could be used against Sonus if that company persists in a legal attack against MBI and Mallinckrodt. Court papers obtained from U.S. District Court for the Western District of Washington in Seattle state that Sonus has alleged patent infringement against MBI and Mallinckrodt. MBI and Mallinckrodt could potentially fire back with a patent infringement case of their own. Or, the two companies could use the MBI patents to negotiate a cross-licensing agreement with Sonus.

At present, MBI and Mallinckrodt are sticking with their original plan, alleging in both the Seattle court and at the PTO that the Sonus patent on perfluorocarbon is invalid. The two companies have made similar claims regarding validity to the PTO about this and other patents held by Nycomed and ImaRx (SCAN 3/4/98). Because each of the patents covers the use of perfluorocarbon, the holders could allege patent infringement. MBI believes the patents are invalid because the underlying methods and technologies were described by others in publications, including some in peer-reviewed journals, before the patents were issued.

The company has been compelled to take legal actions in the past and will continue to take the actions necessary to keep Optison on the market and to continue forward, regardless of whether those actions involve court litigation, patent challenges, or negotiated business arrangements, according to Robert Giargiari, director of investor relations at MBI.

"I think there are many possibilities open to us as things proceed," he said.