Sonus files NDA for EchoGen agent

Sonus Pharmaceutical passed a major milestone last week with thefiling of a new drug application for its EchoGen ultrasound contrastagent. The move triggered a $4 million payment from U.S. marketingpartner Abbott Laboratories, adding to a $3 million payment fromJapanese partner Daiichi Pharmaceutical, which Sonus announcedlast month.

EchoGen is a perfluorocarbon-based agent developed by Dr. StephenQuay, who also developed MRI contrast agent Omniscan. Sonus wentpublic last year to raise cash to fund further development ofthe agent (SCAN 12/27/95). Last week's NDA, which Sonus said wasfiled ahead of schedule, is for both radiology and cardiologyapplications of EchoGen.

Simultaneously with the NDA announcement, Sonus said that preliminaryresults from a phase II clinical trial indicate that EchoGen-enhancedultrasound appears to be useful in distinguishing malignant frombenign lesions after suspicious lumps are discovered with mammographicscreening. In a study of 16 patients at Hammersmith Hospital inLondon by Dr. David Cosgrove, EchoGen assisted in the diagnosisof suspicious lesions in 100% of cases.

In other Sonus news, the company is shopping European licensingrights for its EchoGen agent to prospective partners after Guerbetof France declined to exercise an option on the product. Sonusis in advanced discussions with two companies that would takeGuerbet's place in the European market, said Quay, who is Sonuspresident and CEO. Sonus expects to file for European approvalof EchoGen in the fourth quarter.

Sonus and Guerbet entered the option agreement in October 1994,with Guerbet paying an initial option fee of $3.1 million. Sonusultimately received a total of $4 million from Guerbet, an amountthat was converted into 549,000 shares of common stock when Sonuswent public.

Sonus and Guerbet were unable to reach an agreement on a licensingdeal due to differences that Quay declined to specify. The differenceswere not related to EchoGen's performance in clinical trials,Quay said.