PathoGenesis Corporation Goes International; Seattle-based Company Launches Drug in Canada and Argentina, Signs Distribution Agreements in Europe.

SEATTLE--(BUSINESS WIRE)--May 26, 1999--

PathoGenesis Corporation (Nasdaq:PGNS) has expanded internationally by launching its drug TOBI(R) (tobramycin solution for inhalation) in Canada and Argentina.

These are the first markets outside the U.S. to approve TOBI, which is indicated for the management of cystic fibrosis patients with Pseudomonas aeruginosa infections. In addition, the company has laid the groundwork for future distribution of TOBI throughout Europe.

"We're very excited about introducing TOBI into Canada and Argentina," said Bill Gantz, chairman and chief executive officer of PathoGenesis. "It's the first of many steps in making this drug available to patients throughout the world."

In February, the Health Protection Branch of Canada as well as the Ministry of Health and Social Action in Argentina approved TOBI, an inhaled antibiotic that treats lung infections associated with cystic fibrosis. There are more than 3,000 Canadians and more than 700 Argentineans with cystic fibrosis. PathoGenesis recently began selling TOBI in these countries to treat patients with P. aeruginosa infections associated with the disease.

PathoGenesis is currently seeking regulatory approval for TOBI in the United Kingdom and Australia. The U.K. is the lead country for seeking approval to market the drug in the European Union. To pave the way for future distribution in Europe, the company recently signed agreements with companies to distribute TOBI in Germany, Sweden, Norway, Denmark and Finland. PulmoPharm will distribute the drug to pulmonologists and pediatricians throughout Germany and Swedish Orphan will distribute TOBI in the Nordic countries.

"Our partnerships with these companies will help us facilitate our entry into Europe," said Gantz. "We're excited about forging relationships with companies that share our commitment to cystic fibrosis and the broader pulmonary market."

Currently, TOBI is being used throughout the United States to treat cystic fibrosis patients. In addition, PathoGenesis recently announced positive results from a Phase II clinical trial using TOBI to treat bronchiectasis, an irreversible condition of damaged, dilated airways that is usually complicated by persistent bacterial infections. The company is preparing for an upcoming Phase III study.

"With the development of TOBI, we've made great strides in treating cystic fibrosis patients and making their lives better," said Gantz. "By expanding the use of this drug to include other severe lung infections and by expanding into other markets, we'll be helping thousands of people throughout the world."

Seattle-based PathoGenesis Corp. is a pharmaceutical company that develops drugs to treat chronic infectious diseases -- lung infections, in particular -- where there is a significant need for improved therapy. In addition to TOBI, PathoGenesis is developing other drug candidates to treat serious chronic lung infections including those common in cystic fibrosis, bronchiectasis and tuberculosis patients. PathoGenesis' stock is traded on the NASDAQ National Market System under the symbol PGNS. The company's Web site is located at www.pathogenesis.com.

Note: This news release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements are subject to known and unknown risks, uncertainties or other factors that may cause the company's actual results to be materially different from historical results or any results expressed or implied by such forward-looking statements. Factors that might cause such a difference include, but are not limited to, uncertainties related to the fact that PathoGenesis only began commercial operations in 1998, its dependence on TOBI, the degree of penetration of its markets and frequency of TOBI's use by patients, third party reimbursement and product pricing, seasonal impacts on hospitalizations or exacerbations experienced by cystic fibrosis patients, variability in wholesaler ordering patterns, drug development and clinical trials, competition and alternative therapies, and other factors described in PathoGenesis' filings with the Securities and Exchange Commission, including the company's Form 10-K for 1998 and Exhibit 99.1 to that Form 10-K.