By Kim Coghill

Washington Editor

Transkaryotic Therapies Inc. (TKT) said it will appeal a judgment handed down Wednesday by the High Court of Justice in London in a patent infringement lawsuit brought by Kirin-Amgen Inc. involving TKT's Dynepo.

Kirin-Amgen, the Japanese affiliate of Thousand Oaks, Calif.-based Amgen Inc., filed suit against TKT, of Cambridge, Mass., claiming that TKT would infringe on European Patent No. 0 148 605 B2 for Epogen alfa if it marketed Dynepo in the United Kingdom.

The English High Court of Justice combined the lawsuit against TKT with a similar claim filed by Amgen against Basel, Switzerland-based Roche Holding Ltd. Amgen prevailed in both cases.

TKT's stock (NASDAQ:TKTX) closed Wednesday at $15.10, down $3.30, or 18 percent, while Amgen's stock (NASDAQ:AMGN) closed at $51.87, up 36 cents.

The controversy surrounds Epogen alfa, Amgen's billion-dollar blockbuster anemia therapeutic, a recombinant form of erythropoietin, a red blood cell production-regulating hormone. New Brunswick, N.J.-based Johnson & Johnson markets Epogen, under the name Procrit, in the UK.

TKT and its partner, Frankfurt, Germany-based Aventis Pharma AG, in August filed a marketing authorization application in the UK to sell Dynepo. TKT describes Dynepo as a human erythropoietin for treatment of anemia.

Roche currently sells its version of Epogen in the UK while TKT was seeking to do so. Roche could not be reached for comment.

The judge ruled that "one of four claims was not infringed on a literal basis but would be infringed when the claim is construed on a purposive basis [doctrine of equivalents]. The other three claims were found to be invalid," said Justine Koenigsberg, TKT's director of corporate communications.

Amgen spokesman Jeff Richardson said in order for the judge to rule in Amgen's favor, only one claim had to be determined valid. "As far as we are concerned, we won. This ruling says those companies have infringed and now the court will decide whether they will ask Roche to take their product off the market."

Koenigsberg said the battle isn't over for TKT. Not only will TKT appeal this decision, but the company also appealed a similar decision handed down in the U.S. in January. (See BioWorld Today, Jan. 23, 2001.)

Massachusetts U.S. District Court Judge William Young ruled in favor of Amgen in its suit charging TKT with eight claims of patent infringement related to three patents covering Epogen alfa.

Koenigsberg said the appeal has been filed in the U.S. Court of Appeals in the Federal Circuit in Washington.

Richardson said Amgen has pending lawsuits regarding Epogen alfa in several other countries that will be decided country by country.

Even the bad news for TKT released Wednesday will not necessarily impact the company long term, Thomas Dietz, a senior analyst with Pacific Growth Equities in San Francisco, said in a research note. "While this news is negative for the stock, we believe that investors have for some time been focused on TKT's other assets and opportunities and following some near-term turnover, we believe that the stock has good opportunity to recover."

He said TKT's Replagal is expected to receive approval and begin to launch in Europe on a country-by-country basis beginning in the third quarter. "Our visibility into the timing for approval of Replagal in the U.S. remains unclear subsequent to the company's announcement early in January that the company had received a 'Complete Review Letter' and that the FDA had requested additional information," he said. (See BioWorld Today, Jan. 5, 2001.)

Replagal is an enzyme replacement therapy for the treatment of Fabry disease. The product has been granted orphan status, but is similar to Fabrazyme, a product for the same indication being developed by Cambridge, Mass.-based Genzyme General. The two companies are involved in a patent fight over the products. (See BioWorld Today, June 19, 2000, and June 26, 2000.)