london

The legal tussle about rights to the thermostable enzyme Taq DNA polymerase has taken a new turn with a decision by the Australian Patent Office (APO) to withdraw patent rights to the enzyme in its native form issued to Swiss company Hoffmann-La Roche.

The decision has been welcomed by officials at New England Biolabs (NEB), which had led a challenge — together with the company Bresatec (now Bresagen) — to Roche's Australian patent on Taq , used extensively in laboratories as part of the polymerase chain reaction technique.

But Roche, which is also facing a court challenge to the US Taq patent from the laboratory equipment company Promega, has shrugged off the Australian decision. It argues that it has further information to back up its patent application which it has yet to present to the courts. (The company's patents to recombinant Taq and related products were upheld.)

The decision by the APO examiner focused on ‘prior art’, and in particular on claims by NEB and Promega, both of which have been selling versions of Taq , that its existence had been known to other researchers before its claimed ‘discovery’ by the US company Cetus in the mid-1980s.

The examiner supported, for example, the claim that a thermostable enzyme extracted by Russian scientists in the 1970s was essentially identical to that described in the patent application. The rejection of this argument by the European Patent Office last year was largely responsible for Roche being awarded the European patent on all forms of Taq (see Nature 384, 100; 1996)

Donald G. Comb, president of NEB, claimed last week that the APO decision “affirms the view of many scientists in the world that this and similar patents to native Taq DNA polymerase should never have been issued”. Officials from Promega express the hope that “the US court, as well as the EPO in upcoming opposition proceedings, will follow Australia's lead”.

But Roche said on Monday (24 November) that it had “for formal reasons” not been able to present to the APO the “strong evidence” it had provided to the EPO refuting opponents' claims of ‘prior art’. Roche says it is “confident” that it will win an appeal it has now lodged with the Federal Court in Sydney.