The U.S. Patent and Trademark Office (PTO) has rejected a broadpatent owned by Hoffmann-La Roche Inc. relating to alpha interferon,the subject of much debate and legal action since the filing of thesepatent applications began in the late 1970s.BioWorld learned late Thursday that Hoffman-La Roche has 60 daysfrom May 6, when the re-examination action was mailed, to respond. ARoche official said that his office received the notice on Thursday, andhe would not be able to comment further except that he expects theclaims will ultimately be accepted by the PTO.If the rejection is upheld, companies no longer would have to paylicensing fees to Roche, and it would open the door for development ofalpha interferon by other companies. Also, it could substantiallyweaken Roche's position overseas, where there is more competition.Further details of the action and potential ramifications were unclearbecause the parties involved were unavailable for comment.Roche Added To Original ClaimThe patent, No. 4,503,035, deals with the claim of development of ahomogenous alpha interferon at a high purity level. The rejection of thepatent centers on the PTO finding that the patentees added to theiroriginal claims, thus invalidating earlier ones. In the meantime, othersskilled in the art could have reached the same conclusions.Roche, of Nutley, N.J., holds the patent that was developed byGenentech Inc., of South San Francisco. In May 1985, Roche reached aworldwide cross-licensing agreement with Schering-Plough, whichholds U.S. and European patents on the drug under an agreement withBiogen Inc., which cloned its version of the molecule in Switzerland.Both recombinant interferons are synthesized in Escherichia coli.Roche's alpha interferon is called Roferon-A, Schering-Plough's isIntron-A.Interferon Sciences Inc., of New Brunswick, N.J., has a license, underthe Roche patent, for the use of its non-recombinant interferon intreating genital warts. It pays Roche 8 percent in royalties. Among theindications alpha interferon is approved for are AIDS-related Kaposi'ssarcoma, hairy cell leukemia and hepatitis.In the PTO's Action In Reexamintation report, the examiner said thatpatentees' claims for priority . . . for the full scope of inventionsclaimed must be denied for any date before Dec. 26, 1979 for thefollowing reasons:y Patentees did not describe homogenous human interferon having amolecular weight about 21,000 daltons, i.e., 24,000 daltons, andspecific activity on human cells . . .y Patentees now acknowledge that they made more than one discovery,each after the other in time . . . that showed that alpha interferon wasnot one protein, as previously thought, but was a family of structurally-related proteins exhibiting distinct but closely related primary aminoacid sequences.Because of that acknowledgment, the examiner wrote, the PTO isobliged to revisit the basis for patentees' original claim for priority.y The issue is whether patentees' original applications without aminoacid sequencing information had shown that they invented the fullscope of the subject matter claimed in the patent.Fourteen claims were rejected. Claim 1 was rejected on prior art.Claims 2-4 were rejected as obvious. And Claims 5-14 were rejected asobvious over articles written in Science or Proceedings of the NationalAcademy of Sciences, which disclosed techniques to purify variousinterferon species.
-- Jim Shrine and David N. Leff
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