LAVAL, Quebec _ Investor uncertainty was the order of the dayover BioChem Pharma Inc. shares on news Wednesday that auniversity had been awarded a patent for the antiviral drug 3TC, afirst-line therapy for HIV-infected patients.
By Wednesday afternoon, the company's shares (ME:BCH) hadfallen C$6.20 to C$39.50 per share. The stock was off US$4.375 toUS$28.75 on NASDAQ at the same time.
This followed an announcement that the U.S. Patent and TrademarkOffice had awarded patent No. 5,539,116 to Emory University, ofAtlanta, on 3TC. On issuance of the patent, Emory filed an action forpatent infringement against BioChem Pharma along with its alliancepartner, Glaxo Wellcome Inc., who under a license agreement,manufactures and sells 3TC under the trade name Epivir worldwide.
The complaint, filed in Atlanta, seeks damages for the sale anddistribution of Epivir. It does not, however, attempt to stop sales ofEpivir or to remove the product from the market.
Ezra Lwowski, an analyst at Yorkton Securities Inc., of Toronto, toldBioWorld Today there will be a great deal at stake over the ensuingchallenge from Emory. Not only is 3TC being sold as a first-linetherapy in combination with AZT and protease inhibitors for thetreatment of HIV infection and AIDS, but it's also in Phase IIIclinical trials for the treatment of chronic hepatitis B infection, apotentially multi-billion dollar market.
It is estimated that potential sales for 3TC in the U.S. for treatment ofHIV could top US$300 million this year. BioChem Pharma, in theirsecond quarter results, reported royalty revenues from the sale of3TC of more than US$7.29 million.
BioChem Pharma's 3TC has been in the forefront of scientific news.At the XI International Conference on AIDS several weeks ago inVancouver, promising results on its effectiveness as an anti-HIV drugin combination with other drugs were presented.
And Monday, BioChem Pharma said a major study on 3TC had beenterminated eight months ahead of schedule after an interim reviewrevealed that among the 1,892 HIV positive patients involved in thestudy, progression to the combined endpoint of AIDS or death wasreduced by 54 percent for those treated with 3TC together with theirexisting therapies, such as AZT, compared to placebo given with thepatients' current therapies.
The clinical endpoint study, designated CAESAR after the countriesinvolved in the study (Canada, Australia, Europe, South Africa), wasinitiated in March 1995 to determine the effect of the anti-HIVtherapeutic effect of 3TC on survival or delay in disease progression.
Christine Lennon, vice president of corporate communications forBioChem Pharma, said "We consider the patent issued to EmoryUniversity to be invalid and intend to vigorously challenge thepatent."
Lennon also said that Glaxo Wellcome markets Epivir under licensefrom the company under U.S. patent No. 5,047,407 filed in 1989 andissued on Sept. 10, 1991.
"The grant of Emory's patent does not affect BioChem's alreadyissued pioneering patents," she added.
3TC is one of the optical isomers of BCH-189, which originally wasdiscovered by the late Bernard Belleau, of BioChem Pharma. The1991 patent covers the "composition of matter" i.e., how to obtain themixture BCH-189. Emory contends that it does not cover theindividual optical isomer which is being marketed as Epivir.
Dennis Liotta and Woo-Baeg Choi, both of Emory University, claimto have discovered a process to separate the mirror image compoundsof BCH-189, and filed a patent application describing this inventionon Feb. 1, 1990. A continuation of this application was issuedTuesday as U.S. patent No. 5,539,116.
According to a statement issued by Glaxo Wellcome, the companyhas been aware of the series of patent application covering 3TC fromEmory for several years. n
-- Peter Winter Special To BioWorld Today
(c) 1997 American Health Consultants. All rights reserved.