[From the Antiviral Agents Bulletin, Feb. 1996]
Generic Drug Companies and NIH Denied AZT Patent Appeal
The U.S. Supreme Court has denied considering appeals by two generic drug companies challenging U.S. patents assigned to Glaxo Wellcome Co. covering use of AZT for treatment of HIV-infection and AIDS. The denial was made without comment or dissent. Thus, an earlier appeals court finding that the patents were valid (discussed in the December 1994 Bulletin, p. 364) remains in force, and Glaxo Wellcome is recognized as the sole inventor and assignee for the main U.S. patents covering use of AZT (Retrovir) for treatment of HIV-infection and AIDS. As discussed in the October 1994 Bulletin (p. 300), August 1993 Bulletin (p. 235) and other articles in recent years, the generic drug companies, Barr Laboratories (Pomona, NY) and Novopharm, Inc. (Schaumberg, IL), challenged the validity and the granting of sole assignment of AZT patents to Burroughs Wellcome Co. (now Glaxo Wellcome).
The case originally started in 1991 with the generic drug companies posing the argument that scientists at the National Cancer Inst. (NCI, NIH; Bethesda, MD) made key contributions to the discovery and demonstration of the utility of AZT for treatment of HIV/AIDS. While NCI scientists developed the underlying technologies for HIV drug testing, were the only lab willing and able to screen agents for anti-HIV activity at the time, and provided documentation of AZTÕs in vitro efficacy of HIV, Burroughs Wellcome scientists were the first to conceive of the invention. This included filing a U.K. patent application claiming the utility of AZT for treatment of HIV-infection based upon the activity of AZT against a model murine retrovirus before submitting blinded samples of AZT to NCI for screening. The generic drug companies claimed that Burroughs WellcomeÕs patents were invalid because they failed to properly attribute NCI researchers as co-inventors. As a result of the recent ruling, Glaxo Wellcome retains sole U.S. rights for manufacture and marketing of AZT for treatment of HIV-infection and AIDS until the main patent expires in 2005.
Had the Supreme Court found the patents invalid and declared NIH a coassignee, the two generic drug companies were ready to quickly start marketing generic AZT (equivalent to Retrovir from Glaxo Wellcome) in the U.S. Last year Barr Labs. received FDA approval for its generic AZT contingent upon receiving U.S. patent rights. Much of the original impetus and support for the patent challenge from the National Institutes of Health (NIH) and treatment activists rose from economics. At the time, AZT was the only drug available for treatment of HIV-infection and cost about $10,000 or more annually, about four times its current price. The suit was originally filed by treatment and consumer activist groups, then joined and assumed by the generic drug companies. NIH did not directly join the court proceedings but lent its official support to the patent challenge, granted both companies nonexclusive licenses for any patent rights it might receive and agreed to allow the drug companiesÕ patent suit expenses to be deducted from any future licensing royalties. Despite NIH officially supporting inventorship rights for its researchers, in the final stages of the case as it reached the Supreme Court, the U.S. Justice Department filed briefs siding with Glaxo Wellcome citing earlier court decisions as being consistent with underlying patent policies. Generic AZT has been available in Canada for several years and several companies manufacture and market AZT in countries where Glaxo Wellcome lacks sufficient patent protection for its use for treatment of HIV-infection and AIDS.