Monday, September 28, 1998
It was only a matter of time before the issue of generic biologics
arose for the biotech industry - a matter of time about as long as the patent
life of a biologic.
It is unfortunate that the issue has arisen in the context
of a dispute between two companies in the sector, Amgen Inc. and Transkaryotic Therapies Inc., rather than as part of a reasoned discussion of the scientific
and regulatory issues involved in creating generic biologics. Nevertheless,
now that the question is before the industry, it makes sense to take a look
at the technological and regulatory issues before rushing to judgement about
political and business strategies that could have long-term and unforeseen effects
on the entire sector.
Lawyers and lobbyists representing some of America's most successful
biotech and pharmaceutical companies last week debated the merits and implications
of AMGN's proposals to persuade Congress to modify the Waxman-Hatch Amendments
(see Amgen Presses Ahead, A5). Waxman-Hatch made today's generic drug
industry possible by allowing generic manufacturers to engage in R&D using
others' patented drugs without fear of litigation, and to gain marketing approval
on the basis of bioequivalence rather than full-blown clinical trials.
AMGN (Thousand Oaks, Calif.) wants to prevent TKTX (Cambridge,
Mass.) from using Waxman-Hatch to shield GA-EPO, a rival version of AMGN's Epogen
erythropoietin (EPO) from patent infringement litigation during the clinical
development period (see BioCentury, Sept. 21).
While third parties do not want to become entangled in the
dog fight, the dispute turns up the temperature on a simmering issue: generic
and second-generation biologics. Patent terms on several important biotech products
such as tPA and some of the interleukins will expire around the
turn of the century and some companies are already positioning themselves to
produce bioequivalent products. At the same time, companies like TKTX are developing
products that they claim represent a second generation that could have superior
efficacy and/or safety.
Barriers to biologic generics
The argument over biologic generics hinges on several interrelated issues, including the complexity of proteins, the fact that the actual makeup of a protein will vary depending on how it is manufactured, and other residues of the manufacturing process, all of which may affect side effects and efficacy.