In the meantime, Roche is cashing in on Tamiflu. The neuraminidase inhibitor has proven effective against all strains of influenza,
provided it's taken within 48 hours of infection. In vitro laboratory tests have shown Tamiflu to work against H5N1. And although
researchers caution that lab results don't always translate to the real world, they apparently do translate into real revenue.
Tamiflu's global sales through Q3 2005 were up 362 percent over the same period last year, while the company's total earnings
are up 17 percent from a year ago.
Paul Offit, vaccine expert
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Anticipating a surge in global demand, Roche doubled its manufacturing capacity of Tamiflu in each of the last two years.
By the middle of 2006, Roche expects its production capacity to have increased eight- to ten-fold since 2003, according to
Roche medical director Dominick Iacuzio. But supply still lags behind demand. In October the company temporarily suspended
delivery of its drug in the US to prevent "Tamiflu runs" and bulk purchases from people who try to hoard the product for personal
use. A Roche spokesperson said the company has enough drugs to manage any outbreak in the United States.
Concern over a possible shortage prompted governments and competitors to make runs at Roche's patent as well. So far, Roche
has rebuffed outside companies' requests to produce Tamiflu, citing unique steps in manufacturing—a 10-part process that includes
an explosive step involving hydrogen gas and a complicated formulation step involving ethyl alcohol. But the warning didn't
deter researchers in India and Taiwan, who separately announced in October that they successfully synthesized working versions
of Tamiflu. About the same time, Roche succumbed to mounting pressure and said it would consider granting sublicenses to four
companies—Teva Pharmaceutical Industries, Barr Pharmaceuticals, Mylan Laboratories, and Ranbaxy Laboratories—for pandemic
planning purposes.
Scientists have explored ways to stretch the Tamiflu supply. According to a 2002 Roche study, combining half-doses of Tamiflu
with a generic gout medication may be as effective as a full dose. However, some experts caution that administering partial
doses will only increase the number of Tamiflu-resistant flu strains.
Another issue is whether Tamiflu could—or should—be given prophylactically for flu prevention. Tamiflu is FDA-approved for
prophylactic use, but some consider that counterproductive. "I think that's the worst thing anyone can do," says Ashir Kumar,
MD, a professor of infectious diseases at Michigan State University. "Because if you give it prophylactically, eventually
the virus is going to become resistant."
PowderMed's DNA vaccine delivery device—these so-called "gene guns"—allow users to easily shoot the vaccine into their skin
cells. Pending necessary funding for these devices, DNA vaccines could be on the market within the next "one to two years,"
according to a company spokesperson.
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A second type of antiviral on the market is zanamivir, a GlaxoSmith Kline (GSK) product marketed as Relenza. The drug was
a dud when it was first launched during the 2000-01 flu season, primarily because it was packaged as an inhaled powder. But
faced with a virus as deadly as H5N1, consumers and clinicians are expected to ignore the awkward delivery system.
President George W. Bush announced on October 31 that the government would spend approximately $1 billion to stockpile Tamiflu
and Relenza, the only two available drugs for flu treatment. The dearth of options worries Jeremy Carver, CEO and founder
of the International Consortium on Anti-Virals (ICAV). "Once there's an outbreak and Tamiflu starts being used extensively,
there'll be a selection for a resistant form," Carver says. "Relenza has been shown to be effective against that mutated Tamiflu-resistant
form, but then what do you do once you've got Relenza-resistant viruses?"
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