RESTON, Va. _ Research on AIDS vaccines has already spawnedinnovative, high-tech approaches that could have a profound impacton other viral diseases. Although progress toward an effective AIDSvaccine has been disappointingly slow, experts gathered here at the7th Annual Conference on AIDS Vaccine Development are sharingearly research on a range of new approaches from a live-attenuatedvirus to a hand-held "gene gun" that blasts DNA-coated beadsthrough the skin."All the work that has gone into developing technologies for HIV aregenerating novel approaches that will have applications in a varietyof other viral diseases like Hepatitis B and Hepatitis C, CMV[cyotomegalovirus] and human papilloma virus," Vector SecuritiesInternational analyst Greg Brown told BioWorld at the meeting onMonday. "Those markets are potentially lucrative because theclinical trial sizes could be smaller, the biology of the virus is betterunderstood, the viruses don't mutate, and they're not retroviruses,which makes them easier to deal with in a prophylactic sense."Biotechnology companies outnumbered large pharmaceuticalcompanies in scientific sessions and poster presentations at thisyear's meeting, a reflection of the fact that much of the novel workin the field is coming from small research-based organizations.Brown said it's clear that while large companies are far betterequipped with finances and resources to run clinical trials of AIDSvaccines, biotechnology companies "have the science."Although Brown called the current AIDS vaccine development fielda "huge cesspool" because so many companies have thrown so manyresources at the problem with no success, he still believes that aneffective AIDS vaccine could be a blockbuster product."I don't see it [an AIDS vaccine] as just around the corner in termsof commercial potential, but the temptation _ the thing that keepsdriving people forward here _ is that if you could get a goodprophylactic vaccine for HIV and it could be developed, the marketsare huge. Pricing is a trivial matter because the markets are justhuge," said Brown.Among the biotechnology companies presenting data on AIDSvaccine technologies at the four-day National Institute of Allergyand Infectious Diseases (NIAID) meeting are Genentech Inc., ofSouth San Francisco, Chiron Corp., of Emeryville, Calif., CytelCorp., of San Diego, Therion Biologics Corp., of Cambridge, Mass.,Agricetus Inc., of Middleton, Wisc., Cambridge Biotech Corp., ofWorcester, Mass., and Immune Response Corp., of Carlsbad, Calif.Biotech Will Provide Research For VaccinesBrown said that AIDS vaccine development alliances between tinyVical Inc., of San Diego, and Merck & Co. and Institut Merieux aretypical of the kind of corporate deals that will likely characterizeAIDS vaccine development. "The biotechnology industry will act asthe `R' in `R&D' and the large pharmaceutical companies will do the`D.' Small companies could take things as far as, say, Phase II trialsand then hand them off," said Brown.The two most advanced AIDS vaccines, two different recombinantglycoprotein 120 (gp120) products developed by Genentech andBiocine (a Chiron /Ciba-Geigy joint venture), have progressed onlyas far as Phase II clinical trials. Last summer, the NIAID opted not tofund large Phase III trials of the approach in the U.S. due to concernsabout efficacy potential, the lack of a good clinical infrastructure toconduct the trials and minimal support in the U.S. activistcommunity. Large-scale trials of a prophylactic vaccine could beprohibitively expensive for a company to undertake in the U.S.without government support.But, in a declaration of independence of sorts, the World HealthOrganization (WHO) last month said that large-scale trials of gp120vaccines might be quite appropriate for certain developing countriesfacing a more severe AIDS crisis than the U.S. (See BioWorldToday, Nov. 2, 1994, p. 1)"The WHO imprimatur is very important," said Jack Killen, directorof NIAID's Division of AIDS. "We need to imagine a differentscenario for vaccine development where it actually might beextremely rational for the first efficacy trials that are done with aproduct to be done in a country where there is very highseroincidence. Trials could get done more quickly with fewersubjects more cheaply. We might be able to get answers faster, proveor disprove the concept, and then move on to studies in a biggerpopulation."Killen said that, under the right circumstances, NIAID itself mighthelp support a trial in a developing country. "There is some backingoff from the traditional position that efficacy trials ought to be donefirst in the country of origin of the vaccine," he continued. "Peopleare beginning to recognize that that tradition might be counter-productive in this environment. You should think about where youmight get an answer more quickly." Countries with high incidencerates of HIV infection could enroll clinical trial subjects far fasterthan in the U.S., enabling them to accrue enough patients forstatistically powerful observations about efficacy.Although breakthroughs in AIDS vaccine development are occurringpredominantly in the U.S., 90 percent of new infections areoccurring in the developing world. WHO estimates that between1993 and 2000, at least 26 million people will become infected withHIV-1 _ an average of 10,000 people a day over the seven-yearperiod. Already, over 14 million people worldwide have beeninfected with AIDS, the vast majority of them (11 million) indeveloping countries. In some urban centers of sub-Saharan Africa,WHO estimates that one in three adults is infected. In Thailand,where the first gp120 vaccine efficacy trial may start in a year or so,estimates of the number of HIV-infected individuals increased 10-fold between 1990 and 1993 _from 50,000 to 500,000.Statistics like these prompted WHO to reach a slightly differentconclusion than NIAID on the need and urgency of moving forward,even with the potentially marginally effective gp120 vaccines."Prevention is not very big in this society," said Donald Francis, wholeads Genentech's gp120 project. "I mean we had to make laws forseat belts in this country. People are not yet convinced thatprevention is really a major thing that our society wants to contributeits resources to. The WHO decision shows that the developingcountries that are hit so hard by this epidemic really value vaccinesand prevention." n

-- Lisa Piercey Washington Editor

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