The Eighth International AIDS Conference last week once againconfronted experts with the many complicated issues of thedisease -- scentific, social, ethical and political.
The issues are brought down to a personal level for thosewhose job it is to treat people infected with the virus. Amongthe foremost authorities on treatment is Paul Volberding, chiefof the AIDS program at San Francisco General Hospital anddirector of the Center for AIDS Research at the University ofCalifornia, San Francisco. Besides addressing the conference on"Long Term Studies of Early AZT Use," Volberding listened. Heshared his views of what he heard with BioWorld's associateeditor, Michelle Slade.
BioWorld: What did you consider to be the highlights of theAIDS conference?
Volberding: The press' take-home message seemed to be theissue of non-HIV AIDS. The scientific message was somewhatdifferent. I think the theme lay with the gradual progression --rather than dramatic breakthroughs -- and continued progressin the treatment of HIV, as evidenced by the development ofnew classes of drugs and new understandings about thepathogenesis and quantitations of the disease process.
BW: Did anything cause you to change your views of therapiesnow in development?
Volberding: There are new classes of nucleosides, such as D4T(from Bristol-Myers Squibb Co.), that will shortly be madeavailable by widespread distribution to trusted clinicians. Interms of existing therapies, much of the discussion focused onthe biological differences in isolates of HIV at different pointsin the disease course. The Dutch, in particular, talked aboutsyncytium-producing strains of HIV. The development of thatstrain seems to correlate quite closely with increased viralburden and the clinical disease progression. I think thatquantitating and characterizing the biology of HIV isolates willbecome very important in deciding when therapy should beinitiated and which specific type of therapy should be triedfirst.
BW: What was new for U.S. clinicians?
Volberding: More than coming away with a dramatic newstrategy is the sense that combination therapies do work. Datapresented on AZT and ddI were convincing in that they areeffective therapy drugs. The areas on which I focused were onnew ways of quantitating the virus burden in our patients,which might have clinical applications. That and the continuedinterest in the testing of therapeutic vaccines were areas ofparticular focus.
BW: Which vaccines do you consider particularly promising?
Volberding: I think it's premature to pick candidates right now.All of them are still in very preliminary trials, and most of thetrials use different tests to estimate the efficacy. What we haveto do quickly is begin to compare the different test methods.Until we agree upon some standard approaches, I think itwould be very dangerous to try to guess which might be moreimmunogenic or what type of immune response is preferred.The relative value of humoral vs. cellular immune responsecertainly needs more investigation before we make anyconclusion.
BW: What is the general view regarding the most efficientdrugs, new and old?
Volberding: I think there is a general agreement that theexisting drugs (AZT, ddI and ddC) work quite well. At the sametime, people recognize the need to have more-aggressivestrategies because (drug) resistance seems to develop in time.The current strategies aren't preventing drug resistance, sothere's not a lot of optimism there. There's the sense that wehave made progress and that progress is still possible, butthere's the recognition that we need better therapies.
BW: Is gene therapy still a distant hope for treatment?
Volberding: I think that it's the next therapy that we're goingto watch with a lot of interest. There's no success to point toright now, but the possibility that we might be able to turn offthis infection with gene therapy is something people find quiteintriguing. My personal bias is that its too early to reallycomment on it in terms of clinical applications, although Iwould guess perhaps next year we'll see some results fromclinical trials.
BW: In five years, how do you think you'll be treating thisdisease? What set of tools do you expect to have?
Volberding: There is little doubt that we would have muchmore effective combination therapies. What we really need aredrugs that act in different places against the virus. These seemto be coming down the line quite quickly. Proteases and tatinhibitors are obviously worth watching. We've found someevidence of activity that may be exaggerated, as we've tendedto see in the past. I would guess that in five years therapies indeveloped countries will be much more effective, but that indeveloping countries we won't have made much progress. Iwould expect to have therapeutic vaccines incorporated atsome point, as that treatment does seem promising. Genetherapy still would not be a commonly used therapeuticapproach.
(c) 1997 American Health Consultants. All rights reserved.