Robert Gallo, the controversial co-discoverer of HIV,
yesterday made a sweeping prediction about the future
of protease inhibitors during a lecture at the
International AIDS Conference in Barcelona.
“In two or three years, the PIs will go away, replaced
by viral entry inhibitors and more intelligent use of
reverse transcriptase inhibitors,” the Institute of
Human Virology Director, and Professor of Medicine,
Microbiology and Immunology at the University of
Maryland told a packed Tuesday lunchtime audience.
“I worry about the toxicity of the PI’s,” he told
aidsmap later in the day. “I predict that the protease
inhibitors will go down (in popularity) and maybe go
away. Important as they are, they´re toxic and we are
beginning to see resistance."
“The entry inhibitors that are being tried now – five,
six, seven of them – will cause the next wave of
excitement by the next conference” in Bangkok,
Thailand in 2004.
As for the more “intelligent use” of RTIs, Gallo was
unwilling to name or endorse any particular drug
combination – with the exception of lamivudine - but
said that the key to future success was finding non
cell-cycle dependent RTIs. “Most of the RTIs that are
currently used are cell-cycle dependent, requiring the
cell to be in an active, proliferated state. I believe
that combining three or four non-cell-cycle dependent
RTIs can be an important new approach.”
Gallo´s research team is currently focusing on therapeutic
vaccine research, combining gp120 (HIV's envelope protein) with CD4, which he
considers to offer the most promise for future HIV
treatment.
“I think we can develop therapeutic vaccines and I
hope that we can bring them to the undeveloped nations
of the world,” he said, admitting that these were
still a long way off. “But I can assure you, that for
rich countries, there are new drugs coming, and
they´re coming fast.”
He was critical, howeve, of Vaxgen´s preventative
vaccine, AIDSVAX®, which is now enrolling 16,000
people for an expanded Phase III trial about to
commence in Thailand.
“I am not impressed by vaccines that only use the
envelope of a lab-adapted virus because they
neutralize only a few strains of the most
closely-associated clades,” he said. “I don´t think
that approach is going to work very well, and I don´t
think that any serious scientist thinks it´s going to
work well.”