Could AIDS Drug Have Made a Difference?
"The evidence in this study was unequivocal," he says. "I was
very surprised by the advisory committee's findings. I am very concerned that
they made the wrong decisions, unless there is data that I haven't
Gilead spokeswoman Sheryl Meredith said the firm was disappointed by the
advisory committee's findings. "We were very disappointed, given the basis
of our application, that they were unable to see the positive risk/benefit
ratio for this drug," Meredith tells WebMD. "We were encouraged by that
study that adefovir would be able to benefit patients with few other options.
We had nearly 10,000 patients that had enrolled in our expanded access program.
There was clearly the need for a new compound."
Accompanying the study report is an editorial by John W. Mellors, MD, chief
of infectious diseases and director of the AIDS program at the University of
Pittsburgh Medical Center. The editorial suggests, but does not directly state,
that careful analysis of the risk/benefit ratio for adefovir might have led to
different conclusions than that of the FDA panel.
"I think that [adefovir] was a marginal drug, but it might have had a
niche in those who [had tried many other treatments] with no other treatment
options," Mellors tells WebMD. "It gets down to the question of whether
you withhold salvage therapy from people with no other options."
The Mellors editorial also made the point that the FDA panel intended to
send a message to drug companies that just because a drug is urgently needed,
there must be sufficient data to justify its use.
"I think the message should be out there that we have to know the safety
and activity at the indicated dose," Mellors says. "Just because the
situation is extreme, the standard shouldn't be lowered for approval. That's
the clear message that should get out."
At the same time, Mellors does not want drug companies to become discouraged
from bringing to market new drugs for HIV salvage therapy.
"It should not in any way inhibit efforts to develop drugs in
experienced patients," he says. "It would be a very big shame if that
was what some corporations took home."
- Adefovir is no longer being developed in the U.S. as an AIDS therapy. It
was too toxic, an FDA advisory panel thought, to justify its moderate
- There is a desperate need for new AIDS drugs, especially for people whose
current treatment regimens have failed.
- Many new AIDS drugs are currently in development. The failure of adefovir
is disappointing but should not discourage other drug companies from continuing
their research, according to one expert.