AIDS Vaccine Panel Discussion [Minutes]

7-APR-97 PACHA AIDS VACCINE PANEL DISCUSSION - p. 8

vaccine, once we have an idea, ready to go into humans. So it's a lengthy process.
Once we have a candidate vaccine that's available and approved for use in
humans, the initial exploration of this concept in humans can, again, take anywhere
from 1 to 3 years. At that point, we make decisions about whether the vaccine is doing
what we want it to do, it has performance characteristics that we were hoping to get
out of the vaccine, then it transitions into the product development pipeline. It's at that
point that I believe we have to have prospectively defined development plans with very
hard time lines and milestones, and we move these products forward in an incremental
way, and if time lines and milestones are met, product continues to advance.
Once it gets there, again, it would take either non-performance of the product
in one of the trials telling us that this vaccine in fact is not meeting its milestones or
new basic science which tells us the strategy is unwise in order to stop that
development plan.
The next slide just shows a product development pipeline that I believe is
seriously obstructed at the distal end. It could use some Drano therapy. I think that,
again, there are candidates out there that have a broad range of performance
characteristics that merit pursuing under the best possible circumstances available to us.
This next slide gives us some reasons for why it has been difficult to develop
some of these candidate vaccines. HIV, like malaria and other diseases, is a hard
disease. It's one for which we do not know clearly protective immunity, there are no
good animal models or, at least, there are no validated animal models which correlate
with protected humans, pathogen/host interactions are imperfectly understood. But
also like malaria, this is a catastrophic-level pandemic with far-reaching health and
social impacts.
If we look at malaria, I think we can draw some lessons from the development
of vaccines. So on the next page, you see the historical approach to malaria vaccine
development. You can read through this yourself This form of thoughtful empiricism
has resulted, I believe, in putting us on the cusp of having a potentially highly
efficacious vaccine in the form of the RTSS circumsporozoae vaccine.
If we look at the lessons learned from malaria, we see that efficacy evaluations
of candidates and defined failures did not stagnate basic and developmental research,
efficacy evaluation of selected vaccines and defined failures did not stagnate
development of second- and third-generation approaches, and efficacy evaluation of
selected candidates and defined failures did not stop clinical testing.
The last few frames, which I will just fly through, is how I'd like to briefly
describe our contribution to try to help be a part of the solution of developing vaccines.