February 5, 2001
Given the widespread reports of resistance to many commonly used medications, some companies have focused research efforts on defining new compounds specifically targeted against these resistant strains. This talk presented very early information about new protease inhibitors that at least in test tubes show impressive activity despite resistance to current protease inhibitors.
A medication's potency is the product of several factors -- first, how well it is absorbed; second, how well it gets in to the cell after it is in the blood; and third, how well it binds once it gets there. Medications that are well absorbed, freely available to enter the cell, and bound tightly to the protease inhibitor enzyme once it arrives have the potential to be very potent. However, it is also clear that HIV develops resistance, at least in part, by changing its shape to interfere with the ability of the protease inhibitors to bind once they get there. New compounds therefore are designed to fit into the shape of these new resistant protease inhibitor enzymes. DuPont has defined two compounds, now called DPC 681 and 684, that can readily bind into the enzyme of protease inhibitors that have acquired resistance to all of the currently used protease inhibitors. They have even shown activity against strains that have six to ten protease inhibitor mutations -- which are otherwise quite difficult to control with currently available meds.
While exciting, it is important to remember that the potency of a drug relies on not only how well it can fit into an enzyme, but the ability for a patient to safely take the medication at a dose that will deliver enough drug to do the job. This is the focus of the first phase of studies now ongoing with these compounds. It is always possible that unexpected problems may derail the development of any medication. However, it is also gratifying that companies are pursuing medications specifically for people for whom resistance is their main problem. It is hopeful that several such compounds can be identified by at least a few of the companies working on this important issue. In time, we will have the information needed to know how likely it is that these medications will become available as a treatment option.
|Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.|