[AIDS: ethics and scientific investigation on human beings]. / Sida: éthique et investigation scientifique sur l'être humain.

The experimentation on human beings of one or several therapeutic molecules discovered in laboratory is necessary and important because it helps to find new treatments or new diagnostic methods. But, it presents serious ethical problems. In this article we are analysing the example of the HIV infection. We are succinctly describing the research methods in laboratory for therapeutic molecules, first the experimentation on animals and then on human being in clinical trials. We will then try to show, with several examples, how during these last 25 years of HIV infection, the research of new molecules has not always respected the ethical rules set out in Helsinki declaration, "Code de la santé publique" or "Guide de bonnes pratiques cliniques-ICH" etc. We are discussing here the way to avoid these irregularities.

Synthesis and anti-HIV activity of prodrugs derived from saquinavir and indinavir.

With a view to improving the pharmacological properties, safety and pharmacokinetic profiles of current protease inhibitors, the synthesis of various acyl-substituted saquinavir and indinavir prodrugs, their in vitro stability with respect to hydrolysis and their anti-HIV (LAI and HTLV IIIB) activity and cytotoxicity in CEM-SS and MT4 cells have been investigated. Hydrolysis of the ester bond and liberation of the active free drug was found to be crucial for HIV inhibition: the faster the hydrolysis, the closer the anti-HIV activity was to that of the respective parent drug. This is the case for most of the C-14-substituted indinavir and saquinavir derivatives (IC50 from 10 to 360 nM for ester half-lives of 90 min to 40 h). Concomitantly, the level of HIV inhibition is very low for the prodrugs for which hydrolysis is very slow. This is the case with the myristoyl or oleyl saquinavir esters, owing to the stable masking of the hydroxyl that is part of the peptidomimetic non-cleavable transition state isostere responsible for the inhibitory potency of saquinavir (and indinavir). In contrast, the anti-HIV activity of the monosubstituted C-8 indinavir prodrugs seems not to be correlated with their resistance to hydrolysis, as expected (the C-8 hydroxyl of indinavir is not involved in the transition state isostere). No cytotoxicity was detected for the indinavir and saquinavir prodrugs for concentrations as high as 10 or even 100 microM, thus indicating promising therapeutic potential.

Synthesis and anti-HIV activity of some novel arylphosphate and H-phosphonate derivatives of 3'-azido-2',3'-dideoxythymidine and 2',3'-didehydro-2',3'-dideoxythymidine.

Phosphate and H-phosphonate derivatives of anti-HIV nucleoside analogues (AZT and d4T) were prepared as potential prodrugs of the bio-active free nucleotide and they were evaluated for their inhibitory effects on the replication of HIV-1 in several cell culture systems. One compound exhibited an important anti-HIV-1 activity and proved to be significantly more efficient than the parent nucleoside.