11th European Aids Conference, Madrid, Spain, 24-27 October 2007 (CONFERENCE REPORT‪)‬

New information on antiretroviral therapy demonstrates that treatment is increasingly effective and shows an improving safety profile. The increase in the number of therapeutic tools also mirrors the improvement in the ways of managing anti-HIV therapies. The sector evolves very rapidly, thus the information reported here can easily be superseded at the next meeting. Interesting data from several clinical trials on antiretroviral therapy and resistance to it were reported at this conference. With respect to antiretroviral therapy, remarkable updates on several trials were presented: the MONARK trial, the Gemini study, and the OK04 study. The MONARK trial compared ritonavir-boosted lopinavir (LPV/r) twice-daily monotherapy with LPV/r twice daily+ zidovudine/lamivudine (ZDV/3TC) in naive patients [1]. On-treatment analysis indicated that 80% of patients in the monotherapy arm met the virological response criteria (HIV-RNA 50 copies/ml at week 48 and 400 copies/ml at week 24) compared to a 98% response in the three-drug arm (P = 0.02). The factors predicting virological success in patients receiving monotherapy were analysed and it was found that the viral load decline differed between responders (-1.07 [log.sub.10]) and non-responders (+0.54 [log.sub.10]) at week 1 but not at weeks 2 and 4. In the multivariate analysis, the two factors related to the virological response were: viral load 400 copies/ml at week 4 (OR 7.59, P=0.01) and infection with B versus non-B subtype (OR 6.36, P=0.01). The virological response was reached in 87% of patients with B subtype but in only 65% of patients with non-B subtype. With regard to HIV-RNA suppression 50 copies/ml between week 20 and 48, responses were higher among patients infected with B subtypes, whereas those infected with non-B subtypes frequently reported incomplete adherence. Is this a true biological effect of non-B versus B subtype or is this effect more connected to compliance or demographic factors? Any difference in the frequency of monitoring visits has yet to be analysed.