39th ICAAC opens in San Francisco

The 39th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) has opened in a scorching San Francisco. This annual meeting of the American Society for Microbiology is set to be this year's biggest international infectious diseases meeting, and has attracted over 12,000 delegates from around the world.

Traditionally, ICAAC includes a substantial body of medical research concerning HIV and AIDS, and this is particularly the case in years such as this, where there is no World AIDS Conference to steal the limelight. aidsmap.com will be reporting the key developments in a series of daily news bulletins. Watch out also for a special report in the November issue of AIDS Treatment Update.

Amongst Sunday's key presentations were the following:

• 48 week data from the CNA3005 head-to-head study comparing abacavir/AZT/3TC with indinavir/AZT/3TC in treatment naive patients, which found no difference in efficacy between the two in the study population as a whole. Amongst the sub-group of patients beginning therapy with viral load over 100,000 copies, a greater proportion of indinavir recipients achieved viral load below 50 copies by intent to treat analysis (45%) than in the abacavir arm (31%). However, there was no difference between these two with respect to the time which elapsed before viral load rebounded over 400 copies. This finding is so far unexplained.
• the first data on the use of Glaxo Wellcome's NNRTI, GW420867X, in HIV-positive patients suggests the drug was well tolerated over the short, 28 day study period, and reduced viral load below 400 copies in 70-85% of recipients in combination with AZT/3TC.
• early viral load data from a phase II dose-ranging study of Triangle Pharmaceutical's new NNRTI emivirine (formerly MKC-442), in combination with d4T/ddI in treatment naive patients. Though the drug was generally well tolerated, a short, three day lead-in period did not improve tolerability of the higher 750mg bid dose of emivirine compared to 500mg bid, and the optimal dose remains undefined.
• Biochem Pharma's nucleoside analogue dOTC, similarly, is in phase I/II study. A half-life of approximately fourteen hours makes this a candidate for once daily dosing, though further study will be needed to establish the optimal dose.

Detailed summaries of each day's presentations will be available at Medscape and news highlights can be read at aidsmap.com every day.