HIV Treatment Bulletin - Vol. 6, No. 7, July 2005
Simon Collins and Polly Clayden, HIV i-Base

This annual Resistance Workshop is primarily a meeting for around 230 specialist researchers to discuss drug resistance. With a few exceptions nearly all the attendees present a poster or oral session, and the research submitted each year is the basis for the programme of the meeting. This meeting is mainly aimed at basic scientists, researchers and clinicians, around one quarter of who are from industry.

Reports in HTB from previous years meetings focus on new clinical implications. At this years meeting it was difficult to find many new surprises. To some degree, this was recognised as a limitation by the organisers, who announced that the priorities for selecting abstracts for the 2006 meeting would be data-driven studies with independent validation, and fewer studies dealing just with methodology.

One of the themes at the meeting was the increasing complexity of interpreting resistance test results. Resistance is an increasingly complex science, but it is not going away. Not on a biological level, because once resistance developes in an individual it remains archived. But also neither as a discipline relating to patient management, because potency of every individual HIV drug is insufficient to stall resistance. Even the most potent combinations fail to suppress virus in perhaps a fifth of treatment naïve patients, and this proportion increases with subsequent treatments reducing options for treatment.

Many of these reports included small numbers of patients, and included tentative conclusions. With almost as much time allowed for questions as presentations, virtually no study did not include important caveats to the results, or methodological or validation questions from the audience.

Studies with most important indication for clinical care covered the following subjects and are reported below.

• Genetic factors affecting HIV infection and population differences: immunological factors relating to entry inhibitors
• • Avoiding maternal nevirapine and adding AZT to infant prophylaxis optimal
  • Short course of 3TC and AZT reduces the emergence of nevirapine resistance
  • Higher rates of resistance seen with more sensitive resistance tests
  • Resistance patterns vary by subtype in infants in HIVNET 012 and NVAZ studies
  • Mutations present in majority of women: early analysis suggests a similar rate of resistance in infants
  • Patterns of viral load and resistance in breast milk vary by HIV sub-type
• Reduced replicative capacity of M184V explains benefit of 3TC monotherapy over stopping all drugs
• Interaction between tenofovir and ddI in triple-nucleoside combinations: role of M184V in explaining resistance on failure
• Predicting clinical responses to ddI from genotypic resistance
• Under-detection of transmission of transmitted resistance and impact on treatment response
• Risk of death in UK after diagnosis of 3-class resistance

A pdf file of the abstract book from this meeting is available as part of the AEGiS conference database, and will be posted as html web pages at the same site. (Click the meeting name to download this file).

AIDS Education Global Information System
AEGiS conference database: 14th HIV Drug Resistance Workshop

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