This post is by Center Director Christine Lubinski, reporting from the 2009 IAS conference in Cape Town.
Pedro Cahn, president of Huésped Foundation, an Argentinean AIDS organization involved in HIV/AIDS clinical research, prevention and care, offered a refreshingly candid and provocative HIV treatment update as the second plenary speaker at the IAS conference today. Cahn, a past president of IAS, provided an overview of drugs in development, but he focused most prominently and pointedly on treatment in the developing world.
On the thorny issue of “when to start” HIV patients on antiretroviral therapy, Cahn stated categorically that there is widespread agreement that a CD4 level of 350 should be the minimum threshold. He highlighted the results of the CIPRA study which compared outcomes of ART below 200 versus access from 200-350. In those started below 200 CD4 cells, researchers found four times the mortality and twice as much TB disease. It is also clear that initiation of ART at higher CD4 levels lowers the frequency of drug resistance, thereby preserving the durability of treatment regimens. From his perspective, a change in the treatment threshold of the WHO guidelines is long overdue, although he acknowledged that he served on the guidelines panel.
Cahn expressed concern about the high percentage of patients lost to follow-up in many developing countries and identified the major reasons for this as advanced disease and the requirement of payment for health care services.
He then turned his attention to the problems of D4T regimens—which comprise 60 percent of the regimens prescribed in the developing world. Describing D4T as too toxic and having a lousy resistance profile, he noted it was time to say enough of D4T.
He said viral load testing should be approached with the same “urgency and commitment” that was brought to bear on the need for ART access. Studies have demonstrated that as many as 40 percent of regimen switches made based on CD4 counts and clinical monitoring are unnecessary. Viral load testing would protect regimens, reduce resistance, and lead to further reductions in MTCT, he said.
Moving forward, Cahn said priorities should include cheap diagnostics and monitoring tools, as well as simple and cheap second and third-line regimens.
ART is indeed prevention—prevention of death, disease, and HIV transmission.