HIV-1 drug resistance genotyping - A review of clinical and economic issues

The development of mutations associated with resistance to antiretroviral t herapy (ART) has been shown to be a major cause of treatment failure in pat ients infected with HIV-1. These resistance mutations can he assessed by a genotyping test that probes for specific mutations within the HIV genome or sequences specific genes, at a cost $US500/test (2000 prices). The stated goal of HIV-1 genotyping is to target HIV therapy effectively. This, as sho wn in the preliminary research, should result in better clinical outcomes a nd a lower incidence of virological failure and may be associated with lowe r costs of treatment. Failure of ART may result in an increase in costs of at least $US250 per patient per month, as assessed in 1 study, with costs r ising further as patients experience multiple virological failures. Therefo re, there is an economic as well as a therapeutic premium on the prevention of ART failure. The actual economic cost of genotyping has been preliminarily explored in t he context of the antiretroVIRal ADAPTation (VIRADAPT) trial, which found n o significant difference in the 1-year treatment cost of patients with and without genotyping. There is some evidence of cost neutrality or savings wi th genotypic testing but it needs to be further explored within the context of carefully framed prospective trials.