French researchers have reported that 14 out of 37 treatment naive individuals who took part in the STADI trial of d4T/ddI developed resistance mutations associated with AZT after 24-48 weeks (a codon 215 mutation in 9 out of 15 cases).
These findings, reported in the journal AIDS in September (issue 13), follow a similar report at the Third International Workshop on HIV Drug Resistance and Treatment Strategies in June. That report highlighted the development or persistence of AZT-related mutations in treatment-naive individuals who received at least six months of d4T treatment as part of a triple regimen. Three out of 70 developed codon 215 mutations and one patient developed the Q151M multi-drug resistance mutation (Calvez). See Resistance to NRTIs on this site for further details of this study.