The maturation inhibitor bevirimat (PA-457) can be active in patients carrying HIV type-1 non-B subtypes and recombinants.

BACKGROUND

Bevirimat (PA-457) is the first candidate of a new family of antiretroviral drugs, the maturation inhibitors. Its action is based on disruption of the protease cleavage of the Gag precursor region. Six resistance mutations have been described and analysed in virus from both treatment-naive and protease inhibitor (PI)-experienced patients, but only in the subtype B of HIV type-1 (HIV-1) virus. Thus, genotypic resistance in non-B subtypes still requires analysis.

METHODS

HIV-1 sequences of different subtypes (54 B, 81 non-B and recombinants) were analysed for the presence of resistance mutations to bevirimat, located within the capsid (CA) protein and spacer peptide 1 (SP1) cleavage site.

RESULTS

No resistance mutations were found, although polymorphisms appeared in some CA-SP1 residues. The C-terminal CA protein and the N-terminal SP1 presented high conservation, whereas C-terminal SP1 was highly variable in sequence and length, with unknown influence in resistance acquisition.

CONCLUSIONS

The results of the present study confirm an absolute conservation of the residues involved in bevirimat in vitro resistance in a large panel of HIV-1 subtypes and recombinants from both treatment-naive and PI-experienced patients. Treatment alone seemed to increase the polymorphisms account in CRF02_AG recombinant sequences; however, the influence of natural polymorphisms needs to be explored.