Aptivus resistant HIV still responds to darunavir

German drugmaker Boehringer Ingelheim says that development of V82L or T protease mutations following treatment with its HIV protease inhibitor Aptivus (tipranavir), has a limited impact on viral susceptability to subsequent darunavir therapy. The conclusion, which is based on analysis of viral isolates harvested during the RESIST trial program, was presented at the Conference on Retroviruses and Opportunistic Infections, held in Los Angeles, USA.

In the analysis 20 viral samples, all of which contained the V82L/T mutation, were examined for their susceptability to both Aptivus and darunavir. The company added that it compared baseline viral load levels with those seen following virologic failure as a result of the mutation. The data showed that, while viral susceptability to Aptivus decreased 55-fold from the initiation of therapy, susceptability to darunavir-based treatment did not change.

BI explained that no correlation between the resistance profiles of the two drugs had been observed in its analysis, and added that the results indicate that HIV-infected individuals who have developed resistance to Aptivus may still be suitable for darunavir therapy.