Objective: First clinical virological evaluation of anti-HIV treatment with HIV reverse transcriptase (RT) and protease inhibitors.
Design: Descriptive.
Setting: Academic Medical Centre of the University of Amsterdam, the Netherlands.
Method: From January 1, 1996, until May 1, 1997, HIV-RNA levels were determined in sequential serum or plasma samples obtained sequentially of 384 patients over a period of 3.1 years on average (minimum 0.5, maximum 10 years). Of these patients 318 had sustained treatment for at least 6 months. The effect on HIV-RNA serum or plasma levels was evaluated in this particular group, of which 224 (70.4%) had been pretreated with antiretroviral drugs (experienced patients) and 94 (29.6%) had not (naive patients).
Results: Of the naive patients 8.5% were treated with a combination of two, 89.4% with three and 2.1% with four anti-HIV drugs. Preceding their current treatment, an average of more than two other anti-HIV regimens had been administered to the experienced patients. From 1987 until May 1997 a total of 834 treatments were registered among the 224 patients: 202 mono, 223 double, 340 triple, 60 quadruple and 9 other combination treatments. After six months 84% of the triple combination treatments in the naive patients and 61% in the experienced patients resulted in RNA levels < or = 10(3) copies/ml (p = 0.008). Of 68 patients who failed on treatment 36 (52.9%) showed resistance associated mutations in HIV reverse transcriptase. In 6/43 (14%) of these patients resistance associated mutations in protease were found as well. Genotypic resistance could not always be confirmed phenotypically.
Conclusion: Our preliminary results indicate that in a majority of cases triple combination treatment including at least one HIV protease inhibitor was successful. Nevertheless, in 16% of the therapy-naive and 39% of the therapy-experienced patients the anti-HIV effect of treatment was insufficient.