Experience with darunavir in HIV-infected adults enrolled in a US expanded access program: results from a single...

A multicenter, international, expanded access program (EAP) was initiated in October 2005 for patients failing multiple antiretroviral regimens. The primary objective was to provide early access to darunavir (DRV) (PREZISTA) co-administered with low-dose ritonavir (DRV/r) for antiretroviral-experienced patients who failed multiple regimens and had limited treatment options; the secondary objective was to gather additional DRV/r safety information.

Following initiation of DRV/r 600/100 mg bid, patients were evaluated at baseline, Weeks 4 and 12, and every 12 weeks thereafter for changes in CD4 cell counts and HIV-1 RNA levels. Safety and tolerability were also evaluated.

Results from patients treated at a single US EAP center in Houston, Texas (N = 38; mean age 47 years; 92% male; 60% Caucasian, 24% Black, 16% Hispanic) are presented. At time of analysis, 38 and 23 patients completed 12 and 24 (+/- 1) weeks of therapy, respectively. At Weeks 12 and 24, the mean change in viral load (VL) from baseline was -1.96 log(10) copies/mL (n = 38) and -2.17 log(10) copies/mL (n = 22), and 54% and 50% of patients achieved HIV-1 RNA < 50 copies/mL, respectively. Mean CD4 cell count increased by 109 cells/mm(3) from baseline to Week 24. DRV/r was generally safe and well tolerated. Most adverse events (AEs) were mild to moderate in severity (nine events considered possibly related to DRV); neither of the two serious AEs was considered related to DRV/r.

Although this study reflects results from only a small cohort of patients at a single center, among this community-based population of highly treatment-experienced patients, DRV/r 600/100 mg bid provided clinically meaningful decreases in VL, an undetectable rate similar to that seen in the POWER studies, and was well tolerated with infrequent AEs.