Costs to Achieve Undetectable HIV RNA with Darunavir-Containing Highly Active Antiretroviral Therapy in Highly Pretreated Patients
Background: Very few studies have evaluated the cost of highly active antiretroviral therapy (HAART) per successful treatment in HIV-infected patients. Objectives: To evaluate the cost of achieving undetectable plasma HIV-RNA levels in highly treatment-experienced, HIV-1-infected adults receiving darunavir/ritonavir (DRV/r 600 mg/100mg twice a day) or control protease inhibitor (PI)-based HAART. Methods: The mean annual per-patient cost of DRV/r and control PI-based HAART was determined from the proportional use of antiretroviral agents in the DRV/r and control PI arms of the pooled POWER 1 and 2 trials, applying drug acquisition costs for 13 healthcare settings. The mean annual cost per patient of achieving undetectable plasma HIV-RNA levels (<50 copies/mL) was calculated by dividing the cost of each treatment by the proportion of patients with undetectable plasma HIV-RNA levels after 48 weeks in the DRV/r (45%) and control PI (10%) arms of the POWER trials. Results: Whereas absolute costs of treatment were 1–19% higher with DRV/r versus control PI-based HAART depending on the healthcare setting, the mean annual per-patient cost of achieving undetectable plasma HIV-RNA levels was 73–78%lower. These cost savings were maintained in the sensitivity analyses, adjusting for control PI and enfuvirtide use, and the number of active drugs in the background regimen. The incremental annual cost per additional patient achieving undetectable plasma HIV-RNA levels with DRV/r versus control PI-based HAART in POWER 1 and 2 (d4148) compared favourably with that determined for enfuvirtide (d137 740; TORO trials) and tipranavir/ritonavir (d32 176; RESIST) versus control therapy. Conclusions: DRV/r-based HAART provided consistent reductions in the cost of achieving undetectable plasma HIV-RNA levels compared with control PI-based therapy in highly treatment-experienced patients across various healthcare settings. The incremental cost per additional patient achieving undetectable plasma HIV-RNA levels with DRV/r versus control PI-based HAART was also lower than that calculated for other treatment options in this population. These results suggest that DRV/r is an economically viable option for highly treatment-experienced patients.