Analysis of Treatment Costs for HIV RNA Reductions and CD4 Increases for Darunavir Versus Other Antiretrovirals in Treatment-Experienced, HIV–Infected Patients

Abstract

Background: For patients with preexisting HIV drug resistance, a wide range of antiretrovirals are used, with differences in efficacy and cost. The additional cost per incremental 25 cell rise in CD4 count, or 0.5 log reduction in HIV RNA, was calculated for 8 antiretrovirals using pivotal clinical trials data. Method: For approved antiretrovirals in HIV therapy–experienced patients, 24–week efficacy (benefit over control in HIV RNA and CD4 count) was extracted from pivotal trials in published reports and compared with the additional treatment cost versus the control arm of each trial (2006 US wholesale acquisition costs). Treatment costs in the POWER trials were calculated directly from the treatment use database. Results: Data were available from 11 clinical trials in more than 4,000 antiretroviral treatment-experienced patients: Gilead 907 (TDF vs. placebo), TORO1/2 (T-20/OBR vs. OBR), RESIST–1/2 (TPV/r vs. control PI), BMS-045 (ATV/r vs. LPV/r), CONTEXT (fAPV/r vs. LPV/r), CAESAR (3TC vs. placebo), CNA3002 (ABC vs. placebo), and POWER 1/2 (DRV/r vs. control PI). Additional cost per 0.5 log reduction in HIV RNA was $152 for ritonavir–boosted darunavir (DRV/r), $4,453 for lamivudine (3TC), $4,274 for abacavir (ABC), $4,641 for tenofovir (TDF), and $13,217 for enfuvirtide (T-20). Cost per 25 cell rise in CD4 ranged from $132 for darunavir/r to $16,464 for T-20. Conclusion: There is a wide range of costs associated with efficacy improvements across the classes of antiretrovirals used for antiretroviral treatment–experienced patients. This analysis does not account for differences in toxicity, use of concomitant medications, or long-term adherence, which could also influence value assessments.

Keywords:

• darunavir
• enfuvirtide
• health economics
• nucleoside analogues
• protease inhibitor