Analysis of costs by CD4 count category for the darunavir/r 600/100 mg bid and control protease inhibitor arms of the POWER 1 and 2 trials.

Background: HIV-infected people with low CD4 counts are at higher risk of AIDS and incur increased health care costs from in-patient stays and medications.

Method: In the POWER 1 and 2 trials, patients were treated with optimized nucleoside reverse transcriptase inhibitors and optional enfuvirtide (T-20), plus darunavir/ritonavir (DRV/r) or control protease inhibitor (PI). UK data on costs of care by CD4 count were combined with the data on antiretroviral treatment use and CD4 counts from the POWER trials to calculate expected health care costs.

Results: The mean annual UK cost of care (excluding antiretrovirals [ARVs]) was 23,780 pounds, 13,762 pounds, 7,032 pounds, and 7,032 pounds for patients with CD4 <50, 50-200, 200-350, and >350 cells/muL respectively. In the POWER trials, at week 48, the proportions of patients with CD4 counts in these categories were 7%, 36%, 29%, and 27% for the DRV/r arm versus 23%, 28%, 27%, and 22% for the control PI arm. The mean predicted annual per-patient cost of care was 11,170 pounds for DRV/r versus 12,873 pounds for control PI.

Conclusion: By raising CD4 counts to levels where the risk of AIDS events is reduced, DRV/r treatment is predicted to lower patient care costs for ARV-experienced, HIV-infected individuals in the first year of treatment.