Week 96 efficacy and safety of darunavir/ritonavir monotherapy vs. darunavir/ritonavir with two nucleoside reverse transcriptase inhibitors in the PROTEA trial

OBJECTIVES

PROTEA is a randomized controlled trial to assess the efficacy and safety of darunavir/ritonavir (DRV/r) monotherapy as an alternative to triple therapy.

METHODS

Patients fully suppressed on first-line antiretrovirals (viral load < 50 HIV-1 RNA copies/mL) were switched to DRV/r 800/100 mg once daily, either as monotherapy (n = 137) or with two nucleoside reverse transcriptase inhibitors (NRTIs) (n = 136). Treatment failure was HIV-1 RNA level ≥ 50 copies/mL at week 96 or discontinuation of study treatment [Food and Drug Administration (FDA) snapshot algorithm].

RESULTS

Patients were mainly male and white, with mean age 44 years. In the primary efficacy analysis, the percentage of patients with HIV-1 RNA < 50 copies/mL by week 96 [intent to treat (ITT)] was lower in the DRV/r monotherapy arm (103 of 137 patients; 75%) than in the triple therapy arm (116 of 136 patients; 85%) [difference -10.1%; 95% confidence interval (CI) -19.5, -0.7%]. In the switch-included analysis, monotherapy was noninferior to triple therapy. In a post hoc analysis, for patients with nadir CD4 count ≥ 200 cells/μL, rates of HIV-1 RNA suppression were 82 of 96 patients (85%) in the DRV/r monotherapy arm and 88 of 106 patients (83%) in the triple therapy arm. No treatment-emergent primary protease inhibitor mutations were detected in either arm. The frequency of adverse events was similar in the two arms; however, one patient in the monotherapy arm was hospitalized with HIV encephalitis and elevated cerebrospinal fluid HIV-1 RNA.

CONCLUSIONS

In this study, in patients with HIV-1 RNA < 50 copies/mL at baseline, switching to DRV/r monotherapy showed lower efficacy vs. triple therapy at week 96 in the primary ITT switch-equals-failure analysis, particularly in patients with CD4 counts < 200 cells/μL.

Protease inhibitor monotherapy is effective in controlling human immunodeficiency virus 1 shedding in the male genital tract

Cross-sectional study comparing seminal human immunodeficiency virus type 1 (HIV-1) shedding in patients receiving boosted protease inhibitor monotherapy (mtPI/rtv) (n = 66) versus triple therapy (TT) (n = 61). Seminal HIV-1 shedding rates in patients with undetectable plasma HIV-RNA were 16.0% on mtPI/rtv compared with 28.6% on TT (p 0.173). Aviraemic status and time on viral suppression were independently associated with lack of seminal HIV-1 shedding. During TT, non PI/rtv-based regimens were associated with a better control of HIV infection in semen despite similar time on viral suppression. The use of mtPI/rtv in well-controlled patients is not associated with increased seminal HIV excretion compared with TT.

Lopinavir/Ritonavir Monotherapy as Second-line Antiretroviral Treatment in Resource-Limited Settings: Week 104 Analysis of AIDS Clinical Trials Group (ACTG) A5230

BACKGROUND

The AIDS Clinical Trials Group (ACTG) A5230 study evaluated lopinavir/ritonavir (LPV/r) monotherapy following virologic failure (VF) on first-line human immunodeficiency virus (HIV) regimens in Africa and Asia.

METHODS

Eligible subjects had received first-line regimens for at least 6 months and had plasma HIV-1 RNA levels 1000-200 000 copies/mL. All subjects received LPV/r 400/100 mg twice daily. VF was defined as failure to suppress to <400 copies/mL by week 24, or confirmed rebound to >400 copies/mL at or after week 16 following confirmed suppression. Subjects with VF added emtricitabine 200 mg/tenofovir 300 mg (FTC/TDF) once daily. The probability of continued HIV-1 RNA <400 copies/mL on LPV/r monotherapy through week 104 was estimated with a 95% confidence interval (CI); predictors of treatment success were evaluated with Cox proportional hazards models.

RESULTS

One hundred twenty-three subjects were enrolled. Four subjects died and 2 discontinued prematurely; 117 of 123 (95%) completed 104 weeks. Through week 104, 49 subjects met the primary endpoint; 47 had VF, and 2 intensified treatment without VF. Of the 47 subjects with VF, 41 (33%) intensified treatment, and 39 of 41 subsequently achieved levels <400 copies/mL. The probability of continued suppression <400 copies/mL over 104 weeks on LPV/r monotherapy was 60% (95% CI, 50%-68%); 80%-85% maintained levels <400 copies/mL with FTC/TDF intensification as needed. Ultrasensitive assays on specimens with HIV-1 RNA level <400 copies/mL at weeks 24, 48, and 104 revealed that 61%, 62%, and 65% were suppressed to <40 copies/mL, respectively.

CONCLUSIONS

LPV/r monotherapy after first-line VF with FTC/TDF intensification when needed provides durable suppression of HIV-1 RNA over 104 weeks.

CLINICAL TRIALS REGISTRATION

NCT00357552.

A prospective cohort study of neurocognitive function in aviremic HIV-infected patients treated with 1 or 3 antiretrovirals

BACKGROUND

The evolution of neurocognitive performance in aviremic human immunodeficiency virus (HIV)-positive patients treated with <3 antiretrovirals is unknown.

METHODS

We prospectively included aviremic (≥1 year) HIV-positive patients, without concomitant major neurocognitive confounders, currently receiving boosted lopinavir or darunavir as monotherapy (n = 67) or triple antiretroviral therapy (ART) (n = 67) for ≥1 year. We evaluated neurocognitive function (7 domains) at baseline and after 1 year. We performed analysis of covariance to evaluate if 1 additional year of exposure to monotherapy compared with triple ART had an effect on Global Deficit Score (GDS) changes after adjustment for potential confounders. We also compared the evolution of neurocognitive performance and impairment rates.

RESULTS

Intention-to-treat analysis showed that monotherapy did not influence 1-year GDS change after adjustment for significant confounders (age, ethnicity, duration of therapy, hepatitis C virus status, and HOMA-IR index); the adjusted effect was -0.04 (95% confidence interval, -.14 to .05; P = .38). Neurocognitive stability was observed with monotherapy and triple therapy (GDS crude mean change, -0.09 [95% confidence interval, -.16 to -.01] vs -0.08 [-.14 to -.02]), after 1 year of follow-up, similar proportions of patients changed neurocognitive status from impaired to unimpaired (monotherapy, 4 of 18 [22.2%]; triple therapy, 4 of 19 [21.1%]; P = .91) and vice versa (monotherapy, 5 of 44 [10.2%] and triple therapy, 3 of 45 [6.3%]; P = .48). Similar results were observed in an on-treatment analysis and with use of clinical ratings instead of GDS changes.

CONCLUSIONS

The number of antiretrovirals included in the ART regimen does not seem to influence the evolution of neurocognitive function in HIV-infected patients with suppressed plasma viremia.

Antiretroviral treatment switch strategies for lowering the costs of antiretroviral therapy in subjects with suppressed HIV-1 viremia in Spain

BACKGROUND

The current economic recession in European countries has forced governments to design emergency measures to reduce spending on drugs, including antiretroviral therapy (ART). Switching antiretroviral drugs for others that have the same efficacy and safety profile at a lower cost (cost-reduction measures, CRM) could prove to be a valid means of generating savings.

METHODS

Descriptive study of prospective consensus-based CRM undertaken in 2011 in a Catalonian hospital HIV unit among patients with prolonged plasma HIV-1 RNA <50 copies/mL.

RESULTS

During the study period, we made 673 switches (87.5% more than the previous year), of which 378 (56.2%) were CRM (16% of all patients treated), leading to a savings of €87,410/month. Switching tenofovir/emtricitabine for abacavir/lamivudine was the most common CRM (129, 31.3%), followed by simplification to boosted protease inhibitor monotherapy (bPImono, 102, 26%). The CRM that generated the greatest saving were switching to bPImono (38%), withdrawal or replacement of raltegravir (24%), switching tenofovir/emtricitabine for abacavir/lamivudine (13%), and switching to nevirapine (5%). Cost savings with CRM were slightly higher than those achieved with medication paid for by clinical trial sponsors (€80,333/month) or through discount arrangements (€76,389/month).

CONCLUSION

Proactively switching antiretroviral therapy in selected treated patients with sustained virological suppression can generate significant cost savings in pharmacy spending in developed countries. These findings have implications for decision makers in designing safe strategies that maintain HIV-1 suppression at lower costs.