NNRTI/PI Toxicity Switch to Darunavir Study
The purpose of the study is to examine the effects of switching from antiretroviral combinations that includes efavirenz (Sustiva®), lopinavir/ritonavir (Kaletra®) or atazanavir/ritonavir (Reyataz®/Norvir®) in individuals experiencing side effects from one of these agents, and replacing these with a new HIV medication called Darunavir also given with ritonavir (Norvir®).
The study will primarily investigate the effect of change in medication on the subjects viral load (the levels of the HIV virus in the blood), on immunological parameters (CD4 count) and on other safety parameters (such as cholesterol) and also quality of life.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Phase IV, Two-arm, Open-label, Single-centre Randomised Pilot Study to Assess the Feasibility of Immediate or Deferred Switching of HIV-infected Individuals Intolerant of Efavirenz, Ritonavir-boosted Lopinavir or Ritonavir-boosted Darunavir|
- The improvement of NNRTI/PI associated toxicity after 4 weeks of therapy with ritonavir boosted darunavir. [ Time Frame: 20 days ] [ Designated as safety issue: No ]
- Viral load suppression below 50 copies/ml post switch [ Time Frame: between 20 and 60 days ] [ Designated as safety issue: No ]
- Viral load < 400 copies/ml post switch [ Time Frame: between 20 and 60 days ] [ Designated as safety issue: No ]
- Toxicity [ Time Frame: 60 days ] [ Designated as safety issue: Yes ]
- Health related quality of life questionnaires [ Time Frame: Baseline, 20 and 60 days ] [ Designated as safety issue: No ]
- Changes in fasting triglycerides post switch [ Time Frame: 20 days and 60 days ] [ Designated as safety issue: No ]
- Adherence as measured via questionnaire [ Time Frame: baseline, 20 days and 60 days ] [ Designated as safety issue: No ]
- Tolerability as measured by tolerability index questionnaire (HIV patients symptoms profile [ Time Frame: baseline, 20 days and 40 days ] [ Designated as safety issue: No ]
|Study Start Date:||October 2008|
|Study Completion Date:||July 2010|
|Primary Completion Date:||July 2010 (Final data collection date for primary outcome measure)|
Active Comparator: Group 1
Immediate switch from NNRTI/PI to DRV/r
two 400mg tablets (800mg) once daily
Active Comparator: Group 2
Switch after 10 weeks from NNRTI/PI to DRV/r
one 100mg capsule once daily
Other Name: Trade Name: Norvir
The advent of highly active antiretroviral therapy (HAART) has revolutionised the treatment of HIV disease, with both patients and physicians enjoying the marked reductions in HIV related morbidity and mortality. However, as long term therapeutic success has become a realistic goal of treatment, there are increasing reports of toxicities associated with therapy.
Indeed since the advent of HAART the major reason for change in therapy has not been a lack of efficacy associated with drug regimens but the toxicity associated with individual agents. Although the potential adverse events associated with antiretrovirals are manifold there are signature treatment-limiting toxicities associated with particular agents such as EFV and CNS/neuropsychiatric adverse events, LPV/r and gastrointestinal toxicity and ATV/r and jaundice.
A recent study performed at the Chelsea and Westminster hospital showed that 61% of regimen switches were due to toxicity and the majority of these occurred after 12 weeks of therapy.
Darunavir is a recently licensed protease inhibitor which requires ritonavir boosting.Currently DRV/r is licensed for use in treatment-experienced individuals. In triple-class experienced patients ritonavir boosted darunavir has been associated with greater viral load reductions when combined with optimized background (OB) than OB alone. A study of PI experienced patients randomized to receive Kaletra or ritonavir boosted darunavir with optimised background therapy showed significantly higher rates of virological suppression in the DRV/r arm; rates of toxicities were similar overall but less diarrhoea in the DRV/r than the Kaletra arm. Darunavir is licensed twice daily and has a high barrier to the development of resistance. DRV/r dosed at 800/100mg once daily has been compared with LPV/r in treatment-naïve subjects. DRV/r was non-inferior to LPV/r overall and performed significantly better than LPV once daily and in subjects with a high baseline viral load. DRV/r and LPV/r have also been compared head to head in 'early'treatment-experienced patients (failing first or second line therapy but LPV-naive). Overall DRV/r exhibited superiority to LPV/r with 77% and 67% achieving viral suppression to less than 50 copies/ml by intent-to-treat analysis respectively (95% confidence interval for the difference 2-17%; p <0.0001). Animal studies have shown a low risk of teratogenesis associated with DRV.
This study aims to investigate whether substitution of NNRTI/PI with ritonavir boosted darunavir leads to resolution of toxicity associated with these drugs, continued virological suppression and immunological reconstitution and whether this is associated with an improvement in quality of life.