Twenty-four-week efficacy and safety of switching virologically suppressed HIV-1-infected patients from nevirapine immediate release 200 mg twice daily to nevirapine extended release 400 mg once daily (TRANxITION)

Efficacy and safety of switching from nevirapine immediate-release twice daily to nevirapine extended-release once daily in virologically suppressed HIV-infected patients: a retrospective cohort study in Taiwan

Background

Whether the non-inferior efficacy and safety results of switching virologically suppressed HIV-1-infected patients from nevirapine immediate-release (NVP-IR) to NVP extended-release (NVP-XR) demonstrated in the TRANxITION study conducted in Europe and North America are also applicable to virologically suppressed HIV-infected Taiwanese patients remains unknown. We evaluated the comparative safety and efficacy of continuing NVP-IR versus switching to NVP-XR in virologically suppressed HIV-infected Taiwanese adults receiving combined antiretroviral therapy (cART) regimens.

Methods

We conducted a retrospective cohort study at Kaohsiung Veterans General Hospital from April 1, 2013, to March 31, 2015. Eighty-four virologically suppressed HIV-infected adults receiving NVP-IR cART were split into two groups: those continuing with NVP-IR (n = 49) and those being switched to NVP-XR (n = 35). Demographic characteristics, clinical variables, and laboratory findings were compared. Therapeutic drug monitoring of steady-state plasma NVP concentrations and genotype analysis of CYP2B6 516 were also performed in 22 participants. The primary endpoint was continued virological suppression at the end of the study. Secondary endpoints were time to loss of virological response and adverse events.

Results

During a mean follow-up of 18.4 months, the NVP-XR group demonstrated similar success at maintaining virological response compared with the NVP-IR group (82.9% vs. 85.7%; P = 0.72). Cox regression analysis indicated that there were no significant differences between NVP regimens for time to loss of virological response (hazard ratio: 0.940; P = 0.754). Furthermore, there were no significant differences in adverse events between these two groups. In the 22 participants, there was a non-significantly lower level of steady-state plasma NVP concentrations in the NVP-XR group than in NVP-IR recipients (5145.0 ng/mL vs. 6775.0 ng/mL; P = 0.267). The prevalence of CYP2B6 516 GT was 86.6%, and there was no significant difference in the distribution of CYP2B6 516 between these two groups.

Conclusions

We found that switching from NVP-IR to NVP-XR appeared to have similar safety and efficacy compared with continuing NVP-IR among virologically suppressed, HIV-infected Taiwanese patients. Our finding of higher C_trough levels in both groups compared with other studies conducted in Caucasian populations and the high prevalence of CYP2B6 516 GT requires further investigation in a larger Taiwanese cohort.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2371-3) contains supplementary material, which is available to authorized users.

A Randomized Switch From Nevirapine-Based Antiretroviral Therapy to Single Tablet Rilpivirine/Emtricitabine/Tenofovir Disoproxil Fumarate in Virologically Suppressed Human Immunodeficiency Virus-1-Infected Rwandans

There is a need to improve antiretroviral options in Africa. This study shows switching from a neviripine-based treatment to co-formulated rilpivirine/emtricitabine/tenofovir disoproxil fumarate in virologically suppressed Rwandans is safe and non-inferior to continued nevirapine-based therapy at 24 weeks.

Background. Many human immunodeficiency virus (HIV)-infected patients remain on nevirapine-based antiretroviral therapy (ART) despite safety and efficacy concerns. Switching to a rilpivirine-based regimen is an alternative, but there is little experience with rilpivirine in sub-Saharan Africa where induction of rilpivirine metabolism by nevirapine, HIV subtype, and dietary differences could potentially impact efficacy.

Methods. We conducted an open-label noninferiority study of virologically suppressed (HIV-1 ribonucleic acid [RNA] < 50 copies/mL) HIV-1-infected Rwandan adults taking nevirapine plus 2 nucleos(t)ide reverse-transcriptase inhibitors. One hundred fifty participants were randomized 2:1 to switch to coformulated rilpivirine-emtricitabine-tenofovir disoproxil fumarate (referenced as the Switch Arm) or continue current therapy. The primary efficacy endpoint was HIV-1 RNA < 200 copies/mL at week 24 assessed by the US Food and Drug Administration Snapshot algorithm with a noninferiority margin of 12%.

Results. Between April and September 2014, 184 patients were screened, and 150 patients were enrolled; 99 patients switched to rilpivirine-emtricitabine-tenofovir, and 51 patients continued their nevirapine-based ART. The mean age was 42 years and 43% of participants were women. At week 24, virologic suppression (HIV-1 RNA level <200 copies/mL) was maintained in 93% and 92% in the Switch Arm versus the continuation arm, respectively. The Switch Arm was noninferior to continued nevirapine-based ART (efficacy difference 0.8%; 95% confidence interval, −7.5% to +12.0%). Both regimens were generally safe and well tolerated, although 2 deaths, neither attributed to study medications, occurred in participants in the Switch Arm.

Conclusions. A switch from nevirapine-based ART to rilpivirine-emtricitabine-tenofovir disoproxil fumarate had similar virologic efficacy to continued nevirapine-based ART after 24 weeks with few adverse events.

Presence of Tablet Remnants of Nevirapine Extended-Release in Stools and Its Impact on Virological Outcome in HIV-1-Infected Patients: A Prospective Cohort Study

Background

Nevirapine extended-release (NVP-XR) taken once daily remains an effective antiretroviral agent for patients infected with HIV-1 strains that do not harbor resistance mutations. Presence of tablet remnants of NVP XR in stools was reported in 1.19% and 3.05% of subjects in two clinical trials. However, the prevalence may have been underestimated because the information was retrospectively collected in the studies.

Methods

Between April and December 2014, we prospectively inquired about the frequency of noticing tablet remnants of NVP XR in stools in HIV-1-infected patients who switched to antiretroviral regimens containing NVP XR plus 2 nucleos(t)ide reverse-transcriptase inhibitors. Patients were invited to participate in therapeutic drug monitoring of plasma concentrations of NVP 12 or 24 hours after taking the previous dose (C12 and C24, respectively) of NVP XR using high-performance liquid chromatography. The information on clinical characteristics, including plasma HIV RNA load and CD4 lymphocyte count, at baseline and during follow-up was recorded.

Results

During the 9-month study period, 272 patients switched to NVP XR-based regimens and 60 (22.1%) noticed tablet remnants of NVP XR in stools, in whom 54.2% reported noticing the tablet remnants at least once weekly. Compared with patients who did not notice tablet remnants, those who noticed tablet remnants had a higher mean CD4 lymphocyte count (629 vs 495 cells/mm³, P = 0.0002) and a similar mean plasma HIV RNA load (1.57 vs 1.61 log₁₀ copies/mL, P = 0.76) on switch. At about 12 and 24 weeks after switch, patients who noticed tablet remnants continued to have a similar mean plasma HIV RNA load (1.39 vs 1.43 log₁₀ copies/mL, P = 0.43; and 1.30 vs 1.37 log₁₀ copies/mL, P = 0.26, respectively), but had a lower median NVP C12 (3640 vs 4730 ng/mL, P = 0.06), and a similar median NVP C24 (3220 vs 3330 ng/ml, P = 0.95) when compared with those who did not notice tablet remnants.

Conclusions

The presence of tablet remnants of NVP XR in stools is not uncommon in HIV-1-infected Taiwanese patients receiving NVP XR-based antiretroviral regimens, which does not have an adverse impact on the virological and immunological outcomes.

Lower pill burden and once-daily antiretroviral treatment regimens for HIV infection: A meta-analysis of randomized controlled trials

Once-daily compared with twice-daily antiretroviral therapy regimens increased adherence; however, the difference was modest and not associated with a difference in virological suppression. In addition, higher pill burden was associated with lower rates of virological suppression, whether once- or twice-daily regimens.

Background. Contemporary antiretroviral treatment regimens are simpler than in the past, with lower pill burden and once-daily dosing frequency common. We performed a meta-analysis of randomized controlled trials (RCTs) to investigate the impact of pill burden and once-daily vs twice-daily dosing on ART adherence and virological outcomes.

Methods. A literature search of 4 electronic databases through 31 March 2013 was used. RCTs comparing once-daily vs twice-daily ART regimens that also reported on adherence and virological suppression were included. Study design, study population characteristics, intervention, outcome measures, and study quality were extracted. Study quality was rated using the Cochrane risk-of-bias tool.

Results. Nineteen studies met our inclusion criteria (N = 6312 adult patients). Higher pill burden was associated with both lower adherence rates (P = .004) and worse virological suppression (P < .0001) in both once-daily and twice-daily subgroups, although the association with adherence in the once-daily subgroup was not statistically significant. The average adherence was modestly higher in once-daily regimens than twice-daily regimens (weighted mean difference = 2.55%; 95% confidence interval [CI], 1.23 to 3.87; P = .0002). Patients on once-daily regimens did not achieve virological suppression more frequently than patients on twice-daily regimens (relative risk [RR] = 1.01; 95% CI, 0.99 to 1.03; P = .50). Both adherence and viral load suppression decreased over time, but adherence decreased less with once-daily dosing than with twice-daily dosing.

Conclusions. Lower pill burden was associated with both better adherence and virological suppression. Adherence, but not virological suppression, was slightly better with once- vs twice-daily regimens.