Effectiveness and Risk Factors for Virological Outcome of Raltegravir-Based Therapy for Treatment-Experienced HIV-Infected Patients

Determinants of viral load suppression failure among HIV adults on ARV attending health care facilities: a retrospective study in Tanga region, Tanzania

BACKGROUND

Availability and accessibility of Antiretroviral drugs (ARV's) improve the lives of People living with HIV (PLHIV) by improving client's immune system to overcome infections and prevent the development of AIDS and other HIV complications. Combination therapy, early initiation of ART, newer ART drugs, single dosage and drug affordability significantly contribute in the reduction of viral multiplication and suppression of HIV to undetectable plasma levels.

METHODS

A retrospective longitudinal study design study was conducted from 1st October, 2018 to 30th June 2022 in all supported HIV care and treatment health facilities in Tanga region which were supported by Amref Health Africa, Tanzania. The participants were HIV adult patients aged 15 years and above on ART and attended the clinic at least once after ART initiation. Viral load suppression levels are defined with viral load <1,000 HIV RNA copies/ml (viral load suppression). Cox proportional hazard regression models were employed to identify risk factors for virological failure. P values were two-sided, and we considered a P<0.05 to be statistically significant.

RESULTS

Fifty-nine thousand five hundred three adult clients >15 years whom were on ART were included in the analysis to determine the level of plasma Viral Load suppression after being on ART. Female 41,304 (69.4%) and male 18,199 (30.6%). Only four percent (2,290) were found to be unsuppressed i.e having plasma Viral Load >1,000cp/ml while 96% (57,213) were virally suppressed. Several factors were independently associated with virologic failure that included; age between 15 - <25 years (HR: 2.82, 95% CI 1.96 - 4.04), BMI <18.5 (HR: 1.69, 95% CI 1.23 - 2.30), advanced WHO stage IV (HR: 1.60, 95% CI 1.12 - 2.24), CD4 cell count <350 (HR: 2.61, 95% CI 2.12 - 3.23), poor adherence (HR: 1.98, 95% CI 1.80 - 2.18) and not using DTG based drug (HR: 11.8, 95% CI 9.74 - 14.3).

CONCLUSION

Virologic failure was observed in this study among clients with young age, advanced WHO stage IV, not using DTG based regimen, poor drug adherence and second line regime. To improve Viral Load Suppression among these clients; the existing HIV intervention strategies should be taken care by targeting the identified risk factors.

Long-term outcomes of highly experienced people with HIV undergoing salvage therapy with raltegravir

Raltegravir and other third-line drugs have shown promise in improving outcomes in treatment-experienced patients. However, the efficacy and tolerability of these agents vary. This study assessed real-life virologic success, long-term survival, and adverse events in patients receiving raltegravir or other third-line drugs as salvage regimens. This retrospective cohort study included adults who experienced treatment failure (human immunodeficiency syndrome-1 RNA plasma viral load >1000 copies/mL) and subsequently initiated raltegravir or other third-line drugs (darunavir/ritonavir, maraviroc, or etravirine). Propensity score matching methods were employed to account for differences at the time of switching from failing antiretroviral therapy regimens. The matched subset was analyzed using the Kaplan-Meier method and Generalized Wilcoxon tests to evaluate the probability of achieving virologic suppression (plasma viral load <50 copies/mL). Mortality rates, toxicity, treatment interruption, virologic failure, and loss to follow-up were determined using Poisson regression. One hundred and sixty-eight patients initiating salvage regimens were included, with 123 receiving raltegravir and 45 other third-line drugs. Propensity score matching resulted in a subset of 90 patients, 45 in each group. During the follow-up period, there were no significant differences observed between the groups in terms of virologic suppression (77.8% vs 82.2%, P = .73), mortality rates (4.04 vs 6.18 persons per 100 person-years [p-y]; P = .67), drug toxicity (0.00 vs 2.06 persons per 100 p-y; P = .49), treatment interruption (8.07 vs 0.00 persons per 100 p-y; P = .06), virologic failure (2.02 vs 4.12 persons per 100 p-y; P = .61), and loss of follow-up (6.05 vs 4.12 persons per 100 p-y; P = .70). Our findings indicate comparable survival and virological success rates between raltegravir and other drugs used in salvage regimens. Similar rates of drug toxicity, treatment interruption, virologic failure, and loss of follow-up were also observed. These results suggest that raltegravir may be a viable option for salvage therapy, demonstrating outcomes comparable to other third-line drugs in real life.

Predictors of virological failure and time to viral suppression of first line integrase inhibitor based antiretroviral treatment

Background

Integrase strand transfer inhibitors (InSTIs) are recommended for first-line treatment of persons with human immunodeficiency virus (HIV). We identified risk factors, including baseline minor InSTI resistance mutations, for treatment failure of InSTI-based regimens.

Methods

We studied time-to-treatment failure and time to viral suppression among 1419 drug-naive patients in the Swiss HIV Cohort Study. We performed Cox regression models adjusted for demographic factors, baseline HIV RNA/CD4 cell counts, AIDS-defining events, and the type of InSTI. In 646 patients with a baseline genotypic resistance test of the integrase, we studied the impact of minor integrase resistance mutations.

Results

We observed 121 virological failures during 18 447 person-years of follow-up. A baseline viral load ≥100 000 copies/mL (multivariable hazard ratio [mHR], 2.2; 95% confidence interval [CI], 1.3–3.6) and an AIDS-defining event (mHR, 1.8; 95% CI. 1.1–3.0) were associated with treatment failure. CD4 counts between 200 and 500 cells/µL (mHR, 0.5; 95% CI, .3–.8) and >500 cells/µL (mHR, 0.4; 95% CI, .2–.7) were protective. Time to suppression was shorter in lower viral load strata (mHR, 0.7; 95% CI, .6–.8) and in dolutegravir-based therapy (mHR, 1.2; 95% CI, 1.0–1.4). Minor resistance mutations were found at baseline in 104 of 646 (16%) patients with no effect on treatment outcome.

Conclusions

Factors associated with treatment failure on InSTI-based first-line regimen remained similar to those of older treatments, in particular high viral load and low CD4 counts.

Effectiveness of integrase strand transfer inhibitors among treatment-experienced patients in a clinical setting

OBJECTIVE

Characterize virologic and immunologic outcomes of INSTI-based antiretroviral therapy (ART) in experienced patients with and without virologic failure.

DESIGN

Prospective clinical cohort.

METHODS

ART-experienced, INSTI-naive participants in the University of North Carolina Center for AIDS Research HIV Clinical Cohort (UCHCC) initiating an INSTI-containing regimen 2007-2016 were followed from INSTI initiation (baseline) to the earliest of: outcome of interest, loss to follow-up (LTFU, 1 year without clinical visit), or death. Outcomes of interest were virologic failure (first of two consecutive viral loads at least 200 copies/ml more than 2 weeks apart, or one viral load ≥200 before LTFU) and immune recovery (first CD4 ≥500 cells/μl). Patients with baseline viral load at least 50 copies/ml were given 24 weeks before meeting virologic failure criteria. Kaplan-Meier curves and Cox proportional hazards models compared INSTI regimens and patient characteristics.

RESULTS

Of 773 patients, 32% were women, 59% African-American, and 42% had a viral load at least 50 copies/ml at INSTI initiation. After 2 years, 5% of patients with baseline viral load less than 50 copies/ml experienced virologic failure, compared with 35% of patients with baseline viral load at least 50 copies/ml (P < 0.01). Among patients with baseline viral load less than 50 copies/ml, dolutegravir/NRTIs was associated with longer time to virologic failure [adjusted hazard ratio (aHR) 0.11, 95% confidence interval (CI) 0.01-0.80], whereas among patients with baseline viral load at least 50 copies/ml, raltegravir/NRTIs was associated with longer time to virologic failure (aHR 0.35, 95% CI 0.18-0.68), both compared with elvitegravir/NRTIs. After 5 years suppressed, irrespective of baseline viral load, 61% of patients experienced immune recovery.

CONCLUSION

In this cohort, INSTI-containing regimens led to low virologic failure rates in patients switching ART while suppressed. Viremic patients initiating INSTIs were at high risk of virologic failure during follow-up.

The clinical pharmacology of integrase inhibitors

Introduction: Treatment of HIV infection has consistently evolved in the last three decades. A steady improvement in efficacy tolerability, safety, and practical aspects of treatment intake has made HIV infection much easier to manage over the long term, and in optimal treatment conditions the life expectancy of persons living with HIV infection now approaches the values of the general population. The last category of antiretrovirals to be fully developed for clinical use is the one of strand-transfer integrase inhibitors (INSTIs). Areas covered: In this review, the evolution of the knowledge on INSTIs use in the clinical setting is reviewed, analyzed, and interpreted. Emphasis is placed on the properties possibly accounting for several superiority results achieved by INSTIs in non-inferiority designed comparative clinical trials, which led to their inclusion as first line options in all versions of HIV therapeutic guidelines. Expert commentary: Some unprecedented clinical-pharmacological properties of INSTIs, such as their rapid and sustained action against HIV replication, the optimal tolerability and safety profile and a clinically proven robust genetic barrier are the main factors justifying the successful clinical use of INSTIs. Based on these unique features, novel INSTIs-based treatment modalities are being developed, including the reduction of antiretroviral regimens to two drugs only.