Efficacy and safety of raltegravir for treatment of HIV for 5 years in the BENCHMRK studies: final results of two randomised, placebo-controlled trials

Real-world prevalence of integrase inhibitor resistance and virological failure since adoption as guideline-preferred therapy

Background

Limited data reporting real-world prevalence of integrase strand transfer inhibitor resistance (INSTI-R) in the USA are available because their recommendation as first-line treatment in 2017. Reported national surveillance data in the USA estimated INSTI-R to be 6.3% as of 2018. This article aims to describe estimated prevalence of INSTI-R within a single clinic network in Chicago, IL, USA, and identify risk factors for resistance and virological failure (VF).

Methods

This was a retrospective, single-centre study of adults with HIV starting an INSTI-containing regimen between September 2017 and 2020. The primary endpoint was the difference in INSTI-R of the sample population compared with the national prevalence. Other outcomes included VF and documented INSTI-R mutations.

Results

Of 948 participants screened, 321 were included. Eight people had baseline INSTI-R testing results available, of which five had INSTI-R at baseline for an estimated prevalence of 1.6%. This estimation was significantly less than the national estimated prevalence of 6.3% (p<0.001). VF occurred in 26 (7.8%) individuals. Because no participants acquired INSTI-R during the study period, investigators were unable to identify risk factors associated with the development of INSTI-R. People with high pre-treatment viral loads had 1.21 (95% CI 1.05-1.39) higher odds of VF.

Conclusions

Amongst participants on INSTI-containing regimens, INSTI-R rates were estimated to be lower than the estimated national prevalence. Detectable pre-switch viral loads were more associated with VF than undetectable viral loads.

Conversion of raltegravir carrying a 1,3,4-oxadiazole ring to a hydrolysis product upon pH changes decreases its antiviral activity

Raltegravir (RAL), a human immunodeficiency virus (HIV)-1 integrase inhibitor, has been administered as part of antiretroviral therapy. Studies in patients with HIV-1 have shown high variability in the pharmacokinetics of RAL, and in healthy volunteers, coadministration of proton-pump inhibitors has been shown to increase the plasma RAL concentrations. Here, we found that RAL containing a 1,3,4-oxadiazole ring is converted to a hydrolysis product (H-RAL) with a cleaved 1,3,4-oxadiazole ring at pH 1.0 and 13.0 conditions in vitro, thereby reducing the anti-HIV activity of the drug. The inclusion of cyclodextrins (beta-cyclodextrin [βCD], random methyl-βCD [RAM-βCD], and hydroxypropyl-βCD [HP-βCD]) can protect RAL from pH-induced changes. The conversion of RAL to H-RAL was detected by using various mass spectrometry analyses. The chromatogram of H-RAL increased in a time-dependent manner similar to another 1,3,4-oxadiazole-containing drug, zibotentan, using high-performance liquid chromatography. Oral bioavailability and target protein interactions of H-RAL were predicted to be lower than those of RAL. Moreover, H-RAL exhibited significantly reduced anti-HIV-1 activity, whereas combinations with βCD, RAM-βCD, and HP-βCD attenuated this effect in cell-based assays. These findings suggest that βCDs can potentially protect against the conversion of RAL to H-RAL under acidic conditions in the stomach, thereby preserving the anti-HIV-1 effect of RAL. Although clinical trials are needed for evaluation, we anticipate that protective devices such as βCDs may improve the pharmacokinetics of RAL, leading to better treatment outcomes, including reduced dosing, long-term anti-HIV-1 activity, and deeper HIV-1 suppression.

Editorial to the Special Issue "Clinical Immunology in Italy, with Special Emphasis to Primary and Acquired Immunodeficiencies: A Commemorative Issue in Honor of Prof. Fernando Aiuti"

Fernando Aiuti (Figure 1), born in Urbino on 8 June 1935, suddenly died on 9 January 2019, leaving a great void not only among his family members and those who knew him and appreciated his great humanity and acute intelligence, but in the entire immunological scientific community [...].

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.

Week 240 Efficacy and Safety of Fostemsavir Plus Optimized Background Therapy in Heavily Treatment-Experienced Adults with HIV-1

INTRODUCTION

Efficacy and safety of the attachment inhibitor fostemsavir + optimized background therapy (OBT) were evaluated through 48 and 96 weeks in the phase 3 BRIGHTE trial in heavily treatment-experienced (HTE) adults failing their current antiretroviral regimen. Here, we report 240-week efficacy and safety of fostemsavir + OBT in adults with multidrug-resistant human immunodeficiency virus (HIV)-1 in BRIGHTE.

METHODS

Heavily treatment-experienced adults failing their current regimen entered the randomized cohort (RC; 1-2 fully active antiretrovirals available) or non-randomized cohort (NRC; no fully active antiretrovirals available) and received open-label fostemsavir + OBT (starting Day 8 in RC and Day 1 in NRC). Endpoints included proportion with virologic response (HIV-1 RNA < 40 copies/mL, Snapshot), immunologic efficacy, and safety.

RESULTS

At Week 240, 45% and 22% of the RC and NRC, respectively, had virologic response (Snapshot); 7% of the RC and 5% of the NRC had missing data due to coronavirus disease 2019 (COVID-19)-impacted visits. In the observed analysis, 82% of the RC and 66% of the NRC had virologic response. At Week 240, mean change from baseline in CD4+ T-cell count was 296 cells/mm3 (RC) and 240 cells/mm3 (NRC); mean CD4+/CD8+ ratio increased between Weeks 96 and 240 (RC 0.44 to 0.60; NRC 0.23 to 0.32). Between Weeks 96 and 240, four participants discontinued for adverse events, one additional participant experienced a drug-related serious adverse event, and six deaths occurred (median last available CD4+ T-cell count, 3 cells/mm3). COVID-19-related events occurred in 25 out of 371 participants; all resolved without incident.

CONCLUSION

Through ~5 years, fostemsavir + OBT demonstrated durable virologic and immunologic responses with no new safety concerns between Weeks 96 and 240, supporting this regimen as a key therapeutic option for HTE people with multidrug-resistant HIV-1.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02362503.

Integrase Strand Transfer Inhibitor Use in Children with Perinatal HIV-1 Infection: A Narrative Review

Integrase strand transfer inhibitors (INSTIs), including raltegravir (RAL), dolutegravir (DTG), elvitegravir (EVG), bictegravir (BIC), and cabotegravir (CAB), are increasingly used, given excellent data on their efficacy, effectiveness, and tolerability profile in adults, while data in children are accumulating. To review the most recent evidence on the efficacy, effectiveness, safety, and resistance of INSTIs in children, a quick narrative review of the available literature data was performed using the MEDLINE/PubMed and Scopus databases, including only English-language studies, published between 2009 and 2022. Six studies (259 children) on RAL use, 17 studies (3,448 children) on DTG, 2 studies (73 children) on EVG, and 1 study (102 children) on BIC were retrieved. Results on efficacy and effectiveness were close to those reported in adult studies, suggesting similarities between children and adult population. Resistance to RAL was detected in four studies, ranging between 5.0% to 35.3% of participants. In four studies resistance to DTG occurred in 12.4% to 22% of children. Adverse events to RAL have been uncommon reported. In studies on EVG, 8% to 74% of children developed uveitis, nausea, or abdominal pain. In DTG studies, the proportion of weight gain ranged from 10% to 87%, and neuropsychiatric effects ranged 1% to 16% of participants. One BIC study reported adverse events >10% of participants. The evidence supports high efficacy and low toxicity of INSTIs in pediatric and adolescent populations.

Factors associated with human immunodeficiency virus-1 low-level viremia and its impact on virological and immunological outcomes: A retrospective cohort study in Beijing, China

OBJECTIVES

We evaluated the impact of low-level viremia (LLV) on virological failure and immune reconstitution among people living with human immunodeficiency virus type 1 (HIV-1) treated with different antiretroviral regimens in Beijing, China.

METHODS

Human immunodeficiency virus type 1-positive adults who were registered at an infectious disease hospital in Beijing between January 1, 2005 and January 1, 2020 were administered antiretroviral therapy (ART) and whose viral load and CD4 counts were monitored were included in this retrospective cohort study. Univariate and multivariate logistic regression analyses were performed to identify risk factors associated with LLV in patients on different ART regimens. Cox proportional hazard model was employed to analyze the virological suppression and immune reconstitution cumulative probability in patients with LLV during follow-up.

RESULTS

A total of 10 124 HIV-1-infected participants was included. LLV occurred in 723 (8.2%), 204 (10.9%), 133 (8.6%), and 53 (14.4%) patients on first-line ART, second-line ART, third-line ART, and simplified regimens, respectively. Virological failure occurred in 514 (5.8%), 289 (15.5%), 86 (5.5%), and 34 (9.2%) patients on first-line ART, second-line ART, third-line ART, and simplified regimens, respectively. Earlier enrollment, lower baseline CD4 count, and higher baseline viral load were risk factors associated with LLV. LLV was related to increased hazards of virological failure compared to viral suppression of ≤50 copies/ml for those on first-line ART.

CONCLUSIONS

The risk of virological failure and poor immune reconstitution increases when LLV occurs. Targeted viral load and CD4 count monitoring are recommended for people living with HIV-1 with LLV to improve health-related outcomes.

Integrase Strand Transfer Inhibitor (INSTI) Genotypic Resistance Analysis in Treatment-nNaive, INSTI Free Antiretroviral-Experienced and INSTI-Experienced Turkish Patients Infected with HIV-1

BACKGROUND AND OBJECTIVE

Integrase strand transfer inhibitors (INSTIs) are currently the standard of practice for first-line HIV therapy for most patients. We evaluated the mutations associated with INSTI resistance in naive HIV-1 infected patients and treated them with antiretrovirals (ART).

METHODS

The study, conducted in the 2018 - 2020 period, included 50 ART-naïve patients, 69 INSTI free ART-experienced patients, and 82 INSTI-experienced patients. INSTI resistance mutations were interpreted using the Stanford University HIVdb Program algorithm.

RESULTS

INSTI resistance was not detected in ART naïve patients. At least one INSTI resistance mutation was detected in 10% of the INSTI-free patients and 29% of the INSTI-treated patients. Major INSTI-mutations E138K, Y143R, S147G, Q148R, N155H, and E157Q were found in raltegravir. Additional mutations, E92Q, E138K, G140A, S147G, and Q148R were found in elvitegravir; E192Q, E138K/T, G140A/S, S147G, Q148H/R, N155H, E157Q were found in dolutegravir (DTG) experienced patients. According to all drug classes, drug resistance mutation prevalences were determined at the rate of 60%, 46%, and 46% in the RAL, EVG, and DTG groups, respectively.

CONCLUSION

Our findings provide data for treatment and resistance management of INSTIs and may provide feedback for INSTIs resistance surveillance consensus-building efforts. In viral rebound under INSTI treatment, INSTI-resistant mutations follow typical INSTI resistance pathways and high resistance rates. INSTI resistance genotypic analysis should be considered before any DTG-based regimes can be initiated in the future, and reduced DTG susceptibility should be carefully monitored and investigated.

Effectiveness of integrase strand transfer inhibitors in HIV-infected treatment-experienced individuals across Europe

OBJECTIVES

To explore the effectiveness and durability of integrase strand transfer inhibitor (INSTI)-based regimens in pre-treated subjects.

METHODS

Treatment-experienced individuals starting an INSTI-based regimen during 2012-2019 were selected from the INTEGRATE collaborative study. The time to virological failure [VF: one measurement of viral load (VL) ≥ 1000 copies/mL or two ≥ 50 copies/ml or one VL measurement ≥ 50 copies/mL followed by treatment change] and to INSTI discontinuation were evaluated.

RESULTS

Of 13 560 treatments analysed, 4284 were from INSTI-naïve, non-viraemic (IN-NV) individuals, 1465 were from INSTI-naïve, viraemic (IN-V) individuals, 6016 were from INSTI-experienced, non-viraemic (IE-NV) individuals and 1795 were from INSTI-experienced, viraemic (IE-V) individuals. Major INSTI drug resistance mutations (DRMs) were previously detected in 4/519 (0.8%) IN-NV, 3/394 (0.8%) IN-V, 7/1510 (0.5%) IE-NV and 25/935 (2.7%) IE-V individuals. The 1-year estimated probabilities of VF were 3.1% [95% confidence interval (CI): 2.5-3.8] in IN-NV, 18.4% (95% CI: 15.8-21.2) in IN-V, 4.2% (95% CI: 3.6-4.9) in IE-NV and 23.9% (95% CI: 20.9-26.9) in IE-V subjects. The 1-year estimated probabilities of INSTI discontinuation were 12.1% (95% CI: 11.1-13.0) in IN-NV, 19.6% (95% CI: 17.5-21.6) in IN-V, 10.8% (95% CI: 10.0-11.6) in IE-NV and 21.7% (95% CI: 19.7-23.5) in IE-V subjects.

CONCLUSIONS

Both VF and INSTI discontinuation occur at substantial rates in viraemic subjects. Detection of DRMs in a proportion of INSTI-experienced individuals makes INSTI resistance testing mandatory after failure.

Virologic outcomes among adults with HIV using integrase inhibitor-based antiretroviral therapy

BACKGROUND

Integrase strand transfer inhibitor (InSTI)-based regimens have been recommended as first-line antiretroviral therapy (ART) for adults with HIV. But data on long-term effects of InSTI-based regimens on virologic outcomes remain limited. Here we examined whether InSTI improved long-term virologic outcomes compared with efavirenz (EFV).

METHODS

We included adults from the North American AIDS Cohort Collaboration on Research and Design who initiated their first ART regimen containing either InSTI or EFV between 2009 and 2016. We estimated differences in the proportion virologically suppressed up to 7 years of follow-up in observational intention-to-treat and per-protocol analyses.

RESULTS

Of 15 318 participants, 5519 (36%) initiated an InSTI-based regimen and 9799 (64%) initiated the EFV-based regimen. In observational intention-to-treat analysis, 81.3% of patients in the InSTI group and 67.3% in the EFV group experienced virologic suppression at 3 months after ART initiation, corresponding to a difference of 14.0% (95% CI 12.4-15.6). At 1 year after ART initiation, the proportion virologically suppressed was 89.5% in the InSTI group and 90.2% in the EFV group, corresponding to a difference of -0.7% (95% CI -2.1 to 0.8). At 7 years, the proportion virologically suppressed was 94.5% in the InSTI group and 92.5% in the EFV group, corresponding to a difference of 2.0% (95% CI -7.3 to 11.3). The observational per-protocol results were similar to intention-to-treat analyses.

CONCLUSIONS

Although InSTI-based initial ART regimens had more rapid virologic response than EFV-based regimens, the long-term virologic effect was similar. Our findings may inform guidelines regarding preferred initial regimens for HIV treatment.

Clinical Effectiveness of Integrase Strand Transfer Inhibitor-Based Antiretroviral Regimens Among Adults With Human Immunodeficiency Virus: A Collaboration of Cohort Studies in the United States and Canada

BACKGROUND

Integrase strand transfer inhibitor (InSTI)-based regimens are now recommended as first-line antiretroviral therapy (ART) for adults with human immunodeficiency virus, but evidence on long-term clinical effectiveness of InSTI-based regimens remains limited. We examined whether InSTI-based regimens improved longer-term clinical outcomes.

METHODS

We included participants from clinical cohorts in the North American AIDS Cohort Collaboration on Research and Design who initiated their first ART regimen, containing either InSTI (ie, raltegravir, dolutegravir, and elvitegravir-cobicistat) or efavirenz (EFV) as an active comparator, between 2009 and 2016. We estimated observational analogs of 6-year intention-to-treat and per-protocol risks, risk differences (RDs), and hazard ratios (HRs) for the composite outcome of AIDS, acute myocardial infarction, stroke, end-stage renal disease, end-stage liver disease, or death.

RESULTS

Of 15 993 participants, 5824 (36%) initiated an InSTI-based and 10 169 (64%) initiated an EFV-based regimen. During the 6-year follow-up, 440 in the InSTI group and 1097 in the EFV group incurred the composite outcome. The estimated 6-year intention-to-treat risks were 14.6% and 14.3% for the InSTI and EFV groups, respectively, corresponding to a RD of 0.3% (95% confidence interval, -2.7% to 3.3%) and a HR of 1.08 (.97-1.19); the estimated 6-year per-protocol risks were 12.2% for the InSTI group and 11.9% for the EFV group, corresponding to a RD of 0.3% (-3.0% to 3.7%) and a HR of 1.09 (.96-1.25).

CONCLUSIONS

InSTI- and EFV-based initial ART regimens had similar 6-year composite clinical outcomes. The risk of adverse clinical outcomes remains substantial even when initiating modern ART.

INSTI-Based Initial Antiretroviral Therapy in Adults with HIV, the HIV Outpatient Study, 2007-2018

We evaluated treatment duration and viral suppression (VS) outcomes with integrase strand transfer inhibitor (INSTI)-based regimens versus other contemporary regimens among adults in routine HIV care. Eligible participants were seen during January 1, 2007 to June 30, 2018 at nine U.S. HIV clinics, initiated antiretroviral therapy (ART) (baseline date), and had ≥2 clinic visits thereafter. We assessed the probability of remaining on a regimen and achieving HIV RNA <200 copies/mL on initial INSTI versus non-INSTI ART by Kaplan-Meier analyses and their correlates by Cox regression. Among 1,005 patients, 335 (33.3%) were prescribed an INSTI-containing regimen and 670 (66.7%) a non-INSTI regimen, which may have included non-nucleoside reverse transcriptase inhibitors, protease inhibitors, and other agents. In both groups, most patients were male, nonwhite, and aged <50 years. Comparing the INSTI with non-INSTI group, the median baseline log₁₀ HIV viral load (VL; copies/mL) was 4.6 versus 4.5, and the median CD4⁺ cell count (cells/mm³) was 352 versus 314. In Kaplan-Meier analysis, the estimated probabilities of remaining on initial regimens at 2 and 4 years were 58% and 40% for INSTI and 51% and 33% for non-INSTI group, respectively (log-rank test p = .003). In multivariable models, treatment with an INSTI (vs. non-INSTI) ART was negatively associated with a regimen switch [hazard ratio (HR) 0.67, 95% confidence interval (CI) 0.56-0.81, p < .001] and was positively associated with achieving VS (HR 1.52; CI 1.29-1.79, p < .001), both irrespective of baseline VL levels. Initial INSTI-based regimens were associated with longer treatment durations and better VS than non-INSTI regimens. Results support INSTI regimens as the initial therapy in U.S. treatment guidelines.

Mortality Among Persons Entering HIV Care Compared With the General U.S. Population : An Observational Study

BACKGROUND

Understanding advances in the care and treatment of adults with HIV as well as remaining gaps requires comparing differences in mortality between persons entering care for HIV and the general population.

OBJECTIVE

To assess the extent to which mortality among persons entering HIV care in the United States is elevated over mortality among matched persons in the general U.S. population and trends in this difference over time.

DESIGN

Observational cohort study.

SETTING

Thirteen sites from the U.S. North American AIDS Cohort Collaboration on Research and Design.

PARTICIPANTS

82 766 adults entering HIV clinical care between 1999 and 2017 and a subset of the U.S. population matched on calendar time, age, sex, race/ethnicity, and county using U.S. mortality and population data compiled by the National Center for Health Statistics.

MEASUREMENTS

Five-year all-cause mortality, estimated using the Kaplan-Meier estimator of the survival function.

RESULTS

Overall 5-year mortality among persons entering HIV care was 10.6%, and mortality among the matched U.S. population was 2.9%, for a difference of 7.7 (95% CI, 7.4 to 7.9) percentage points. This difference decreased over time, from 11.1 percentage points among those entering care between 1999 and 2004 to 2.7 percentage points among those entering care between 2011 and 2017.

LIMITATION

Matching on available covariates may have failed to account for differences in mortality that were due to sociodemographic factors rather than consequences of HIV infection and other modifiable factors.

CONCLUSION

Mortality among persons entering HIV care decreased dramatically between 1999 and 2017, although those entering care remained at modestly higher risk for death in the years after starting care than comparable persons in the general U.S. population.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Summary of 2021 Clinical Guidelines for the Diagnosis and Treatment of HIV/AIDS in HIV-infected Koreans

Since the establishment of the Committee for Clinical Guidelines for the Diagnosis and Treatment of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) by the Korean Society for AIDS in 2010, clinical guidelines have been prepared in 2011, 2013, 2015, and 2018. As new research findings on the epidemiology, diagnosis, and treatment of AIDS have been published in and outside of Korea along with the development and introduction of new antiretroviral medications, a need has arisen to revise the clinical guidelines by analyzing such new data. The clinical guidelines address the initial evaluation of patients diagnosed with HIV/AIDS, follow-up tests, appropriate timing of medication, appropriate antiretroviral medications, treatment strategies for patients who have concurrent infections with hepatitis B or C virus, recommendations for resistance testing, treatment for patients with HIV and tuberculosis coinfections, and treatment in pregnant women. Through these clinical guidelines, the Korean Society for AIDS and the Committee for Clinical Guidelines for the Diagnosis and Treatment of HIV/AIDS contributes to overcoming AIDS by delivering latest data and treatment strategies to healthcare professionals who treat AIDS in the clinic.

Simplification to dual therapy containing lamivudine and raltegravir or dolutegravir in HIV-infected patients on virologically suppressive antiretroviral therapy

BACKGROUND

Antiretroviral dual regimens including lamivudine and one boosted PI or dolutegravir are warranted in order to optimize combination ART (cART), prevent long-term toxicity and reduce the cost of treatments.

OBJECTIVES

We hypothesized that a maintenance dual regimen of lamivudine plus raltegravir would be effective and as well tolerated as the dual maintenance combination of lamivudine plus dolutegravir.

METHODS

We performed an observational, retrospective study of HIV-infected patients on suppressive ART who switched to a dual regimen containing lamivudine 300 mg once daily plus raltegravir 1200 mg once daily or dolutegravir 50 mg once daily.

RESULTS

In total, 109 patients (79 men; mean age 46.4 years; mean CD4+ T lymphocyte count 605 cells/mm3) were enrolled. Overall, 50 subjects switched to lamivudine plus raltegravir (Group A) and 59 to lamivudine plus dolutegravir (Group B). After 12 months, 45 patients (90%) in Group A and 52 (88.1%) in Group B had HIV RNA <20 copies/mL. No patients had severe adverse effects in either group, and the percentages of patients with mild adverse effects were comparable, except for a higher incidence of headache and sleeping disturbances in Group B than in Group A (30.5% versus 14%, P < 0.001). A comparable and non-significant weight increase was reported in both groups (+1.91 kg in Group A and +2.28 kg in Group B).

CONCLUSIONS

In our study, dual therapies containing lamivudine plus raltegravir or dolutegravir in virologically suppressed patients showed high and comparable efficacy, as well as good tolerability.

Virologic failure after 48 weeks of raltegravir-based regimen in low HIV-1 incidence setting

Background

With the advent of next generation integrase strand transfer inhibitors, the rates of virologic failure in treated subjects are expected to decrease. In this study, we analyzed the mutation patterns leading to virologic failure before and after starting integrase strand transfer inhibitor-based regimen as first-line or salvage therapy.

Methods

Between 2016 and 2019, blood samples were received from 258 patients with HIV-1 infection. Plasma HIV-1 RNA concentrations, and pol gene sequences were determined at baseline, and 16–48 weeks of treatment with integrase strand transfer inhibitor-based regimen. Only patients who did not achieve viral suppression at 48 weeks of integrase strand transfer inhibitor-based treatment were eligible for the current study.

Results

Virologic failure was observed in seven patients on raltegravir-based regimen. All patients with virologic failure but one were infected with CRF01_AE virus subtype. Raltegravir based-regimen was offered as first-line therapy for four patients, and as salvage therapy for three patients. M184V mutation associated with high level resistance to lamivudine and emtricitabine was detected in six out of seven patients. Primary mutations (Y143C, N155H, T66I, G118R, E138K) conferring high level resistance to raltegravir were detected in only three patients. Pre-existing polymorphic integrase mutation (T97A) was detected in two patients. Furthermore, two patients reported low adherence to treatment.

Conclusions

Emergence of primary mutations in the integrase gene can account for virologic failure in less than half of patients on raltegravir-based regimen. Low adherence to treatment, pre-existing accessory mutations, and resistance to reverse transcriptase inhibitors may have some role in virologic outcome.

Long-term Outcomes in a Large Randomized Trial of HIV-1 Salvage Therapy: 96-Week Results of AIDS Clinical Trials Group A5241 (OPTIONS)

BACKGROUND

Short-term (48-week) results of the OPTIONS trial showed that nucleoside reverse transcriptase inhibitors (NRTIs) can be safely omitted from salvage therapy as long as the regimen has a cumulative activity of >2 active antiretroviral medications. The long-term durability of this approach and outcomes in persons who have more-extensive HIV-1 drug resistance are uncertain.

METHODS

Participants with virologic failure and anticipated antiretroviral susceptibility received an optimized regimen and were randomized to omit or add NRTIs. A separate group with more resistance (cumulative activity ≤2 active agents) received an optimized regimen including NRTIs.

RESULTS

At week 96, among 360 participants randomized to omit or add NRTIs, 70% and 65% had HIV-1 RNA <200 copies/mL, respectively. Virologic failure was uncommon after week 48. Younger age and starting fewer new antiretroviral medications were associated with higher odds of virologic failure. In the highly resistant group, 53% had HIV-1 RNA <200 copies/mL at week 96.

CONCLUSIONS

HIV-1 salvage therapy can safely omit NRTIs without compromising efficacy or durability of response as long as the new regimen has a cumulative activity of >2 active drugs. Younger people and those receiving fewer new antiretrovirals require careful monitoring. Even among individuals with more-extensive resistance, most achieve virologic suppression.

CLINICAL TRIALS REGISTRATION

NCT00537394.

Integrase Strand Transfer Inhibitors Are Effective Anti-HIV Drugs

Integrase strand transfer inhibitors (INSTIs) are currently recommended for the first line treatment of human immunodeficiency virus type one (HIV-1) infection. The first-generation INSTIs are effective but can select for resistant viruses. Recent advances have led to several potent second-generation INSTIs that are effective against both wild-type (WT) HIV-1 integrase and many of the first-generation INSTI-resistant mutants. The emergence of resistance to these new second-generation INSTIs has been minimal, which has resulted in alternative treatment strategies for HIV-1 patients. Moreover, because of their high antiviral potencies and, in some cases, their bioavailability profiles, INSTIs will probably have prominent roles in pre-exposure prophylaxis (PrEP). Herein, we review the current state of the clinically relevant INSTIs and discuss the future outlook for this class of antiretrovirals.

Absence of Integrase Inhibitor-Associated Resistance Among Antiretroviral Therapy-Naïve HIV-1-Infected Adults in Guangdong Province, China, in 2018

Background

Antiretroviral therapy (ART) containing an integrase strand transfer inhibitor (INSTI) plus two nucleoside reverse-transcriptase inhibitors has been recommended as a first-line regimen for ART-naïve HIV-1-infected patients in the latest Chinese Guidelines for Diagnosis and Treatment of HIV/AIDS.

Objective

To determine the prevalence of INSTI-related mutations among ART-naïve HIV-1-infected adults in Guangdong, China, in 2018.

Methods

The entire integrase gene was amplified from blood plasma. Demographic and epidemiological information was collected. INSTI mutations and antiretroviral susceptibility were interpreted using the Stanford University HIV Drug Resistance Database HIVdb program.

Results

Of 927 samples, 827 integrase sequences were successfully obtained. Among them, no major resistance mutations to INSTIs were identified, and four accessory mutations, including T97A (0.12%, 1/827), A128T (0.24%, 2/827), E157Q (0.85%, 7/827), and G163R (0.24%, 2/827), were found in twelve individuals. Two patient samples contained the G163R mutation conferring low-level resistance to elvitegravir and raltegravir.

Conclusion

The overall prevalence of INSTI mutations remains low. Drug resistance mutation testing for the detection of INSTI drug resistance mutations in HIV treatment-naïve patients should be considered due to the circulation of polymorphisms contributing to INSTI resistance and the expected increasing use of this class of drugs.

Antiretroviral therapy and liver disorders in the OPERA® cohort

Introduction:

A comprehensive assessment of liver disorders was conducted among people living with HIV (PLWH) on a new antiretroviral regimen based on common core agents.

Methods:

Treatment-naïve and experienced PLWH first initiating dolutegravir (DTG), elvitegravir (EVG), raltegravir (RAL), or darunavir (DRV) in the OPERA^® cohort were included if they had ⩾1 liver chemistry test performed both within 12 months before regimen start and over follow-up. Liver disorders were defined as a diagnosis of drug-induced liver injury (DILI) or moderate/severe liver chemistry elevations (LCE). History of liver disorders experienced within 12 months of initiation was summarized. Liver disorders occurring during follow-up were described as prevalent (all disorders) or incident (disorders occurring among PLWH without a history of liver disorders or advanced liver fibrosis).

Results:

Out of 16,024 PLWH, 38% initiated DTG, 43% EVG, 5% RAL, and 14% DRV. EVG users were younger and had a lower likelihood of comorbidities or lipid-lowering agent use than DTG users. EVG users were significantly less likely to have a history of moderate/severe LCE or to have prevalent moderate LCE. RAL users were older and had a higher likelihood of comorbidities or lipid-lowering agent use than DTG users. RAL users were significantly more likely to have a history of advanced liver fibrosis and prevalent moderate/severe LCE during follow-up. DRV users were older and had a lower likelihood of lipid-lowering agent use than DTG users. There was no difference in history of LCE, nor in prevalent or incident LCE between DRV and DTG users. No DILI diagnoses were recorded. Discontinuation following a liver disorder was rare (<1%) across all groups.

Conclusion:

While PLWH with comorbidities may have been channeled away from EVG and toward DTG and RAL, the incidence of moderate/severe LCE did not differ between DTG and EVG, RAL, and DRV.

Plain language summary

Liver disorders and HIV treatment

A comprehensive assessment of liver disorders was conducted using data from the OPERA^® cohort, which provides anonymous patient-level clinical data from electronic health records. People living with HIV (PLWH) who were starting a new HIV treatment regimen that included one of four common HIV drugs were included in this study. Liver disorders included drug-induced liver injury (DILI) and moderate or severe liver chemistry elevations. History of a disorder was defined as liver disorders that occurred before starting the new treatment. Prevalent disorders were those that occurred after starting the new treatment in the whole population. Incident disorders were those that occurred after starting the new treatment, but only among PLWH without any history of liver disorders.

Out of 16,024 PLWH, 38% initiated dolutegravir (DTG), 43% elvitegravir (EVG), 5% raltegravir (RAL), and 14% darunavir (DRV). EVG users were younger and less likely to have other diseases or use cholesterol lowering drugs compared to DTG users. They were also less likely to have a history of moderate/severe liver chemistry elevations or to have prevalent moderate liver chemistry elevations. RAL users were older and more likely to have other diseases or use cholesterol lowering drugs compared to DTG users. They were also more likely to have prevalent moderate/severe liver chemistry elevations than DTG users. DRV users were older and less likely to use cholesterol lowering agents compared to DTG users. There was no difference in history of liver chemistry elevations, or in prevalent, or incident liver chemistry elevations between DRV and DTG users. There were no DILI diagnoses and discontinuation of treatment following liver disorders was rare across all groups. Overall, the incidence of liver disorders after starting a new HIV treatment regimen did not differ between four common antiretroviral drugs.

HIV-1 resistance patterns to integrase inhibitors in Chilean patients with virological failure on raltegravir-containing regimens

In this viewpoint we would like to describe our results in terms of resistance pattern in Chilean patients with virological failure (VF) on raltegravir (RAL)-containing-regimens and highlight the need for the concomitant availability of genotypic resistance testing to integrase strand transfer inhibitors (INSTIs) introduction in antiretroviral regimens, particularly in countries in South America. Indeed we found in our study the presence of two or more primary mutations in some of the participants which is associated with cross-resistance to all INSTIs. By using timely genotyping, we could optimally manage these patients, early after detection of VF.

HIV-1 Integrase Inhibitors: A Comparative Review of Efficacy and Safety

The newest class of antiretrovirals for all persons living with HIV are the integrase strand transfer inhibitors (INSTIs). Since 2007, five INSTIs have been introduced: raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir. The INSTIs have favorable pharmacokinetic and pharmacodynamic properties, which contribute to both their effectiveness and their ease of use. With the exception of cabotegravir, each INSTI is US Food and Drug Administration approved for treatment-naïve individuals initiating antiretroviral therapy. All of the INSTIs, except raltegravir, are approved for antiretroviral treatment simplification for virologically suppressed patients without INSTI resistance. Data also support the use of dolutegravir and raltegravir in individuals with antiretroviral resistance as part of an optimized antiretroviral regimen. INSTIs are generally well tolerated by people living with HIV compared with older classes of antiretrovirals, but emerging data suggest that some INSTIs contribute to weight gain. Due to their efficacy, safety, and ease of use, HIV treatment guidelines recommend oral INSTIs as preferred components of antiretroviral therapy for individuals initiating therapy. The newest INSTI, cabotegravir, represents an alternative to oral administration of life-long antiretroviral therapy with the availability of a long-acting injectable formulation. This review summarizes the current use of INSTIs in adults living with HIV, highlighting the similarities and differences within the class related to pharmacodynamics, pharmacokinetics, safety, dosing, and administration that contribute to their role in modern antiretroviral therapy.

Uptake and Discontinuation of Integrase Inhibitors (INSTIs) in a Large Cohort Setting

BACKGROUND

Despite increased integrase strand transfer inhibitor (INSTI) use, limited large-scale, real-life data exists on INSTI uptake and discontinuation.

SETTING

International multicohort collaboration.

METHODS

RESPOND participants starting dolutegravir (DTG), elvitegravir (EVG), or raltegravir (RAL) after January 1, 2012 were included. Predictors of INSTI used were assessed using multinomial logistic regression. Kaplan-Meier and Cox proportional hazards models describe time to and factors associated with discontinuation.

RESULTS

Overall, 9702 persons were included; 5051 (52.1%) starting DTG, 1933 (19.9%) EVG, and 2718 (28.0%) RAL. The likelihood of starting RAL or EVG vs DTG decreased over time and was higher in Eastern and Southern Europe compared with Western Europe. At 6 months after initiation, 8.9% (95% confidence interval: 8.3% to 9.5%) had discontinued the INSTI (6.4% DTG, 7.4% EVG, and 14.0% RAL). The main reason for discontinuation was toxicity (44.2% DTG, 42.5% EVG, 17.3% RAL). Nervous system toxicity accounted for a higher proportion of toxicity discontinuations on DTG (31.8% DTG, 23.4% EVG, 6.6% RAL). Overall, treatment simplification was highest on RAL (2.7% DTG, 1.6% EVG, and 19.8% RAL). Factors associated with a higher discontinuation risk included increasing year of INSTI initiation, female gender, hepatitis C coinfection, and previous non-AIDS-defining malignancies. Individuals in Southern and Eastern Europe were less likely to discontinue. Similar results were seen for discontinuations after 6 months.

CONCLUSIONS

Uptake of DTG vs EVG or RAL increased over time. Discontinuation within 6 months was mainly due to toxicity; nervous system toxicity was highest on DTG. Discontinuation was highest on RAL, mainly because of treatment simplification.

Integrase Inhibitor-Based Antiretroviral Therapy Among Women Living with HIV: Data from the OPERA Cohort

BACKGROUND

Women face unique complexities in HIV treatment yet are underrepresented in antiretroviral therapy (ART) studies.

OBJECTIVE

This analysis assessed the one-year durability of the first integrase strand transfer inhibitor (INSTI)-based regimens prescribed to women in a large cohort of patients living with HIV in care.

METHODS

Women with HIV who initiated their first INSTI-containing regimen between 08/12/2013 and 11/30/2015 were identified in the OPERA cohort, a collaboration of 79 US outpatient clinics. Discontinuation within the first year of treatment with an INSTI was compared between dolutegravir (DTG), raltegravir (RAL) and elvitegravir (EVG), using multivariable Cox regression and Kaplan- Meier estimates. Virologic response and regimen modifications were described and compared across INSTIs.

RESULTS

A total of 537 treatment-naïve (DTG: 39%, EVG: 48%, RAL: 13%) and 878 treatmentexperienced (DTG: 57%, EVG: 29%, RAL: 13%) women were analyzed. In the first twelve months after initiation, women taking EVG or RAL were more likely to discontinue their initial INSTI than those taking DTG among both treatment-naïve (adjusted hazard ratio EVG vs. DTG: 1.59 (95% CI: 1.09, 2.39); RAL vs. DTG: 2.46 (1.49, 4.05)) and treatment-experienced women (EVG vs. DTG: 1.39 (1.02, 1.88); RAL vs. DTG: 2.17 (1.51, 3.12)). Following discontinuation of the initial INSTI, women commonly switched to a regimen containing a different drug from the INSTI class (treatment-naïve DTG: 34%, RAL: 33% EVG: 41%; treatment-experienced DTG: 23%, RAL: 19% EVG: 41%).

CONCLUSION

In treatment-naïve and treatment-experienced women living with HIV, women taking DTG had the lowest risk for early (≤1 year) discontinuation.

Nothing is perfect: the safety issues of integrase inhibitor regimens

INTRODUCTION

Since the administration of the first integrase strand transfer inhibitor (INSTI) in 2007, most international treatment guidelines consider INSTI-based regimens to be the preferred antiretroviral combinations for HIV-1-infected patients as a result of their safety and efficacy profile. INSTIs are generally well tolerated, and reported rates of discontinuation due to drug-related adverse events (AEs) have been very low to date. However, recent reports indicate that physicians should be aware of potential INSTI-related AEs to ensure good clinical practice.

AREAS COVERED

The authors performed a critical review of the safety issues affecting INSTIs based on published evidence from original studies and new data from researchers.

EXPERT OPINION

Almost all antiretroviral drugs, including INSTIs, are associated with undesirable AEs. Dolutegravir in particular has been associated with more frequent AEs such as neuropsychiatric disorders, neural tube defect in newborns, and weight gain. Data with bictegravir in routine practice are still scarce. While this association and its clinical relevance are not clear, physicians should be alert to the appearance of the aforementioned AEs and others in the future. In the meantime, INSTIs continue to be the preferred option in guidelines on antiretroviral therapy.

HIV-1 integrase drug-resistance mutations in Iranian treatment-experienced HIV-1-infected patients

The latest class of antiretrovirals (ARVs), including integrase strand transfer inhibitors (INSTIs), has been demonstrated to be effective for antiretroviral therapy (ART). Despite all the distinguishing characteristics of these drugs, including a high genetic barrier to resistance and lower toxicity than other ARVs, unfortunately, INSTI drug resistance mutations (DRMs) have occasionally been observed. The aim of this study was to investigate the presence of DRMs associated with INSTIs among treatment-experienced HIV-1-infected patients. From June 2012 to December 2018, a total of 655 treatment-experienced HIV-1-infected patients enrolled in this cross-sectional survey. Following amplification and sequencing of the HIV-1 integrase region of the pol gene, DRM and phylogenetic analysis were successfully carried out on the plasma samples of patients who had a viral load over 1,000 IU/ml after at least 6 months of ART. Out of the 655 patients evaluated, 62 (9.5%) had a viral load higher than 1,000 IU/ml after at least 6 months of ART. Phylogenetic analysis showed that all of the 62 HIV-1 patients experiencing treatment failure were infected with CRF35_AD, and one of these patients (1.6%) was infected with HIV-1 variants with DRMs. The DRMs that were identified belonged to the INSTI class, including E138K, G140A, S147G, and Q148R. This survey shows that DRMs belonging to the INSTI class were detected in an Iranian HIV patient who has experienced treatment failure. Therefore, regarding the presence of DRMs to INSTIs in ART-experienced patients, it seems better to perform drug resistance mutation testing in HIV patients experiencing treatment failure before changing the ART regimen and prescribing this class of medication.

Raltegravir 1200 mg Once Daily vs 400 mg Twice Daily, With Emtricitabine and Tenofovir Disoproxil Fumarate, for Previously Untreated HIV-1 Infection: Week 96 Results From ONCEMRK, a Randomized, Double-Blind, Noninferiority Trial

Supplemental Digital Content is Available in the Text.

Background:

Raltegravir 1200mg (2×600mg tablets) once daily (QD) demonstrated noninferior efficacy and similar safety to raltegravir 400mg twice daily (BID) at week 48 of the ONCEMRK trial. Here, we report the week 96 results from this study.

Methods:

ONCEMRK is a phase 3, multicenter, double-blind, noninferiority trial comparing raltegravir 1200mg QD with raltegravir 400mg BID in treatment-naive HIV-1–infected adults. Participants were assigned (2:1) to raltegravir 2×600mg QD or 400mg BID, both with emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) for 96 weeks. Randomization was stratified by screening HIV-1 RNA and hepatitis B/C status. Efficacy was assessed as the proportion of participants with HIV-1 RNA <40 copies per milliliter (Food and Drug Administration Snapshot approach); the noninferiority margin was 10 percentage points.

Results:

Of the 797 participants who received study therapy (84.6% were men, 59.3% were white, and mean age was 35.9 years), 694 completed 96 weeks of treatment (87.6% QD; 84.4% BID), with few discontinuations because of lack of efficacy (1.1% for both groups) or adverse events (1.3% QD; 2.3% BID). At week 96, 81.5% (433/531) of QD recipients and 80.1% (213/266) of BID recipients achieved HIV-1 RNA <40 copies per milliliter (difference 1.4%, 95% confidence interval: −4.4 to 7.3). CD4⁺ T-cell counts increased >260 cells/mm³ from baseline in both groups. Resistance to raltegravir was infrequent, occurring in 0.8% of each treatment group through week 96. Adverse event rates were similar for the 2 regimens.

Conclusions:

In HIV-1–infected treatment-naive adults receiving FTC/TDF, raltegravir 1200mg QD demonstrated noninferior efficacy to raltegravir 400mg BID that was durable to week 96, with a safety profile similar to raltegravir 400mg BID.

Antiviral activity of HIV-1 integrase strand-transfer inhibitors against mutants with integrase resistance-associated mutations and their frequency in treatment-naïve individuals

The development of resistance to human immunodeficiency virus 1 (HIV-1) integrase strand-transfer inhibitors (INSTI) has been documented; however, knowledge of the impact of pre-existing integrase (IN) mutations on INSTI resistance (INSTI-R) is still evolving. The frequency of HIV-1 IN mutations in 2177 treatment-naïve subjects was investigated, along with the INSTI susceptibility of site-directed mutant viruses containing major and minor INSTI-R mutations. Total 6 of 39 minor INSTI-R mutations (M50I, S119P/G/T/R, and E157Q) were found in >1% of IN-treatment-naïve subjects with no impact on INSTI susceptibility. When each combined with major INSTI-R mutation, M50I, S119P, and E157Q led to decreased susceptibility to elvitegravir but remained sensitive to dolutegravir and bictegravir.

Risk of elevation of serum creatine kinase among HIV-positive individuals receiving dolutegravir-based combination antiretroviral therapy

We aimed to compare the risks of creatine kinase (CK) elevation between patients receiving dolutegravir-based antiretroviral therapy (ART) and those receiving non-integrase strand transfer inhibitor (InSTI)-based ART.HIV-positive patients seeking HIV outpatient care between February 2017 and March 2018 were retrospectively reviewed to collect information on ART, practices of vigorous exercise, and laboratory tests including CK level, plasma HIV RNA load, and concurrent medications. The incidences of CK elevation were estimated among patients receiving dolutegravir-based ART and those receiving non-InSTI-based ART.During the 14-month study period, 1406 patients (mean age 39.4 years and 96.9% being male) were included. The incidence rate of grade 3 or grade 4 CK elevation (>10-fold of the upper limit of normal) was 2.0 per 100 person-years of follow-up (PYFU) and 1.3 per 100 PYFU in the dolutegravir and non-InSTI group, respectively (P = .32). While dolutegravir group had a higher rate of CK elevation of any level than non-InSTI group (22.9 vs 17.4 per 100 PYFU, P = .01), the risk was associated with weight (adjusted odds ratio [aOR], per 10-kg increase, 1.03; 95% CI, 1.02-1.04), duration of exercise (aOR, per 1-hour increase, 1.02; 95% CI 1.01-1.03), but not with dolutegravir-based ART (aOR, 1.00; 95% CI, 0.99-1.06) after adjusting for the testing frequency of serum CK in the multivariate generalized estimating equation model. No patients were hospitalized or switched ART due to CK elevation.Serum CK elevation was associated with weight and duration of exercise among HIV-positive patients receiving ART, but not with dolutegravir-based ART.

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.

Safety and efficacy at 240 weeks of different raltegravir formulations in children with HIV-1: a phase 1/2 open label, non-randomised, multicentre trial

BACKGROUND

Raltegravir is an integrase inhibitor approved for use in adults and children with HIV-1 infection, but there are no data on the long-term use of this medication in children. We aimed to assess the long-term safety, tolerability, pharmacokinetics, and efficacy of multiple raltegravir formulations in children aged 4 weeks to 18 years with HIV-1 infection.

METHODS

In this phase 1/2 open-label multicentre trial (IMPAACT P1066), done in 43 IMPAACT network sites in the USA, South Africa, Brazil, Botswana, and Argentina, eligible participants were children aged 4 weeks to 18 years with HIV-1 infection who had previously received antiretroviral therapy (ART), had HIV-1 RNA higher than 1000 copies per mL, and no exposure to integrase inhibitors. Participants were separated into five age groups and enrolled in six cohorts. Three formulations of open-label raltegravir-adult tablets, chewable tablets, and granules for oral suspension-were added to individualised optimised background therapy, according to the age and weight of participants. The primary outcome at 48 weeks has been previously reported. In the 240-week follow-up, outcomes of interest included graded clinical and laboratory safety of raltegravir formulations during the study and virological efficacy (with virological success defined as HIV-1 RNA reduction of >1 log₁₀ from baseline or HIV-1 RNA <400 copies per mL) at week 240. The primary analysis group for safety and efficacy comprised patients treated only with the final selected dose of raltegravir. This trial is registered with ClinicalTrials.gov, number NCT00485264.

FINDINGS

Between August, 2007, and December, 2012, 220 patients were assessed for eligibility, and 153 were enrolled and treated. Of these patients, 122 received only the final selected dose of raltegravir (63 received adult tablets, 33 chewable tablets, and 26 oral granules), and one was not treated. There were few serious clinical or laboratory safety events noted, with two patients having a drug-related adverse event (skin rash), which led one patient to discontinue the study treatment. The addition of raltegravir to an individually optimised ART regimen resulted in virological success at week 240 in 19 (44·2%, 95% CI 29·1-60·1) of 43 patients receiving 400 mg tablets, 24 (77·4%, 58·9-90·4) of 31 patients receiving the chewable tablets, and 13 (86·7%, 59·5-98·3) of 15 patients receiving oral granules. Among patients with virological failure, raltegravir resistance was noted in 19 (38%) of 50 patients who had virological rebound after initial suppression and had samples at virological failure available for testing.

INTERPRETATION

Our study suggests that raltegravir can be used for the treatment of HIV-1 infection in children as young as 4 weeks, with the expectation of long-term safety and efficacy, but should be used with caution among older children who had previous extensive antiretroviral therapy.

FUNDING

National Institute of Allergy and Infectious Diseases, National Institute of Child Health and Human Development, National Institute of Mental Health, and Merck.

Integrase Inhibitors: After 10 Years of Experience, Is the Best Yet to Come?

The era of the integrase strand transfer inhibitors (INSTIs) for the treatment of human immunodeficiency virus (HIV) infection began with raltegravir in 2007. Since that time, several other INSTIs have been introduced including elvitegravir, dolutegravir, and, most recently, bictegravir, that have shown great utility as part of antiretroviral regimens in both treatment-naive and treatment-experienced patients. At present, antiretroviral guidelines fully endorse the INSTI class as part of all first-line treatment regimens. After 10 years of experience with INSTIs, newer agents are on the horizon such as cabotegravir and MK-2048 for potential use as either HIV pre-exposure prophylaxis or maintenance therapy. This review provides a brief overview of the INSTI class including agents currently available and those still in development, reviews available data from both completed and ongoing clinical trials, and outlines simplification strategies using INSTIs.

Long-term tolerability and effectiveness of raltegravir in Japanese patients: Results from post-marketing surveillance

Antiretroviral agents are approved in Japan based on non-clinical and clinical data reported from overseas. Neither the long-term tolerability nor the effectiveness of raltegravir or other integrase strand transfer inhibitors in Japan is known. This study reports on the long-term tolerability and effectiveness of raltegravir in Japanese clinical practice using data collected through approximately 9 years of post-marketing surveillance. This observational survey used data on human immunodeficiency virus (HIV) infected patients initiated treatment with raltegravir between 2008 and 2017 in the HIV-related drug (HRD) cooperative survey to assess the safety and effectiveness of raltegravir in real world clinical practice. There were totally 1,303 patients prescribed raltegravir across 30 institutions; 1,293 patients and 1,178 patients were included for the safety and effectiveness analyses, respectively. The overall risk of adverse drug reaction was 17.25%, with abnormal hepatic function and hyperlipidaemia (<1.5%) having the highest proportion. Median HIV-1 RNA viral loads rapidly decreased below 40 copies/mL after 3 months of raltegravir use in treatment-naïve patients, and consistently sustained below 40 copies/mL after the start of raltegravir use in treatment-experienced patients. Among the patients who were treated for 7 years, 92.00% (95% CI: 73.97–99.02) maintained HIV-1 RNA viral load below 50 copies/mL. Additionally, CD4⁺ cell counts exceeded >500 cells/μL in treatment-naïve and treatment-experienced patients after 3 years and 4 years of treatment, respectively. In Japanese HIV patients, long-term treatment with raltegravir is well-tolerated and effective at viral suppression as measured by HIV-1 RNA levels and subsequent change in CD4⁺ cell counts. Such benefits can be expected for not only treatment-naïve but also treatment-experienced patients.

Prevalence and determinants of resistance mutations in HIV-1-infected patients exposed to integrase inhibitors in a large Italian cohort

OBJECTIVES

The aim of the study was to analyse the prevalence of integrase resistance mutations in integrase strand transfer inhibitor (INSTI)-experienced HIV-1-infected patients and its predictors.

METHODS

We selected HIV-1 integrase sequences from the Antiviral Response Cohort Analysis (ARCA) database, derived from INSTI-experienced patients between 2008 and 2017. Differences in the prevalence of resistance to raltegravir (RAL), elvitegravir (EVG) and dolutegravir (DTG) were assessed by χ² test and predictors of resistance were analysed by logistic regression.

RESULTS

We included 462 genotypes from INSTI-exposed individuals: 356 'INSTI-failing' patients and 106 'previously INSTI-exposed' patients (obtained a median of 42 weeks after INSTI discontinuation [interquartile range (IQR) 17-110 weeks]). Overall, at least low-level resistance (LLR) to any INSTI (Stanford 8.5 algorithm) was detected in 198 (42.9%) cases. The most frequent INSTI resistance mutation was N155H, followed by Q148H/K/R, G140A/C/S, E138A/K/T and Y143C/H/R. Y143R and E138A were more prevalent in viral subtype B versus non-B [5.2 versus 1.5%, respectively (P = 0.04), and 3.1 versus 0%, respectively (P = 0.02)]. Overall, the Q148H/K/R plus G140A/C/S and/or E138A/K/T pattern, defining an intermediate level of resistance to DTG, was detected in 70 (15%) cases. Independent predictors of at least LLR to any INSTI were current use versus past use of INSTIs, a lower genotypic sensitivity score (GSS) for contemporary antiretroviral drugs used, and having an integrase sequence obtained in calendar year 2016 as compared to 2008-2009.

CONCLUSIONS

The results support integrase resistance testing in INSTI-experienced patients. Emergence of INSTI resistance is facilitated by the reduced genetic barrier of the regimen as a consequence of resistance to companion drugs. However, INSTI resistance may become undetectable by standard population sequencing upon INSTI discontinuation.

New antiretroviral agent use affects prevalence of HIV drug resistance in clinical care populations

OBJECTIVE

To estimate the prevalence of HIV drug resistance over time and identify risk factors for multiclass resistance.

DESIGN

Prospective clinical cohort of HIV-infected patients at the University of North Carolina.

METHODS

Among antiretroviral therapy (ART)-experienced patients in care 2000-2016, we estimated annual prevalences of cumulative resistance, defined as at least one major mutation by drug class. Clinical data and multiple imputation were used when genotypic data were missing, and mutations were carried forward in time. We estimated resistance odds ratios comparing characteristics of patients in care in 2016.

RESULTS

A total of 3682 patients contributed 23 169 person-years. Prevalence of at least one major resistance mutation, irrespective of viral suppression, peaked in 2005 with 49% (95% confidence interval 46, 52) and decreased to 38% (35, 40) in 2016. Resistance to nucleoside reverse transcriptase inhibitors, protease inhibitors, and nonnucleoside reverse transcriptase inhibitors also peaked in 2005-2007 and decreased to 28 (26, 31), 14 (12, 16), and 27% (24, 29) in 2016, respectively. In 2016, prevalence of integrase strand transfer inhibitor (INSTI) resistance was 2% (1, 3) and triple-class resistance 10% (9, 12). Over the study period, cumulative resistance was frequent among patients with detectable viremia, but uncommon among patients initiating ART post-2007. Among 1553 patients in care in 2016, ART initiation at an older age, with an INSTI, and with higher CD4 cell counts were associated with resistance to fewer or no classes.

CONCLUSION

Prevalence of resistance to older ART classes has decreased in the last 10 years in this clinical cohort, whereas INSTI resistance has increased but remained very low. Patients with viremia continue to have a high burden of resistance even if they initiated ART recently.

Profile of bictegravir/emtricitabine/tenofovir alafenamide fixed dose combination and its potential in the treatment of HIV-1 infection: evidence to date

Modern pharmacologic management of people living with HIV involves the use of fixed dose combinations of antiretrovirals that are simple to take, well tolerated, and highly effective. Specific recent pharmacologic advancements include 1) the second-generation integrase strand transfer inhibitors (dolutegravir and bictegravir) that consistently show less side effects, high tolerability, minimal drug interactions, and rapid rates of HIV viral load decline and 2) tenofovir alafenamide, a prodrug of tenofovir that concentrates in lymphoid tissue and minimizes off target effects. Bictegravir/emtricitabine/tenofovir alafenamide or B/F/TAF is a recently approved fixed dose combination that incorporates these new advancements in the management of HIV. This review focuses on the data supporting the use of B/F/TAF, reviews clinically relevant findings, and highlights the unanswered questions that may limit its clinical utility.

Association of raltegravir use with long-term health outcomes in HIV-infected patients: an observational post-licensure safety study in a large integrated healthcare system

BACKGROUND

Raltegravir became the first integrase inhibitor to gain FDA approval; but with limited evidence documenting long-term risks in real world care, especially for major health outcomes of interest.

OBJECTIVE

Assess raltegravir safety in clinical practice within an integrated health system.

METHODS

We conducted a cohort study of HIV-infected adults within Kaiser Permanente California from 2005 to 2013. We compared patients initiating raltegravir during the study period with two groups; a historical cohort (started new antiretroviral regimen [ART] 2005-2007) and a concurrent cohort that did not initiate raltegravir (2007-2013). We used multivariate Cox proportional hazard regression to obtain hazard ratios (HR) for pre-specified incident health outcomes, employing propensity scores to adjust for potential confounding.

RESULTS

The population included 8,219 HIV-infected adults (raltegravir cohort N = 1,757; 4,798 patient-years), with greater years known HIV-infected among raltegravir patients. The raltegravir cohort had increased HR for AIDS-defining (HR 2.69 [1.53-4.71]; HR 1.85 [1.21-2.82]) and non-AIDS-defining malignancies (HR 2.26 [1.29-3.94]; HR 1.88 [1.26-2.78]) relative to both comparison cohorts. Compared to the historical cohort we found no significant difference in all-cause mortality; the raltegravir cohort experienced increased HR for all-cause mortality compared to concurrent (HR 1.53 [1.02-2.31]). Raltegravir appeared protective of lipodystrophy when compared to the historical cohort but associated with increased incidence compared to concurrent. There were no significant differences in the incidence of hepatic, skin, or cardiovascular events.

CONCLUSIONS

The potentially elevated risk for malignancy and mortality with raltegravir and residual confounding merits further investigation. We demonstrate the value of observational cohorts for monitoring post-licensure medication safety.

Similar long-term efficacy of dual therapy containing raltegravir and a boosted protease inhibitor versus standard triple therapies in pretreated HIV-1-infected patients in a retrospective, real-life cohort of 14 years

OBJECTIVES

Raltegravir is used in many antiretroviral combinations, but its use in treatment-experienced patients without knowledge of baseline resistance is discussed controversially as a number of comparative studies have shown a higher rate of virological failure. However, it has been used frequently for the management of treatment failure, as it was the first integrase inhibitor to become available, and thus offered new options for patients with multiple resistance. The strategic use of raltegravir in this setting is examined in this study.

METHODS

In order to examine the efficacy of raltegravir in second and later lines of antiretroviral combinations, data for 740 patients from three clinical cohorts were analysed with a focus on the combinations that were used. These were stratified into the combination of two nonnucleoside reverse transcriptase inhibitors and raltegravir (2NRTIs + RAL), the combination of a boosted protease inhibitor and raltegravir (bPI + RAL), and other raltegravir-containing combinations.

RESULTS

The overall rate of virological suppression to < 50 HIV-1 RNA copies/mL was 69.5%. Although the baseline rate of virological suppression was higher for 2NRTIs + RAL than for the other strata, the outcomes were similar for all three groups at weeks 24, 48, 72 and 96.

CONCLUSIONS

These data indicate that, in a real-life setting, raltegravir can be used with a high virological success rate in treatment-experienced patients, and that the different combinations analysed (2NRTIs + RAL, bPI + RAL and others) show comparable rates of virological suppression.

Integrase Strand Transfer Inhibitor Resistance Mutations in Antiretroviral Treatment-naïve Patients in Korea: a Prospective, Observational Study

The present study investigated prevalence of integrase strand transfer inhibitors (INSTI) resistance mutations in HIV-1-infected antiretroviral therapy (ART)-naïve patients in Korea. From 106 plasma samples, amplification and sequencing of integrase genes was performed, and major or minor mutations were calculated by the Stanford HIV drug resistance mutation interpretation algorithm. No major INSTI resistance mutations were found, and 14 minor mutations were detected in 13 (12.3%) patients. The present data support the recommendation that routine testing for INSTI resistance mutations before starting ART is not necessary.

Incident AIDS or Death After Initiation of Human Immunodeficiency Virus Treatment Regimens Including Raltegravir or Efavirenz Among Adults in the United States

Background.

The long-term effectiveness of human immunodeficiency virus (HIV) treatments containing integrase inhibitors is unknown.

Methods.

We use observational data from the Centers for AIDS Research Network of Integrated Clinical Systems and the Centers for Disease Control and Prevention to estimate 4-year risk of AIDS and all-cause mortality among 415 patients starting a raltegravir regimen compared to 2646 starting an efavirenz regimen (both regimens include emtricitabine and tenofovir disoproxil fumarate). We account for confounding and selection bias as well as generalizability by standardization for measured variables, and present both observational intent-to-treat and per-protocol estimates.

Results.

At treatment initiation, 12% of patients were female, 36% black, 13% Hispanic; median age was 37 years, CD4 count 321 cells/µL, and viral load 4.5 log10 copies/mL. Two hundred thirty-five patients incurred an AIDS-defining illness or died, and 741 patients left follow-up. After accounting for measured differences, the 4-year risk was similar among those starting both regimens (ie, intent-to treat hazard ratio [HR], 0.96 [95% confidence interval {CI}, .63-1.45]; risk difference, -0.9 [95% CI, -4.5 to 2.7]), as well as among those remaining on regimens (ie, per-protocol HR, 0.95 [95% CI, .59-1.54]; risk difference, -0.5 [95% CI, -3.8 to 2.9]).

Conclusions.

Raltegravir and efavirenz-based initial antiretroviral therapy have similar 4-year clinical effects. Vigilance regarding longer-term comparative effectiveness of HIV regimens using observational data is needed because large-scale experimental data are not forthcoming.

Virologic suppression and CD4+ cell count recovery after initiation of raltegravir or efavirenz-containing HIV treatment regimens

OBJECTIVE

To explore the effectiveness of raltegravir-based antiretroviral therapy (ART) on treatment response among ART-naive patients seeking routine clinical care.

DESIGN

Cohort study of adults enrolled in HIV care in the United States.

METHODS

We compared virologic suppression and CD4 cell count recovery over a 2.5 year period after initiation of an ART regimen containing raltegravir or efavirenz using observational data from a US clinical cohort, generalized to the US population of people with diagnosed HIV. We accounted for nonrandom treatment assignment, informative censoring, and nonrandom selection from the US target population using inverse probability weights.

RESULTS

Of the 2843 patients included in the study, 2476 initiated the efavirenz-containing regimen and 367 initiated the raltegravir-containing regimen. In the weighted intent-to-treat analysis, patients spent an average of 74 (95% confidence interval: 41, 106) additional days alive with a suppressed viral load on the raltegravir regimen than on the efavirenz regimen over the 2.5-year study period. CD4 cell count recovery was also superior under the raltegravir regimen.

CONCLUSION

Patients receiving raltegravir spent more time alive and suppressed than patients receiving efavirenz, but the probability of viral suppression by 2.5 years after treatment was similar between groups. Optimizing the amount of time spent in a state of viral suppression is important to improve survival among people living with HIV and to reduce onward transmission.

A safety evaluation of raltegravir for the treatment of HIV

INTRODUCTION

Raltegravir (RAL) was the first commercialized agent from a new drug class with an innovative target, the integrase. Since its introduction in clinical practice RAL has become widely used for the treatment of HIV-1 infected patients. A decade after its approval, this article reviews key evidence from RAL with a special interest on safety outcomes. Areas covered: Pharmacologic, safety and efficacy data of RAL from clinical trials and post-commercialization published reports are hereby summarized after a literature review including PubMed search, relating proceedings and abstracts from relevant international HIV conferences, assessment reports from European and United States regulatory agencies and treatment guidelines (World Health Organization, United States Department of Health and Human Services and European AIDS Clinical Society), up to October 2017. Most frequent search terms were 'raltegravir', 'safety', 'adverse events', 'efficacy' and 'integrase-inhibitors'. Expert opinion: Despite the arrival of new integrase strand transfer inhibitors (INSTIs) with advantages in terms of dosing convenience (elvitegravir, ELV) and higher genetic barrier (dolutegravir, DTG), RAL has stood the test of time and its overall favourable safety profile, without significant appearance of unexpected adverse events, vouch for its relevance in the antiretroviral armamentarium.

Development of Protein-Protein Interaction Inhibitors for the Treatment of Infectious Diseases

Protein-protein interaction (PPI) inhibitors are a rapidly expanding class of therapeutics. Recent advances in our understanding of PPIs and success of early examples of PPI inhibitors demonstrate the feasibility of targeting PPIs. This review summarizes the techniques used for the discovery and optimization of a diverse set PPI inhibitors, focusing on the development of PPI inhibitors as new antibacterial and antiviral agents. We close with a summary of the advances responsible for making PPI inhibitors realistic targets for therapeutic intervention and brief outlook of the field.

Similar efficacy and tolerability of raltegravir-based antiretroviral therapy in HIV-infected patients, irrespective of age group, burden of comorbidities and concomitant medication: Real-life analysis of the German 'WIP' cohort

Only limited efficacy and tolerability data on raltegravir (RAL) use are currently available. Study objectives were to describe the efficacy and tolerability profile of RAL-based antiretroviral therapy (ART) in routine clinical practice in Germany. The WIP study (WIP = "Wirksamkeit von Isentress unter Praxisbedingungen", Efficacy of Isentress under routine clinical conditions) was a prospective, multi-centre cohort study in Germany. Human immunodeficiency virus (HIV)-infected patients aged ≥ 18 years in whom combinational ART with RAL 400 mg BID was indicated were enrolled. The primary endpoint was virologic response (HIV-RNA <50 copies/mL; non-completion equals failure) after 48 weeks. Of 451 patients, 85.1% (n = 384) were still receiving RAL at week 48. At baseline (BL), the prevalence of concomitant diseases was higher in patients of the age group ≥50 years (94.2% vs. 75.7%) as well as concomitant medications (74.8 % vs. 55.4%). Virologic response at week 48 was 74.7% (overall), 75.0% (naïve at BL), 81.5% (suppressed at BL), 47.1% (interrupted previous treatment at BL) and 64.9% (failing at BL), without significant differences by age group. A significant correlation of achievement of HIV-RNA <50 copies/mL was seen with treatment status at BL (p = 0.004). In addition, 77.3 % of the patients with a CD4 cell count >200 cells/µL at BL achieved HIV-RNA <50 copies/mL (p = 0.029). RAL was well tolerated with 80 adverse events (AEs) in 49 patients (10.9%) and 8 serious AEs (SAEs) in 6 patients (1.3%) reported to be drug related. A total of 22 patients (4.9%) discontinued treatment due to AEs. The WIP study shows that the previously reported efficacy and safety profile of RAL can be achieved in a population with multiple comorbidities and comedications, with no major difference observed in ageing patients (≥50 years) vs. younger patients. RAL is therefore an attractive treatment option in routine medical care in Germany.