Long-term efficacy and safety of raltegravir in the management of HIV infection

The Integrase: An Overview of a Key Player Enzyme in the Antiviral Scenario

Integration of a desossiribonucleic acid (DNA) copy of the viral ribonucleic acid (RNA) into host genomes is a fundamental step in the replication cycle of all retroviruses. The highly conserved virus-encoded Integrase enzyme (IN; EC 2.7.7.49) catalyzes such a process by means of two consecutive reactions named 3'-processing (3-P) and strand transfer (ST). The Authors report and discuss the major discoveries and advances which mainly contributed to the development of Human Immunodeficiency Virus (HIV) -IN targeted inhibitors for therapeutic applications. All the knowledge accumulated over the years continues to serve as a valuable resource for the design and development of effective antiretroviral drugs.

Diffuse Large B-Cell Lymphoma in the HIV Setting

Despite the widespread use of combined antiretroviral therapy (cART) and the subsequent decrease in AIDS-defining cancers, HIV-related lymphomas remain a leading cause of morbidity and mortality in people with HIV (PWH). Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL) subtype in PWH. This lymphoma is a heterogeneous disease including morphological variants and molecular subtypes according to the cell of origin or the mutation profile. In the pre-cART era, treatment with standard-dose chemotherapy induced high rates of toxicity and outcomes were very poor. The introduction of cART and the incorporation of infection prophylaxis allowed the use of conventional intensive chemotherapy regimens used in the general population, such as R-CHOP or R-EPOCH. The use of cART during chemotherapy treatment was initially controversial due to the potential risk of adverse drug-drug interactions. However, the availability of current cART regimens with less potential to cause drug interactions and evidence that cART improves survival rates in NHL strongly support the use of cART in PWH with DLBCL. Consequently, interdisciplinary collaboration between HIV specialists and hemato-oncologists for the management of potential interactions and overlapping toxicities between antiretroviral and antineoplastic drugs is crucial for the optimal treatment of PWH with NHL.

Hodgkin Lymphoma in People Living with HIV

Simple Summary

Hodgkin lymphoma (HL) is a non-AIDS defining neoplasm, but people living with HIV (PLWH) have between a 5- and 26-fold higher risk of developing it than the general population. Epstein-Barr virus is present in almost all HIV-related HL cases, and plays an important role in its etiopathogenesis. Despite the aggressive characteristics, the prognosis of HL affecting PLWH is similar to that of the general population if patients are treated following the same recommendations. Administration of cART concomitantly with chemotherapy is highly recommended. However, this combination may be challenging due to drug–drug interactions and overlapping toxicity. Thus, interdisciplinary collaboration between hemato-oncologists and HIV specialists is crucial for the optimal treatment of both lymphoma and HIV infection.

Abstract

Despite widespread use of combined antiretroviral therapy (cART) and increased life expectancy in people living with HIV (PLWH), HIV-related lymphomas (HRL) remain a leading cause of cancer morbidity and mortality for PLWH, even in patients optimally treated with cART. While the incidence of aggressive forms of non-Hodgkin lymphoma decreased after the advent of cART, incidence of Hodgkin lymphoma (HL) has increased among PLWH in recent decades. The coinfection of Epstein–Barr virus plays a crucial role in the pathogenesis of HL in the HIV setting. Currently, PLWH with HRL, including HL, are treated similarly to HIV-negative patients and, importantly, the prognosis of HL in PLWH is approaching that of the general population. In this regard, effective cART during chemotherapy is strongly recommended since it has been shown to improve survival rates in all lymphoma subtypes, including HL. As a consequence, interdisciplinary collaboration between HIV specialists and hemato-oncologists for the management of potential drug–drug interactions and overlapping toxicities between antiretroviral and antineoplastic drugs is crucial for the optimal treatment of PLWH with HL. In this article the authors review and update the epidemiological, clinical and biological aspects of HL presenting in PLWH with special emphasis on advances in prognosis and the factors that have contributed to it.

Severe rhabdomyolysis and acute asymptomatic pancreatitis following the concomitant use of Biktarvy in the setting of hyperosmolar diabetic crisis

Biktarvy (bictegravir/emtricitabine/tenofovir alafemanide), which has been recently approved for the treatment of HIV, is a single-pill regimen that associates bictegravir and a novel integrase strand transfer inhibitor (INSTI) with a combination of two nucleoside reverse transcriptase inhibitors (NRTI) of emtricitabine and tenofovir alafemanide. Among treatment complications, rhabdomyolysis has been reported in association with some NRTI and INSTI but never with bictegravir. Acute pancreatitis has also been reported recently with another INSTI, dolutegravir. We report here a 62-year-old man with diabetes and HIV infection, and receiving Biktarvy for 1 month. He presented to the emergency department for muscular pain and fatigue. He was on treatment with Descovy (tenofovir alafenamide/emtricitabine) and Viramune (nevirapine) for 2 years but he recently asked for a regimen simplification. Severe rhabdomyolysis and acute pancreatitis were diagnosed. Although the aetiology of these events could be multifactorial, it cannot be ruled out that this episode could be linked to a potential side effect of bictegravir.

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 Once-Daily Tablet: A Review in HIV-1 Infection

A once-daily tablet formulation (Isentress^® HD; Isentress^® 600 mg) of the integrase strand transfer inhibitor raltegravir is now available for the treatment of HIV-1 infection. The 600 mg tablet has improved bioavailability versus the existing twice-daily 400 mg tablet (due, at least in part, to differences in tablet dissolution) and the recommended dosage is 1200 mg (i.e. two 600 mg tablets) once daily. In combination with emtricitabine/tenofovir disoproxil fumarate in treatment-naïve adults, once-daily raltegravir 1200 mg provided virological suppression non-inferior to that seen with twice-daily raltegravir 400 mg over 48 and 96 weeks in the phase 3 ONCEMRK trial. The once-daily raltegravir regimen was also generally well tolerated in this study, displaying a tolerability profile similar to that of the twice-daily regimen. The once-daily tablet simplifies and improves the convenience of raltegravir regimens, although its impact on adherence has yet to be determined. Thus, once-daily raltegravir tablets are a convenient alternative to twice-daily raltegravir tablets for the treatment of HIV-1, further expanding the therapeutic options available to meet the diverse needs of this patient population.

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.

Recent advances in the discovery of small-molecule inhibitors of HIV-1 integrase

AIDS caused by the infection of HIV is a prevalent problem today. Rapid development of drug resistance to existing drug classes has called for the discovery of new targets. Within the three major enzymes (i.e., HIV-1 protease, HIV-1 reverse transcriptase and HIV-1 integrase [IN]) of the viral replication cycle, HIV-1 IN has been of particular interest due to the absence of human cellular homolog. HIV-1 IN catalyzes the integration of viral genetic material with the host genome, a key step in the viral replication process. Several novel classes of HIV IN inhibitors have been explored by targeting different sites on the enzyme. This review strives to provide readers with updates on the recent developments of HIV-1 IN inhibitors.

AIDS is an epidemic disease that endangers the lives of millions of people across the world. The AIDS virus, also known as HIV, has developed resistance to the majority of available drugs on the market, thus requiring the need for new drugs. HIV integrase is one of the key viral enzymes required for viral cell proliferation. Since there is no similar enzyme in the human body, major emphasis is being made to develop therapeutics for this novel target. The drugs that are at various stages of development for this target are reviewed here.

Prevalence of resistance to integrase strand-transfer inhibitors (INSTIs) among untreated HIV-1 infected patients in Morocco

Objective

The integrase strand-transfer inhibitors (INSTIs) are an important class in the arsenal of antiretroviral drugs designed to block the integration of HIV-1 cDNA into the host DNA through the inhibition of DNA strand transfer. In this study for the first time in Morocco, the complete HIV-1 integrase gene was analysed from newly diagnosed patients to evaluate the prevalence of natural polymorphisms and INSTIs resistance-associated mutations in the integrase gene.

Results

The 864pb IN coding region was successfully sequenced from plasma sample for 77 among 80 antiretroviral naïve patients. The sequences were interpreted for drug resistance according to the Stanford algorithm. Sixty samples were HIV-1 subtype B (78%), fourteen CRF02_AG (18%), two subtype C and one subtype A. Overall 81 of 288 (28%) amino acid IN positions presented at least one polymorphism each. We found 18 (36.73%), 42 (25.76%) and 21 (27.27%) of polymorphic residues assigned to the N-Terminal Domain, Catalytic Core Domaine and the C-Terminal Domain positions respectively. Primary INSTIs resistance mutation were absent, however secondary mutations L74IM, T97A were detected in four samples (5.2%). These results demonstrate that untreated HIV-1 infected Moroccans will be susceptible to INSTIs.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3492-5) contains supplementary material, which is available to authorized users.

Ex vivo activation of CD4+ T-cells from donors on suppressive ART can lead to sustained production of infectious HIV-1 from a subset of infected cells

The fate of HIV-infected cells after reversal of proviral latency is not well characterized. Simonetti, et al. recently showed that CD4⁺ T-cells containing intact proviruses can clonally expand in vivo and produce low-level infectious viremia. We hypothesized that reversal of HIV latency by activation of CD4⁺ T-cells can lead to the expansion of a subset of virus-producing cells rather than their elimination. We established an ex vivo cell culture system involving stimulation of CD4⁺ T-cells from donors on suppressive antiretroviral therapy (ART) with PMA/ionomycin (day 1–7), followed by rest (day 7–21), and then repeat stimulation (day 21–28), always in the presence of high concentrations of raltegravir and efavirenz to effectively block new cycles of viral replication. HIV DNA and virion RNA in the supernatant were quantified by qPCR. Single genome sequencing (SGS) of p6-PR-RT was performed to genetically characterize proviruses and virion-associated genomic RNA. The replication-competence of the virions produced was determined by the viral outgrowth assay (VOA) and SGS of co-culture supernatants from multiple time points. Experiments were performed with purified CD4⁺ T-cells from five consecutively recruited donors who had been on suppressive ART for > 2 years. In all experiments, HIV RNA levels in supernatant increased following initial stimulation, decreased or remained stable during the rest period, and increased again with repeat stimulation. HIV DNA levels did not show a consistent pattern of change. SGS of proviruses revealed diverse outcomes of infected cell populations, ranging from their apparent elimination to persistence and expansion. Importantly, a subset of infected cells expanded and produced infectious virus continuously after stimulation. These findings underscore the complexity of eliminating reservoirs of HIV-infected cells and highlight the need for new strategies to kill HIV-infected cells before they can proliferate.

Stable latent reservoirs of HIV persist despite suppressive antiretroviral therapy (ART) and cause rebound viremia following interruption of ART. New HIV cure strategies aim to deplete the latent reservoir by reversing HIV latency and promoting the death of cells containing inducible proviruses. Multiple latency reversing agents have been discovered, with the most effective compounds also causing T-cell activation. We investigated the ex vivo effects of cell activation on HIV-infected cells from individuals on stable suppressive ART. Latency reversal through robust cell activation led to diverse outcomes of infected cells. Although many infected cells appeared to be eliminated following T-cell activation, a subset of HIV-infected cells persisted and could expand, including those that can produce infectious virus. These findings highlight the need for new therapies that kill HIV-infected cells before they can proliferate.

Maraviroc/raltegravir simplification strategy following 6 months of quadruple therapy with tenofovir/emtricitabine/maraviroc/raltegravir in treatment-naive HIV patients

OBJECTIVE

We assessed the virological efficacy of a 6 month maraviroc/raltegravir simplification strategy following 6 months of quadruple therapy combining tenofovir disoproxil fumarate/emtricitabine with maraviroc/raltegravir.

METHODS

HIV-1-infected naive patients were enrolled in an open label, single-arm, Phase 2 trial. All patients received maraviroc 300 mg twice daily, raltegravir 400 mg twice daily and tenofovir/emtricitabine for 24 weeks. Patients with stable HIV-RNA <50 copies/mL stopped tenofovir/emtricitabine at week (W) 24 and pursued maraviroc/raltegravir until W48. The primary endpoint was the virological response defined by HIV-RNA <50 copies/mL at W48.

RESULTS

Thirty-three patients were analysed. Patients were mostly male (94%), Caucasians (91%), MSM (82%); their median age was 42 years. At baseline, median CD4 cell count was 453 cells/mm³ and HIV-RNA was 4.3 log copies/mL. All patients had CCR5-tropic viruses by genotropism and phenotropism assays. All but one patient had an HIV-RNA < 50 copies/mL at W24 and entered the simplification phase. Virological success was maintained at W48 in 88% (90% CI 79%-97%) of patients. N155H mutation was detected at failure in one patient. No tropism switch was observed. Raltegravir and maraviroc plasma exposure were satisfactory in 92% and 79% of 41 samples from 21 patients. Five severe adverse events (SAEs) were observed up to W48; none was related to the study drugs. Four patients presented grade 3 AEs; none was related to the study. No grade 4 AE was observed. No patient died.

CONCLUSIONS

Maraviroc/raltegravir maintenance therapy following a 6 month induction phase with maraviroc/raltegravir/tenofovir/emtricitabine was well tolerated and maintained virological efficacy in these carefully selected patients.

Lung cancer in HIV-infected patients in the combination antiretroviral treatment era

The advent of combination antiretroviral treatment (cART) has been followed by a decrease in HIV-associated morbidity and mortality, but also by an apparent increase in the incidence of non-AIDS-defining cancers (NADCs). The risk of lung cancer is substantially higher in HIV-infected patients than in the general population, in part due to aging and tobacco use, and it is the most frequent NADC. The management of lung cancer in HIV-infected patients has some peculiarities that need to be taken into account. This review focuses on the epidemiology, risk factors, and clinical management of lung cancer in HIV-infected patients. In addition, screening tools and future perspectives are also discussed.

Pregnancy is associated with elevation of liver enzymes in HIV-positive women on antiretroviral therapy

Objective:

The objective of this study is to assess whether pregnancy is associated with an increased risk of liver enzyme elevation (LEE) and severe LEE in HIV-positive women on antiretroviral therapy (ART).

Design:

Two observational studies: the UK Collaborative HIV Cohort (UK CHIC) study and the UK and Ireland National Study of HIV in Pregnancy and Childhood (NSHPC).

Methods:

Combined data from UK CHIC and NSHPC were used to identify factors associated with LEE (grade 1–4) and severe LEE (grade 3–4). Women starting ART in 2000–2012 were included irrespective of pregnancy status. Cox proportional hazards were used to assess fixed and time-dependent covariates including pregnancy status, CD4⁺ cell count, drug regimen and hepatitis B virus/hepatitis C virus (HBV/HCV) coinfection.

Results:

One-quarter (25.7%, 982/3815) of women were pregnant during follow-up, 14.2% (n = 541) when starting ART. The rate of LEE was 14.5/100 person-years in and 6.0/100 person-years outside of pregnancy. The rate of severe LEE was 3.9/100 person-years in and 0.6/100 person-years outside of pregnancy. The risk of LEE and severe LEE was increased during pregnancy [LEE: adjusted hazard ratio (aHR) 1.66 (1.31–2.09); severe LEE: aHR 3.57 (2.30–5.54)], including in secondary analyses excluding 541 women pregnant when starting ART. Other factors associated with LEE and severe LEE included lower CD4⁺ cell count (<250 cells/μl), HBV/HCV coinfection and calendar year.

Conclusion:

Although few women developed severe LEE, this study provides further evidence that pregnancy is associated with an increased risk of LEE and severe LEE, reinforcing the need for regular monitoring of liver biomarkers during pregnancy.

Selective and rapid determination of raltegravir in human plasma by liquid chromatography-tandem mass spectrometry in the negative ionization mode

A selective and rapid high-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of raltegravir using raltegravir-d3 as an internal standard (IS). The analyte and IS were extracted with methylene chloride and n-hexane solvent mixture from 100 µL human plasma. The chromatographic separation was achieved on a Chromolith RP-18e endcapped C₁₈ (100 mm×4.6 mm) column in a run time of 2.0 min. Quantitation was performed in the negative ionization mode using the transitions of m/z 443.1→316.1 for raltegravir and m/z 446.1→319.0 for IS. The linearity of the method was established in the concentration range of 2.0-6000 ng/mL. The mean extraction recovery for raltegravir and IS was 92.6% and 91.8%, respectively, and the IS-normalized matrix factors for raltegravir ranged from 0.992 to 0.999. The application of this method was demonstrated by a bioequivalence study on 18 healthy subjects.