Nucleoside reverse transcriptase inhibitors in combination therapy for HIV patients: systematic review and meta-analysis

Virological outcomes and genotypic resistance on dolutegravir-based antiretroviral therapy versus standard of care in children and adolescents: a secondary analysis of the ODYSSEY trial

BACKGROUND

ODYSSEY showed superior efficacy for dolutegravir-based antiretroviral therapy (ART) versus standard of care (SOC) in children living with HIV starting first-line or second-line ART aged 4 weeks or older. Here, we aim to compare virological outcomes and resistance in the dolutegravir group versus SOC for first-line and second-line ART up to 96 weeks.

METHODS

ODYSSEY was an open-label, multicentre, randomised, non-inferiority trial done in 29 centres in seven countries (Germany, Spain, South Africa, Thailand, the UK, Uganda, and Zimbabwe). ODYSSEY recruited children living with HIV aged at least 28 days and younger than 18 years, weighing at least 3 kg, starting first-line ART (ODYSSEY A), or switching to second-line therapy after treatment failure (ODYSSEY B). Children were randomly assigned (1:1) to dolutegravir plus two nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs; dolutegravir group) versus the SOC group (non-nucleoside reverse transcriptase inhibitor [NNRTI], boosted protease inhibitor, or non-dolutegravir integrase strand-transfer inhibitor, plus two NRTIs). Two randomised cohorts were combined in this exploratory analysis: children weighing at least 14 kg were enrolled between Sept 20, 2016, and June 22, 2018, and children weighing less than 14 kg were enrolled between July 5, 2018, and Aug 26, 2019. Virological failure was defined as an inadequate virological response at week 24 with an ART switch or confirmed HIV-1 RNA viral load of at least 400 copies per mL after week 36. Virological suppression was defined as two consecutive viral loads of less than 400 copies per mL and was compared between groups, including an ART switch and death as competing risks. Children with virological failure were tested for post-failure genotypic resistance, with baseline results used to identify emergent resistance. Development of emergent resistance was a secondary trial outcome and all other outcomes are exploratory. ODYSSEY was registered with ClinicalTrials.gov (NCT02259127), EUDRACT (2014-002632-14), and ISRCTN (ISRCTN91737921).

FINDINGS

In ODYSSEY at enrolment, 381 participants started first-line ART (ODYSSEY A: 189 in the dolutegravir group and 192 in the SOC group) and 407 participants started second-line ART (ODYSSEY B: 202 in the dolutegravir group and 205 in the SOC group). 72 participants in ODYSSEY A and 13 participants in ODYSSEY B weighed less than 14 kg. 401 (51%) of 788 participants were female and 387 (49%) were male. Virological suppression occurred significantly earlier in the dolutegravir group (adjusted [cause-specific] hazard ratio [HR] 1·57 [95% CI 1·35 to 1·83]; p<0·0001). Overall, 51 (13%) participants had virological failure by 96 weeks in the dolutegravir group versus 86 (22%) in the SOC group (including 18 [10%] vs 43 [22%] in ODYSSEY A and in 33 [16%] vs 43 [21%] in ODYSSEY B; adjusted HR 0·56 [0·40 to 0·79]; p=0·0011). Among ODYSSEY B participants starting dolutegravir, virological failure was higher in children starting zidovudine (HR 2·22 [1·01 to 4·88]; p=0·048) and similar in those starting tenofovir disoproxil fumarate (1·19 [0·50 to 2·83]; p=0·70) compared with abacavir. Time to virological suppression was marginally faster in participants receiving second-line dolutegravir and abacavir with high-level abacavir resistance at baseline compared with those with no, low-level, intermediate-level resistance (cause-specific HR 1·70 [1·01 to 2·85]; p=0·046); and failure rates by week 96 were similar (HR 0·90 [0·23 to 3·61]; p=0·88). An estimated 1% (95% CI 0 to 2) of participants in the dolutegravir group versus 20% (14 to 26) in the SOC group in ODYSSEY A had emergent resistance to at least one drug-class within their first-line regimen (risk difference -20% [-25 to -14]; p<0·0001); 4% (1 to 6) versus 5% (2 to 8) had resistance to drug within their initial second-line regimen (risk difference -1% [-5 to 3]; p=0·60). 3% (0 to 5) of participants in the dolutegravir group had emergent integrase strand-transfer inhibitors resistance compared with 3% (1 to 6) of participants in the SOC group who had emergent resistance to the anchor drug (risk difference 0% [-4 to 3]; p=0·78).

INTERPRETATION

Dolutegravir led to faster virological suppression and lower risk of virological failure than NNRTIs and boosted protease inhibitor-based SOC. Participants starting second-line dolutegravir-based ART with an abacavir or tenofovir backbone were at lower risk of virological failure than those starting zidovudine. During first-line therapy, dolutegravir protected against emergent resistance; starting second-line therapy, the risk of emergent resistance to nucleoside reverse transcriptase inhibitor backbone, and anchor drugs, was similar among participants starting dolutegravir within their second-line regimen and those starting mainly boosted protease inhibitor-based SOC.

FUNDING

Penta Foundation, ViiV Healthcare, and UK Medical Research Council.

Design and Synthesis of ZnII -Coordination Polymers Anchored with NSAIDs: Metallovesicle Formation and Multi-drug Delivery

A series of coordination polymers synthesized from a bis-pyridyl linker, namely 4,4'-azopyridine (L), selected non-steroidal-anti-inflammatory drugs (NSAIDs), namely diclofenac (Dic), ibuprofen (Ibu), flurbiprofen (Flu), mefenamic acid (Mefe), and naproxen (Nap), and Zn(NO₃ )₂ were characterized by single crystal X-ray diffraction. One of the coordination polymers, namely CP3 derived from Flu, was able to form metallovesicles in DMSO, DMSO/H₂ O and DMSO/DMEM (biological media) as revealed by TEM, AFM and DLS. Metallovesicle formation by CP3 was further supported by loading a fluorescent dye, namely calcein, as well as an anti-cancer drug, doxorubicin hydrochloride (DOX), as revealed by UV-vis and emission spectra, and fluorescence microscopy. DOX-loaded metallovesicles of CP3 (DOX@CP3-vesicle) could be delivered in vitro to a highly aggressive human breast cancer cell line, namely MDA-MB-231, as revealed by MTT and cell migration assays, and also cell imaging performed under laser scanning confocal microscope (LSCM). Thus, a proof of concept for developing a multi-drug delivery system derived from a metallovesicle for delivering an anti-cancer drug to cancer cells is demonstrated for the first time.

Micellar carriers for the delivery of multiple therapeutic agents

Multi-drug therapy is described as a simultaneous or sequential administration of two or more drugs with similar or different mechanisms of action and is recognized as a more efficient solution to combat successfully, various ailments. Polymeric micelles (PMs) are self-assemblies of block copolymers providing numerous opportunities for drug delivery. To date various micellar formulations were studied for delivery of drugs, nutraceuticals and genes; a few of them are in clinical trials. It was observed that there is an immense need for the development of PMs embedding multiple therapeutic agents to combat various ailments, including cancers, HIV/AIDS, malaria, multiple sclerosis, hypertension, infectious diseases, cardiovascular and metabolic diseases, immune disorders and many psychiatric disorders. Several combinations of drug-drug, drug-nutraceutical, drug-gene and drug-siRNA explored to date are detailed in this review, with a special emphasis on their potential and future perspectives. A summary of various preparation methods, characterization techniques and applications of PMs are also provided. This review presents a holistic approach on multi-drug delivery using micellar carriers and emphasizes on the development of therapeutic hybrids embedding novel combinations for safer and effective therapy.

Investigational reverse transcriptase inhibitors for the treatment of HIV

INTRODUCTION

While considerable advances have been made in the development of antiretroviral agents, there is still work to be done. Reverse transcriptase inhibitors are important drugs for the treatment of HIV, and considerable research is currently ongoing to develop new agents and to modify currently existing agents.

AREAS COVERED

Herein, the authors discuss both investigational nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), including agents that are in various stages of development. They also discuss novel formulations that are being investigated for currently available drugs, and discuss the advantages that these new formulations may provide.

EXPERT OPINION

New formulations and co-formulations of currently existing antiretrovirals will represent an important area of development, as a means to improve adherence for HIV-positive individuals. New formulations will continue to be developed, with a focus on allowing for less-frequent administration, as well increasing drug concentrations at local sites such as vaginal tissue, rectal tissue and sites in the immune system.

Derivatives of mesoxalic acid block translocation of HIV-1 reverse transcriptase

The pyrophosphate mimic and broad spectrum antiviral phosphonoformic acid (PFA, foscarnet) was shown to freeze the pre-translocational state of the reverse transcriptase (RT) complex of the human immunodeficiency virus type 1 (HIV-1). However, PFA lacks a specificity domain, which is seen as a major reason for toxic side effects associated with the clinical use of this drug. Here, we studied the mechanism of inhibition of HIV-1 RT by the 4-chlorophenylhydrazone of mesoxalic acid (CPHM) and demonstrate that this compound also blocks RT translocation. Hot spots for inhibition with PFA or CPHM occur at template positions with a bias toward pre-translocation. Mutations at active site residue Asp-185 compromise binding of both compounds. Moreover, divalent metal ions are required for the formation of ternary complexes with either of the two compounds. However, CPHM contains both an anchor domain that likely interacts with the catalytic metal ions and a specificity domain. Thus, although the inhibitor binding sites may partly overlap, they are not identical. The K65R mutation in HIV-1 RT, which reduces affinity to PFA, increases affinity to CPHM. Details with respect to the binding sites of the two inhibitors are provided on the basis of mutagenesis studies, structure-activity relationship analyses with newly designed CPHM derivatives, and in silico docking experiments. Together, these findings validate the pre-translocated complex of HIV-1 RT as a specific target for the development of novel classes of RT inhibitors.

Polymeric micelles for multidrug delivery and combination therapy

The use of conventional therapy based on a single therapeutic agent is not optimal to treat human diseases. The concept called "combination therapy", based on simultaneous administration of multiple therapeutics is recognized as a more efficient solution. Interestingly, this concept has been in use since ancient times in traditional herbal remedies with drug combinations, despite mechanisms of these therapeutics not fully comprehended by scientists. This idea has been recently re-enacted in modern scenarios with the introduction of polymeric micelles loaded with several drugs as multidrug nanocarriers. This Concept article presents current research and developments on the application of polymeric micelles for multidrug delivery and combination therapy. The principles of micelle formation, their structure, and the developments and concept of multidrug delivery are introduced, followed by discussion on recent advances of multidrug delivery concepts directed towards targeted drug delivery and cancer, gene, and RNA therapies. The advantages of various polymeric micelles designed for different applications, and new developments combined with diagnostics and imaging are elucidated. A compilation work from our group based on multidrug-loaded micelles as carriers in drug-releasing implants for local delivery systems based on titania nanotubes is summarized. Finally, an overview of recent developments and prospective outlook for future trends in this field is given.

Pharmacokinetics of antiretroviral drug varies with formulation in the target population of children with HIV-1

The bioequivalence of formulations is usually evaluated in healthy adult volunteers. In our study in 19 HIV-1-infected Ugandan children (1.8-4 years of age, weight 12 to <15 kg) receiving zidovudine, lamivudine, and abacavir solutions twice a day for ≥24 weeks, the use of scored tablets allowed comparison of plasma pharmacokinetics of oral solutions vs. tablets. Samples were collected 0, 1, 2, 4, 6, 8, and 12 h after each child's last morning dose of oral solution before changing to scored tablets of Combivir (coformulated zidovudine + lamivudine) and abacavir; this was repeated 4 weeks later. Dose-normalized area under curve (AUC)(0-12) and peak concentration (C(max)) for the tablet formulation were bioequivalent with those of the oral solution with respect to zidovudine and abacavir (e.g., dose-normalized geometric mean ratio (dnGMR) (tablet:solution) for zidovudine and abacavir AUC(0-12) were 1.01 (90% confidence interval (CI) 0.87-1.18) and 0.96 (0.83-1.12), respectively). However, lamivudine exposure was ~55% higher with the tablet formulation (AUC(0-12) dnGMR = 1.58 (1.37-1.81), C(max) dnGMR = 1.55 (1.33-1.81)). Although the clinical relevance of this finding is unclear, it highlights the impact of the formulation and the importance of conducting bioequivalence studies in target pediatric populations.

Calculation of direct antiretroviral treatment costs and potential cost savings by using generics in the German HIV ClinSurv cohort

Background/Aim of the Study

The study aimed to determine the cost impacts of antiretroviral drugs by analysing a long-term follow-up of direct costs for combined antiretroviral therapy, cART,-regimens in the nationwide long-term observational multi-centre German HIV ClinSurv Cohort. The second aim was to develop potential cost saving strategies by modelling different treatment scenarios.

Methods

Antiretroviral regimens (ART) from 10,190 HIV-infected patients from 11 participating ClinSurv study centres have been investigated since 1996. Biannual data cART,-initiation, cART-changes, surrogate markers, clinical events and the Centre of Disease Control- (CDC)-stage of HIV disease are reported. Treatment duration was calculated on a daily basis via the documented dates for the beginning and end of each antiretroviral drug treatment. Prices were calculated for each individual regimen based on actual office sales prices of the branded pharmaceuticals distributed by the license holder including German taxes.

Results

During the 13-year follow-up period, 21,387,427 treatment days were covered. Cumulative direct costs for antiretroviral drugs of €812,877,356 were determined according to an average of €42.08 per day (€7.52 to € 217.70). Since cART is widely used in Germany, the costs for an entire regimen increased by 13.5%. Regimens are more expensive in the advanced stages of HIV disease. The potential for cost savings was calculated using non-nucleotide-reverse-transcriptase-inhibitor, NNRTI, more frequently instead of ritonavir-boosted protease inhibitor, PI/r, in first line therapy. This calculation revealed cumulative savings of 10.9% to 19.8% of daily treatment costs (50% and 90% substitution of PI/r, respectively). Substituting certain branded drugs by generic drugs showed potential cost savings of between 1.6% and 31.8%.

Conclusions

Analysis of the data of this nationwide study reflects disease-specific health services research and will give insights into the cost impacts of antiretroviral therapy, and might allow a more rational allocation of resources within the German health care system.

Abacavir and lamivudine for the treatment of human immunodeficiency virus

INTRODUCTION

The introduction of combination antiretroviral therapy (cART) in 1996 dramatically changed the survival and the quality of life of people living with human immunodeficiency virus (HIV). Viral replication can be controlled by using a combination of more than 30 licensed drugs. Despite the fact that many advances have been made in the last 20 years of experience with antiretrovirals, certain needs remain to be addressed, such as the presence of chronic inflammation, the long-term side effects of newly introduced drugs and eradication. Abacavir (ABC) and lamivudine (3TC) are licensed in a fixed-dose combination to be administered once daily with other antiretroviral agents for the treatment of HIV.

AREAS COVERED

This article provides an extensive review of the evidence on the combination of ABC 600 mg and 3TC 300 mg. Specifically, it discusses the chemistry-- including the phrarmacodynamics, resistance to treatment, pharmacokinetics and metabolism--and formulations available. It also looks at clinical efficacy, including safety and tolerability.

EXPERT OPINION

In the last few years, new data regarding human leukocyte antigen (HLA) B*5701 testing to prevent the hypersensitivity reaction due to ABC have been presented, providing a landmark in the management of adverse events in HIV, and later a previously unexpected correlation of the recent exposure to ABC with an increased risk of cardiovascular disease. This review presents the current situation with regard to the long-term efficacy and safety data on the ABC/3TC combination.

Open-label randomized multicenter selection study of once daily antiretroviral treatment regimen comparing ritonavir-boosted atazanavir to efavirenz with fixed-dose abacavir and lamivudine

BACKGROUND

The side-effects of anti-retroviral drugs are different between Japanese and Caucasian patients. Severe central nerve system (CNS) side-effects to efavirenz and low rate of hypersensitivity against abacavir characterize the Japanese.

OBJECTIVE

The objective of this study was to select a once daily regimen for further non-inferior study comparing the virological efficacy and safety of the first line once daily antiretroviral treatment regimens in the current HIV/AIDS guideline.

METHODS

The study design was a randomized, open label, multicenter, selection study. One arm was treated with efavirenz and the other with ritonavir-boosted atazanavir. A fixed-dose lamivudine plus abacavir were used in both arms. The primary endpoint was virologic success (viral load less than 50 copies/mL) rate at 48 weeks. Patients were followed-up to 96 weeks with safety as the secondary endpoint. Clinicaltrials.Gov (NCT00280969) and the University hospital Medical Information Network (UMIN000000243).

RESULTS

A total of 71 participants were enrolled. Virologic success rates in both arms were similar at week 48 [efavirenz arm 28/36 (77.8%); atazanavir arm 27/35 (77.1%)], but were decreased at week 96 to 55.6% in the efavirenz arm and 68.8% in the atazanavir arm (p=0.33). At the 96-week follow-up, 52.8% of the EFV arm and 34.3% of the ATV/r arm reached total cholesterol more than 220 mg/dL and required treatment. None of the patients developed cardiovascular complications in this study by week 96.

CONCLUSION

There was no significant difference in the efficacy of efavirenz and ritonavir-boosted atazanavir combined with lamivudine plus abacavir at 48 weeks. The evaluation of safety was extended to 96 weeks, which also showed no significant difference in both arms.