Emerging role of integrase inhibitors in the management of treatment-experienced patients with HIV infection

COVID-19 Pandemic: Outbreak, Potential Vaccines And Medications

The outbreak of the current global pandemic caused by the spread of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed an unprecedented threat to global health and economy across the whole world. As of today, the number of cases diagnosed with SARS-CoV-2 is exceeding 271 million with over 5.32 million deaths globally. Despite the high throughput technology and considerable advances in sciences, the outbreaks of the COVID-19 pandemic present a colossal challenge to scientific community. Scientists and clinicians all over the world are putting tremendous efforts to develop effective treatments to combat this deadly pathogen, at least to contain it momentarily until an adequate treatment regimen is available. Conventionally, vaccines have been developed as one of the therapeutic strategies to restrict infectious diseases. Although several vaccines are in the pipeline, evaluation of efficacy in animals’ studies and human are time-consuming. On the other hand, several drugs already in clinical use are being employed to test their efficacy against SARS-CoV-2. Some of these drugs have been already used as anti-viral drugs and others have been used for different therapeutic purposes. In this review, we summarize the ongoing efforts to control the dissemination of SARS-CoV-2 and highlight the potential prophylactic and therapeutic measures including the recently developed vaccines in the foreseeable future. Moreover, we emphasize an importance of having a customized strategy that can be easily and quickly employed to overcome possible future outbreaks.

Treatment durability and virological response in treatment-experienced HIV-positive patients on an integrase inhibitor-based regimen: an Australian cohort study

Background: Integrase inhibitors (INSTI) are a newer class of antiretroviral (ARV) drugs that offer additional treatment options for experienced patients. Our aim is to describe treatment durability and virological outcomes in treatment-experienced HIV-positive patients using INSTI-based regimens. Methods: All patients in the Australian HIV Observational Database who had received an INSTI-based regimen ≥ 14 days as well as previous therapy were included in the study. We defined two groups of treatment-experienced patients: (1) those starting a second-line regimen with INSTI; and (2) highly experienced patients, defined as having prior exposure to all three main ARV classes, nucleoside reverse transcriptase inhibitor, nonnucleoside reverse transcriptase inhibitors and protease inhibitors, before commencing INSTI. Survival methods were used to determine time to viral suppression and treatment switch, stratified by patient treatment experience. Covariates of interest included age, gender, hepatitis B and C co-infection, previous antiretroviral treatment time, patient treatment experience and baseline viral load. Results: Time to viral suppression and regimen switching from INSTI initiation was similar for second-line and highly experienced patients. The probability of achieving viral suppression at 6 months was 77.7% for second-line patients and 68.4% for highly experienced patients. There were 60 occurrences of regimen switching away from INSTI observed over 1274.0 person-years, a crude rate of 4.71 (95% CI: 3.66-6.07) per 100 person-years. Patient treatment experience was not a significant factor for regimen switch according to multivariate analysis, adjusting for relevant covariates. Conclusions: We found that INSTI-based regimens were potent and durable in experienced HIV-positive patients receiving treatment outside clinical trials. These results confirm that INSTI-based regimens are a robust treatment option.

Dolutegravir for the treatment of HIV

INTRODUCTION

Development of new antiretroviral drugs which are highly potent, tolerable over the long term and with a high genetic barrier to resistance is essential for the treatment of a chronic viral disease that requires life-long therapy with near-perfect medication adherence. Integrase inhibitors (INI) are a new class of antiretroviral drugs that block the action of HIV integrase, which catalyses several key steps in the virus life cycle which are essential for insertion of the viral genome into the DNA of host cell.

AREAS COVERED

Dolutegravir (DTG), a second-generation INI currently in the late stage of clinical development, is an effective orally available drug with a long half-life that does not need to be pharmacologically enhanced, is effective as a once daily drug in the absence of INI resistance mutations and twice daily in presence of INI resistance mutations.

EXPERT OPINION

DTG, as other drugs in the INI class, appears safe and well tolerated. Results from ongoing large Phase III studies will bring more generalizable and robust information on the long-term effects of DTG.

Elvitegravir: a once-daily inhibitor of HIV-1 integrase

INTRODUCTION

Elvitegravir (EVG) is a potent inhibitor of HIV-1 integrase (IN) undergoing Phase III clinical trials. It blocks the strand-transfer step in a multi-step process that allows double-stranded cDNA to be irreversibly incorporated within the host DNA. It is the second member of the HIV-1 IN inhibitor class, following raltegravir. Co-administration with a CYP3A inhibitor, such as ritonavir or cobicistat, substantially increases EVG plasma exposure and prolongs elimination half-life.

AREAS COVERED

A Medline review of Phase II and III trials involving EVG as well as a review of abstracts from major HIV and infectious disease conferences from 2010 to 2011 was conducted. EVG produces rapid and durable virologic suppression when combined with active background therapy. Trials investigating the efficacy of once-daily co-formulated elvitegravir/cobicistat/emtricitabine/tenofovir (EVG/COBI/FTC/TDF) demonstrate a high rate of virologic suppression with fewer CNS and psychiatric adverse events compared with co-formulated efavirenz/emtricitabine/tenofovir. The resistance profile for EVG is similar to raltegravir.

EXPERT OPINION

Co-formulated EVG/COBI/FTC/TDF is an option for the treatment of antiretroviral naïve and experienced patients. Once-daily dosing offers an advantage over raltegravir, but the requirement for pharmacologic boosting increases regimen complexity. Dolutegravir in development offers a favorable resistance profile and no requirement for pharmacologic boosting.

The role of therapeutic drug monitoring in the management of patients with human immunodeficiency virus infection

Therapeutic drug monitoring (TDM) is a well-established method to optimize dosing regimens in individual patients for drugs that are characterized by a narrow therapeutic range and large interindividual pharmacokinetic variability. For some antiretroviral drugs, mainly nonnucleoside reverse transcriptase inhibitors and protease inhibitors, TDM has been proposed as a means to improve the response in human immunodeficiency virus-infected patients. In contrast, nucleoside reverse transcriptase inhibitors do not show a predictable plasma concentration-response (toxicity, efficacy) relationship, and intracellular analyses are expensive. Therefore, TDM is generally not recommended for this class of drugs. TDM has been successfully applied in the clinical practice for certain antiretroviral drugs, but there are ongoing research efforts on the use and refinement of TDM for human immunodeficiency virus treatment, and convincing data from randomized trials are still needed. The best pharmacokinetic measures of drug exposure such as trough and peak concentrations or concentration ratios have not been unambiguously established.

Microwave assisted organic synthesis (MAOS) of small molecules as potential HIV-1 integrase inhibitors

Integrase (IN) represents a clinically validated target for the development of antivirals against human immunodeficiency virus (HIV). In recent years our research group has been engaged in the stucture-function study of this enzyme and in the development of some three-dimensional pharmacophore models which have led to the identification of a large series of potent HIV-1 integrase strand-transfer inhibitors (INSTIs) bearing an indole core. To gain a better understanding of the structure-activity relationships (SARs), herein we report the design and microwave-assisted synthesis of a novel series of 1-H-benzylindole derivatives.

Chemistry and structure-activity relationship of the styrylquinoline-type HIV integrase inhibitors

In spite of significant progress in anti-HIV-1 therapy, current antiviral chemo-therapy still suffers from deleterious side effects and emerging drug resistance. Therefore, the development of novel antiviral drugs remains a crucial issue for the fight against AIDS. HIV-1 integrase is a key enzyme in the replication cycle of the retrovirus since it catalyzes the integration of the reverse transcribed viral DNA into the chromosomal DNA. Efforts to develop anti-integrase drugs started during the early nineties, culminating with the recent approval of Raltegravir. The discovery and the development of the styrylquinoline inhibitor class was an important step in the overall process. In this review we have described the key synthetic issues and the structure-activity relationship of this family of integrase inhibitors. Crystallographic and docking studies that shed light on their mechanism of action are also examined.

Genetic diversity on the integrase region of the pol gene among HIV type 1-infected patients naive for integrase inhibitors in São Paulo City, Brazil

The presence of mutations associated with integrase inhibitor (INI) resistance among INI-naive patients may play an important clinical role in the use of those drugs Samples from 76 HIV-1-infected subjects naive to INIs were submitted to direct sequencing. No differences were found between naive (25%) subjects and subjects on HAART (75%). No primary mutation associated with raltegravir or elvitegravir resistance was found. However, 78% of sequences showed at least one accessory mutation associated with resistance. The analysis of the 76 IN sequences showed a high polymorphic level on this region among Brazilian HIV-1-infected subjects, including a high prevalence of aa substitutions related to INI resistance. The impact of these findings remains unclear and further studies are necessary to address these questions.