Safety, efficacy, and pharmacokinetics of rilpivirine: systematic review with an emphasis on resource-limited settings

The vast majority of people living with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome reside in the developing world, in settings characterized by limited health budgets, critical shortages of doctors, limited laboratory monitoring, a substantial burden of HIV in children, and high rates of coinfection, in particular tuberculosis. Therefore, the extent to which new antiretrovirals will contribute to improvements in the management of HIV globally will depend to a large extent on their affordability, ease of use, low toxicity profile, availability as pediatric formulations, and compatibility with tuberculosis and other common drugs. We undertook a systematic review of the available evidence regarding drug interactions, and the efficacy and safety of rilpivirine (also known as TMC-278), and assessed our findings in view of the needs and constraints of resource-limited settings. The main pharmacokinetic interactions relevant to HIV management reported to date include reduced bioavailability of rilpivirine when coadministered with rifampicin, rifabutin or acid suppressing agents, and reduced bioavailability of ketoconazole. Potential recommendations for dose adjustment to compensate for these interactions have not been elaborated. Trials comparing rilpivirine and efavirenz found similar outcomes up to 96 weeks in intent-to-treat analysis; failure of rilpivirine was mainly virological, whereas failure among those exposed to efavirenz was mainly related to the occurrence of adverse events. Around half of the patients who fail rilpivirine develop non-nucleoside reverse transcriptase inhibitor resistance mutations. The incidence of Grade 2–4 events was lower for rilpivirine compared with efavirenz. Grade 3–4 adverse events potentially related to the drugs were infrequent and statistically similar for both drugs. No dose-response relationship was observed for efficacy or safety, and the lowest dose (25 mg) was selected for further clinical development. The potential low cost and dose of the active pharmaceutical ingredient means that rilpivirine can potentially be manufactured at a low price. Moreover, its long half-life suggests the potential for monthly dosing via nonoral routes, with promising early results from studies of a long-acting injectable formulation. These characteristics make rilpivirine an attractive drug for resource-limited settings. Future research should assess the potential to improve robustness and assess the clinical significance of interaction with antituberculosis drugs

Review of the safety, efficacy, and pharmacokinetics of elvitegravir with an emphasis on resource-limited settings

Integrase inhibitors represent an important new class of antiretroviral drugs. Elvitegravir, the second available integrase inhibitor to be submitted for regulatory approval appears to be a promising once-daily agent when combined with other antiretroviral drugs. Elvitegravir has demonstrated good efficacy and safety, with minimal side effects and no specific requirements in terms of laboratory monitoring. In addition, elvitegravir is available as a fixed-dose combination. However, the drug requires boosting and this leads to a number of drug–drug interactions and necessary dose adjustment when dosing with certain drugs, including dose reduction in the presence of atazanavir, lopinavir, rifabutin, and ketoconazole, and dose increase for ethinyl estradiol when co-administered with boosted elvitegravir. The main advantage of elvitegravir lies in its potential to be administered as a once-daily, single pill. Limitations include dose adjustment requirements, a relatively low genetic barrier to resistance, high price, and lack of data for use in children. Clinical trials addressing specific challenges encountered in resources-limited settings should be encouraged

Preferred antiretroviral drugs for the next decade of scale up

Global commitments aim to provide antiretroviral therapy (ART) to 15 million people living with HIV by 2015, and recent studies have demonstrated the potential for widespread ART to prevent HIV transmission. Increasingly, countries are adapting their national guidelines to start ART earlier, for both clinical and preventive benefits. To maximize the benefits of ART in resource-limited settings, six key principles need to guide ART choice: simplicity, tolerability and safety, durability, universal applicability, affordability and heat stability. Currently available drugs, combined with those in late-stage clinical development, hold great promise to simplify treatment in the short term. Over the longer-term, newer technologies, such as long-acting formulations and nanotechnology, could radically alter the treatment paradigm. This commentary reviews recommendations made in an expert consultation on treatment scale up in resource-limited settings

Highlights from the 3rd international HIV/viral hepatitis Co-infection meeting - HIV/viral hepatitis: improving diagnosis, antiviral therapy and access

The International AIDS Society convened the 3rd International HIV/Viral Hepatitis Co-Infection Meeting on 17 July 2016 as part of the pre-conference program preceding the 21st International AIDS Conference held in Durban, South Africa. The meeting brought together a diversity of scientific, technical and community interests to discuss opportunities and challenges for increased prevention, diagnosis and treatment of viral hepatitis in people living with HIV, particularly in low- and middle-income settings. The objectives of the meeting were: i. To review the latest therapeutic developments in viral hepatitis; ii. To identify challenges such as high cost of medications for hepatitis C virus (HCV) and risk of developing viral resistance, and successes, such as the provision of HCV treatment in community-based settings, movements to reduce drug costs and increasing access, in relation to scaling up diagnosis, screening, antiviral treatment and prevention of viral hepatitis; iii. To advance the agenda for elimination of viral hepatitis as a public health problem. Discussions centred around the six key interventions outlined by the World Health Organization Global Health Sector Strategy on Viral Hepatitis 2016–2021: hepatitis B virus (HBV) vaccination (including birth dose); safe injection practices plus safe blood; harm reduction among people who inject drugs; safer sex practices; hepatitis B treatment; and hepatitis C cure. This article summarizes the main issues and findings discussed during the pre-conference meeting. One of the recommendations from the meeting delegates is universal implementation of birth dose vaccination for HBV without further delay to prevent mother-to-child transmission of infection. There is also the need to implement screening and treatment of hepatitis among pregnant women. A call was made for concerted efforts to be put together by all stakeholders towards addressing some of the structural barriers, including criminalization of drug use, discrimination and stigma that people living with viral hepatitis face. Finally, the need for greater advocacy was highlighted to enable access to therapy of viral hepatitis at lower cost than currently prevails. Implementation of these resolutions will help in achieving the target of eliminating viral hepatitis as a public health threat

Leave no one behind: response to new evidence and guidelines for the management of cryptococcal meningitis in low-income and middle-income countries

In 2018, WHO issued guidelines for the diagnosis, prevention, and management of HIV-related cryptococcal disease. Two strategies are recommended to reduce the high mortality associated with HIV-related cryptococcal meningitis in low-income and middle-income countries (LMICs): optimised combination therapies for confirmed meningitis cases and cryptococcal antigen screening programmes for ambulatory people living with HIV who access care. WHO's preferred therapy for the treatment of HIV-related cryptococcal meningitis in LMICs is 1 week of amphotericin B plus flucytosine, and the alternative therapy is 2 weeks of fluconazole plus flucytosine. In the ACTA trial, 1-week (short course) amphotericin B plus flucytosine resulted in a 10-week mortality of 24% (95% CI −16 to 32) and 2 weeks of fluconazole and flucytosine resulted in a 10-week mortality of 35% (95% CI −29 to 41). However, with widely used fluconazole monotherapy, mortality because of HIV-related cryptococcal meningitis is approximately 70% in many African LMIC settings. Therefore, the potential to transform the management of HIV-related cryptococcal meningitis in resource-limited settings is substantial. Sustainable access to essential medicines, including flucytosine and amphotericin B, in LMICs is paramount and the focus of this Personal View

Analysis of minimum target prices for production of entecavir to treat hepatitis B in high- and low-income countries

BACKGROUND: In 2013, an estimated 686,000 people died from hepatitis B virus (HBV) infection worldwide. Mass treatment programmes for hepatitis B will require very low drug costs. International treatment guidelines recommend first-line monotherapy with either entecavir or tenofovir disoproxil fumarate (TDF). While the basic patent on TDF expires in 2017/8, entecavir is already generic in several countries, including the US. The chemical structure of entecavir is related to abacavir, which costs <$200 per person-year in low-income countries. METHODS: The clinical efficacy, chemical structures, daily doses, routes of chemical synthesis, costs of raw materials and patent expiry dates were analysed for entecavir and TDF. Costs of sustainable, generic production were calculated for entecavir, and compared with published originator and generic prices in high- and low-income countries. RESULTS: With a daily dose of 0.5 mg, one year's supply of entecavir treatment requires <0.2 g of active pharmaceutical ingredient (API) per person, estimated to cost$4/year, based on quotations of API production from generic suppliers. With an additional $20 per year for formulation/packaging and a 50$36/person-year, substantially lower than current originator and generic prices. Entecavir is no longer under patent protection in the USA, China, Brazil and South Africa, with European expiry in 2017. Given differences in daily dosing, production volumes for entecavir would be 600 times lower than TDF (300 mg once daily) for treating the same numbers of patients. CONCLUSIONS: Mass treatment for hepatitis B with generic entecavir could be achieved at very low cost in all countries, provided that important projections can be met in terms of pricing for the API and finished dosage form