Novel treatment strategies and advances in care have transformed the lives of people living with HIV (human immunodeficiency virus). Antiretroviral therapy (ART), once-daily single-tablet regimens (STRs), and PrEP (pre-exposure prophylaxis) are some major milestones that have changed the trajectory of the deadly disease.
The change has been disruptive, but HIV continues to remain a global public issue. Worldwide, around 38 million people are living with HIV and there is an unmet need for more effective drug candidates and strategies for treatment as well as prevention of new infections.
This article covers some recent developments in the management of HIV.
The Advent of Long-Acting Therapies
Long-acting therapies are set to make a huge difference in the lives of people living with HIV. These therapies don’t need to be taken daily and can be dosed weekly or monthly - a feature that may improve patient convenience and improve treatment adherence by eliminating the daily reminder of treatment.
Long-acting therapies can be specifically useful in the pediatric populations with HIV, a group with huge unmet needs. By reducing the frequency of treatment administration in children, long-acting therapies can improve quality of life and adherence to regimens.
ViiV Healthcare’s CABENUVA, approved by the FDA in January 2021, is the first long-acting injectable HIV treatment in the market. The therapy consisting of one cabotegravir injection and one rilpivirine injection needs to be administered just once a month. FDA also approved VOCABRIA (cabotegravir) 30 mg tablets which should be taken in combination with oral rilpivirine (EDURANT) for one month before starting treatment with CABENUVA to ensure the medications are well-tolerated before switching to the extended-release injectable formulation.
In December 2021, FDA approved ViiV’s Apretude (cabotegravir extended-release injectable suspension) for pre-exposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV. Apretude is given first as two initiation injections administered one month apart, and then every two months thereafter.
Apart from ViiV Healthcare, Gilead is expected to complete regulatory filings this year for their long-acting self-injectable HIV treatment lenacapavir. Lenacapavir must be injected once every six months. If approved, the HIV-1 capsid inhibitor will be the first approved treatment of its kind. Lenacapavir (in combination with other treatments) is being developed for heavily treated patients who have become resistant to multiple drugs, a particularly difficult-to-treat group of patients.
HIV Vaccines – A Promising Strategy to Fight HIV
An effective HIV vaccine can help combat HIV and is seen as a potential strategy to curb this deadly disease. Mosaic-based vaccines and messenger RNA (mRNA) vaccines are some novel technologies being evaluated.
Mosaic-based vaccines consist of mosaic immunogens, such as a mosaic glycoprotein 140 (gp140). These immunogens, which are delivered through viral vectors, have the capacity to induce a broad immune response as they are made up of pieces of different HIV strains.
In September 2021, Janssen’s mosaic-based HIV vaccine candidate failed to offer substantial protection against the disease in the Phase IIb Imbokodo clinical trial in women in sub-Saharan Africa. The company decided to discontinue the Imbokodo study.
The Imbokodo study is discontinued, but Janssen is continuing the Phase 3 Mosaico study. The Mosaico study is testing the safety and efficacy of a different composition of the HIV vaccine regimen among men who have sex with men (MSM) and transgender individuals. The trial is being conducted in the Americas and Europe where different strains of HIV are circulating.
The success with mRNA vaccines for COVID-19 has generated hopes that mRNA techniques can also be used in HIV. Many research groups including the International AIDS Vaccine Initiative (IAVI) are working towards this mission. Moderna, the company which developed the COVID-19 mRNA vaccine is set to test its vaccine candidate mRNA-1644 for HIV. mRNA-1644 is based on the same mRNA platform as the COVID-19 vaccine.
Apart from mRNA vaccines, researchers are also considering replicating viral vector-based (Vesticular Stomatitis Virus) vaccine comprising a recombinant VSV vector that incorporates an HIV envelope gene...
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