Patients taking a cocktail of anti-retroviral pills every day to manage HIV may soon be able to switch to a monthly injection following successful trials.
Findings of twin trials that enrolled more than 1,000 people in 16 countries show that long-acting medicines have proven as effective as daily pills in preventing HIV from replicating.
Currently, most people infected with the HIV virus take a combination of three or more tablets per day to prevent the virus replicating and triggering AIDS.
In final stage trials, an injection of two anti-retroviral drugs —cabotegravir and rilpirivine—was found to be just as effective as the standard treatment.
The drugs, which are among the first of several long-acting anti-retroviral medicines in development, are given once a month as an injection; and researchers hope the injection will tackle one of the toughest challenges in the fight against HIV: ensuring that people take ARVs consistently.
Skipped doses put people with HIV, and their sexual partners, at risk. In 2017 Kenya was among seven African countries picked to carry out large-scale trials for the new long-acting injectable drug known as cabotegravir (CAB) among uninfected women.
The clinical trials enrolled 3,200 HIV-uninfected, sexually-active women in six other countries — Uganda, Botswana, Malawi, Swaziland, South Africa, and Zimbabwe. The study examined the safety and effectiveness of the injectable drug compared to the daily oral PrEP pills.
Researchers say long-acting medicines could ensure that the vast majority of people who are prescribed ARVs — the standard treatment for HIV — successfully suppress the virus, in line with goals set by the United Nations, whose aim is to have countries reduce HIV transmission by 90 per cent in the next decade.
'A KIND OF FREEDOM'
“Instead of being reminded that you have HIV 365 days a year, it’s reduced to just 12.
That gives people a kind of freedom,” said Chloe Orkin, a HIV researcher who reported the trial findings at the recent Conference on Retroviruses and Opportunistic Infections in the US.
In the 1990s, researchers developed combinations of antiretroviral drugs that transformed HIV from a death sentence into a chronic condition kept in check by daily pills.
But sticking to the daily pill schedule can prove tricky. Some people cannot easily reach clinics to get a regular supply of drugs, for instance, — a problem that longer-lasting medications could ease.
Last year, a study found that under-dosing and resistance to a group of HIV drugs (nevirapine-based regimens) among infants and young children were a hindrance to viral load suppression as more Kenyan youth and children may be developing resistance to antiretroviral medicines.
Bitter medication and lack of appropriate formulations and fixed-dose combinations for children were also making it difficult for children to swallow the antiretrovirals (ARVs).
In adolescents, high viral loads resulted from non-adherence because of stigma, poor transition to adult care, and lack of social support.
The antiretroviral injections tested in the trials include a mixture of cabotegravir and rilpivirine.
Each drug blocks HIV from replicating but in different ways. The medicines remain in the body’s tissues and leach out over weeks.
The combination was developed by ViiV Healthcare, a drug company in the United Kingdom that was spun off from pharmaceutical companies GlaxoSmithKline and Pfizer.
One of the clinical trials compared virus levels in blood samples from 556 people with HIV who had not previously taken antiretroviral drugs.
For 11 months, participants got either monthly injections or daily doses of three common oral antiretroviral pills.
The other trial had a similar design but enrolled 616 people who had been taking the standard combination of antiretroviral pills for at least six months before the study started.
Not only did the injections keep HIV in check as effectively as pills in both studies, but in each study, more than 85 per cent of people on injections said they preferred the monthly regimen.
According to HIV researcher Chloe Orkin, daily doses grow tiresome, and become toxic as people grow old.
Some drugs also interact negatively with other medications that people might take as they age, such as treatments for high blood pressure.
Orkin expects periodic injections of two HIV drugs to take less of a toll than a daily three-drug dose.