Hope for patients as once-every-two-months ARVs show promise

Two years ago, some 162 Kenyan women living with HIV agreed to stop taking the daily ARV pills.

They would instead receive an injection once every two months. The injectable drug was already proven to suppress HIV. But it had never been tested as a treatment option in Africa.

Researchers have now the much-awaited released results on how the injection performed, raising hopes of its early approval for use in Kenya.  

The results reveal that the long-acting injectable for HIV treatment is just as effective as daily oral pills in suppressing HIV among adults in Africa.

The Kenyan women were among 512 participants in this study, known as CARES, which was conducted across eight sites in Kenya, Uganda, and South Africa.

The Kenyan sites are at The Aga Khan Hospital, Kemri in Kericho and Ampath in Eldoret.

Half of the women are still on the daily ARV pills while the others receive the once-every-two-months injectable known as Cabenuva (containing cabotegravir and rilpivirine drugs).

The researchers have been following the participants for the last two years.

“This trial demonstrated that switching to long-acting therapy maintained high levels of viral suppression that were non-inferior to continuing an oral regimen,” the researchers say in results published in The Lancet Infectious Diseases on Wednesday.

They found that 96 per cent of participants in the injectable group maintained viral loads below 50 copies per mL, compared to 97 per cent in the oral therapy group.

The women were recruited between September 2021, and August 31, 2022, and were tested for viral suppression every six months.

The study also assessed the safety profile of the injectable. Adverse events of grade 3 or greater severity were more frequent in the injectable group (nine per cent) compared to the oral therapy group (four per cent).  Grade 3 events are symptoms that are severe or medically significant but not immediately life-threatening.

Two participants in the injectable group experienced virological failure and developed drug resistance, while none in the oral therapy group did. However, the overall rate of virological failure was very low, researchers say.

Their paper is titled “Switch to long-acting cabotegravir and rilpivirine in virologically suppressed adults with HIV in Africa (CARES): week 48 results from a randomised, multicentre, open-label, non-inferiority trial.”

They said the results of this study are significant for several reasons. First, the injectable regimen's non-inferior efficacy offers an alternative for individuals who may struggle with daily pill adherence.

“This is particularly important in African settings, where the stigma and logistical challenges associated with daily medication can be substantial,” they said in the paper, published in the Lancet Infectious Diseases journal.

The Kenyan researchers are Prof Reena Shah of the Aga Khan University Hospital, Nairobi, Abraham Siika and Charity Wambui of Moi University, and Josphat Kosgei of the Kenya Medical Research Institute.

The World Health Organization in 2020 licensed the two injectable ARVs because studies done in Europe, the Americas and Asia showed they are as good as the daily pills.

In December 2022, the Star spoke to researchers overseeing the trial in Uganda, Kenya and South Africa.

“But these studies were done among males in those regions and here [in Africa] it's mostly women who are affected. The HIV subtype here is also different. Our disease environment is also different and we have more pregnancies. So it was necessary to repeat those studies here to generate guidelines for WHO,”  Dr Cissy Kityo, a Ugandan epidemiologist who is overseeing the trial in the three countries said.

Cabenuva is approved in the US, Canada, the European Union (under the brand names Vocabria and Rekambys), Australia and Switzerland among other countries.

In the US, a list price of $4,000 a month is given by the website drugs.com but costs vary depending on the treatment plan, costs of hospital visits and any negotiated discounts.

Speaking to Star separately on Thursday, Prof Omu Anzala, director of the Kenya Aids Vaccine Initiative, said HIV treatment research is now moving toward long-acting drugs.

Prof Anzala did not take part in the Cabenuva research.

“A drug that can sustain you for a period of three months or more before you take another one or a drug that can take you for six months before you take another one, that will actually enhance adherence. It will ensure that individuals don't drop and stop their treatment,” he said.

“And that in that way, they issues of sustaining viral load and sustaining suppression will actually be achieved. Because we know that when the virus is totally suppressed, that individual is unlikely to transmit the infection to somebody else.”