[LIMA, PERU] Affordability and mass distribution will be critical to the success of a long-lasting injectable HIV prevention drug that has proven highly effective in human trials, say global health specialists.

US pharma company Gilead Sciences is seeking regulatory approval for the drug lenacapavir in a number of African countries — a key step towards making it available across the region, where almost one in 25 people live with HIV.

Lenacapavir is a long-acting pre-exposure prophylaxis (PrEP) product, a treatment that works by stopping HIV from getting into the body and making copies of itself.

Unlike oral PrEP treatments, which are taken daily, the drug is administered at six-month intervals and is the longest acting injectable produced to date.

In a late-stage trial, Lenacapavir reduced HIV infection by 96 per cent among diverse groups, including men who have sex with men and transgender and non-binary people.

Only two out of more than 2,000 people involved in the PURPOSE 2 study went on to contract HIV, according to data released at the International AIDS Society’s HIV Research for Prevention Conference in Lima, Peru earlier this month.

The findings build on the earlier PURPOSE 1 study, where no cisgender women – those who identify with the gender they were born with – contracted HIV while on the drug.

Hasina Subedar, senior technical advisor at South Africa’s Department of Health, says the real-world impact of lenacapavir will depend on the drug’s pricing and availability.

“If it’s affordable, lenacapavir could significantly reduce new infections here,” she told SciDev.Net.

The drug’s twice-yearly administration could overcome the issue of patients not sticking with their medication, a key problem with oral PrEP, says Colleen Kelley, associate professor of Medicine at Emory University, in the US.

She believes lenacapavir could be particularly beneficial in areas where regular access to healthcare is difficult, describing it as a “highly effective tool for HIV prevention that is not dependent on daily oral adherence”.

Mitchell Warren, executive director of AVAC, a non-profit that focuses on equitable access to HIV prevention options, called the drug’s promise “remarkable” but emphasised the importance of ensuring broad availability.

“We’re calling for an aggressive effort to make lenacapavir available to at least one million people in low- and middle-income countries within the first year of its rollout,” Warren told SciDev.Net.

He stressed that large-scale production and a robust supply chain were important to ensuring the drug reaches those who need it most.

In Africa, where healthcare systems are often strained, the cost of treatment is a major concern.

Gilead has entered into voluntary licensing agreements to allow the production of generic versions of lenacapavir, but the pricing structure remains unclear.

Early models suggest that, to achieve widespread uptake, a year’s supply of lenacapavir would need to cost around US$40 – comparable to the price of oral PrEP.

According to Warren, countries like Zambia and Kenya, which have experience implementing HIV prevention programmes, are expected to be early adopters and will be a litmus test of real-world impact. If successful, this could drive demand for the generic version and lower the price over time.

Gilead Sciences plans to begin regulatory processes by the end of 2024 in 18 low- and middle-income countries with a high HIV burden, including Botswana, Kenya, Uganda, South Africa, Nigeria, Tanzania, Zambia and Malawi.

The company says it has entered into non-exclusive, royalty-free licensing agreements with six generic manufacturers, including Dr. Reddy’s, Emcure, and Mylan, to produce and sell generic versions of lenacapavir in 120 resource-limited countries., with the aim of supporting low-cost access.

Gilead also says it plans to provide the product at no profit to the company until generic manufacturers can fully support demand.

“Given the transformative potential of lenacapavir for prevention, our focus is on making it available as quickly and broadly as possible where the need is greatest,” said Daniel O’Day, chairman and chief executive officer of Gilead.

“Gilead teams have been working with urgency to bring on high-volume generic manufacturers now, so that we can ensure a rapid transition to these voluntary license partners after lenacapavir for PrEP is approved,” he added.

Gilead says it is working within regulatory frameworks such as the European Medicines Agency’s EU Medicines for All initiative, in a bid to expedite country-level approval of the drug and WHO pre-qualification.

The drug has been approved in Europe and the US as a treatment for HIV/AIDS but does not yet have regulatory approval anywhere in the world.

Once approved, producing enough lenacapavir to create a reliable supply chain in Africa could be a significant challenge, according to Warren.

He says previous PrEP rollouts have shown the importance of consistent availability, to build and maintain trust in the community.

There are also concerns about whether patients will return for their injections every six months.

“The potential is exciting, but we still have many questions,” added Warren.

Chilufya Kasanda, from Zambia’s Treatment Advocacy and Literacy Campaign, stressed the need to offer a choice of treatment options.

“The desire and appetite from the community is huge, but even with that, we need to respect that communities will keep changing their thinking around products,” said Kasanda.

This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.