Vaccine-like drug to prevent HIV ‘could be ready early next decade’
UK drugmaker steps up investment in long-acting medication to protect those exposed to the virus
A vaccine-like drug administered once a year to prevent HIV could be ready just after 2030, according to drugmaker ViiV, transforming management of a virus that has killed nearly 40mn people in an epidemic that has lasted more than four decades.
While there is no vaccine to treat HIV, a virus that can lead to Aids, pre-exposure prophylaxis (PrEP) has reduced transmission rates by offering protection to those who may be exposed to the virus.
Most PrEP therapies rely on taking oral medications daily or when unprotected sex might take place, but the potential emergence of a prevention drug with the characteristics of a vaccine could dramatically reduce the burden on patients and health authorities globally.
HIV drug developer ViiV is accelerating research into VH184, an antiretroviral drug designed to block the action of the integrase enzyme which inserts the genetic code of the HIV virus into the host cell’s DNA.
Kimberly Smith, head of research and development at ViiV, said a long-acting drug administered every 12 months would soon be attainable: “I can’t say when, but not too far beyond the end of this decade. It will be possible, I believe.”
“[VH184] has demonstrated a very long half-life in pre-clinical studies,” she told the Financial Times. “We need to determine if that very long half-life translates to humans.”
Long-acting drugs are given intramuscularly every month or less frequently, releasing chemicals over a long period of time. Meg Doherty, head of the HIV programme at the World Health Organization, said ViiV’s long-acting drug pipeline was “exciting” but stressed the need to ensure low-cost, universal coverage.
“It will be important to continue to ensure these [HIV] regimens and new approaches will be available to all — including people living in low- and middle-income countries,” she said.
ViiV, a GSK majority-owned venture with Pfizer of the US and Japan’s Shionogi, told investors last week that it had raised its sales growth projection to between 6 and 8 per cent between 2021 and 2026, as its bet on long-acting drugs offsets the “patent cliff” — or loss of exclusivity — for its blockbuster oral treatment dolutegravir.
The company has two long-acting drugs based on cabotegravir, another integrase inhibitor, approved by regulators: Cabenuva, in combination with another molecule, for treatment of patients who have contracted HIV, and its PrEP medication Apretude. These non-oral products are typically taken monthly or every two months.
Smith said people have started saying Apretude is “almost like a vaccine . . . you basically get your shot and then you don’t think about it anymore, unlike the need to take something every day”.
“Certainly, you know, the longer we get with those intervals, the more it feels like that,” she added, likening it to yearly flu and Covid-19 shots. US-based Gilead Sciences is also developing long-acting HIV treatments.
While Deb Waterhouse, ViiV’s chief executive, said there was strong uptake of long-acting PrEP drugs in the US, the picture was more mixed in the EU despite their regulatory approval.
Reimbursement has to be negotiated with every country individually, and while some governments had shown interest, many had not placed orders because they had been able to control HIV caseloads with cheaper oral treatments.
Access to long-acting drugs in poorer nations with high HIV rates remains patchy, despite the signing of licences for their generic manufacture. Médecins Sans Frontières refused to sign a non-disclosure agreement on pricing requested by ViiV for an access deal in Mozambique and other countries.
Waterhouse said it was looking to find “the middle ground” with MSF and finalise a resolution “because we want them to be partners”.
“It will be a shame if there is a repeat of what we see now with [long-acting PrEP], where people in Africa with the greatest burden of HIV, have little access to it for prevention,” the WHO’s Doherty said.