Three decades ago a controversial ad aired in Australia featuring the ‘Grim Reaper’ bowling down adults and children. The ad was intended to raise awareness of human immunodeficiency virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS).
The hard-hitting 1987 ad stated that over 50,000 men, women and children in Australia carried the AIDS virus and that if not stopped it could result in more Australian lives lost than in World War Two. The message focused on prevention being the only cure.
While the ad was considered successful due to a decline in the numbers of people diagnosed with HIV after 1987, the Grim Reaper ad saw an unintended backlash against gay men. Stigma around HIV exists to this day. There still remains no cure for HIV but treatments have been developed which means a diagnosis is no longer a death sentence. Antiretroviral therapies (ART), introduced in 1996, have resulted in a reduction in the number of people being diagnosed with AIDS and enable people with HIV to maintain an undetectable viral load.
Implant may provide HIV prevention
In Australia, around 1000 people are diagnosed with HIV annually while 11 percent of HIV positive people are not aware they are infected. Early diagnosis remains key and there continues to be a focus on prevention. Pre-exposure prophylaxis (PrEP) is the regular use of antiretroviral therapies among people who are at high risk of contracting HIV. After extensive trials, PrEP was added to the Australian Pharmaceutical Benefits Scheme (PBS) in 2018.
PrEP can be taken via ‘on-demand dosing’ for short duration coverage or taken daily for extended protection from contracting HIV. Post-exposure prophylaxis (PEP) is also available for people who have potentially been very recently exposed to HIV. Research shows that when taken consistently PrEP can significantly reduce the HIV infection in high-risk people. However, the medication is not without side effects and also requires patient adherence. Some studies have found that almost half of people who start taking PrEP stop taking it after a few weeks or months, particularly in third-world countries.
At the International AIDS Society (IAS) Conference on HIV Science held, in Paris last month, a study was presented which looked at the efficacy and safety of long-acting injectable drugs for HIV prevention. Participants in the study were injected with cabotegravir, an integrase inhibitor, and results found that the injectable was safe when administered every eight weeks.
Other treatment currently in development include an implant loaded with islatrivir, an HIV prevention drug which is proving effective in clinical trials being conducted by Merck. At the recent IAS Conference Merck demonstrated the impact of long-acting implant formulations through a study which involved 16 non-HIV adult participants who received either 54mg or 62mg of islatravir via implant, or a placebo. The implants were removed after 12 weeks and participants were followed for another four weeks to determine how long the drug remained in their system.
Merck is now planning a phase two study to test the implant in a larger, more diverse cohort. It is hoped that the implant will provide HIV prevention coverage for up to a year and also that the delivery method could be used for treatment of HIV in the future.