ASHM Report Back
Clinical posts from members and guests of the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) from various international medical and scientific conferences on HIV, AIDS, viral hepatitis, and sexual health.
Talk by Professor Ian McGowan on long-acting ARVs (LAARVs).
- Research from NYC (MSM) indicates high rates of willingness, and that a majority would prefer an injection.
- Research from Africa (women) indicates that injection/implant/vaginal ring (as PrEP) would be preferred.
Current development of LAARVs is both for treatment and prevention.
Requirements for LAARVs as injection:
- Infrequent dosing (every 2-3 months)
- Practical injection volume (<4mL)
- Doesn’t require cold-chain storage
Rilpivirine and cabotegravir most likely candidates of current generation of medications.
- Have only been evaluated in the context of clinical trials (phase 1 and 2); adherence data likely to vary in the real world (and depending on whether being given as PrEP or treatment)
- Tolerability good; patient satisfaction overall good
- Efficacy signal in cabotegravir (animal studies)
- Injection-site reactions reasonably frequent over time (highest at first injection)
- Long-acting rilpirivine detectable in tissue (plasma/endocervical and vaginal fluid) up to >500 days (!) later – which is concerning for risk of resistance. Therefore cabotegravir more promising for use as long-acting PrEP (and phase 3 studies planned) – cabotegravir involves 4 week oral lead-in then Q8 weekly injection.
Novel NRTI “EFdA” also promising based on animal modelling; currently at phase 1 studies in humans. Animal models indicate that long-acting formulation could be effective up to 1yr.
As mentioned elsewhere – TAF silicone tubing implant and biodegradable implants both promising for use as PrEP.
Main challenges with LAARVs:
- Safety (need oral lead-in)
- Acceptability (needs real-world data)