26 October 21

Ending HIV

Long-acting injectable PrEP: Everything you need to know

There are some new developments for PrEP that might change the way you take it in the future. PrEP is highly effective at preventing HIV infection, and right now, it comes in a pill form you can take daily, on demand, or periodically, depending on your circumstances and preferences.

But changes in the HIV treatment space signal the potential for a long-acting injectable PrEP to be available soon. Read on to know more about the new HIV prevention medication on the block.

What is long-acting injectable PrEP?

Long-acting injectable PrEP is a HIV prevention medication that is injected (instead of a pill) and is effective for a longer time period than the pill forms.

How does long-acting injectable PrEP work?

There are a couple of options for long-acting PrEP, including injections and implants. None are currently approved for use anywhere in the world, so it’s a bit of a ‘watch this space’.

One drug called cabotegravir is currently being studied as a long-acting form of PrEP. Cabotegravir is a new long-acting anti-retroviral that has just been approved in some parts of the world, including Australia, for use as a HIV treatment. It is being marketed as Cabenuva.

These cabotegravir studies are investigating the option of a health professional giving one injection into the glute muscle (your butt) every two months. The studies are incredibly promising: two of them finished early because the injections were so successful at preventing HIV. It’s likely this one will be the first long-acting injectable PrEP available.

There are other options also being investigated, but they are in very early stages of testing. Another drug called lenacapavir could be available as a subcutaneous (under the skin) injection, possibly only every six months.

A third option, islatravir, could be used as a prevention implant, effective for about a year. The implant is a small plastic rod that sits under the skin in your arm, utilising similar technology to contraception implants.

These are the options being investigated, but it’s likely that things might change as clinical trials progress. It’s still early days so there are a few unknowns, but already some advantages and disadvantages are clear.

What are the advantages of long-acting PrEP?

The biggest benefit of long-acting PrEP is just that: it’s long-acting. Many of these options mean one trip to the doctor every two months, six months, or even a year, and then you don’t have to think about taking PrEP for a while.

If you’re the type of person that forgets to take your pills, then long-acting PrEP allows for more of a set-and-forget option (as long as you remember to get to the doctor for your next injection or implant!).

It also means no need to carry around medication, allowing freedom for things like travel, and being protected for any random hook-ups that might get ‘bumped’ into your schedule.

The current ways to take PrEP pills orally give us some flexibility from a daily pill regime. However, these new ways aren’t an option for some of us, including trans and gender diverse folks, so long-acting injectable PrEP could mean more options for everyone who needs PrEP.

What are the disadvantages of injectable PrEP?

The flipside to long-acting options is that you may need to have them administered by a health professional, which could mean the slight inconvenience of more trips to the doctor.

Because long-acting PrEP is, well, long-acting, it stays in your body for a long time. That means that if you decide to stop taking PrEP, you might still have the drug in your system, and while it might not be enough to prevent HIV, it might be just enough for your body to develop a resistance to that class of drug, which can cause issues for a treatment regime if you become HIV positive. This is less of an issue for lenacapavir, because it’s a brand new class of drug, but for cabotegravir, at the moment it’s recommended you take oral PrEP for a year after stopping injections, to prevent this.

When will injectable PrEP be available in Australia?

It’s expected that cabotegravir could be approved for use as PrEP in the USA by the end of the year, but it will take a while for it to make it to Australia. Once it’s approved in Australia, it could still be prohibitively expensive. New drugs are often pretty expensive before they have competitors, and the government has to make decisions around the benefits versus the cost when they decide whether or not to subsidise a drug.

We’re still a few years away from lenacapavir and islatravir, but progress is happening. As more options become available, it’s possible they’ll also become more affordable.

So, hold on to your PrEP pills for now, and watch this space. And remember, you don’t necessarily have to take them every day, depending on your circumstances. There are new ways to take PrEP, so do what’s right for you.