The expanded listing of cabotegravir will offer an alternative to those for whom daily oral PrEP isn’t an option.
The PBAC has recommended that Australia’s first long-acting injectable HIV pre-exposure prophylaxis, Apretude, be subsidised by the PBS for anyone for whom daily oral PrEP tablets are contraindicated.
Apretude’s active ingredient, cabotegravir, is an integrase strand transfer inhibitor which disrupts the HIV replication cycle and is currently listed by the PBS, in combination with rilpivirine, as an injectable antiviral treatment for people living with HIV.
Last year, WHO recommeded that all countries include cabotegravir in their HIV prevention toolkit alongside oral PrEP as it is a “safe and highly effective prevention option for people at substantial risk of HIV infection”.
While cabotegravir was approved for use as in HIV prevention by the TGA last year, the decision to recommend it for PBS subsidies was deferred by the PBAC in July.
The committee said that although it recognised the “clinical need”, more consideration was needed “to achieve an equitable and cost-effective listing”.
After a revised proposal from ViiV Healthcare, the drug’s sponsor, the PBAC recommended that Apretude be listed for streamline authority required prescription after September’s intracycle meeting.
“The PBAC considered the revised restriction appropriately allows a simpler clinical assessment of whether an individual is likely to have compromised efficacy with oral PrEP and would experience a benefit from a long-acting injectable alternative,” the meeting outcome read.
Subject to this “revised restriction”, Apretude will only be PBS listed for patients for whom the currently listed oral HIV PrEP tablets are contraindicated.
At the moment, the PBS-subsidised option for HIV PrEP is oral tenofovir/emtricitabine tablets taken daily.
According to LGBTQIA+ advocacy group ACON, long-acting injectable forms of HIV prevention and treatment are a convenient alternative to daily oral pills.
Infact, results from a phase 3 RCT published last year in the Lancet showed that cabotegravir was “superior at preventing infection” and, according to co-author Dr Mina Hosseinipour from the University of North Carolina, around 78% of the enrolled women preferred injections over daily pills.
Additionally, injections offer another option for those with gastro-intestinal issues, pill fatigue and groups, including trans people, for whom on-demand/event-based PrEP may not be recommended, according to ACON.
The injections reduce the need to carry medication, potentially reducing the opportunity for stigma. However, this may be compromised by the need to visit a doctor or a clinic for injections, said ACON.
While those taking daily oral PrEP may only have to visit a prescriber a few times a year for repeat prescriptions, because injectables must be administered by a health professional every couple of months, this may equate to 6-12 appointments a year, ACON added in its policy paper.
“The added inconvenience of extra medical appointments limits the benefit of the long-acting treatment or prevention for some people, especially those who have difficulty accessing medical care, whether due to cost, geographic location, stigma and discrimination, or other factors,” the policy paper said.
For those who do wish to start on cabotegravir injections for HIV prevention, initiation requires two 600mg doses a month apart, followed by continuous doses of the same volume every two months.
Doses must be within seven days of the calculated dosing date. If an injection cannot be performed within the allotted time, oral cabotegravir can be taken daily until the subsequent injection.
But individuals who miss an injection should be clinically reassessed and tested for HIV, the production information said. If more than two months pass since an injection, the regime should be stated again from initiation.
Oral doses can also be used as a lead-in to assess tolerability prior to administration.
Patients must be over 12 years old, weigh more than 35kg and be HIV negative to be eligible.
Cabotegravir injections are not suitable for those with HIV or with unknown HIV status, hypersensitivity to cabotegravir or any other ingredients in the formula, or anyone on rifampicin, rifapentine, phenytoin, phenobarbital, carbamazepine and oxcarbazepine.
According to the product information, hepatotoxicity was seen in a small number of individuals on Apretude.