Longer-acting Aripiprazole on the PBS

A new longer-acting formulation of aripiprazole, Abilify Asimtufii®, is now listed on the Pharmaceutical Benefits Scheme (PBS). This injection is administered once every two months and is indicated for the maintenance treatment of schizophrenia and the prevention of manic and mixed episodes in bipolar I disorder.

Currently, PBS subsidy for Abilify Asimtufii® is limited to patients with schizophrenia who have already been stabilised on once-monthly aripiprazole (i.e. Abilify Maintena®). Eligible patients can transition to Abilify Asimtufii® when their next monthly Abilify Maintena® dose is due.

A 32-week open-label study compared the safety and tolerability of aripiprazole two-monthly injection with that of the monthly formulation. Key findings include:

• A similar incidence of treatment-emergent adverse events in each group
• Weight gain and injection-site pain were the most commonly reported adverse events
• Injection-site pain was more frequent in the two-monthly group (18.2% vs 9.0%)
• Plasma concentrations of aripiprazole were comparable in the two groups
• No new safety concerns were identified.

Compared to oral therapy, long-acting injectable antipsychotics are associated with improved adherence and more stable plasma levels. They may offer many clinical benefits, including a reduced risk of relapse and hospitalisation, and an improved quality of life.

A comparison of aripiprazole formulations is shown in Table 1.

Table 1. Comparison of aripiprazole formulations