PBS Changes for Adalimumab

The Pharmaceutical Benefits Scheme (PBS) introduced some changes to adalimumab listings on 1 April 2021. Four biosimilar brands have been ‘a-flagged’ with the originator brand, and a new reduced volume formulation of Humira® has been added.

The new Humira® product contains the same active ingredient but is formulated without the citrate buffer. Studies demonstrate that citrate buffers are associated with more pain on injection than histidine buffers or isotonic saline. Minimising the pain of subcutaneous injections offers obvious patient benefits as well as potentially improving compliance. This is important as Humira® is indicated for many chronic conditions, such as rheumatoid arthritis and Crohn’s disease.

Two randomised, single-blind studies compared the tolerability of the two Humira® formulations in patients with rheumatoid arthritis. The pooled results demonstrate a 54% mean reduction in pain immediately after injection for the citrate-free formulation. The study was not able to identify which factor in the new presentation was most significant (i.e. the formulation, reduced volume, or needle size).

The original Humira® formulations are now designated ‘Supply Only’ and may only be dispensed on the PBS using prescriptions written prior to 1 April 2021. AbbVie advises that the original Humira® formulation will eventually be discontinued.