Apremilast on the PBS

From 1 January 2021, apremilast is available on the Pharmaceutical Benefits Scheme (PBS). Apremilast is PBS listed for the treatment of severe chronic plaque psoriasis that has a significant effect on quality of life. Patients must be unable to take methotrexate or have achieved an inadequate response following at least six weeks of methotrexate therapy.

Apremilast is a phosphodiesterase 4 (PDE4) inhibitor. Inhibition of PDE4 increases cyclic adenosine monophosphate (cAMP), an important regulator of innate and adaptive immune functions. The result is reduced production of inflammatory cytokines such as interleukin (IL)-17, IL-23, and tumour necrosis factor-alpha (TNF-α), and an increase in anti-inflammatory mediators such as IL-10.

The safety and efficacy of apremilast were studied in the ESTEEM-2 trial. Significantly more patients in the apremilast group achieved ≥75% improvement in their Psoriasis Area and Severity Index (PASI) score compared to placebo (28.8% versus 5.8%). The mean change in PASI score was -50.9% for apremilast compared to -15.8% for placebo. The most commonly reported adverse events were diarrhoea and nausea. The apremilast dosing schedule includes an initial titration period which is intended to minimise gastrointestinal adverse effects.