Disease modifying therapies for relapsing-remitting multiple sclerosis: Use and costs in Australia (1996-2019)

New disease modifying therapies (DMT) to control relapsing-remitting multiple sclerosis (RRMS) have been introduced to the market in the past few years and are now widely used in Australia.

To analyse the dispensed use of government subsidised RRMS DMTs in Australia from 1996 to 2019.

We obtained data of dispensed use of DMTs from the Australian Government's Pharmaceutical Benefits Scheme (PBS) administered by Medicare Australia. We measured use as defined daily dose (DDD) per 100,000 population per day. We obtained jurisdictional population data from the Australian Bureau of Statistics.

Total DMT use increased by an average of 18% annually, from 2.4 (in 1996) to 69.9 DDD/100,000/day in 2019. Interferon β1B was the most commonly used medicine between 1996 and 2000, Interferon β1A between 2001 and 2014, and fingolimod subsequently. Among Australian states, Tasmania (the southernmost state) had the highest dispensed DMT use of 94.6 DDD/100,000/day in 2019. Concession beneficiaries under the Government's PBS had both lower use and cost per patient than general beneficiaries did. Fingolimod and ocrelizumab accounted for 55% of total expenditure on MS drug therapy in 2019.

The use of oral DMTs might increasingly replace parenteral treatments in the near future. Given the current substantial government expenditure on oral DMTs, it will be imperative to examine the real world effectiveness of DMTs.