• Biological disease-modifying antirheumatic drugs (bDMARDs) for rheumatoid arthritis (RA) treatment were among the first high-cost medicines to be subsidised in Australia. • High-cost medicines pose several challenges to the Australian National Medicines Policy, which aims to provide timely access to effective medicines at a cost individuals and the community can afford. Thus, novel restriction criteria were developed to encourage cost-effective use of bDMARDs. • Government expenditure on bDMARD subsidies for RA treatment grew to about $383 million in 2014. • Evidence that initiation and continuation criteria for bDMARDs meet usually applied cost-benefit criteria is lacking. • The combined expenditure on tocilizumab, certolizumab pegol and golimumab (added to the Australian Government's Pharmaceutical Benefits Scheme in 2010) was $93 million in 2014, which is 210% over the initial estimate. • Present and future challenges with regard to bDMARDs for RA and other high-cost drugs include improved expenditure predictions, monitoring of cost-effectiveness in relation to actual use and strategic development, regulation and use of biosimilars. • Ten years of documentation on clinical and laboratory findings indicating eligibility to initiate and continue on bDMARDs remains un-used. These data represent an untapped opportunity to promote quality of use of bDMARDs and biosimilars and to improve cost predictions for high-cost drugs.