OBJECTIVESBiosimilars improve patient access by providing cost-effective treatment options. This study assessed the potential for savings and expanded patient access with increased use of two biosimilar disease modifying anti-rheumatic drugs (DMARDs): (a) approved adalimumab biosimilars and (b) the first tocilizumab biosimilar, representing an established biosimilar field and a recent biosimilar entrant in France, Germany, Italy, Spain, and the United Kingdom (UK).METHODSSeparate ex-ante analyses were conducted for each country, parameterized using country-specific list prices, unit volumes annually, and market shares for each therapy. Discounting scenarios of 10%, 20%, and 30% were tested for tocilizumab. Outputs included direct cost-savings associated with drug acquisition or the incremental number of patients that could be treated if savings were redirected. Two biosimilar conversion scenarios were tested.RESULTSSavings associated with a 100% conversion to adalimumab biosimilar ranged from €10.5 to €187 million (UK and Germany, respectively), or an additional 1,096 to 19,454 patients that could be treated using the cost-savings. Introduction of a tocilizumab biosimilar provided savings up to €29.3 million in the most conservative scenario. Exclusive use of tocilizumab biosimilars (at a 30% discount) could increase savings to €28.8 to €113 million or expand access to an additional 43% of existing tocilizumab users across countries.CONCLUSIONThis study demonstrates the benefits that can be realized through increased biosimilar adoption, not only in an untapped tocilizumab market, but also through incremental increases in well-established markets such as adalimumab. As healthcare budgets continue to face downwards pressure globally, strategies to increase biosimilar market share could prove useful to help manage financial constraints.