OBJECTIVES: Availability of biosimilars on the European market presents a threat to branded biologics, both the reference drugs and other products used in the same indication. The objective of this study was to understand the impact of biosimilar entry on list price of branded biologics for autoimmune diseases, as well as assess the potential net price implications. METHODS: In-depth secondary research was conducted to identify and review biologic-specific guidelines in EU5 countries (France, Italy, Spain, UK, Germany) and analyse the price evolution of infliximab and etanercept after the entry of biosimilars. RESULTS: Biosimilar prescribing guidelines have been established across EU5, resulting in considerable price pressure on originators and other drugs. In the UK, while no list price changes have been observed for branded infliximab and etanercept, at the net level the average cost per defined daily dose of infliximab has dropped by 59% since the introduction of a biosimilar, according to NHS England. No list price changes have been observed in Germany either, but biosimilar prescribing quotas have been set up by sick funds (GKV) and physician associations (KV) incentivising physicians to meet or surpass them, with regional variation of 19% to 70%. In France, the MoH has set biosimilar prescription target of 70% for treatment-naïve patients, with substitution allowed for biosimilars included in the ANSM ‘similar biologic group’ (11 groups as of 2017). In Italy, regional guidelines recommend that 75% of ulcerative colitis patients are prescribed the lowest-priced infliximab (biosimilar or branded), while some Spanish regions consider all anti-TNFs (both originators and biosimilars) as therapeutically equivalent, which encourages economic prescribing. CONCLUSIONS: Across EU5, guidelines and prescription quotas encourage the use of ‘best value’ (lowest priced) biologics. With anti-TNFs considered largely interchangeable and clinicians encouraged to prescribe rationally, competitive pricing is likely to become the main determinant of access.