In reporting its 2026 first-quarter earnings, Amgen indicated a 37% reduction in Enbrel sales revenue compared with the first quarter of 2025. Was this related directly to the January 1 implementation of the MFP price for Enbrel or just a continuing trend in its sales? What does it mean for the etanercept biosimilars?
On January 1, 2026, Medicare-negotiated prices for the first set of targeted drugs went into effect. Among these products was Enbrel (etanercept), the only drug on this list with impending biosimilar competition. Although biosimilar competition in this category will not be introduced until 2028, the maximum fair price (MFP) program will threaten manufacturers of etanercept biosimilars as well as other biosimilar makers.
Amgen Continues to See Enbrel Sales Decline
In reporting its 2026 first-quarter earnings, Amgen indicated a 37% drop in Enbrel sales revenue compared with the first quarter of 2025. In its press release, Amgen stated, “The decline in net selling price reflects the impact of US Medicare part D price setting under the Inflation Reduction Act…as well as increased 340B program mix.” We assume that this also considers increased catastrophic benefit liability for the manufacturer owing to part D redesign.
None of this is surprising: Amgen has reported lower net sales revenues for Enbrel every year since 2020. Nearly all of its Enbrel sales revenue is US-based. Three etanercept biosimilars have been sold in Europe for more than 6 years, and Pfizer holds commercial rights to Enbrel outside of North America. It reported Enbrel sales revenues of $627 million in 2025, which is also 9% lower than in 2024).
This continuing downward trend in the US is likely the result of several factors: (1) heavy competition from other branded anti-TNF agents and interleukins, (2) lower-priced biosimilar competition in the adalimumab and ustekinumab categories, (3) the recently implemented MFP pricing, and (4) other market factors (e.g., 340B mix of sales, part D redesign).
The MFP Effect: A 67% Discount on Enbrel and What It Means Down the Road for Biosimilar Makers
The lower MFP price for Enbrel, which is 67% below the previous WAC price, does result in lower net selling price for Amgen and thus lower revenues. We just don’t know how much it contributed to Enbrel’s first-quarter sales decline.
Overall, this spells worrisome news for the two currently approved etanercept biosimilars (by Samsung Bioepis and Sandoz). It likely means that whatever market shares the biosimilar manufacturers can attain when they do launch, it will be worth significantly less in total revenue dollars than they initially anticipated. If we extrapolate the sales figures from the first quarter to the full year, total 2026 US revenue for Enbrel will be approximately $1.3 billion. Based on continuing revenue declines (not necessarily from prescription volume declines), this figure can easily dip below the $1 billion mark (i.e., the definition of a blockbuster drug) by the end of the year.
Because of the multiple factors affecting Amgen’s Enbrel earnings, it may not provide the best evidence to support biosimilar manufacturers’ fears about the Inflation Reduction Act, reported earlier. Yet it does make sense that the MFP will lower sales expectations for biologics that were (or are) considered targets for biosimilar competition. This will make the decision to spend R&D resources on those prospective biosimilars less enticing.
This article was written by our Director of Content, Stanton Mehr. Stan has been writing commentary and reporting news about the biosimilar industry since the submission of the first biosimilar 351(k) application to the FDA 13 years ago. Since that time, BR&R has been tracking the US biosimilar marketplace, with the industry’s original, comprehensive and updated database of biosimilar filings with the FDA.