Tracking Two Bills to Remove the Clinical Efficacy Study Requirement for Biosimilar Development

Proposals in the House and Senate, both titled the Expedited Access to Biosimilars Act, may officially remove the FDA’s requirement for clinical efficacy studies for biosimilar candidates.

On July 15^th, a new bipartisan bill was introduced into the House of Representatives that would expand access to biosimilars by modernizing the FDA’s biosimilar approval process. This could be paired with a similar proposal just reaching Senate Committee discussion. Both of these proposals seek to reduce the cost of biosimilar development through squeezing out the need for comparative efficacy studies.

As reported earlier, the FDA in October 2025 announced a draft guidance that would achieve the same end, to remove the mandate for late-stage clinical efficacy trials for biosimilar manufacturers. However, a final guidance has not yet been released.

Introduced by Representatives Nick Langworthy (R-NY) and Kim Schrier, MD (D-WA), the Expedited Access to Biosimilars Act (HR 9661) could codify long-awaited regulatory changes to comparative trial expectations in the 351(k) biosimilar pathway.

According to a press release from Congressman Langworthy’s office, the act would eliminate unnecessary regulatory hurdles while preserving the FDA’s authority to require additional studies whenever scientifically warranted. This supports the October 2025 announcement of a draft guidance for removal of a mandate for phase 3 clinical efficacy studies for biosimilars. A key stipulation of the proposal would be a requirement for FDA to notify manufacturers early in the review process if additional late-stage comparative efficacy studies will be required. The aim would be to provide greater certainty around the clinical trial resources required for a successful biosimilar application process as well as avoiding unnecessary delays in the application process.

A number of associations have express support for the legislation including the Association for Accessible Medicines, the American Society of Health-System Pharmacists, and America’s Health Insurance Plans, among others.

The Senate’s 2025 Proposal

A Senate proposal by the same name (S.1414), introduced in April 2025 by Senator Rand Paul (R-KY), seeks largely the same goals. It has languished in the Committee on Health, Education, Labor, and Pensions, without additional cosponsors, until now. A committee meeting is scheduled for July 22 to finally consider this legislative proposal. It has one co-sponsor (Sen. Mike Lee, R-UT).

We’ll be monitoring whether the Expedited Access to Biosimilars Act can break through for an eventual debate and vote on either the House or Senate floor.

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.

Another Big 3 PBM Settles With FTC on Rebates, Passthroughs, and Price Spreads

The Federal Trade Commission has reached a tentative settlement with the Big 3 PBM Caremark, which should increase the PBM’s transparency and has the potential for further reducing the use of rebate-based pharmaceutical pricing models.

In the latest salvo in the Federal Trade Commission’s (FTC’s) war on PBM practices, begun in 2024, it has reached a tentative settlement with CVS Health’s subsidiary Caremark, which should increase the pharmacy benefit manager’s (PBM’s) transparency and has the potential for further reducing the use of rebate-based pharmaceutical pricing models.

Announced on July 14, this is the second settlement with a Big 3 PBM formally announced by the FTC. A previous agreement with Express Scripts was reached in February, and the FTC stated in its press release that it is in active negotiations with OptumRx for a similar type of settlement.

TrumpRx Purchases to Count Towards Drug Deductibles

One of the interesting aspects of the settlement is the agreement by Caremark to incorporate purchases through TrumpRx under insureds’ pharmacy benefit—it will be counted toward drug deductible expenditures, as a standard offering to plan sponsors. These purchases would also be counted towards out-of-pocket maximums.

In addition, under the consent order, Caremark will be required to:

Cease discriminating against low wholesale acquisition cost (WAC) versions of a drug on its standard formularies
Provide a standard offering to plan sponsors that ensures that rebates will be passed through to members at the point of sale and that members’ out-of-pocket costs are no longer higher than the net cost to plan sponsors
Provide a standard offering to all plan sponsors that allows the plan sponsor to transition off rebate guarantees and spread pricing
Increase transparency for plan sponsors, assumedly through more frequent and comprehensive reporting
Separate the fees paid by drug manufacturers to PBMs or GPOs from list prices in its standard offering
Stop interfering with the ability of pharmacies in its networks to work with pharmacy hub service providers

These FTC agreements appear to be a valuable advantage for future biosimilars offered under the pharmacy benefit. Without a rebate-based reimbursement advantage, PBMs will have less incentive to retain reference products on their drug formulary, which opens the door to earlier access (and preference) of biosimilar agents.

Impact on Private-Label Arrangements for Biosimilars

It may also shed more light on private-label arrangements and pricing, through the transparency provision. Perhaps, the agreement will even inhibit the practice, through the provision prohibiting discrimination against low-WAC agents.

In these private-label arrangements, the biosimilars sold through the PBM distributor (in CVS’s case, Cordavis) are often substantially higher than other biosimilar brands, so that the PBM can profit from the price spread.

As a result, manufacturers of adalimumab and ustekinumab biosimilars, for example, have had to compete against their own private-label versions for market share. More importantly, it closed the access window on the fingers of manufacturers who did not reach private-label agreements, as these PBMs control more than 80% of the US prescription market, discouraging new biosimilar development.

There was no mention in the agreement about Caremark serving as a fiduciary to its clients, however, which would have further spotlighted the conflict of interest represented by these private-label arrangements.

According to the FTC, these terms are very similar to the terms reached in the settlement with Express Scripts earlier this year. The consent agreement is not finalized until a public comment of 30 days has elapsed.

Are Two Pegfilgrastims for Accord BioPharma Better Than One?

The FDA has approved the eighth pegfilgrastim biosimilar; now Accord BioPharma owns two of them: newly approved Ennumo and Udenyca

Accord BioPharma and its parent company Intas Pharmaceuticals announced that had it received approval on July 9th for a new pegfilgrastim biosimilar, which it has dubbed Ennumo (pegfilgrastim-pccg). The new biosimilar has been approved for all of the indications of the reference product Neulasta.

Why Two Pegfilgrastims?

What makes this approval interesting is that Accord and Intas already have a pegfilgrastim biosimilar, the product Udenyca, which is the number 2 pegfilgrastim product as of the end of 2025 (according to IQVIA). Udenyca was approved in 2018 by the FDA, and Accord acquired Udenyca once the original manufacturer, Coherus, decided to exit the biosimilar market. In the press release announcing the newest approval, Accord stated that it now has three separate granulocyte colony-stimulating factor, and “two distinct pegfilgrastim biosimilars” in its portfolio.

BR&R contacted Accord regarding how they intend to differentiate the two pegfilgrastim biosimilars. At present, Udenyca is available as both an injectable and in on-body injector forms. The new biosimilar Ennumo is available in the injectable form only. Otherwise, there is no difference in terms of dosing or indication. While Accord did not respond in time for publication, it may be possible that Accord intends to stop marketing Udenyca as an injectable, allowing Ennumo to take its place, or potentially selling only one brand or the other to certain segments of the US audience.

“Every FDA approval marks a step forward in our mission to expand patient access to high-quality, affordable biologic therapies,” said Chrys Kokino, President, Accord North America. “With Ennumo, we now offer healthcare providers the largest G-CSF portfolio in the world from a single biosimilar company.”

However, it is not yet clear how the additional pegfilgrastim biosimilar improves access. Overall, eight pegfilgrastim biosimilars are marketed today, in addition to the reference product.

Why State Employee Health Plans Should Push Hard for Biosimilar Use

A focus on biosimilars will save individual state employee health plans a conservative average of over $17 million, based on net costs.

A new survey from the Pacific Research Institute found that a greater focus on biosimilar utilization will save individual state employee health plans on average over $17 million each year, based on net costs.

In 2024, the year on which savings calculations were based, adalimumab biosimilars had begun to significantly cut into Humira’s market share, and savings were already being registered in a number of biologic categories, especially the oncology-related therapies.

State employee health plan savings with biosimilars

The study used data from CMS, IQVIA estimates, and a third party’s estimate of nonretail prescription drug expenditures. Based on these three sources, state private health insurance plans spent $20 billion on biologics in 2024. The author, Wayne Winegarden, PhD, Senior Fellow at Pacific Research Institute, confirmed to BR&R that these estimates are based on net prices, not gross costs. He estimates that roughly one-quarter of those expenditures were spent on biosimilars in categories of biologics with biosimilar competition, or a total of 7% of overall biologic expenditures.

State Employee Health Plans Save Big With Biosimilars

The research assumed two different scenarios: (1) biosimilars attain 52% of the biologic volume in categories with biosimilar competition (or 15% of overall biologic expenditures) and (2) 81% within those categories, or 24% of the overall biologic spend.

The author found that across the US, savings ranges from $871 million to $1.8 billion each year. From the analysis of individual states’ public employee health plans, biosimilars will save annually in the range in the from $0.9 million in Wyoming to $88.4 million in California (conservative scenario). In the more aggressive scenario, the biosimilars savings range was $1.8 million in Wyoming and $178.9 million in California.

Dr. Winegarden concludes, “Due to the savings potential, prioritizing biosimilars in state employee health plans will enhance the fiscal soundness of the state budget while ensuring state employees have access to efficacious treatments. This is an easy win-win outcome that will benefit both taxpayers and state employees.”

In Other Biosimilar News

According to a report in the Korea Biomedical Review, Celltrion was given the FDA interchangeability designation for its rituximab biosimilar product Truxima. This is perplexing for all of the reasons I’ve stated in the past: (1) the drug is not covered under the pharmacy benefit so it is not subject to the sole automatic substitution purpose of the designation and (2) the interchangeability designation does not in any way infer that the product is better than another biosimilar, yet the report noted that “Truxima remains the only rituximab biosimilar officially recognized by the FDA as interchangeable with the reference product, which it believes will provide a competitive advantage through greater physician confidence and market differentiation.” Any suggestion that an interchangeable is better than a conventional biosimilar is false. Rituximab biosimilars were first approved in 2018. How much additional confidence do prescribers need?

Samsung Bioepis Reboots Byooviz Marketing With Harrow at the Helm

Samsung BIoepis announced that it has relaunched Byooviz US marketing efforts with Harrow, the ophthalmology product commercialization partner it signed last July; Lupin receives FDA approval for its own ranibizumab biosimilar.

On July 1, Samsung Bioepis announced that the pause in marketing for its ranibizumab biosimilar Byooviz has come to a close, with the relaunch of the product with its new marketing partner Harrow.

Approved in September 2021 as the first ranibizumab biosimilar, Byooviz marketing efforts had dropped off since December 2025, when Biogen’s commercialization rights to the product were reverted back to Samsung Bioepis. Biogen had been responsible for commercialization of the product in the US.

“Today marks an exciting new chapter for Byooviz in the US. As the first FDA-approved biosimilar to Lucentis, Byooviz has already demonstrated its value in expanding access to critical retinal disease treatments. With Harrow now leading commercialization efforts, we are reigniting our commitment to ensuring patients and retina specialists across America to have access to this quality-proven, safe and effective biosimilar option,” said Linda Choi MacDonald, Executive Vice President and Global Head of Commercial, Samsung Bioepis. “We believe this relaunch will ultimately help more patients with critical ophthalmic diseases to receive the vision-saving treatments they need.”

A Difficult Road for Ranibizumab Biosimilars

Byooviz failed to gain traction for its intended market—patients with wet age-related macular degeneration, macular edema following retinal vein occlusion, or myopic choroidal neo vascularization. It reached its peak marketshare of about 8% in 2024, trailing its biosimilar competitor (Cimerli, then at 34%).

Overall, the biosimilar market for ranibizumab has a long climb back into the utilization picture: Byooviz has only 2% share, according to the latest Samsung Bioepis Biosimilar Market Report; Cimerli’s share dropped to zero, after a pause in marketing by Sandoz, caused by falling average sales prices. According to Q2 2026 report, ASP prices ranged from $320 to $398 for a 0.5-mg injection. However, the CMS July 2026 ASP file indicate a range of $255.45 for the reference product Lucentis to $1,204.85 for Byooviz for the 0.5-mg injection.

It is likely that the aflibercept market represents a greater opportunity for Samsung, Harrow, and the rest of the biosimilar industry relative to the ranibizumab category. Not only has ranibizumab had to battle for share against agents like aflibercept and newer technologies, but the use of off-label, compounded bevacizumab is also a constant threat.

Harrow will also market Samsung’s aflibercept biosimilar, Opuviz, when it is launched later this year.

Lupin Joins the Ranibizumab Fray

In related news, Lupin had announced that its own ranibizumab biosimilar has been approved in early June. This product, dubbed Ranluspec (ranibizumab-hkdz), will be available both as a vial and prefilled syringe.

In the company’s press release, Dr. Cyrus Karkaria, President – Biotechnology, Lupin, stated, “The US FDA approval of our biosimilar ranibizumab underscores our scientific expertise in biologics development and manufacturing, and reinforces our commitment to expanding access to advanced, affordable therapies for patients worldwide.”

When is a Biosimilar a Biosimilar?

In 2026, is the definition of a biosimilar the same for countries’ drug regulatory systems around the globe? A recently published scoping survey attempted to answer the question.

Although there has been a decade of interest in moving towards global biosimilar regulatory standards, we first must answer a more foundational question: Is the definition of a biosimilar the same worldwide?

You may suspect that the answer is obvious, but then again, why are we asking it? Is it a trick question? Years ago, the answer was not so simple. Those of us covering the biosimilar field in the 2010s will recall that some Indian companies, for example, were producing what might be considered “follow-on” medicines by the FDA’s regulatory standards, but were promoting them as biosimilars.

No Guidances by FDA on Follow-on vs. Biosimilar Products

The FDA’s own regulatory definition was not set in stone: Basaglar, the second insulin glargine product to receive FDA approval, is a biosimilar but technically not a biosimilar. Even today, there may be some confusion as to whether Basaglar is considered a biosimilar or a follow-on product. It was indeed approved by the FDA under a 505(b)2 application, principally because insulins were not considered eligible for the 351(k) approval pathway until 2020. The FDA would probably support that it is clinically equivalent to Lantus in any way that matters. Yet, from a regulatory perspective, it was not evaluated as part of the biosimilar pathway, so it cannot be designated a biosimilar.

The same can be said for Granix, the second filgrastim product approved by the FDA, which underwent its approval process before the 351(k) was implemented (and under which Zarxio was licensed). It is important to note that the FDA itself has not tried to improve clarity by announcing retrospectively that these agents can be considered either biosimilar or an equivalent.

A Survey of Biosimilar Definitions

So, is a biosimilar a biosimilar throughout the world? An article published in JAMA Health Forum described a survey of 19 countries’ biosimilar regulatory guidelines. These included 12 with emerging and developing economies and 7 with advanced economies, according to the World Health Organization classification. The authors, from the University of San Francisco and GlaxoSmithKline, found that most countries define “biosimilarity as the absence of differences in the medicine’s quality, safety, and efficacy compared with the RP. Sixteen countries explicitly required comparability exercises to demonstrate biosimilarity, and 13 countries specified that the same RP must be used in these studies.

“Of the 19 countries in the study sample, 17 (89%) have adopted the WHO’s biosimilar terminology; the exceptions were Indonesia, which uses the term follow-on biological in addition to biosimilar,and Tanzania, which uses the term similar biotherapeutic product. A total of 17 countries (89%; except India and South Korea) define biosimilarity according to the absence of differences in quality, safety, and efficacy between the biosimilar and the reference product, although in some countries (Egypt, Turkey, UK, and US), this is heavily implied rather than explicitly stated. Most countries (n = 16 [84%]) require comparability exercises (by definition), but 3 (Mexico, Indonesia, and China) do not explicitly include this requirement.”

The authors also stated that all advanced economies waived the need for clinical efficacy and immunogenicity testing when justifiable, but guidelines from emerging and developing economies differed on clinical study waivers.”

Interestingly, one of the areas of least consensus is that of biosimilar naming and labeling guidance provided. Countries such as France, Germany, Japan, and South Korea do not specify any requirements, whereas the UK, US, and Canada do, among the WHO advanced economic sector. Among countries in the emerging and developing economic region, China and Mexico do have naming and labeling guidelines, whereas Brazil, India, and Indonesia do not. The area of greatest agreement seemed to be in acceptance of extrapolation, with all but Saudi Arabia among the surveyed countries with published extrapolation guidelines.

Scoping surveys such as this are necessary steps in a march towards global regulatory standards for biosimilars. They show not only how far we’ve come in reaching basic agreements, but also how far we need to go. Perhaps, most importantly, they show us areas where a push for global standards would have the least likelihood of success.

Sunshine Lake Pharma and Lanexa Biologics Get Their First FDA Biosimilar Approval

The Guangdong, China–based generics manufacturer and its commercialization partner Lanexa Biologics received FDA approval for their insulin glargine biosimilar Langlara. In addition to its insulin glargine product, which is approved in China, other biosimilars may follow based on Sunshine Lake’s other existing insulin formulations.

Another insulin glargine biosimilar has joined the ranks of Semglee and Rezvolglar. A new, lesser-known manufacturer from China has received its first FDA approval, joining the ranks of insulin glargine competitors in the US. The product, Langlara (insulin glargine-aldy) was approved by the FDA in late April. Langlara is manufactured by Guandong, China–based Sunshine Lake Pharma Co, Ltd (we think–see below).

The drug will be commercialized in the US by a Lannett subsidiary called Lanexa Biologics. Lannett had an insulin glargine biosimilar in the pipeline, and was expected to file for FDA approval several years ago. Instead, it filed for Chapter 11 bankruptcy. Lannett emerged from bankruptcy in June 2023. In July 2025, Aurobindo Pharma began the process of acquiring Lannett. According to Lannett, upon completion of the acquisition, Lanexa Biologics will become a free-standing company, and will focus exclusively on biosimilar commercialization in the US.

Tim Crew, CEO of Lannett, stated, “Often, the greatest barrier to care for patients living with diabetes is the cost or the availability of the medicine itself. Upon the launch of Langlara, supported by the tremendous manufacturing scale of our partner, patients will have expanded access to a safe, affordable and available treatment option.”

It is unknown at present whether (or how) this biosimilar approval is related to the earlier Lannett drug candidate. However, Lannett’s press release also refers to a collaboration with Sunshine Lake Pharma on the latter’s short-acting insulin aspart biosimilar candidate, which is also approved in China. Sunshine Lake Pharma also has an R human insulin and 70/30 mix insulin among its product portfolio.

The Chinese-end of this partnership is possibly even more complex. Clicking on the website for Sunshine Lake Pharma leads to HECpharm.com, which also operates under the name Guangdong Dongguangyang Pharmaceutical. The HECpharm.com website explains that Dongguangyang Pharmaceutical was founded in 2003, the same date as listed for Sunshine Lake Pharma. A merger occurred between Sunshine Lake and a Dongguangyang Changjiang Pharmaceutical, in 2025, and yet another name is mentioned on the website—Dongguangyang Lake. In the US, a subsidiary named HEC Pharm USA Inc is based in Plainsboro, New Jersey, but that website’s link was inoperative when checked for this article. Yet, the FDA’s approval letter for Langlara was directed to “Sunshine Lake Pharma Co, Ltd, c/o HEC Pharm USA Inc,” indicating that HEC Pharm USA was operating as the liaison with the FDA during the approval process. Perhaps HEC Pharm is a parent company in this maze of entities. In any case, there is a new insulin glargine biosimilar approved in the US on behalf of a confusing organization in China!

Alvotech Submits First Entyvio Biosimilar Application to FDA

The first 351(k) application for a vedolizumab (Entyvio) biosimilar has been submitted by Alvotech. If approved, the biosimilar would be marketed by Teva. Alvotech also resubmitted biosimilar applications for golimumab and aflibercept.

On June 8, Alvotech announced that the FDA has accepted its biologic licensing application for AVT16, a biosimilar candidate for the reference drug Entyvio. This marks the first FDA 351(k) drug application for a vedolizumab biosimilar.

In its press release, Joseph McClellan, Chief Operating Officer of Alvotech, stated, “FDA acceptance of the BLA for AVT16 is another important step in advancing our mission to increase access to biologic medicines for patients worldwide. Our proposed interchangeable biosimilar to Entyvio builds on our experience in immunology and reflects the strength of our fully integrated development and manufacturing platform.”

Vedolizumab, an integrin-receptor antagonist, is currently approved to treat adults with moderate-to-severe ulcerative colitis and Crohn’s disease. The reference product is available in both intravenous infusion and subcutaneous injections.

Takeda’s US Entyvio net revenues were over $4 billion in 2024, but the biologic has been targeted for Medicare maximum fair price negotiation. The negotiated price will be implemented on January 1, 2028, unless biosimilar launch is imminent. The original drug patent is set to expire in 2026.

Intravenous Infusion vs. Subcutaneous Injection

AVT16 would be available only as an intravenous infusion. Alvotech’s biologic licensing application does not cover the subcutaneous injectable. A separate investigational product, AVT80, promises a biosimilar version of the prefilled syringe and autoinjector administration. Alvotech noted that the European Medicines Agency has received a marketing application for both AVT16 and AVT80. It is not clear whether Alvotech and its marketing partner Teva, intends to market these products under separate brand names if approved. The patent on the subcutaneous formulation may not expire until the 2030s, according to some sources, which may play into Alvotech’s decision to separate the FDA applications.

In Other Alvotech Biosimilar News

In November 2025, Alvotech received complete response letters from the FDA on two products—its biosimilar versions of golimumab and aflibercept. On June 4, 2026, the biosimilar manufacturer revealed that it had resubmitted its 351(k) applications to the FDA for both products (AVT05 for golimumab and AVT06 for aflibercept). Alvotech noted that it expects an FDA decision within 6 months. The complete response letters cited production facility issues, and not data or clinical quality questions. The latest FDA surveillance inspection of the Reykjavik production facility was completed by May 11, according to the company.

How Comfortable Are Neurologists With Biosimilar Prescribing?

With the October 2025 launch of Tyruko (natalizumab), neurologists have now been exposed to three different biosimilar categories, and one has been around since before the COVID-19 pandemic.

It’s logical to assume that when a specialty is exposed to biosimilar competition for the first time, acceptance and uptake of the biosimilar might be slow. The effort to educate specialists around the safety and efficacy of the biosimilar(s) may take time. In the past, manufacturers of the reference products countered competition with misleading marketing efforts to preserve their revenues. To cite just two examples, this occurred with gastroenterologists with the introduction of infliximab and with ophthalmologists with the launch of the first ranibizumab biosimilar. And then of course, there was the slow acceptance of adalimumab, based on different formulations.

Last October, the natalizumab biosimilar Tyruko was launched by Sandoz, primarily for the treatment of multiple sclerosis. Will neurologists’ biosimilar prescribing follow this stunted path? Only if you think natalizumab marks the first foray of biosimilars into the field of neurology medicine. In reality, this is not the case.

Eculizumab and Rituximab Biosimilars in the Neurology Toolbox

One reason that neurologists’ biosimilar prescribing will be quicker is that natalizumab is actually the third biosimilar used by these specialists. Eculizumab is usesd to treat patients with the neurological condition generalized myasthenia gravis. That drug has been available as a biosimilar since March 2025.

Although many neurologists have moved from the eculizumab reference drug Soliris to the follow-on brand Ultomiris, the appearance of biosimilars has likely exposed them to more prior authorization and/or step therapy, encouraging the use of lower-cost eculizumab biosimilars. Additionally, their experience with buy-and-bill eculizumab biosimilars gave them a brief preview of buy-and-bill reimbursement for the natalizumab biosimilar.

Another factor impacting neurologists’ biosimilar prescribing is not so obvious: A significant portion have been prescribing rituximab and its biosimilars off label to treat some neurologic disorders, including myasthenia gravis, multiple sclerosis, and neuromyelitis optica spectrum disorder. And rituximab biosimilars were approved since 2018.

Neurologists May Be More Comfortable With Biosimilars Than You Think

In working on a survey of 40 practicing neurologists for a biosimilar manufacturer and marketer, it became apparent that the respondents were far more familiar with biosimilars than we may have assumed.

In the case of the present survey, which was conducted just before the launch of Tyruko, 41% of the neurology sample had indicated they had experience with rituximab biosimilar prescribing s within the previous 12 months. This may have contributed to the view by 40% of the sample that the use of either eculizumab or natalizumab biosimilars would not have any effect on their practice. An additional 22% believed the biosimilars might actually result in greater profits. This should certainly make it easier for makers of biosimilar forms of market-leading Ocrevus, when they are launched in 2028.

Watch for further insights from this survey project in the next month, once the full results are published.

The Effect of MFP on Enbrel Sales, and Biosimilar Implications

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.