Projected US Savings From Biosimilars, 2021-2025

ABSTRACT

Objectives: Biologics account for an increasing share of US prescription drug spending. Biosimilars could lower biologic prices through competition, but barriers to increasing both supply and uptake remain. We projected US biosimilar savings from 2021 to 2025 under different scenarios.

Study Design: We projected US spending on biologics over a 5-year period under 3 scenarios: (1) a baseline scenario holding quarter 4 (Q4) of 2020 market conditions constant; (2) under main assumptions allowing for biosimilar market growth and entry; and (3) an upper-bound scenario assuming greater biosimilar uptake, more robust price competition, and quicker biosimilar entry.

Methods: We first analyzed 2014-2020 US volume and price data from IQVIA’s MIDAS database for biologics already facing biosimilar competition to inform model parameter values. We used these inputs to project biosimilar entry, biosimilar volume shares, biosimilar prices, and reference biologic prices. We calculated 2021-2025 new savings from biosimilar competition vs the Q4 2020 baseline.

Results: Estimated biosimilar savings from 2021 to 2025 under our main approach were $38.4 billion, or 5.9% of projected spending on biologics over the same period. Biologics first facing biosimilar competition from 2021 to 2025 accounted for $26.1 billion of savings, with $12.2 billion from evolving market conditions for already-marketed biosimilars. Furthermore, $24.6 billion of savings under our main approach were from downward pressure on reference biologic prices rather than lower biosimilar prices. Savings were substantially higher ($124.5 billion) under the upper-bound scenario.

Conclusions: Biosimilar savings from 2021 to 2025 were $38.4 billion under our main assumptions. Greater savings may be feasible if managed care and other settings increase biosimilar utilization and promote competition.

Am J Manag Care. 2022;28(7):329-335. https://doi.org/10.37765/ajmc.2022.88809

Takeaway Points

Although biosimilars have the potential to lower prices through competition, barriers to biosimilar uptake may limit these savings. We projected biosimilar savings from 2021 to 2025 under several scenarios.

• Projected savings were $38.4 billion under main assumptions vs conditions as of quarter 4 (Q4) of 2020 (5.9% of spending on biologics).
• $26.1 billion (68.1%) of estimated savings were from new biosimilars.
• $24.6 billion (64.2%) of estimated savings were from downward pressure on reference biologic prices.
• Estimated savings were substantially higher ($124.5 billion) under an upper-bound scenario.
• Prices and biosimilar market shares already achieved by Q4 2020 resulted in an additional savings of $52.9 billion from 2021 to 2025.

Prescription drugs are often separated into 2 categories: “conventional” small molecule drugs and biologics. Whereas conventional drugs are synthesized chemically and are typically easier to describe scientifically, biologics are manufactured in living systems and are more complex and harder to characterize.¹ Average prices for biologics are much higher than those for small molecule drugs for several reasons, including differences in therapeutic classes and clinical use, payment policies, and limited competition.² In 2017, biologics accounted for 2% of US prescriptions by volume but 37% of net spending on prescription drugs.³ Due in part to favorable returns on investments, many recent and upcoming drugs are biologics, including those to treat cancer and other life-threatening diseases.⁴

Biosimilars, which are highly similar versions of brand-name reference biologics, are a key component of the national strategy to tackle high and growing spending on prescription drugs.⁵ Compared with other countries, the United States was relatively late in establishing a pathway for biosimilar market entry. The European Medicines Agency implemented a biosimilars approval pathway in 2005, approving its first biosimilar in 2006. In contrast, the US FDA lacked the authority to implement a regulatory approval pathway for biosimilars until the Biologics Price Competition and Innovation Act (BPCIA) was enacted as part of the Affordable Care Act in 2010. The FDA’s regulatory approval pathway, like those in other countries, relies on biosimilars’ similarity to reference biologics as evidence of safety and efficacy.⁶ The first US biosimilar was approved in 2015. As of December 31, 2020, 7 biologics faced biosimilar competition in the United States, with additional biosimilars on the horizon.

Conceptually, competition between biosimilars and reference biologics has the potential to drive down prices and reduce spending. In practice, the magnitude of these reductions varies depending on the competitive environment for each biologic; the extent to which insurers and pharmacy benefit managers use formularies, utilization management, and other tools to encourage the use of lower-cost alternatives; and patient and prescriber perceptions of biosimilars.^7,8 Managed care organizations, payers, and policy makers have an interest in better understanding the potential for existing and future biosimilars to help control price and spending growth for biologics. Several stakeholders support policy changes to address uptake concerns, the extent of price competition, and incentives for long-term sustainability in the US biosimilar market.^9-11

In this paper, we estimate new 2021-2025 US savings from biosimilars under different scenarios vs a baseline of biosimilar market shares and prices already achieved by quarter 4 (Q4) of 2020. For additional context, we also estimate total historical and projected biosimilar savings from 2014 to 2025.

METHODS

Overview

We projected 2021-2025 spending on 60 biologics under 3 scenarios. In the first (“baseline”) scenario, we projected spending for the 7 biologics facing biosimilar competition as of Q4 2020 (bevacizumab, epoetin, filgrastim, infliximab, pegfilgrastim, rituximab, and trastuzumab) while holding biosimilar and reference biologic market shares and prices constant at Q4 2020 levels and with no new biosimilars. In the second (“main approach”) scenario, we estimated spending that allowed existing biosimilar markets to mature and new biosimilar entry based on assumptions grounded in past US biosimilar experience. A third “upper-bound” scenario estimated spending that assumed greater biosimilar entry, volume shares, and price competition compared with assumptions used in the main approach. We then calculated 2021-2025 “new” savings from biosimilar competition (under the main approach and upper-bound scenarios) vs the Q4 2020 baseline scenario.

For comparison, we also calculated total historical and projected biosimilar savings from 2014 to 2025 vs a counterfactual that assumed the absence of biosimilars, as if the BPCIA had never been enacted. This total savings estimate combines 3 separate components: (1) historical savings from 2014 to 2020; (2) projected 2021-2025 savings at already-achieved Q4 2020 market shares and prices; and (3) projected 2021-2025 new savings from expanded biosimilar competition (our “main approach” analysis).

Data Sources

We used Q1 2014 to Q4 2020 IQVIA MIDAS data, which contain US sales and volume estimates for individual biologic products, as the primary data source to project savings.¹² IQVIA MIDAS data are designed to support country-level trend and pattern analyses. MIDAS estimates are projected from IQVIA’s audits of standardized manufacturer, wholesaler, and other invoices. This methodology results in reliable estimates of real-world activity for these intended uses, but they remain estimates. The MIDAS data used in this analysis were obtained under license from IQVIA.Our MIDAS extract was prepared on March 2, 2021.

We calculated MIDAS-based prices by dividing manufacturer sales by volume, measured in terms of IQVIA “standard units,” which for biologics are typically a count of vials, syringes, pens, or other counting units. The MIDAS sales data reflect amounts paid to manufacturers prior to the application of rebates and other discounts that can ultimately result in significantly lower net sales (and therefore lower net prices). However, MIDAS data may incorporate certain discounts (for example, prices from the 340B Drug Pricing Program), as long as they appear as lower prices recorded on invoices.

We used MIDAS data with CMS quarterly average sales price (ASP) data as an alternative source for net prices. ASP is a volume-weighted average of net prices, including rebates and most other discounts, reported by manufacturers to CMS with a 2-quarter lag. CMS uses ASP to set payment rates for Medicare Part B drugs, which are often administered by providers. As a result, ASP data were available for only some biologics.

Study Biologics

Our modeling includes biologics that are already subject to biosimilar competition and those that may experience biosimilar competition in the future. We identified 256 active ingredients in the MIDAS data that were categorized in MIDAS as biologics and sold in the United States at any time between 2014 and 2020. These active ingredients accounted for $1.14 trillion in 2014-2020 sales at manufacturer prices. We excluded 132 active ingredients that each had less than $100 million in 2020 US sales (at manufacturer prices), as they are unlikely to face biosimilar competition because of their limited potential for profitable biosimilar development. We excluded 64 additional active ingredients for other reasons: (1) 34 with 12-year data exclusivity expiration after December 31, 2025, the end of our study period^13,14; (2) 23 categorized as biologics in MIDAS but not eligible for the biosimilar regulatory approval pathway because their FDA regulatory approval is via the Federal Food, Drug, and Cosmetic Act rather than the Public Health Service Act; and (3) 7 blood products, for which the applicability of the biosimilar regulatory approval pathway is unclear. The resulting list included 60 active ingredients (“biologics”) used in our analysis (see the eAppendix [available at ajmc.com] for a full list). These 60 biologics accounted for $724.4 billion in sales from 2014 to 2020 at manufacturer prices, or 63.4% of sales across all biologics over the same period.

We compiled information on the status of US biosimilar development programs from news releases, news articles, and the Generics and Biosimilars Initiative (GaBI).^15,16 We assigned each of the 60 biologics to 1 of 6 status categories indicating the level of biosimilar competition: biosimilar launched, biosimilar approved but not launched, biosimilar under FDA review, biosimilar in late clinical development, biosimilar in early development, or no available information. Seven had biosimilar versions sold in the United States by Q4 2020: (1) bevacizumab, (2) epoetin, (3) filgrastim, (4) infliximab, (5) pegfilgrastim, (6) rituximab, and (7) trastuzumab.

Selection of Price Data Source

Neither MIDAS nor ASP data perfectly measure net prices for biologics. ASP data may be lower than MIDAS manufacturer prices if rebates play a significant role in determining net price. For example, rebates to payers may be relatively large when manufacturers of pharmacy-dispensed biologics compete for preferred formulary placement. In other cases, MIDAS prices may be lower than in ASP because MIDAS captures 340B discounts excluded from ASP. We expect that both data sets overestimate actual net prices. Most biologics were present in both data sets, and we used the lower price for each biologic to approximate net prices as closely as possible; prices in MIDAS were lower than in ASP for nearly all biologics. We adjusted MIDAS prices downward for adalimumab and certain insulins to reflect likely omitted rebates in MIDAS manufacturer prices.¹⁷ (See the eAppendix for details.)

Estimating Savings

A detailed summary of our modeling approach is available in the eAppendix. We projected changes in total volume linearly for each biologic. In practice, volume may deviate from linear trends because of various factors, including changes in clinical practice, availability of new treatments, growing population or disease prevalence, and a demand response from lower-priced biosimilars.^18,19

We projected reference biologic prices using linear extrapolation from 2014-2020 quarterly data for biologics without biosimilar competition as of Q4 2020, and from all quarters prior to biosimilar entry for existing biosimilar markets. We developed and applied time-dependent assumptions on biosimilars’ share of total volume, reference biologic prices with and without biosimilar competition, and biosimilar vs reference biologic prices from an analysis of 2014-2020 data for biologics facing biosimilar competition by Q4 2020. For our baseline scenario, we held biosimilar and reference biologic volume shares and prices constant at Q4 2020 levels for these 7 biologics.

For biologics without biosimilar competition by Q4 2020, we calculated savings as if biosimilars entered the market in each quarter during our study period. We then calculated biosimilar savings for each biologic by applying entry probability assumptions. The likelihood of biosimilar entry increased over time and varied based on the current state of biosimilar development.

We separately tallied direct savings from lower biosimilar prices relative to projected reference biologic prices, and indirect savings from downward pressure on reference biologic prices facing biosimilar competition. We report savings estimates overall, separately for direct and indirect savings, and for individual biologics. The sensitivity analyses vary the particular inputs and are described in more detail in the eAppendix.

RESULTS

Spending under the baseline scenario holding Q4 2020 biosimilar conditions constant without new biosimilar entry was $648.0 billion over the 5-year period. Spending under the main approach scenario, including new savings from expanded biosimilar competition, was $609.6 billion over the same period, for savings vs the baseline scenario of $38.4 billion (5.9%). For comparison, US spending on all prescription drugs was roughly $500 billion at manufacturer prices in 2020 based on MIDAS data, and spending on all prescription drugs over a 5-year period would likely be in excess of $2.5 trillion. Our biosimilar savings estimate of $38.6 billion is roughly 1.5% of this rough estimate of total spending on prescription drugs over the 5-year period.

For comparison, total historical and projected biosimilar savings from 2014 to 2025 were $102.5 billion, including $11.2 billion in historical savings from 2014 to 2020, $52.9 billion in projected 2021-2025 savings at already-achieved Q4 2020 market shares and prices, and $38.4 billion in projected 2021-2025 new savings from expanded biosimilar competition (Figure 1).

The bulk of new savings under our main approach, $26.1 billion (68.1% of total new biosimilar savings), is from expected new biosimilars from 2021 to 2025. Figure 2 details new savings for individual biologics under our main approach, grouped by existing vs new biosimilar markets. Savings for other specific biologics are reported in the eAppendix. Despite contributing to savings only from 2023 to 2025, adalimumab accounted for $19.5 billion (50.8%) of savings, whereas savings from new insulin biosimilar entry were $4.1 billion (10.6%). All other biologics without current biosimilar competition accounted for savings of $2.6 billion (6.7%). Additional savings from evolving conditions in existing biosimilar markets from 2021 to 2025 account for $12.2 billion in savings in that time period.

Figure 2 also decomposes the “direct” savings from lower biosimilar vs reference biologic prices and “indirect” savings from downward pressure on reference biologic prices under our main approach. Direct savings were $13.7 billion (35.8%) compared with indirect savings of $24.6 billion (64.2%) across all study biologics.

Figure 3 illustrates the contributions to savings for select biologics on a quarter-by-quarter basis under our main approach. The area under the curve in Figure 3 represents the total estimated savings of $38.4 billion from 2021 to 2025. The projected entry of adalimumab biosimilars in 2023 results in an inflection point in quarterly savings, whereas contributions of biologics with currently marketed US biosimilars increased slightly over time.

Figure 4 compares 5-year projected savings from biosimilars under our main approach vs other scenarios. Doubling entry probabilities yielded increased savings of $46.5 billion (a 21.1% increase over our main approach). Increasing biosimilar volume share by 50% raised projected savings to $48.3 billion (an increase of 25.8% over main approach savings), whereas decreasing biosimilar prices by 25% yielded savings of $52.8 billion (an increase of 37.6%). Total savings were $82.4 billion (more than double main approach savings) when we assumed that biosimilar competition drives an additional 25% reduction in reference biologic prices. As noted earlier, downward pressure on reference biologic prices is the primary driver of savings.

The upper-bound scenario, which simultaneously applies all these individual alternative assumptions, increases savings to $124.2 billion, or roughly a fifth of expected spending on biologics ($648.0 billion) over the 5-year period. Insulins contributed $13.9 billion to the upper-bound scenario (vs $4.1 billion under our main approach).

DISCUSSION

Under our main approach assumptions, we estimate total 2021-2025 savings from biosimilars of $38.4 billion, or 5.9% of projected total spending on biologics from 2021 to 2025. Across all biologics, savings from downward pressure on reference biologic prices accounted for nearly two-thirds of estimated savings ($24.6 billion); the remainder resulted from lower biosimilar prices relative to their reference biologics. Although it can be informative to compare biosimilar and reference product prices,20 this approach omits a significant share of savings resulting from lower reference biologic prices. This is particularly relevant given the consistent price increases observed for reference biologics prior to biosimilar entry.²¹

New biosimilar entrants from 2021 to 2025, including adalimumab and insulins, contributed 68.1% of total new biosimilar savings. Importantly, we assumed that already-approved biosimilars for adalimumab would enter the market in early 2023. Although earlier entry could increase savings, the associated legal risk to manufacturers makes this unlikely. There are few major biologic reference products besides adalimumab and insulins for which biosimilar entry appears likely before 2025. The actual contributions of new biosimilar entry may be less than we estimate because we modeled entry after the end of the data exclusivity period for each biologic, which may occur earlier than the expiration of key patents as in the case of adalimumab.

Further uptake and price reductions from already-approved biosimilars contributed $12.2 billion in savings from 2021 to 2025. Although not the focus of our analysis, we projected that spending on biologics from 2021 to 2025 would be $52.9 billion higher without gains in biosimilar market share and price reductions already achieved by Q4 2020. Depending on context, either our main estimates of incremental new savings vs a Q4 2020 baseline ($38.4 billion) or aggregate savings vs a “no biosimilars” counterfactual ($91.3 billion) may be of greater interest to managed care organizations and policy makers. Our estimate of new savings from biosimilars is relatively modest compared with 2 recent studies that estimated savings of $69 billion to $140 billion from 2020 to 2024,²² and of $24 billion to $150 billion from 2017 to 2026.²³ Both studies calculated savings under a range of volume share and price ratio assumptions. However, our analysis uses more recent data to inform estimates, more comprehensively decomposes savings by source and biologic, and is clearer on the baseline case used as a counterfactual to tally savings. Unobserved off-invoice discounts may make our estimates of net prices too high, despite our use of both MIDAS and ASP data, as well as price adjustments for adalimumab and insulins. If so, our savings estimates will be biased.

Although the FDA can designate biosimilars as “interchangeable” with reference biologics, provided certain criteria are satisfied, only 1 currently marketed US biosimilar, Semglee, a biosimilar to insulin glargine, has this designation.²⁴ Interchangeable biosimilars may be perceived as closer substitutes to reference biologics, and as a result, they may achieve larger market shares and yield steeper price reductions in reference biologics than we considered in our modeling scenarios. Interchangeable biosimilars may also give managed care plans greater ability to steer utilization toward the lower-cost versions and give pharmacists incentives to select the version with the lowest acquisition cost. Given consistent insulin price increases,^25,26 recent regulatory actions, and the growing call to designate these products as “interchangeable,”^27,28 additional insulin biosimilar manufacturers may pursue interchangeability. Although insulins accounted for a small share of savings under our main approach ($4.1 billion, or 10.6%), this value increased to $13.9 billion under more aggressive assumptions on biosimilar entry, uptake, and price competition, all of which may be more feasible with an interchangeable designation. Beyond insulins, there is already 1 approved (but not yet sold) interchangeable biosimilar to Humira (adalimumab),²⁹ with potentially more on the horizon. Interchangeable adalimumab biosimilars may accelerate price reductions and volume share growth.

There are many other uncertainties in how biosimilars in the United States will evolve over time. Our savings estimates are based on entry timing, volume share, and pricing assumptions, all of which were chosen to best represent prior US biosimilar and reference biologic trends observed through Q4 2020. Although future US experience for individual biologics will almost certainly deviate from our assumptions, the results presented here were relatively robust to changes in the underlying assumptions. Compared with our main approach, our upper-bound savings estimate of $124.2 billion was, as expected, much larger when we simultaneously increased biosimilar entry, uptake, and price competition across all biologics. Future research should focus on the likely impacts of specific policy proposals and assessing how the number of competitors, market size, and other factors drive the magnitude of savings.

The assumptions used in our alternate scenarios may be feasible today in some parts of the US health care system. Some payers and health systems, such as Kaiser Permanente and the Veterans Health Administration, have used their direct control over prescriber decision-making to achieve much higher biosimilar volume shares than others.^30,31 However, achieving greater use of biosimilars across the entire US health care system may require coordinated new policies and managed care strategies. Several policy changes could increase biosimilar uptake—for example, paying the same rates for reference biologics and their biosimilars,^32,33 keeping separate rates but paying a higher margin for biosimilars,³⁴ or decreasing patient cost sharing for biosimilars.³⁵ More broadly, Congress, the FDA, and individual states could explore ways to promote biosimilars that can be substituted for reference biologics. Many of these strategies also have the potential to increase price competition between biosimilars and reference biologics.

Separately, Congress could revisit BPCIA’s “patent dance” and other provisions governing when and how biosimilars first enter the market, focusing on avoiding cases in which litigation and settlements result in much later biosimilar entry compared with other countries (for example, adalimumab and etanercept, as discussed earlier). Earlier biosimilar entry in these cases would allow biosimilars to gain market share and accumulate savings more quickly.

The United States is unique among higher-income countries in having high reference biologic prices, which typically increase over time. However, broader US policies aiming to reduce reference biologic prices could leave less headroom for biosimilar savings to accrue. Depending on their design, these policies may affect incentives for industry to invest in biosimilar development.

CONCLUSIONS

We project that biosimilars will lower spending on biologics by $38.4 billion from 2021 to 2025, with the bulk of savings accruing from new downward pressure on reference biologic prices and from new biosimilar entry. Savings are substantially higher ($124.2 billion) under an alternate upper-bound scenario assuming quicker biosimilar entry, greater biosimilar volume share, and more robust price competition. Each of these alternative market characteristics could be the aim of managed care strategies and future US policy. 

Author Affiliations: RAND Corporation (AM, CB), Arlington, VA; Office of the Assistant Secretary for Planning and Evaluation, HHS (KF, ZE, JFO, SM, AJ), Washington, DC.

Source of Funding: Office of the Assistant Secretary for Planning and Evaluation, HHS. Dr Jessup’s contributions to study design and writing primarily occurred when she worked at the Office of the Assistant Secretary for Planning and Evaluation; she is currently affiliated with the HHS Office of Inspector General. The opinions presented in this paper are of the authors only and do not represent the views of their employers.

Author Disclosures: The authors report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design (AM, KF, ZE, SM, AJ); acquisition of data (AM, CB, ZE, SM); analysis and interpretation of data (AM, CB, KF, ZE, JFO, SM, AJ); drafting of the manuscript (AM, CB, JFO, SM, AJ); critical revision of the manuscript for important intellectual content (AM, CB, KF, ZE, JFO, AJ); statistical analysis (AM); obtaining funding (AM, KF, ZE); administrative, technical, or logistic support (CB); and supervision (AM, ZE).

Address Correspondence to: Andrew Mulcahy, PhD, MPP, RAND Corporation, 1200 S Hayes St, Arlington, VA 22202. Email: amulcahy@rand.org.

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