How HCP attitudes are shaping biosimilar market growth

With more than a dozen Humira biosimilars in market and a wave of expected oncology and checkpoint inhibitor biosimilars set to launch starting in 2028, this class of drugs is clearly having “a moment.” Given that biosimilar revenues are projected to grow from $10 billion today to more than $125 billion by 2033, it’s imperative that manufacturers of both biosimilars and their reference products understand adoption drivers and barriers among healthcare providers (HCPs).

In 2023, we surveyed payers and HCPs across a range of specialties to explore their attitudes toward prescribing biosimilars and switching patients to biosimilars from biologics. Given the fragmented nature of the U.S. healthcare system, individual doctors in the U.S. play an outsize role in treatment adoption compared with their counterparts in Europe.

In Europe, single-payer healthcare systems and tender-based procurement have fueled significant biosimilar adoption, where the more-centralized approach to healthcare has allowed for clearer, more standardized decision-making around biosimilars. This system has helped overcome many concerns that often hinder adoption in the U.S.

Our 2023 survey revealed that many HCPs were initially hesitant to adopt biosimilars due to concerns about these drugs’ structural differences from their reference products, potential safety and efficacy impacts and uncertainty around interchangeability.

In the past two years, there has been a surge in real-world evidence supporting biosimilars, along with greater regulatory clarity in the U.S., Europe and beyond, as agencies have established clear standards for safety, efficacy and interchangeability. To gauge HCP attitudes toward both existing and anticipated biosimilars, this year ZS interviewed 14 HCPs representing immunology, allergy, oncology, ophthalmology and neurology.

Insight no. 1: Insurance coverage looms large in the eyes of the HCP. With HCPs growing increasingly comfortable prescribing biosimilars, including for indication extrapolation for new therapeutic areas (70%), insurance coverage heavily influences their decision-making. Every HCP in our survey cited patient insurance coverage as a crucial determinant for prescribing, with safety, efficacy, supply chain reliability and out-of-pocket costs also playing critical roles.

Insight no. 2: Biosimilars lack clinical differentiation, so secondary factors matter. Because biosimilars offer no major clinical advantage over reference biologics, HCPs are looking beyond safety and efficacy for differentiation across the class. Lower net prices remain the preeminent differentiator, but manufacturers can differentiate their products from the pack through patient support programs (including education and financial assistance) and supply chain reliability.

Insight no. 3: The emerging importance of combination therapies. A key finding is the importance of biosimilar compatibility in combination therapies. As the next wave of biosimilars approaches—including potential biosimilars for immune checkpoint inhibitors such as Keytruda—it will be critical to seamlessly integrate them into combination protocols.

Insight no. 4: The declining importance of interchangeability. When we polled HCPs in 2023, interchangeability emerged as a critical factor driving HCP prescribing activities. Two years later, doctors say the absence of an interchangeability designation doesn’t affect their prescribing practices when considering a biosimilar versus a reference biologic.

Insight no. 5: Next-generation and cross-class competition will shape biosimilar adoption behaviors. The impact of next-generation and cross-class biologics will vary across specialties, with many HCPs preferring newer branded therapies offering additional benefits over lower-cost biosimilars. Cost, payer coverage and regulatory changes, such as FDA approvals for combination biosimilar therapies, will be key factors influencing prescribing behaviors moving forward.

While biosimilars are gaining traction across healthcare, adoption patterns differ significantly across therapeutic areas. Physicians weigh multiple factors—ranging from clinical familiarity and payer policies to next-generation innovations and patient preferences—when deciding whether to prescribe a biosimilar or stick with a reference biologic.

To better understand these dynamics, we examined biosimilar adoption trends across key specialties, uncovering how oncologists, immunologists and allergists, ophthalmologists and neurologists are approaching this evolving market.

Oncology. Oncology served as the original testing ground for biosimilar adoption, when manufacturers pitted multiple biosimilars against a trio of blockbuster oncology biologics and quickly eroded prices for reference products. This therapeutic area is now expecting another wave of biosimilar competition, with blockbusters Yervoy and Perjeta nearing patent expirations and Keytruda and Opdivo set to follow in 2028.

Oncologists we surveyed expressed a strong interest in branded subcutaneous formulations of current biologics, given their lower administration time and general patient preference compared with intravenous administration. This could hinder biosimilar uptake, although financial considerations such as payer coverage will also play a role. A majority of oncologists in our survey said they expect to switch to biosimilars in combination therapies, assuming FDA approval, comparable toxicity profiles and favorable coverage. Oncologists expect payers’ utilization management (UM) strategies, such as step edits and quantity limits, to affect up to 30% of prescribing behavior. While payer policies remain unknown today, UM strategies that add more barriers to prescribing biologics could spur stronger-than-expected biosimilar uptake.

Immunologists and allergists are adapting to a rapidly evolving treatment landscape, indicating their increasing preference for next-generation biologics over older therapies and their biosimilars. Our research indicates high traction for newer branded therapies such as Skyrizi, as its improved efficacy profile makes it an attractive option compared with Stelara biosimilars. For Stelara and Dupixent biosimilars, HCPs say payer coverage will largely dictate prescribing decisions. In addition, they expect UM strategies to drive prescribing decisions by between 5% and 10%. While biosimilars provide cost advantages, their uptake will depend on how restrictive payer policies are and whether newer branded therapies continue to differentiate themselves clinically.

As with other specialties, many ophthalmologists said they prefer to continue prescribing current treatments or next-gen biologics over biosimilars—unless payer policies mandate biosimilars. Efficacy, safety and supply chain reliability are driving their preference for biologics. HCPs don’t expect a major shift toward biosimilars for Eylea and Lucentis, as physician caution and modest cost savings compared with oncology and immunology biosimilars may limit adoption. Yet ophthalmologists are actively considering newer branded therapies such Eylea HD and Vabysmo, which offer longer dosing intervals and potential clinical advantages—key differentiators in retinal disease management.

HCPs say cost and insurance coverage will be the primary factors influencing biosimilar adoption, though concerns around safety and efficacy remain a barrier. Initially, branded therapies like Ocrevus are expected to maintain strong traction, as their proven efficacy profiles and the comprehensive support programs offered by reference product manufacturers make them the preferred choice over biosimilars. For biosimilars to gain broader acceptance, HCPs emphasize the need for robust patient and provider support programs comparable to those provided by branded manufacturers, ensuring smoother transitions and sustained patient adherence.

Although differences exist between specialties, our research shows that two dominant factors drive HCP prescribing decisions across therapeutic areas, apart from insurance coverage: Clinical performance and out-of-pocket patient costs. For biosimilars to achieve broader acceptance, it's essential to address concerns about safety and efficacy, while also enhancing patient and provider support programs. As the market continues to evolve, navigating the shifting dynamics of payer policies will be crucial. To fully realize the potential of biosimilars to transform healthcare delivery, it’s essential for biosimilar manufacturers to offer tailored strategies that align with the unique needs and preferences of each therapeutic area.

The biosimilar market is primed for significant growth, driven primarily by the loss of exclusivity of major biologics. The anticipated entry of Keytruda biosimilars will play a key role in expanding the market, particularly in the medical benefit segment. As newer manufacturers enter untapped areas like bone and respiratory health, the biosimilars landscape is evolving and competition is intensifying.

Pricing pressure and competitive dynamics

Early waves of biosimilars launches have led to accelerating price erosion in reference biologics, with first-wave oncology biologics experiencing net price drops of between 15% and 30%, and more recent ones—such as Humira—experiencing erosion of 60% or more. Moving forward, oncology and immunology biosimilars are expected to drive the highest price erosion (60%-70%), making sustainability challenging for new entrants. Ophthalmology and bone health, meanwhile, may see slightly lower but still significant price erosion of 30%-40%.

Payer influence and evolving biosimilar distribution channels

This price shift is expected to result in a corresponding increase in biosimilars uptake, driven by evolving payer dynamics. Adoption rates are projected to surpass 30%-40% in established therapeutic areas and reach 15%-20% in new ones. Moderate concessions from payers and providers focused on maintaining average selling price over engaging in gross-to-net competition is likely to fuel this growth.
 

The shift in medical benefit channel flows, with declining physician reimbursement driving more infusions to specialty pharmacies, will influence the distribution and adoption of biosimilars. As the market evolves, the importance of cost sensitivity, insurance coverage and regulatory changes will remain pivotal in shaping the adoption and success of biosimilars. Manufacturers must strategically evaluate their investment decisions based on long-term ROI to achieve sustainability.

The path forward for biosimilar and biologic manufacturers

To remain competitive, biosimilar manufacturers must get the following four things right:

1. Invest in the next wave of biosimilars to maintain a sustainable portfolio.
2. Pursue competitive differentiation beyond price, including through payer-manufacturer partnerships and strong patient support programs.
3. Stay ahead of regulatory uncertainty, as policies can either encourage or constrain biosimilar adoption.
4. Prioritize supply chain stability and align go-to-market strategies with the evolving regulatory environment, as well as payer and pharmacy benefit manager dynamics.

While the biosimilars market presents tremendous growth potential, manufacturers must navigate intense price competition, payer-driven barriers and evolving distribution models. Companies that invest strategically, differentiate effectively and align with payer priorities will be best positioned for long-term success.