As patents expire on biological drugs over the next decade, opportunities for biosimilar development should be growing. The pipeline tells a different story.
The Association for Accessible Medicines (AAM) reports that roughly 90% of the 118 brand-name biologics approaching patent expiration by 2034 do not have a biosimilar in development.
For drug developers, this points to a central challenge. Biosimilars can introduce lower-cost competition for complex biological medicines, but developing a product only makes sense when the scientific, regulatory and commercial considerations support the investment.
Development Concentrates on High-Value Opportunities
Biosimilar pipelines tend to favor biological drugs with high sales potential and nearer-term patent expirations. Products with patent protection extending further into the future have attracted less biosimilar development.
Upcoming patent expirations for high-revenue products continue to draw attention. Merck’s cancer therapy pembrolizumab, for example, has patent protection scheduled to begin expiring in 2028. Additional patents, however, could extend its protection and affect when competitors can enter the market.
Patent strategy is only one factor shaping the market. Insurers, pharmacy benefit managers (PBMs) and brand-name manufacturers disagree about how rebates, coverage decisions and patent practices affect biosimilar competition.
Uptake also presents a challenge. AAM reported that the share of prescriptions filled with a biosimilar in markets where one was available fell from 40% in 2024 to 23% in 2025, driven by reduced uptake of several newly available biosimilars. Unlike generic drugs, not all biosimilars can currently qualify for automatic pharmacy-level substitution. Under current US Food and Drug Administration (FDA) requirements, only biosimilars designated as interchangeable may be substituted for their reference product without consulting the prescriber. This limited adoption can affect the commercial case for investing in additional products.
The FDA Seeks to Reduce Development Requirements
The FDA has taken steps to address barriers within the biosimilar development process.
In spring 2026, the agency reduced some requirements for comparative studies used to evaluate proposed biosimilars against reference products. The changes are intended to simplify development while retaining the evidence necessary for the FDA to assess biosimilarity.
Further changes could come through legislation. Two biosimilar bills under consideration in Congress address regulatory requirements. One would eliminate the current distinction between biosimilars and interchangeable biosimilars, allowing approved biosimilars to be substituted at the pharmacy level without additional studies beyond the studies required for approval. The other would scale back clinical testing requirements for biosimilar licensure.
Approval Does Not Resolve Commercial Barriers
Experience with generic drugs illustrates the distinction between regulatory clearance and commercial launch.
The IQVIA Institute has reported that of the generics receiving FDA approval from 2013 through the first quarter of 2024, more than one-third did not subsequently enter the market. The same analysis found that commercialization after approval can be delayed by more than four years.
Biosimilar developers must also contend with decisions about coverage and product placement. PBMs say they are encouraging biosimilar adoption and point to patent strategies as an obstacle to competition. Brand-name manufacturers argue that PBMs affiliated with insurers and pharmacies can determine which products receive coverage.
These competing positions highlight how factors outside the laboratory and regulatory review process can affect the biosimilar market after development.
Expanding the Biosimilar Pipeline
The stakes extend beyond individual development programs. Biological drugs have contributed to rising pharmaceutical spending, making the absence of biosimilar competition a potential source of unrealized savings.
Cardinal Health summarized the potential consequences in its 2026 Biosimilars Report: “If these challenges persist, fewer biosimilars will enter the market, limiting competition, reducing patient access and preventing the health care system from realizing billions in potential savings.”
As more biologics approach patent expiration, streamlined development and regulatory changes could help turn these opportunities into a stronger biosimilar pipeline.
Did you enjoy this blog post? Check out our other blog posts as well as related topics on our Webinar page.
QPS is a global, full-service, GLP/GCP-compliant contract research organization (CRO) delivering the highest grade of discovery, bioanalysis, preclinical and clinical drug development services. Since 1995, QPS has grown from a small bioanalysis shop into a full-service CRO with 1,200+ employees in the US, Europe, Asia and India. Today, QPS offers expanded pharmaceutical contract R&D services with special expertise in pharmacology, DMPK, toxicology, bioanalysis, translational medicine, PBMC processing, central safety labs, clinical trials, and clinical research services. An award-winning leader focused on bioanalysis and clinical trials, QPS is known for proven quality standards, technical expertise, a flexible approach to research, client satisfaction, turnkey laboratories, Phase I/II clinical units, and multi-site clinical research services. Through continual enhancements in capacities and resources, QPS stands tall in its commitment to delivering superior quality, skilled performance, and trusted service to its valued customers. For more information, visit www.qps.com or email info@qps.com.