Biosimilar Monthly Roundup: October 2025

October 2025 proved to be a pivotal month for the biosimilar landscape, featuring monumental US policy shifts designed to dramatically accelerate development and unlock billions in cost savings, while simultaneously reinforcing the crucial role of biosimilars in enhancing global health system resilience and solidifying market growth through both key product approvals and real-world clinical data.

October 2025 marks a transformative period for biosimilars, with new FDA guidelines accelerating approvals and promising significant cost savings for health care.

Managed care organizations are now evaluating the long-term impact of accelerated regulatory pathways alongside concrete data proving product viability in clinical settings worldwide.

FDA Paves Way for Streamlined Biosimilar Approvals

The FDA issued new draft guidance that stakeholders believe could significantly accelerate the entry of biosimilars into the American market, potentially unlocking substantial cost savings for the health care system.¹

The guidance, titled "Scientific Considerations in Demonstrating Biosimilarity to a Reference Product: Updated Recommendations for Assessing the Need for Comparative Efficacy Studies," updates 2015 recommendations by outlining criteria for waiving the often-costly and time-consuming comparative efficacy study (CES) requirement for biologics license applications (BLAs) under section 351(k).

Historically, CESs have been a significant bottleneck, financially and logistically, in biosimilar development. The new framework emphasizes that advanced analytical technologies are now often more precise at detecting minor differences between highly purified proteins than clinical trials, whose outcomes can be affected by factors like patient variability.

Under the updated criteria, a CES may be waived if the biosimilar and reference product are highly purified and well-characterized analytically; if key quality attributes of the reference product are well understood and measurable via comparative analytical assessment; and if a human pharmacokinetic similarity study is feasible and clinically meaningful. By shifting focus from routine CESs to analytical studies, the FDA aims to reduce development expenses—estimated between $100 million and $300 million per program—and shorten development timelines by several years.

Policy leaders praised the move, with HHS Secretary Robert F. Kennedy Jr stating the guidance replaces “bureaucracy with science, monopolies with competition, and despair with hope.”

Projections suggest that this new framework could help unlock an additional $181 billion in US savings over the next five years, building on the $56 billion already generated by biosimilars.

Despite the enthusiasm, uncertainty remains regarding interchangeability. While officials suggested that all biosimilars should be considered interchangeable to promote automatic substitution, existing laws in 4 states and Puerto Rico currently prohibit automatic substitution, requiring explicit prescriptions. These substitution bans, or the total absence of federal preemption, create ambiguity regarding the immediate practical effect of the federal guidance claims.

Biosimilar Void Persists Despite Regulatory Boost

Even with momentum from the FDA, the “biosimilar void” continues to challenge future market growth. According to industry data, 118 biologics, representing nearly $232 billion in US sales, are expected to lose patent protection between 2025 and 2034, yet only about 10% of these have biosimilars in active development.²

This gap is driven by factors including limited return on investment for rare-disease products, the complexity of manufacturing advanced biologics, prolonged development timelines, and market uncertainty stemming from the Inflation Reduction Act. Stakeholders are warned that development efficiencies must be paired with improved commercial viability for cost savings to materialize.

Global Perspective: Biosimilars Drive Health System Resilience in LAC

The transformative role of biosimilars extends beyond US borders, as highlighted by a narrative review focusing on Latin American and Caribbean (LAC) nations.³ The analysis, published in Current Opinion in Immunology, concluded that biosimilars possess the potential to enhance patient access drastically and ensure long-term sustainability for regional health systems.

The review addressed the prohibitive expense of original biologic therapies in low- and middle-income LAC regions, which has created deep disparities in access to care for complex and chronic conditions like cancer and autoimmune diseases. The authors identified 4 primary economic levers activated by biosimilar introduction: cost reduction, access expansion, market competition, and relief of financial pressure on public sector budgets.

Successful adoption, the authors noted, is fundamentally an issue of health equity and long-term economic stability. However, realizing the full potential depends on the successful implementation of necessary regulatory enhancements and education initiatives across the region’s highly variable and fragmented markets.

Ophthalmology Market Sees Key Approval and Stability Data

In the realm of product news, the FDA approved Celltrion’s Eydenzelt (aflibercept-boav) in October 2025, an aflibercept biosimilar referencing Eylea.⁴ This marks Celltrion’s first FDA-approved biologic in ophthalmology and is the sixth aflibercept approval in the US.

Eydenzelt was approved for treating retinal diseases, including neovascular age-related macular degeneration and diabetic macular edema (DME). The approval was based on clinical data, including a 52-week phase 3 study in patients with DME that met predefined equivalence criteria compared to the reference product.

Furthermore, critical data emerged supporting the logistical viability of existing ophthalmic biosimilars. A study confirmed the extended stability of XSB-001 (Ximluci), a ranibizumab biosimilar used for retinal conditions, under real-world clinical handling conditions. These findings reinforce the utility of XSB-001 in managed care settings by proving the drug's integrity withstands the practical demands of preadministration storage.

References

1. A closer look at new FDA guidance removing barriers to biosimilar development. The Center for Biosimilars^®. October 30, 2025. Accessed November 5, 2025. https://www.centerforbiosimilars.com/view/a-closer-look-at-new-fda-guidance-removing-barriers-to-biosimilar-development
2. Biosimilars improve health system resilience in Latin American, Caribbean nations. The Center for Biosimilars. October 28, 2025. Accessed November 5, 2025. https://www.centerforbiosimilars.com/view/biosimilars-improve-health-system-resilience-in-latin-american-caribbean-nations
3. Real-world stability confirmed for Biosimilar Ximluci in prefilled syringes. The Center for Biosimilars. October 9, 2025. Accessed November 5, 2025. https://www.centerforbiosimilars.com/view/real-world-stability-confirmed-for-ranibizumab-biosimilar-ximluci-in-prefilled-syringes
4. FDA approves Celltrion aflibercept biosimilar: Eydenzelt. The Center for Biosimilars. October 13, 2025. Accessed November 5, 2025. https://www.centerforbiosimilars.com/view/fda-approves-celltrion-aflibercept-biosimilar-eydenzelt