Biosimilars Gastroenterology Roundup: March 2025

In March 2025, the biosimilar industry marked a decade of transformative growth, with a surge in approvals and widespread adoption, though challenges around interchangeability, pharmacy benefit manager (PBM) influence, and regulatory reforms continue to shape its future.

As the biosimilar industry celebrates a decade of growth, the market continues to evolve with expanded treatment options, cost savings, and a flurry of new competitors—yet regulatory challenges, market dynamics, and patient accessibility remain key hurdles to unlocking its full potential.

Early in the month, the US celebrated the 10-year anniversary of the FDA’s landmark approval of the first biosimilar, Sandoz’s Zarxio (filgrastim-sndz).¹ Over the US’ first decade of biosimilars, FDA approvals have surged to 67 across 18 originators, transforming the pharmaceutical landscape with expanded treatment options and significant cost savings. Despite slow initial adoption, biosimilars now account for $36 billion in cumulative savings, with oncology leading in uptake while challenges persist in chronic disease areas like rheumatology and gastroenterology.

However, market entry hurdles, patent litigation, and payer dynamics continue to impact growth, sparking policy debates on interchangeability, PBM influence, and regulatory reforms. As the US looks ahead, the future of biosimilars hinges on addressing these barriers to ensure sustained competition and affordability in the biologics market.

Patients with Crohn disease (CD) or ulcerative colitis (UC) who switched to the infliximab biosimilar CT-P13 demonstrated higher treatment persistence over 2 years (84% for CD; 91% for UC) compared with those new to infliximab (66% for CD; 53% for UC), with no new safety concerns.² The findings reinforce the long-term effectiveness of CT-P13, showing stable or improved disease activity and safety outcomes aligned with previous research.

Tendering has proven to be the most effective strategy for reducing expenditures on anti–tumor necrosis factor biosimilars in the retail setting across multiple Organisation for Economic Co-operation and Development member countries, while price link policies with modest discounts have shown limited impact, and the success of prescribing quotas remains uncertain.³

Countries like Norway, which use competitive tendering, have achieved high biosimilar uptake (99.4% for infliximab), demonstrating its role in market penetration and cost savings. However, increased biosimilar adoption does not always equate to significant financial savings, underscoring the complexity of biosimilar market dynamics and the need for tailored procurement strategies.

Pregnant women with inflammatory bowel disease (IBD) receiving infliximab biosimilars experienced pregnancy outcomes and infant developmental milestones comparable to those treated with the reference product.⁴ Rates of preterm birth, low birth weight, and small for gestational age were similar, and infants reached key developmental milestones at 1 year without notable differences.

Although biosimilar-treated patients had a longer median disease duration, overall pregnancy complications remained rare, and adverse outcomes were comparable. These findings provide crucial support for the safety of infliximab biosimilars during pregnancy, helping inform shared decision-making for expectant mothers with IBD.

The ustekinumab biosimilar market is rapidly expanding, with 2 more competitors—Celltrion’s Steqeyma and Fresenius Kabi/Formycon’s Otulfi—joining the lineup of lower-cost alternatives to Janssen’s blockbuster biologic, Stelara.⁵ These additions bring the total number of FDA-approved ustekinumab biosimilars to 7, all set to launch throughout 2025 for conditions like plaque psoriasis, psoriatic arthritis, CD, and UC. While Amgen’s Wezlana was the first to market under an exclusive deal with Nuvalia, limited access under this agreement has created opportunities for other biosimilars to gain traction.

Other recent entrants Pyzchiva, Yesintek, and Selarsdi have already started shaping the competitive landscape. Notably, Steqeyma entered with an 85% lower wholesale acquisition cost than Stelara, reinforcing biosimilars’ role in improving affordability and access to biologic treatments. As industry leaders emphasize the need for greater accessibility, the growing availability of ustekinumab biosimilars is set to provide more choices for patients and health care providers while driving down costs in the immunology space.

A prospective cohort study found that reverse switching from the infliximab biosimilar SB2 (Flixabi/Renflexis) to the reference infliximab did not significantly impact clinical disease activity or safety in patients with IBD.⁶ The study followed 95 patients who were initially switched to SB2 and then reversed back to the reference infliximab over a period of 48 weeks.

The results showed no major changes in disease activity, C-reactive protein levels, or trough levels of infliximab, and no clinically relevant safety issues arose. The study concluded that reverse switching between the reference infliximab and its biosimilars is a viable practice without compromising treatment effectiveness or patient safety.

The growing availability of adalimumab biosimilars highlights the complexity of biosimilar adoption, as differences in interchangeability, concentration, and formulation impact pharmacy workflows and patient care, according to a piece originally published by Pharmacy Times^®.⁷ While biosimilars are proven safe and effective, understanding these nuances is essential for pharmacists, who play a key role in educating patients and navigating prescribing considerations.

With 10 FDA-approved adalimumab biosimilars now on the market, ensuring clarity on their distinctions and proper use will be crucial for maximizing their potential to increase access and reduce health care costs.

References

1. Jeremias S. From Amjevita to Zarxio: a decade of US biosimilar approvals. The Center for Biosimilars^®. March 6, 2025. Accessed March 28, 2025. https://www.centerforbiosimilars.com/view/from-amjevita-to-zarxio-a-decade-of-us-biosimilar-approvals

2. Ferreri D. Patients with IBD maintain therapy 2 years post switching to infliximab biosimilar. The Center for Biosimilars. March 22, 2025. Accessed March 28, 2025. https://www.centerforbiosimilars.com/view/patients-with-ibd-maintain-therapy-2-years-post-switching-to-infliximab-biosimilar

3. Jeremias S. Smart tendering policies unlock greater biosimilar savings. The Center for Biosimilars. March 20, 2025. Accessed March 28, 2025. https://www.centerforbiosimilars.com/view/smart-tendering-policies-unlock-greater-biosimilar-savings

4. Ferreri D. Comparable pregnancy and infant milestones with infliximab biosimilars vs originator in IBD. The Center for Biosimilars. March 15, 2025. Accessed March 28, 2025. https://www.centerforbiosimilars.com/view/comparable-pregnancy-and-infant-milestones-with-infliximab-biosimilars-vs-originator-in-ibd

5. Jeremias S. More ustekinumab biosimilars join US market share fight. The Center for Biosimilars. March 13, 2025. Accessed March 28, 2025. https://www.centerforbiosimilars.com/view/more-ustekinumab-biosimilars-join-us-market-share-fight

6. Ferreri D. No IBD activity changes following switch from biosimilar to originator infliximab. The Center for Biosimilars. March 3, 2025. Accessed March 28, 2025. https://www.centerforbiosimilars.com/view/no-ibd-activity-changes-following-switch-from-biosimilar-to-originator-infliximab

7. Ferruggia K. Pharmacists play a crucial role in adalimumab biosimilars for patient care. The Center for Biosimilars. March 5, 2025. Accessed March 28, 2025. https://www.centerforbiosimilars.com/view/pharmacists-play-a-crucial-role-in-adalimumab-biosimilars-for-patient-care