What Real World Data Reveal About Biosimilar Adoption at Therapy Initiation

Background and study context

Biosimilars are FDA‑approved biologics, defined as highly similar to a reference product with no clinically meaningful differences in safety and effectiveness. Yet even with increasing availability, real‑world adoption can remain slow, particularly in specialty care, where therapy initiation often involves complex coverage rules, administrative requirements, and patient cost considerations.

To better understand adoption dynamics earlier in the specialty journey, clinical researchers at Accredo Specialty Pharmacy presented a real‑world analysis at the Academy of Managed Care Pharmacy (AMCP) 2026 Annual Conference: Real‑World Adoption Patterns for Adalimumab Biosimilars: A Comparison of Specialty and Other Channels.

The analysis focused on new‑to‑therapy patients prescribed the reference product during 2023, comparing outcomes across a specialty pharmacy channel and other dispensing channels.

“Biosimilar adoption in specialty care is rarely driven by one factor. It reflects the interaction of coverage requirements, product availability, patient cost exposure, and the need to maintain continuity of care.”
— Gail Bridges, PharmD, Clinical Program Senior Director

Why look at therapy initiation?

Much of today’s biosimilar discussion centers on stable therapy populations or formulary strategies. This analysis intentionally looked at new‑to‑therapy patients prescribed the reference product during a period when both reference brands and biosimilars were broadly available, creating a window to examine adoption patterns without formulary exclusion pressure.

By focusing on therapy initiation, the analysis helps clarify how outcomes are shaped not only by what is prescribed, but by what happens after prescribing, as patients navigate coverage, affordability, administrative steps, and product availability as treatment begins.

“By focusing on new‑to‑therapy patients, we can better understand adoption patterns at the start of treatment, before exclusion pressure becomes the primary driver.”
— Stefanie Pitts, PharmD, Clinical Program Senior Manager

What the analysis found

The study evaluated treatment selection at 12 months, including whether patients remained on the reference brand, were on a biosimilar, or moved to an alternate branded inflammatory conditions drug.

At 12 months:

• 7.9% of patients in the specialty pharmacy cohort were on a biosimilar vs 6.3% in other channels.
• 17.6% of patients in the specialty pharmacy cohort moved to an alternate branded inflammatory conditions drug vs 18.2% in other channels.
• 74.5% of patients in the specialty pharmacy cohort remained on the reference brand vs 75.5% in other channels.

For adherence, proportion of days covered (PDC) at 12 months:

• Among biosimilar adopters, PDC was 89.8% in the specialty pharmacy cohort compared with 85.7% in other channels.
• Among patients who moved to an alternate branded inflammatory conditions drug, adherence was similar across cohorts.

Taken together, the findings reinforce an important distinction: biosimilar adoption does not end at prescribing. It is shaped by how patients are supported throughout therapy.

Biosimilar adoption is a system-level challenge

Peer discussion and research presented at AMCP reinforced that biosimilar adoption is shaped by interconnected factors, including:

• Formulary and coverage complexity
• Administrative requirements and prior authorization challenges
• Product availability, including management of multiple National Drug Codes (NDCs) and dosage forms
• Patient out‑of‑pocket cost considerations and copay program differences
• Interchangeability differences
• Continuity‑of‑care considerations tied to the plan of care

These real‑world factors can affect both therapy initiation and ongoing treatment stability, particularly in specialty conditions where maintaining disease control is critical.

The role of specialty pharmacy after prescribing

In a rapidly evolving biosimilar landscape, prescribers are navigating a growing number of product options, delivery devices, and interchangeability considerations. When questions arise, specialty pharmacy teams can serve as a resource—helping providers understand coverage dynamics, administration considerations, and potential cost implications for patients.

The decision to prescribe a biosimilar is made by the patient and prescriber, with Accredo helping carry out the plan of care.

As reflected in the poster findings, specialty pharmacy support for biosimilar complexity includes overseeing multiple NDCs and dosage forms, addressing interchangeability differences, navigating coverage and affordability considerations, providing administration training, and helping close knowledge gaps about biosimilars.

This support helps patients remain engaged with therapy over time and supports adherence and continuity of care.

“When a biosimilar is prescribed as part of the plan of care, factors such as education, navigation, and ongoing support can influence whether patients stay adherent over time.”
— Yvonne Viteri, PharmD, BCACP, Clinical Program Senior Advisor

Why this research matters

This analysis provides practical insight into real‑world biosimilar adoption at therapy initiation—a phase that is particularly sensitive to coverage, administrative, and affordability considerations.

It also reinforces that adoption is shaped not only by clinical appropriateness and prescribing decisions, but by post‑prescribing dynamics that help sustain adherence and support continuity of care over time.

Together, these findings help explain how post‑prescribing support can influence real‑world biosimilar adoption and adherence in specialty care.

Biosimilar adoption is shaped not only by prescribing decisions, but by the post‑prescribing factors that influence adherence and continuity of care in specialty practice.

Learn more

View the full research poster presented at the AMCP 2026 Annual Conference. Click Here