Real-World Evidence on Biosimilar Adherence and Adoption

While patients on reference drugs had higher persistency, patients on biosimilars were more adherent to the medications, according to a poster presented at the Academy of Managed Care Pharmacy annual meeting.¹

Drug persistence was defined as “the act of continuing the treatment for the prescribed duration” and it was measured using persistency curves, while drug adherence was defined as “the extent to which a patient acts in accordance with the prescribed interval, and dose of a dosing regimen,” and it was measured using proportion of days covered (PDC).

The researchers reviewed the reference drugs and biosimilars for infliximab (reference Remicade vs Inflectra/Renflexis), filgrastim (reference Neupogen vs Zarxio), pegfilgrastim (reference Neulasta vs Udenyca/Fulphia), and epoetin alfa (reference Procrit/Epogen vs Retacrit). The drugs were all dispensed from a national specialty pharmacy.

Persistency among patients who received a reference product compared with those who received a biosimilar product was the primary end point of the study. The secondary end points were to compare adherence, incidence of adverse drug events, and patient out-of-pocket medication cost by payer type.

While patients taking reference drugs had higher persistence, there was only a significant difference between the Remicade and Epogen/Procrit groups and their biosimilars. However, patients on all the biosimilars were not only more adherent, but they also had lower out-of-pocket costs compared with patients on reference products. All of the biosimilars had a slightly higher percentage of adverse drug events, expect for Neulasta and its biosimilars.

The researchers listed the following limitations:

• Limited access to patient-specific data, which meant they could not categorize the adverse events by severity
• A lack of generalizability because the data was only collected from 1 specialty pharmacy

“The findings of this study reflect the positive real world implications of utilizing biosimilars from a cost-adherence standpoint,” the authors concluded.

In a second poster on real-world evidence, researchers assessed key stakeholder views on the barriers to biosimilar adoption in the United States, as well as strategies to overcome these barriers.² They assessed changes in perspectives since a 2018 survey.

The multiple choice, mixed qualitative-quantitative web-based survey was conducted in October 2020. The stakeholder groups represented were health plans, pharmacy benefit managers (PBMs), hospitals/clinics, specialty pharmacies, integrated delivery networks, pharmaceutical industry, and employer groups.

Between 2018 and 2020, organization practices regarding biosimilars were significantly different. A higher percentage of organizations promoted biosimilars through formulary tiering in 2020 and a lower percentage based on contracting rebates.

According to the respondents, health plans and PBMs were considered to wield the most influence (43%) when it came to implementing biosimilar adoption. Overall, 17 strategies were viewed as having a positive impact to overcome biosimilar barriers. Real-world evidence was considered an important way to overcome adoption barriers and 55% of respondents said they expect their organization’s investments in real-world evidence on biosimilars to increase in the next 2 to 3 years.

Complete results of the survey are pending.

References

1. Shah K, Lawler L. Real world evidence: impact of biosimilars on patient outcomes at a specialty pharmacy. Presented at: AMCP 2021; April 12-16, 2021. Poster U56.

2. Chung I, Carter J, Simone L, et al. Significance of real-world evidence on biosimilar adoption and reassessing stakeholders' opinions on strategies and barriers to biosimilar adoption. Presented at: AMCP 2021; April 12-16, 2021. Poster U28.