Pharmacists' Perspectives of Biosimilars: A Systematic Review

While biosimilars are less expensive than their originator biologics, various factors are known to impede their uptake in clinical practice including concerns regarding their interchangeability, efficacy, and safety. Pharmacists are well positioned to promote the adoption of biosimilars, thus, the aim of the review was to assess pharmacists' knowledge and perceptions of biosimilars to identify the need for pharmacist-directed biosimilar education.

We conducted a systematic literature search for published articles indexed in MEDLINE via EBSCOHOST, Web of Science, Scopus, Cochrane Library, Dimensions, and Google Scholar databases. We included studies written in English from their earliest publication dates until December 2021. Only studies concerning pharmacists' perspectives on biosimilars were included. Two reviewers extracted data from the studies that included pharmacists' knowledge, perceptions, and opinions about interchangeability and automatic substitution of biosimilars. We also assessed the methodological quality of the included studies using the Joanna Briggs Institute Analytical Cross-Sectional Studies Assessment (JBI-ACSSA) for quantitative studies and the Critical Appraisal Skills Programme (CASP) for qualitative studies.

Out of the 22 studies included in the review, 19 were cross-sectional quantitative studies, and the other three were qualitative studies. The sample size of the included studies ranged from 19 to 1500 participants. The level of knowledge of biosimilars graded as good, considerable, above average, or excellent among pharmacists varied from study to study, with a range of 47-86%. Only 22-51% of pharmacists were comfortable if biosimilars were prescribed for all of the indications previously used for the originator products. Pharmacists' acceptability of switching from the originator to a biosimilar also varied, with a range of 26-84%. However, most pharmacists viewed the substitution of the originator with a biosimilar without physicians' permission as unacceptable. Data from three studies reported that 22-74% of pharmacists had attended biosimilar training. They obtained information about biosimilars from scientific publications, pharmaceutical companies, and continuing education. Based on the criteria of JBI-ACSSA and CASP, the overall methodological quality of the studies ranged from moderate to high. The majority of the studies did not describe the sampling methods used and the strategies to deal with confounding factors.

Pharmacists' knowledge and perception about biosimilars varied and were limited, especially about interchangeability and substitution, efficacy, safety, and indication extrapolation. A better understanding of biosimilars amongst pharmacists could help them to encourage prescribers' acceptance of biosimilars.