Therapeutic Equivalence of Biosimilar and Reference Biologic Drugs in Rheumatoid Arthritis : A Systematic Review and Meta-analysis

Key Points

Question

Are biosimilars of adalimumab, etanercept, and infliximab associated with equivalent treatment compared with their reference biologic drugs for the management of rheumatoid arthritis?

Findings

In this systematic review and meta-analysis of 25 randomized clinical trials that included data on 10 642 patients with rheumatoid arthritis, patients using biosimilars had equivalent clinical responses and functional capacity compared with patients using reference biologic drugs.

Meaning

These findings suggest that biosimilars may yield therapeutically equivalent outcomes compared with reference biologic drugs for the management of rheumatoid arthritis.

Abstract

This systematic review and meta-analysis assesses the efficacy, safety, and immunogenicity associated with biosimilars of adalimumab, etanercept, and infliximab compared with their reference biologics for patients with rheumatoid arthritis.

Abstract

Importance

Biosimilar drugs are potentially lower-cost versions of biologics that may improve access to therapy. However, there is a lack of adequate systematic reviews demonstrating equivalence between these drugs for the treatment of rheumatoid arthritis (RA).

Objectives

To assess the efficacy, safety, and immunogenicity associated with biosimilars of adalimumab, etanercept, and infliximab compared with their reference biologics in patients with RA.

Data Sources

MEDLINE via PubMed, Embase, Cochrane Central Register of Controlled Trials, and LILACS databases were searched from inception to September 2021.

Study Selection

Head-to-head randomized clinical trials (RCTs) of biosimilars of adalimumab, etanercept, and infliximab and their biologic reference drugs for RA were assessed.

Data Extraction and Synthesis

Two authors independently abstracted all data. Meta-analysis was conducted with bayesian random effects using relative risks (RRs) for binary outcomes and standardized mean differences (SMDs) for continuous outcomes, with 95% credible intervals (CrIs) and trial sequential analysis. Specific domains were assessed for the risk of bias in equivalence and noninferiority trials. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline.

Main Outcomes and Measures

Equivalence was tested using prespecified margins for the American College of Rheumatology criteria, with at least 20% improvement in the core set measures (ACR20) (ie, RR, 0.94 to 1.06), and for the Health Assessment Questionnaire–Disability Index (HAQ-DI) (ie, SMD, −0.22 to 0.22). Secondary outcomes included 14 items measuring safety and immunogenicity.

Results

A total of 25 head-to-head trials provided data on 10 642 randomized patients with moderate to severe RA. Biosimilars met equivalence with reference biologics in terms of ACR20 response (24 RCTs with 10 259 patients; RR, 1.01; 95% CrI, 0.98 to 1.04; τ ² = 0.000) and change of HAQ-DI scores (14 RCTs with 5579 patients; SMD, −0.04; 95% CrI, −0.11 to 0.02; τ ² = 0.002) considering prespecified margins of equivalence. Trial sequential analysis found evidence for equivalence for ACR20 since 2017 and HAQ-DI since 2016. Overall, biosimilars were associated with similar safety and immunogenicity profiles compared with reference biologics.

Conclusion and Relevance

In this systematic review and meta-analysis, biosimilars of adalimumab, infliximab, and etanercept were associated with clinically equivalent treatment effects compared with their reference biologics for the treatment of RA.