Clinical question
How do biosimilar medications compare with the original biologic medications for treating conditions like rheumatoid arthritis or inflammatory bowel disease?
Bottom line
Biosimilars and biologics have similar clinical outcomes and adverse events. Given cost, starting patients with or switching to biosimilars should be encouraged.
Evidence
The evidence given below focuses on double-blind RCTs. No differences are statistically significant.
Switching from original to corresponding biosimilar.
-In a publicly funded RCT of 482 patients mostly with inflammatory bowel disease or rheumatologic conditions,1 patients stable on biologic infliximab were randomized to continue biologic infliximab or switch to biosimilar infliximab. At 1 year, the overall proportion with disease “worsening” was 30% for biosimilar and 26% for biologic infliximab. Individual conditions, remission rates, and quality of life were also similar.
- In an RCT of 195 patients with rheumatoid arthritis randomized to continue biologic or switch to biosimilar infliximab,2 after 24 weeks the proportion with 20% or better symptom improvement was 64% for biosimilar and 69% for biologic infliximab.
Starting with either the biosimilar or the biologic. All noninferiority or equivalence studies were funded by the makers of the biosimilars.
-Rheumatoid arthritis:
—In 3 RCTs (N = 1266),3–5 the proportion with 20% or better improvement at 24 weeks was 78% to 93% for biosimilar and 80% to 87% for biologic etanercept.
— In 4 RCTs (N = 1875),6–9 the proportion with 20% or better improvement at 30 weeks7–9 was 61% to 78% for biosimilar and 59% to 65% for biologic infliximab. At 54 weeks it was 64% to 75% for biosimilar and 49% to 71% for biologic infliximab.7,9
-Crohn disease:
—In 1 RCT (N = 220),12 the proportion of patients with clinically relevant changes in symptoms at 30 weeks was 77% for biosimilar and 75% for biologic infliximab.
Serious and overall adverse events, infusion reactions, and antidrug antibody development were similar.1–12
Context
Implementation
Patients taking biologic or biosimilar therapy are at increased risk of infection. Patients should be offered (if needed) vaccines (eg, pneumococcal, zoster, hepatitis A and B) before commencing therapy. Patients taking biologics or biosimilars should not receive live vaccines. Skin cancer and cervical abnormalities might also be increased in patients taking these therapies, so skin checks and annual Papanicolaou tests are recommended.
Notes
Tools for Practice articles in Canadian Family Physician are adapted from articles published on the Alberta College of Family Physicians (ACFP) website, summarizing medical evidence with a focus on topical issues and practice-modifying information. The ACFP summaries and the series in Canadian Family Physician are coordinated by Dr G. Michael Allan, and the summaries are co-authored by at least 1 practising family physician and are peer reviewed. Feedback is welcome and can be sent to toolsforpractice{at}cfpc.ca. Archived articles are available on the ACFP website: www.acfp.ca.
Footnotes
Competing interests
None declared
The opinions expressed in Tools for Practice articles are those of the authors and do not necessarily mirror the perspective and policy of the Alberta College of Family Physicians.
- Copyright© the College of Family Physicians of Canada
References
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