Letter: immunogenicity of infliximab originator vs. CT-P13 in IBD patients

Switching from infliximab to biosimilar in inflammatory bowel disease: overview of the literature and perspective

BACKGROUND

Biological therapy has revolutionized the treatment of inflammatory bowel disease (IBD). After the expiration of patents for biological innovator products, development of biosimilars increased. CT-P13 was the first biosimilar approved for the same indications as the reference product; however, the approval was based on extrapolated data from rheumatoid arthritis and ankylosing spondylitis. Our aim was to review clinical studies about switching from originator infliximab (IFX-O) to biosimilar infliximab (IXF-B) in IBD, focusing on recently published data and the future of biosimilars.

METHODS

The PubMed database was searched for original articles published up to 1 December 2018 reporting data on IFX-B in IBD.

RESULTS

A total of 29 studies assessing switching from IFX-O to IFX-B, 14 assessing induction therapy with IFX-B were found. Efficacy, safety and immunogenicity were discussed. Studies confirm that CT-P13 is safe and equally efficient as the reference product for both induction and maintenance therapy; and that switching from the reference product to biosimilar is non-inferior to continuous biosimilar use. However, efficacy and safety data on Flixabi (SB2) in IBD patients is lacking.

CONCLUSION

Switching from the originator to a biosimilar in patients with IBD is acceptable, although scientific and clinical evidence is lacking regarding reverse switching, multiple switching and cross-switching among biosimilars in IBD patients.

The PROSIT Cohort of Infliximab Biosimilar in IBD: A Prolonged Follow-up on the Effectiveness and Safety Across Italy

BACKGROUND

We report a prospective, nationwide cohort evaluating the safety and effectiveness of CT-P13.

METHODS

A structured database was used to record serious adverse events (SAEs), clinical remission/response, inflammatory biomarkers (CRP and calprotectin), and endoscopic findings.

RESULTS

Eight hundred ten patients with inflammatory bowel disease (IBD) (452 Crohn's disease [CD]) were enrolled. Four hundred fifty-nine patients were naïve to anti-TNFα (group A), 196 had a previous exposure (group B), and the remaining 155 were switched to CT-P13 (group C). All patients were included in the safety evaluation with a mean follow-up of 345 ± 215 days and a total number of 6501 infusions. One hundred fifty-four SAEs were reported (19%), leading to cessation of the biosimilar in 103 subjects (12.7%). Infusion reactions were 71, leading to cessation of the biosimilar in 53 subjects (6.5%), being significantly more frequent in patients pre-exposed to anti-TNFα (P = 0.017). The efficacy of therapy was calculated in 754 IBD patients, with a mean follow-up of 329 ± 202 days. Forty-eight patients had a primary failure (6.4%), and 188 (25.6%) lost response during follow-up. Six hundred twenty-eight (364 CD) and 360 IBD patients (222 CD) completed the follow-up at 6 and 12 months, respectively. At 12 months, patients without loss of response were 71%, 64%. and 82% in groups A, B, and C, respectively (log rank P = 0.01). Clinical/endoscopic scores and inflammatory biomarkers dropped significantly in CD and UC patients (P = 0.01 and P < 0.0001) compared with baseline.

CONCLUSIONS

In this large prospective cohort, no further signals of difference in safety and effectiveness of CT-P13 in IBD has been observed.

The Biosimilar Nocebo Effect? A Systematic Review of Double-Blinded Versus Open-Label Studies

BACKGROUND

Several authors have hypothesized that adverse drug events (ADEs) upon switching from reference biologics to biosimilar products are related to the nocebo effect. However, a thorough and current review of the existing literature has not been conducted.

OBJECTIVE

To evaluate if patient and/or physician knowledge of a switch from a reference biologic product to a biosimilar product was associated with an increase in ADEs likely to be susceptible to the nocebo effect.

METHODS

Studies reporting efficacy and safety outcomes of a switch from a reference product to a biosimilar product were reviewed. Biologics with FDA-approved biosimilars in the United States were considered for review, including adalimumab, bevacizumab, etanercept, and infliximab. Studies were identified by searching controlled vocabulary (e.g., MeSH terms) and keywords within MEDLINE (via PubMed) and Embase. Descriptive statistics were used to quantify subjective and objective complications in double-blinded and single-blinded or open-label studies.

RESULTS

Thirty-one trials including 3,271 patients were reviewed in the full analysis. Median discontinuation rates for any reason were 14.3% (range = 0.0-33.3) in open-label studies compared with 6.95% (range = 5.2-11.0) in double-blinded studies. Discontinuation rates for ADEs were 5.6% (range = 0.0-24.2) in open-label studies versus 3.1% (range = 2.0-5.2) in double-blinded studies, suggesting the nocebo effect does affect biosimilar adoption. Subgroup analyses of antidrug antibody (ADA) development and infusion reactions were similar between infliximab open-label and double-blinded studies. Discontinuation rates for any reason, for ADEs, and for lack of efficacy were generally higher in infliximab open-label trials compared with double-blinded trials. Etanercept biosimilar discontinuation rates for any reason were similar between study designs; however, incidences of injection site reactions and discontinuation rates for ADEs were higher in double-blinded compared with open-label study designs.

CONCLUSIONS

Current evidence is insufficient to confirm a biosimilar nocebo effect, although higher discontinuation rates in infliximab biosimilar open-label studies support this theory. Further studies are needed to evaluate the existence of a biosimilar nocebo effect.

DISCLOSURES

No outside funding supported this study. The authors have no conflicts of interest to disclose.

Antigenic response to CT-P13 and infliximab originator in inflammatory bowel disease patients shows similar epitope recognition

AIM

To test the cross-immunogenicity of anti-CT-P13 IBD patients' sera to CT-P13/infliximab originator and the comparative antigenicity evoked by CT-P13/infliximab originator sera.

METHODS

Sera of patients with IBD with measurable anti-CT-P13 antibodies were tested for their cross-reactivity to 5 batches of infliximab originator and CT-P13. Anti-drug antibody positive sera from treated patients were used to compare antigenic epitopes.

RESULTS

All 42 anti-CT-P13 and 37 anti-infliximab originator IBD sera were cross-reactive with infliximab originator and CT-P13 respectively. Concentration of anti-drug antibodies against infliximab originator or CT-P13 were strongly correlated both for IgG1 and IgG4 (P < 0.001). Anti-CT-P13 sera of patients with IBD (n = 32) exerted similar functional inhibition on CT-P13 or infliximab originator TNF binding capacity and showed reduced binding to CT-P13 in the presence of five different batches of CT-P13 and infliximab originator. Anti-CT-P13 and anti-infliximab originator IBD sera selectively enriched phage-peptides from the VH (CDR1 and CDR3) and VL domains (CDR2 and CDR3) of infliximab. Sera reactivity detected major infliximab epitopes in these regions of infliximab in 60%-79% of patients, and no significant differences were identified between CT-P13 and infliximab originator immunogenic sera. Minor epitopes were localised in framework regions of infliximab with reduced antibody reactivity shown, in 30%-50% of patients. Monoclonal antibodies derived from naïve individuals and ADA-positive IBD patients treated with CT-P13 provided comparable epitope specificity to five different batches of CT-P13 and infliximab originator.

CONCLUSIONS

These results strongly support a similar antigenic profile for infliximab originator and CT-P13, and point toward a safe switching between the two drugs in anti-drug antibody negative patients.

Full Interchangeability in Regard to Immunogenicity Between the Infliximab Reference Biologic and Biosimilars CT-P13 and SB2 in Inflammatory Bowel Disease

BACKGROUND

Infliximab (IFX) biosimilars CT-P13 and SB2 have comparable efficacy, safety, and immunogenicity to the originator Remicade (RMC). However, concerns about cross-switching patients between the 3 brands were raised in the absence of cross reactivity data between them. We aimed to determine whether antibodies to infliximab (ATI) in inflammatory bowel disease (IBD) patients cross-react with RMC, CT-P13, and SB2.

METHODS

Based on previous ATI status, samples from 34 patients participating in the BIOSIM01 study (13 RMC, 9 CT-P13, and 12 switchers) were selected. Patients were treated with either RMC only, or CT-P13 only, or with RMC switched to CT-P13. Additionally, 28 IFX-naïve patients were assayed as controls. In total, 180 samples were analyzed. ATI trough levels were measured in parallel with 3 different bridging Enzyme Linked Immunosorbent Assays constructed using the 3 drugs. Spearman's coefficient and percentages of agreement were used to study the correlation between each assay.

RESULTS

In total, 76 samples out of 152 IFX-treated patient samples were ATI-positive (30 RMC, 14 CT-P13, and 32 switchers). All resulted ATI-positive when either CT-P13 or SB2 bridging assays were used. The overall percentage of agreement was 100% when compared either with CT-P13 or SB2 assays. No significant differences were found among ATI levels and coefficients (Spearman's 0.98 to 1.0, P < 0.0001).

CONCLUSIONS

ATI of RMC-treated, CT-P13-treated or RMC to CT-P13 switched patients show full cross-reactivity with CT-P13 and SB2. Findings suggest that immunodominant epitopes in the reference and CT-P13 drugs are equally present in SB2. Data support full interchangeability between biosimilars in regard to immunogenicity.