Comparison of the ELISA and ECL Assay for Vedolizumab Anti-drug Antibodies: Assessing the Impact on Pharmacokinetics and Safety Outcomes of the Phase 3 GEMINI Trials

AAPS J. 2020 Nov 16;23(1):3. doi: 10.1208/s12248-020-00518-0.


Vedolizumab immunogenicity has been assessed using an enzyme-linked immunosorbent assay (ELISA) with a ~ 0.5 μg/mL drug interference, which may underestimate on-drug immunogenicity. We aimed to compare immunogenicity results between ELISA and the new drug-tolerant electrochemiluminescence (ECL) assay (and the two versions of neutralizing assays, drug-sensitive versus drug-tolerant). The ECL assay drug tolerance is ~ 100 times higher than that of the ELISA (≥ 50 μg/mL vs. 0.5 μg/mL with a 500 ng/mL positive control), and assay sensitivity is < 5 ng/mL for both assays. Vedolizumab immunogenicity was assessed in 2000 GEMINI 1 and 2 patients originally tested by ELISA and retested by ECL assay. Anti-drug antibody (ADA) impact on infusion-related reactions and pharmacokinetics (PK) was examined using descriptive statistics and population PK analyses. By ECL assay, 6% (86/1427) of patients treated with vedolizumab as induction and maintenance therapy tested ADA-positive. Of these, 20 patients were persistently positive and 56 had neutralizing antibodies. By ELISA, 4% (56/1434) of these patients were ADA-positive, 9 were persistently positive, and 33 had neutralizing antibodies. Among 61 patients with infusion-related reactions, 6 (10%) were ADA-positive (2 persistently positive) by ECL assay. By ELISA, 3 (5%) patients were both ADA-positive and persistently positive. Most results (96%) were similar with both assays. In the updated population PK model, ADA-positive status was estimated to increase vedolizumab linear clearance by a factor of 1.10 (95% credible interval 1.03-1.17), which is consistent with previous reports. The impact of ADA on safety and PK modeling remained generally consistent using either ELISA or ECL assay. NCT00783718 and NCT00783692.

Keywords: ELISA; electrochemiluminescence; immunogenicity; vedolizumab.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Monoclonal, Humanized / adverse effects*
  • Antibodies, Monoclonal, Humanized / pharmacokinetics
  • Antibodies, Neutralizing / isolation & purification*
  • Biological Products / adverse effects*
  • Biological Products / pharmacokinetics
  • Biological Variation, Population
  • Clinical Trials, Phase III as Topic
  • Colitis, Ulcerative / blood
  • Colitis, Ulcerative / drug therapy
  • Colitis, Ulcerative / immunology
  • Crohn Disease / blood
  • Crohn Disease / drug therapy
  • Crohn Disease / immunology
  • Drug Monitoring / methods*
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Humans
  • Luminescent Measurements / methods
  • Male
  • Middle Aged
  • Randomized Controlled Trials as Topic
  • Young Adult


  • Antibodies, Monoclonal, Humanized
  • Antibodies, Neutralizing
  • Biological Products
  • vedolizumab

Associated data