Efficacy and Safety Study of ABP 501 Compared to Adalimumab in Subjects With Moderate to Severe Rheumatoid Arthritis

• ABP 501 (Biological), also known as AMJEVITA™, Adalimumab-atto: Solution for subcutaneous injection in pre-filled syringe
• Adalimumab (Biological), also known as HUMIRA®: Solution for subcutaneous injection in pre-filled syringe

Primary outcomes

• Percentage of Participants With an American College of Rheumatology (ACR) 20 Response at Week 24 [Baseline and Week 24]: A participant was a responder if the following 3 criteria for improvement from Baseline were met: * ≥ 20% improvement in tender joint count; * ≥ 20% improvement in swollen joint count; and * ≥ 20% improvement in at least 3 of the 5 following parameters: * Patient's assessment of pain (measured on a 100 mm visual analog scale \[VAS\]); * Patient's global assessment of disease activity (measured on a likert scale from 0 to 10); * Physician's global assessment of disease activity (measured on a likert scale from 0 to 10); * Patient's self-assessment of physical function (Health Assessment Questionnaire - Disability Index \[HAQ-DI\]); * C-Reactive Protein level.

Secondary outcomes

• Change From Baseline in Disease Activity Score 28-C-reactive Protein (DAS28-CRP) [Baseline and weeks 2, 4, 8, 12, 18, and 24]: The DAS28-CRP is a composite score to measure disease activity in patients with rheumatoid arthritis, derived from the following variables: * The number of swollen and tender joints assessed using the 28-joint count; * C-reactive protein (CRP) level * Patient's global assessment of disease activity assessed on a score from 0 to 100 transformed from the result measured on a horizontal scale from 0 (no RA activity at all) to 10 (worst RA activity imaginable). The DAS28-CRP score ranges from approximately zero to ten. Higher DAS28-CRP scores indicate higher disease activity. A repeated measures analysis with the DAS28-CRP change from baseline as the response and the stratification variables, visit, treatment, treatment-by-visit interaction and the baseline DAS28-CRP measurement as predictors in the model was performed.
• Percentage of Participants With an ACR20 Response at Week 2 and Week 8 [Baseline, week 2 and week 8]: A participant was a responder if the following 3 criteria for improvement from Baseline were met: * ≥ 20% improvement in tender joint count; * ≥ 20% improvement in swollen joint count; and * ≥ 20% improvement in at least 3 of the 5 following parameters: * Patient's assessment of pain (measured on a 100 mm visual analog scale \[VAS\]); * Patient's global assessment of disease activity (measured on a likert scale from 0 to 10); * Physician's global assessment of disease activity (measured on a likert scale from 0 to 10); * Patient's self-assessment of physical function (Health Assessment Questionnaire - Disability Index \[HAQ-DI\]); * C-Reactive Protein level.
• Percentage of Participants With an ACR50 Response at Week 24 [Baseline and week 24]: A participant was a responder if the following 3 criteria for improvement from Baseline were met: * ≥ 50% improvement in tender joint count; * ≥ 50% improvement in swollen joint count; and * ≥ 50% improvement in at least 3 of the 5 following parameters: * Patient's assessment of pain (measured on a 100 mm visual analog scale \[VAS\]); * Patient's global assessment of disease activity (measured on a likert scale from 0 to 10); * Physician's global assessment of disease activity (measured on a likert scale from 0 to 10); * Patient's self-assessment of physical function (Health Assessment Questionnaire - Disability Index \[HAQ-DI\]); * C-Reactive Protein level.
• Percentage of Participants With an ACR70 Response at Week 24 [Baseline and Week 24]: A participant was a responder if the following 3 criteria for improvement from Baseline were met: * ≥ 70% improvement in tender joint count; * ≥ 70% improvement in swollen joint count; and * ≥ 70% improvement in at least 3 of the 5 following parameters: * Patient's assessment of pain (measured on a 100 mm visual analog scale \[VAS\]); * Patient's global assessment of disease activity (measured on a likert scale from 0 to 10); * Physician's global assessment of disease activity (measured on a likert scale from 0 to 10); * Patient's self-assessment of physical function (Health Assessment Questionnaire - Disability Index \[HAQ-DI\]); * C-Reactive Protein level.
• Number of Participants With Adverse Events [From the time of first treatment up to 28 days following the last dose of study treatment; 26 weeks.]: Adverse events (AEs) were graded for severity according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 according to the following scale: 1 = mild; 2 = moderate; 3 = severe; 4 = life-threatening; 5 = fatal. A treatment-related AE is defined as an event where the answer to the question "is there a reasonable possibility that the event may have been caused by the Investigational Medicinal Product" was yes. A serious adverse event is defined as an AE that meets at least 1 of the following serious criteria: * fatal * life threatening (places the subject at immediate risk of death) * requires inpatient hospitalization or prolongation of existing hospitalization * results in persistent or significant disability/incapacity * congenital anomaly/birth defect * other medically important serious event.
• Percentage of Participants Who Developed Antibodies to ABP 501 or Adalimumab [Up to week 26]: Two validated assays were used to detect the presence of anti-drug antibodies. Samples were first tested in an electrochemiluminescence (ECL)-based bridging immunoassay to detect anti-drug antibodies (ADA) against ABP 501 and adalimumab (Binding Antibody Assay). Samples confirmed to be positive for binding antibodies were subsequently tested in a non-cell based bioassay to determine neutralizing activity against ABP 501 or adalimumab (Neutralizing Antibody Assay). Developing antibody incidence is defined as a negative or no antibody result at baseline and a positive antibody result at a post-baseline time point.

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

1. Men or women ≥ 18 and ≤ 80 years old
2. Subjects must be diagnosed with rheumatoid arthritis for at least 3 months before baseline
3. Active RA defined as ≥ 6 swollen joints and ≥ 6 tender joints at screening and baseline
4. Subjects must be taking MTX for ≥ 12 consecutive weeks and on a stable dose of 7.5 to 25 mg/week for > 8 weeks prior to receiving the study drug and be willing to remain on stable dose throughout the study
5. Subject has no known history of active tuberculosis

Exclusion Criteria:

1. Class IV RA, Felty's syndrome or history of prosthetic or native joint infection
2. Major chronic inflammatory disease or connective tissue disease other than RA, with the exception of secondary Sjögren's syndrome
3. Prior use of 2 or more biologic therapies for RA
4. Previous receipt of HUMIRA® (adalimumab) or a biosimilar of adalimumab
5. Ongoing use of prohibited treatments

Other Inclusion/Exclusion criteria may apply

Participant flow

Outcome results

• Percentage of Participants With an American College of Rheumatology (ACR) 20 Response at Week 24 (Primary), Number, percentage of participants: ABP 501 74.6; Adalimumab 72.4
• Change From Baseline in Disease Activity Score 28-C-reactive Protein (DAS28-CRP) (Secondary), Least squares mean, units on a scale: ABP 501 -1.01 +/- 0.891; Adalimumab -0.96 +/- 0.890
• Percentage of Participants With an ACR20 Response at Week 2 and Week 8 (Secondary), Number, percentage of participants: ABP 501 35.4; Adalimumab 24.5
• Percentage of Participants With an ACR50 Response at Week 24 (Secondary), Number, percentage of participants: ABP 501 49.2; Adalimumab 52.0
• Percentage of Participants With an ACR70 Response at Week 24 (Secondary), Number, percentage of participants: ABP 501 26.0; Adalimumab 22.9
• Number of Participants With Adverse Events (Secondary), Number, participants: ABP 501 132; Adalimumab 143
• Percentage of Participants Who Developed Antibodies to ABP 501 or Adalimumab (Secondary), Number, percentage of participants: ABP 501 38.3; Adalimumab 38.2

Adverse events

Time frame: From the time of first treatment but on or within 28 days following the last dose of study treatment; 26 weeks.

Serious adverse events by term

Other adverse events by term

• Results publication: Huizinga TWJ, Torii Y, Muniz R. Adalimumab Biosimilars in the Treatment of Rheumatoid Arthritis: A Systematic Review of the Evidence for Biosimilarity. Rheumatol Ther. 2021 Mar;8(1):41-61. doi: 10.1007/s40744-020-00259-8. Epub 2020 Dec 1. PMID 33263165
• Results publication: Cohen S, Genovese MC, Choy E, Perez-Ruiz F, Matsumoto A, Pavelka K, Pablos JL, Rizzo W, Hrycaj P, Zhang N, Shergy W, Kaur P. Efficacy and safety of the biosimilar ABP 501 compared with adalimumab in patients with moderate to severe rheumatoid arthritis: a randomised, double-blind, phase III equivalence study. Ann Rheum Dis. 2017 Oct;76(10):1679-1687. doi: 10.1136/annrheumdis-2016-210459. Epub 2017 Jun 5. PMID 28584187

• MD, Study director, Amgen