Blood samples for adalimumab analysis were collected by venipuncture and serum concentrations of adalimumab were determined using a validated enzyme-linked immunoadsorbent assay (ELISA) method.

Data from participants receiving the new formulation of adalimumab were analyzed for 46 and 47 participants, respectively, at weeks 12 and 24. Data for the participants receiving the current formulation of adalimumab were analyzed for 43 participants at week 12 and 41 participants at week 24.

The Disease Activity Score (DAS28) is a validated index of rheumatoid arthritis disease activity. Twenty-eight tender joint counts, 28 swollen joint counts, C-reactive protein, and general health are included in the DAS28 score. Scores on the DAS28 range from 0 to 10. A DAS28 score >5.1 indicates high disease activity, a DAS28 score <3.2 indicates low disease activity, and a DAS28 score <2.6 indicates clinical remission.

All available data were included. If a subject did not have a value for a given time of evaluation, but did have a value at times previous to this after the study drug treatment began, the last available value was used to replace the missing value.

American College of Rheumatology 20% (ACR20) response. A participant is a responder if the following 3 criteria for improvement from baseline are 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:

  • Physician global assessment of disease activity
  • Patient global assessment of disease activity
  • Patient assessment of pain
  • Disability Index of the Health Assessment Questionnaire
  • CRP (Acute phase reactant (Erythrocyte sedimentation rate/C-reactive protein))

All available data were included. If a subject did not have a value for a given time of evaluation, but did have a value at times previous to this after the study drug treatment began, the last available value was used to replace the missing value.

American College of Rheumatology 50% (ACR50) response. A participant is a responder if the following 3 criteria for improvement from baseline are 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:

  • Physician global assessment of disease activity
  • Patient global assessment of disease activity
  • Patient assessment of pain
  • Disability Index of the Health Assessment Questionnaire
  • CRP (Acute phase reactant (Erythrocyte sedimentation rate/C-reactive protein))

All available data were included. If a subject did not have a value for a given time of evaluation, but did have a value at times previous to this after the study drug treatment began, the last available value was used to replace the missing value.

The Health Assessment Questionnaire - Disability Index (HAQ-DI) is a patient-reported questionnaire specific for rheumatoid arthritis. It consists of 20 questions referring to eight domains: dressing/grooming, arising, eating, walking, hygiene, reach, grip, and daily activities. Participants assessed their ability to do each task over the past week using the following response categories: without any difficulty (0); with some difficulty (1); with much difficulty (2); and unable to do (3). Scores on each task were summed and averaged to provide an overall score ranging from 0 to 3, where zero represents no disability and three very severe, high-dependency disability. The minimal clinically important difference (MCID) defined for the HAQ-DI is ≥0.22. HAQ remission indicating normal physical function is defined by HAQ-DI < 0.5.

All available data were included. If a subject did not have a value for a given time of evaluation, but did have a value at times previous to this after the study drug treatment began, the last available value was used to replace the missing value.

The Short Form 36 (SF-36) determines participants' overall quality of life by assessing 1) limitations in physical functioning due to health problems; 2) limitations in usual role because of physical health problems; 3) bodily pain; 4) general health perceptions; 5) vitality; 6) limitations in social functioning because of physical or emotional problems; 7) limitations in usual role due to emotional problems; and 8) general mental health. Items 1-4 primarily contribute to the physical component summary score (PCS) of the SF-36. Items 5-8 primarily contribute to the mental component summary score (MCS) of the SF-36. Scores on each item are summed and averaged (range = 0 (maximum disability) - 100 (no disability). The standard recall period is four weeks.

All available data were included. If a subject did not have a value for a given time of evaluation, but did have a value at times previous to this after the study drug treatment began, the last available value was used to replace the missing value.

Percentage of participants with anti-adalimumab antibody

An adverse event was defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which did not necessarily have a causal relationship with the treatment. See the Reported Adverse Events Section for more details.

The Visual Analogue Scale (VAS) consisted of a horizontal 100 mm line, with 0 representing "no pain" and 100 representing "worst possible pain". Participants placed a mark on the line representing their current level of pain immediately after injections on Day 1 of the study.