Conditions: Rheumatoid Arthritis
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 1795
Healthy volunteers: no

Brief summary:
The purpose of this clinical research study is to learn if abatacept is safe when co-administered with other approved rheumatoid arthritis medications.

Detailed description:
This was a multinational, multicenter, randomized, double-blind, 2-arm, parallel-dosing designed study. The treatment period was 12 months. Eligible participants were randomized to 1 of 2 treatment groups: abatacept fixed dose approximating 10 mg/kg (based on participant's body weight; 500 mg for participants weighing \< 60kg; 750 mg for participants weighing 60 to 100 kg; and 1 gram for participants weighing \> 100 kg, monthly) or placebo intravenous (IV) infusion. All participants continued their background therapy(ies) for rheumatoid arthritis (RA) (non-biologic or biologic disease-modifying drugs \[DMARDs\], or combination) throughout the double-blind treatment period. Double-blind study medication (abatacept or placebo) was administered on Days 1, 15, 29, and every 28 days thereafter, for a total of 14 doses.

All participants who completed the 12-month double-blind study period (Day 1 through Day 365), were eligible to continue into the open-label period. All eligible participants (active or placebo) were re-allocated to receive abatacept at a weight-tiered dose that approximated 10 mg/kg, based on their Day 365 body weight. Participants continued to receive infusions every 28 days.

Arms:
arm 1: Participants received a fixed dose of abatacept approximating 10 mg/kg (500 mg for participants \< 60 kg, 750 mg for participants 60 to 100 kg and 1 g for participants \> 100 kg). Abatacept was administered intravenously (IV) on Days 1, 15, 29, and every 28 days thereafter, for a total of 14 doses. Participants also received background therapy(ies) for rheumatoid arthritis (RA) (non-biologic or biologic disease-modifying drugs \[DMARDs\], or combination) throughout the double-blind treatment period arm 2: Participants received Placebo (dextrose 5% water \[D5W\] for injection U.S.P or normal saline \[NS\]) for IV infusion administered on Days 1, 15, 29, and every 28 days thereafter, for a total of 14 doses. Participants also received background therapy(ies) for rheumatoid arthritis (RA) (non-biologic or biologic disease-modifying drugs \[DMARDs\], or combination) throughout the double-blind treatment period. arm 3: Participants received abatacept (weight-tiered 10 mg/kg dose) IV every 28 days during the open-label period.

Interventions: intervention 1: Double-blind Abatacept intervention 2: Double-blind Placebo intervention 3: Open-label Abatacept
Intervention descriptions: intervention 1: Concentrate and diluted in a solution, IV, 500 mg (body weight \< 60 Kg); 750 mg (body weight 60-100 Kg); 1000 mg (body weight \> 100 Kg), Once daily, Day 1, 15, and 29. intervention 2: Concentrate and diluted in a solution, IV, 0 mg, Once daily, Day 1, 15, and 29. intervention 3: Concentrate and diluted in a solution, IV, 500 mg (body weight \< 60 Kg); 750 mg (body weight 60-100 Kg); 1000 mg (body weight \> 100 Kg), Once daily, Every 28 days.

Protocol document: