Conditions: Rheumatoid Arthritis
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 54
Healthy volunteers: no

Brief summary:
The primary objective of this study was to evaluate the tolerability and safety of rituximab in combination with methotrexate (MTX) and etanercept or adalimumab in participants with active rheumatoid arthritis (RA). The secondary objective was to explore the efficacy of rituximab in combination with MTX and etanercept or adalimumab in participants with active RA.

Detailed description:
The study consists of 4 parts: screening, treatment, post-treatment, and safety follow-up. Prior to Day 1, participants were discontinued from all disease-modifying anti-rheumatic drugs (DMARDs) except MTX and etanercept or adalimumab. All participants who met eligibility criteria and were enrolled in the trial were randomized to receive 500 mg rituximab or placebo on Day 1 and Day 15. A subset of 18 participants was enrolled initially and followed through Week 12 for safety. The remaining 42 participants were to be enrolled after the last participant in the subset completed Week 12 and the Data Safety Monitoring Board (DSMB) conducted a safety review and approved enrollment of these additional participants. Participants were dosed on Day 1 and Day 15 and followed for 56 weeks, while remaining on their current dose of MTX and etanercept or adalimumab throughout the study. The primary endpoint was assessed at Week 24.

All participants in double-blind treatment, including those who received placebo or rituximab, who met the open label inclusion/exclusion criteria anytime from Week 24 through Week 40, were eligible to enter the open label retreatment phase. These participants received open label rituximab on Day 1 and Day 15 of the retreatment phase, and were followed monthly until Week 24 then every 2 months until Week 56, while remaining on their current dose of MTX and etanercept or adalimumab throughout the study. Participants received 1 course of open label treatment only.

All participants were required to return for safety follow-up (SFU) assessments at Weeks 4, 12, 24, 36, and 48 after withdrawal or completion of the study. Participants whose peripheral CD20+ B cells remained depleted at the end of the SFU periods for the primary and OL portions of the study entered extended safety follow-up (ESFU). Assessments for ESFU were performed at 12-week intervals until peripheral B-cell levels returned to within normal range or baseline level (whichever was lower).

Arms:
arm 1: The double-blind rituximab treatment group received rituximab 500 mg by intravenous (IV) infusion on Day 1 and Day 15. After 24 weeks (primary endpoint completion), participants continued post-treatment follow-up (PTFU) visits through Week 56, and entered a 48-week Safety Follow-Up (SFU). At any time between Week 24 and Week 40 of PTFU, eligible participants could enter the rituximab open label (OL) arm, and "restart" the 56-week treatment/follow-up schedule (rituximab 500 mg by IV infusion on Day 1 and Day 15) prior to the 48-week SFU.

Prior to rituximab infusion, participants were premedicated with methylprednisolone 100 mg IV. Participants received folate ≥5 mg weekly. Background therapy (stable dose for the duration of the study) included: a tumor necrosis factor (TNF) inhibitor; either etanercept 50 mg subcutaneous injection (SC) weekly or adalimumab 40 mg SC once every 2 weeks; methotrexate (MTX) 15 to 25 mg by mouth or by intramuscular injection (IM) weekly. arm 2: The double-blind placebo treatment group received saline solution IV on Day 1 and Day 15. After 24 weeks (primary endpoint completion), participants continued post-treatment follow-up (PTFU) visits through Week 56, and entered a 48-week Safety Follow-Up (SFU). At any time between Week 24 and Week 40 of PTFU, eligible participants could enter the rituximab open label (OL) arm, and "restart" the 56-week treatment/follow-up schedule (rituximab 500 mg by IV infusion on Day 1 and Day 15) prior to the 48-week SFU.

Prior to each infusion of placebo, participants were premedicated with methylprednisolone 100 mg IV. Participants received folate ≥5 mg weekly. Background therapy (stable dose for the duration of the study) included: a tumor necrosis factor (TNF) inhibitor; either etanercept 50 mg subcutaneous injection (SC) weekly or adalimumab 40 mg SC once every 2 weeks; methotrexate (MTX) 15 to 25 mg by mouth or by intramuscular injection (IM) weekly.

Interventions: intervention 1: IDEC-C2B8 (rituximab) intervention 2: Placebo intervention 3: Methotrexate intervention 4: Etanercept intervention 5: Adalimumab intervention 6: Methylprednisolone intervention 7: Folate
Intervention descriptions: intervention 1: Participants will receive 500 mg rituximab on Day 1 and Day 15 intervention 2: Participants will receive placebo on Day 1 and Day 15 intervention 3: Participants must have been treated with MTX ≥15 mg per week and ≤25 mg per week (dose may have been as low as 10 mg if unable to tolerate higher dose) for at least 12 weeks immediately prior to Day 1, at a stable dose for at least 4 weeks and was continued for the study duration. intervention 4: Participants must have been treated with etanercept at 50 mg per week (25 mg twice per week or 50 mg once per week). intervention 5: Participants must have been treated with adalimumab at 40 mg every other week for at least 12 weeks immediately prior to Day 1. intervention 6: Methylprednisolone 100 mg IV was administered by slow infusion to be completed at least 30 minutes prior to each infusion of rituximab or placebo. intervention 7: All subjects also received a stable dose of folate (≥5 mg per week).

Protocol document: