A phase I pharmacokinetics trial comparing PF-05280586 (a potential biosimilar) and rituximab in patients with active rheumatoid arthritis.

AIMS: Pharmacokinetic (PK) similarity was assessed among PF-05280586 (a proposed biosimilar) vs. rituximab sourced from the European Union (rituximab-EU) and the United States (rituximab-US). Pharmacodynamics (PD), overall safety and immunogenicity were also evaluated. METHODS: Patients with active rheumatoid arthritis on a background of methotrexate and inadequate response to one or more tumour necrosis factor antagonist therapies were randomized to intravenous PF-05280586, rituximab-EU or rituximab-US 1000 mg doses on study days 1 and 15. RESULTS: A total of 220 patients were randomized to receive study treatment as assigned. Of these, 198 met per-protocol population criteria for inclusion in the PK data analysis. PF-05280586, rituximab-EU and rituximab-US exhibited similar PK profiles following administration of assigned study drug on days 1 and 15. The 90% confidence intervals of test-to-reference ratios for Cmax , AUCT , AUC0-∞ and AUC2-week were within the bioequivalence margin of 80.00-125.00% for comparisons of PF-05280586 with rituximab-EU, PF-05280586 with rituximab-US, and rituximab-EU with rituximab-US. All treatments resulted in a rapid and profound reduction in CD19+ B cells and sustained profound B cell suppression up to week 25. The incidence of antidrug antibody (ADA) response (n = 7, 10 and 9 for PF-05280586, rituximab-EU and rituximab-US, respectively), time to ADA emergence and ADA titres were similar across treatments. None of the ADA-positive samples was positive for neutralizing activity. No clinically meaningful differences in adverse events were identified. CONCLUSIONS: The study demonstrated PK similarity among PF-05280586, rituximab-EU and rituximab-US. In addition, all treatments showed comparable CD19+ B cell depletion PD responses, as well as safety and immunogenicity profiles.

Comparative assessment of clinical response in patients with rheumatoid arthritis between PF-05280586, a proposed rituximab biosimilar, and rituximab.

AIMS: To evaluate potential differences between PF-05280586 and rituximab sourced from the European Union (rituximab-EU) and USA (rituximab-US) in clinical response (Disease Activity Score in 28 Joints [DAS28] and American College of Rheumatology [ACR] criteria), as part of the overall biosimilarity assessment of PF-05280586. METHODS: A randomised, double-blind, pharmacokinetic similarity trial was conducted in patients with active rheumatoid arthritis refractory to anti-tumour necrosis factor therapy on a background of methotrexate. Patients were treated with 1000 mg of PF-05280586, rituximab-EU or rituximab-US on days 1 and 15 and followed over 24 weeks for pharmacokinetic, clinical response and safety assessments. Key secondary end points were the areas under effect curves for DAS28 and ACR responses. Mean differences in areas under effect curves were compared against respective reference ranges established by observed rituximab-EU and rituximab-US responses using longitudinal nonlinear mixed effects models. RESULTS: The analysis included 214 patients. Demographics were similar across groups with exceptions in some baseline disease characteristics. Baseline imbalances and group-to-group variation were accounted for by covariate effects in each model. Predictions from the DAS28 and ACR models tracked the central tendency and distribution of observations well. No point estimates of mean differences were outside the reference range for DAS28 or ACR scores. The probabilities that the predicted differences between PF-05280586 vs. rituximab-EU or rituximab-US lie outside the reference ranges were low. CONCLUSIONS: No clinically meaningful differences were detected in DAS28 or ACR response between PF-05280586 and rituximab-EU or rituximab-US as the differences were within the pre-specified reference ranges. TRIAL REGISTRATION NUMBER: NCT01526057.

Maintenance of remission following 2 years of standard treatment then dose reduction with abatacept in patients with early rheumatoid arthritis and poor prognosis.

OBJECTIVES: To evaluate maintenance of response while reducing intravenous abatacept dose from ~10 mg/kg to ~5 mg/kg in patients with early rheumatoid arthritis (RA) who achieved disease activity score (DAS)28 (erythrocyte sedimentation rate, ESR) <2.6. METHODS: This 1-year, multinational, randomised, double-blind substudy evaluated the efficacy and safety of ~10 mg/kg and ~5 mg/kg abatacept in patients with early RA with poor prognosis who had reached DAS28 (ESR) <2.6 at year 2 of the AGREE study. The primary outcome was time to disease relapse (defined as additional disease-modifying antirheumatic drugs, ≥2 courses high-dose steroids, return to open-label abatacept ~10 mg/kg, or DAS28 (C reactive protein) ≥3.2 at two consecutive visits). RESULTS: 108 patients were randomised (~10 mg/kg, n=58; ~5 mg/kg, n=50). Three and five patients, respectively, discontinued, and four per group returned to open-label abatacept. Relapse over time and the proportion of patients relapsing were similar in both groups (31% (~10 mg/kg) vs 34% (~5 mg/kg); HR: 0.87 (95% CI 0.45 to 1.69)). Mean steady-state trough serum concentration for the ~10 mg/kg group was 20.3-24.1 µg/mL, compared with 8.8-12.0 µg/mL for the ~5 mg/kg group. CONCLUSIONS: This exploratory study suggests that abatacept dose reduction may be an option in patients with poor prognosis early RA who achieve DAS28 (ESR) <2.6 after ≥1 year on abatacept (~10 mg/kg). TRIAL REGISTRATION NUMBER: NCT00989235.

Interest of modelling in rheumatoid arthritis.

Such as prospective studies can provide evidence-based information for clinicians and regulatory agencies, modelling studies provide useful information when experimental studies are to complex, too long, or too expensive to carry out. If modelling has been widely used in pharmacokinetics, it is in the field of pharmacoeconomics that numerous models have been published in recent years, including models relevant to the management of rheumatoid arthritis (RA). The most common modelling techniques published in RA are decision trees and Markov models which are used to perform cost-effectiveness and cost-utility analyses using real or simulated populations. This paper reviews the main types of modelling techniques used in pharmacoeconomic studies with the aim of clarifying their interest and limitations for the clinicians. Generating such evidence is highly relevant to assisting clinical recommendations and reimbursement decisions towards enabling the optimal management of RA and reducing its overall clinical and economic burden, for the benefits of patients and health systems.

Abatacept in the treatment of patients with psoriatic arthritis: results of a six-month, multicenter, randomized, double-blind, placebo-controlled, phase II trial.

OBJECTIVE: To assess the safety and efficacy of abatacept, a selective T cell costimulation modulator, in patients with psoriatic arthritis (PsA). METHODS: In this 6-month, multicenter, randomized, double-blind, placebo-controlled, phase II study, 170 PsA patients with a psoriasis target lesion (TL) ≥2 cm who had previously taken disease-modifying antirheumatic drugs (DMARDs), including anti-tumor necrosis factor (anti-TNF) agents, were randomized (1:1:1:1) to receive placebo or abatacept at doses of 3 mg/kg, 10 mg/kg, or 30/10 mg/kg (2 initial doses of 30 mg/kg, followed by 10 mg/kg) on days 1, 15, and 29 and then once every 28 days thereafter. The primary end point was the American College of Rheumatology 20% criteria for improvement (ACR20 response) on day 169. Other key end points were magnetic resonance imaging (MRI) scores for joint erosion, osteitis, and synovitis, scores on the Health Assessment Questionnaire (HAQ) and the Short Form-36 (SF-36) health survey, the investigator's global assessment of psoriasis, the TL score, and the Psoriasis Area and Severity Index (PASI) score. RESULTS: Proportions of patients achieving an ACR20 response were 19%, 33%, 48%, and 42% in the placebo, the abatacept 3 mg/kg, the abatacept 10 mg/kg, and the abatacept 30/10 mg/kg groups, respectively. Compared with placebo, improvements were significantly higher for the abatacept 10 mg/kg (P = 0.006) and 30/10 mg/kg (P = 0.022) groups, but not for 3 mg/kg group (P = 0.121). All abatacept regimens resulted in improved MRI, HAQ, and SF-36 scores, with 10 mg/kg showing the greatest improvements. Improvements in the TL and PASI scores were observed in all abatacept arms; a response according to the investigator's global assessment was seen only with 3 mg/kg of abatacept. The safety profiles were similar among the treatment arms. CONCLUSION: The results of this study suggest that 10 mg/kg of abatacept, the approved dosage for rheumatoid arthritis and juvenile idiopathic arthritis, may be an effective treatment option for PsA.

Long-term safety, efficacy and inhibition of radiographic progression with abatacept treatment in patients with rheumatoid arthritis and an inadequate response to methotrexate: 3-year results from the AIM trial.

OBJECTIVE: To evaluate abatacept treatment over 3 years in patients with rheumatoid arthritis (RA) refractory to methotrexate (MTX). METHODS: Patients randomised to abatacept or placebo (+MTX) during the 1-year double-blind period of the Abatacept in Inadequate responders to Methotrexate (AIM) trial received open-label abatacept (+MTX) in the long-term extension (LTE). Safety was assessed for patients who received ≥ 1 dose of abatacept, regardless of randomisation group. Efficacy was assessed for patients randomised to abatacept who entered the LTE. RESULTS: 433 and 219 patients were randomised and treated with abatacept or placebo, respectively; 378 and 161 entered the LTE. At year 3, 440/539 patients were ongoing. No unexpected safety events were observed in the LTE. By year 3, incidence rates of adverse event and serious adverse events were 249.8/100 and 15.1/100 patient-years, respectively. Incidence rates were generally stable over time. At year 3, 84.8%, 63.4% and 37.5% of patients achieved American College of Rheumatology (ACR) criteria of 20, 50 and 70, respectively, compared with 82.3%, 54.3% and 32.4% of patients at year 1. Mean changes in Genant-modified Sharp scores were reduced progressively over 3 years, with significantly greater inhibition during year 3 compared with year 2 (p=0.022 for total score). CONCLUSION: In MTX-inadequate responders with RA, abatacept provided consistent safety and sustained efficacy over 3 years. The data suggest an increasing inhibitory disease-modifying effect on radiographic progression.

Clinical response and tolerability to abatacept in patients with rheumatoid arthritis previously treated with infliximab or abatacept: open-label extension of the ATTEST Study.

OBJECTIVE: To assess the efficacy and safety of abatacept in biological-naive patients with rheumatoid arthritis and an inadequate response to methotrexate treated in the long-term extension (LTE) of the ATTEST trial. METHODS: Patients randomly assigned to abatacept, placebo or infliximab completing the 1-year double-blind period were eligible to receive abatacept ∼10 mg/kg in the open-label LTE. Efficacy to year 2 is presented for patients randomly assigned to abatacept or infliximab who switched to open-label abatacept. Safety data are presented for all patients entering LTE regardless of double-blind treatment. RESULTS: Of 431 patients randomly assigned, 79.8% remained on abatacept at year 2. At years 1 and 2, 19.7% and 26.1% of abatacept and 13.3% and 28.6% of infliximab-to-abatacept patients achieved disease activity score 28-defined remission (<2.6). Safety with abatacept during the cumulative study period was consistent with the double-blind experience, with no increase in adverse event incidence following the switch to abatacept. CONCLUSION: In methotrexate-inadequate responders, abatacept efficacy was maintained over 2 years. For infliximab-to-abatacept patients, efficacy improvements were seen in year 2 after patients switched to abatacept. Switching directly from infliximab to abatacept was well tolerated. These data demonstrate that abatacept provides sustained responses and consistent safety, suggesting that switching from infliximab to abatacept is a viable treatment option.

Improvements in participation in usual daily activities in patients with rheumatoid arthritis treated with abatacept.

OBJECTIVE: To examine changes in activity participation following abatacept treatment for rheumatoid arthritis (RA), and which factors contributed to such changes. METHODS: Data were analyzed from the Abatacept in Inadequate responders to Methotrexate (AIM) and Abatacept Trial in Treatment of Anti-TNF INadequate responders (ATTAIN) clinical trials of abatacept in patients with RA. Activity participation was evaluated by the validated Activity Participation Questionnaire (APaQ), along with measures of clinical response and health-related quality of life. Changes in the APaQ during the two study periods were compared between treatment groups. Multiple regression analyses were performed to investigate the determinants of change in activity participation. The relationship between clinical efficacy measures (including low disease activity state [LDAS], Disease Activity Score 28-defined remission, and European League Against Rheumatism [EULAR] responses) and changes in activity participation were investigated. RESULTS: Statistically significant, substantive improvements in activity participation were observed over the entire study period in patients treated with abatacept. Abatacept-treated patients showed improvements from baseline of 8.4 and 7.3 days in activity participation, compared with 4.5 and 1.4 days in the placebo group (P < 0.005 vs. placebo in both trials), at the end of AIM and ATTAIN, respectively. The Short Form-36 physical and mental component scores, patient global assessment, and the Health Assessment Questionnaire-Disability Index score were found to be the strongest determinants of changes in activity participation. Patients who achieved LDAS, disease remission and good EULAR responses experienced greater improvements in activity participation measures. CONCLUSIONS: Abatacept treatment substantively and significantly improved patients' ability to participate in their usual activities. The gain in activity was closely related to improvements in clinical status, physical function and quality of life.

A single-arm, open-label study to assess the immunogenicity, safety, and efficacy of etanercept manufactured using the serum-free, high-capacity manufacturing process administered to patients with rheumatoid arthritis.

OBJECTIVE: To evaluate the immunogenicity, safety, and efficacy of etanercept (ETN) manufactured using the serum-free, high-capacity manufacturing (SFHCM) process in patients with rheumatoid arthritis (RA). METHODS: In this global, multicenter, open-label, single-arm study (NCT02378506), 187 adult patients with moderate to severe RA received ETN 50 mg once weekly for 24 weeks manufactured using the SFHCM process. Immunogenicity (presence of antidrug antibodies (ADAs) and neutralizing antibodies (NAbs)) was assessed at 12 and 24 weeks. Safety and efficacy were evaluated at 4, 12, and 24 weeks. RESULTS: Eight (4.5%) patients tested positive for ADA, and there were no NAbs detected at any time throughout the study. Ninety (48.1%) patients reported treatment-emergent adverse events (AEs), of which 27 (14.4%) reported injection-site reactions, and 43 (23.0%) reported infections. The majority of AEs were mild or moderate in severity, and the drug was well tolerated. Throughout the duration of the study (week 4 to week 24), there was a progressive increase in the American College of Rheumatology (ACR)-defined responses (ACR20: 55.9%-82.0%, ACR50: 16.1%-57.8%, and ACR70: 3.2%-26.7%) from baseline and the proportion of patients achieving low disease activity and remission, with a corresponding decrease in measures of disease activity. CONCLUSION: The immunogenicity, safety, and efficacy of ETN manufactured using the SFHCM process were similar to the current approved ETN formulation. ClinicalTrials.gov registration: NCT02378506.

Abatacept for rheumatoid arthritis refractory to tumor necrosis factor alpha inhibition.

BACKGROUND: A substantial number of patients with rheumatoid arthritis have an inadequate or unsustained response to tumor necrosis factor alpha (TNF-alpha) inhibitors. We conducted a randomized, double-blind, phase 3 trial to evaluate the efficacy and safety of abatacept, a selective costimulation modulator, in patients with active rheumatoid arthritis and an inadequate response to at least three months of anti-TNF-alpha therapy. METHODS: Patients with active rheumatoid arthritis and an inadequate response to anti-TNF-alpha therapy were randomly assigned in a 2:1 ratio to receive abatacept or placebo on days 1, 15, and 29 and every 28 days thereafter for 6 months, in addition to at least one disease-modifying antirheumatic drug. Patients discontinued anti-TNF-alpha therapy before randomization. The rates of American College of Rheumatology (ACR) 20 responses (indicating a clinical improvement of 20 percent or greater) and improvement in functional disability, as reflected by scores for the Health Assessment Questionnaire (HAQ) disability index, were assessed. RESULTS: After six months, the rates of ACR 20 responses were 50.4 percent in the abatacept group and 19.5 percent in the placebo group (P<0.001); the respective rates of ACR 50 and ACR 70 responses were also significantly higher in the abatacept group than in the placebo group (20.3 percent vs. 3.8 percent, P<0.001; and 10.2 percent vs. 1.5 percent, P=0.003). At six months, significantly more patients in the abatacept group than in the placebo group had a clinically meaningful improvement in physical function, as reflected by an improvement from baseline of at least 0.3 in the HAQ disability index (47.3 percent vs. 23.3 percent, P<0.001). The incidence of adverse events and peri-infusional adverse events was 79.5 percent and 5.0 percent, respectively, in the abatacept group and 71.4 percent and 3.0 percent, respectively, in the placebo group. The incidence of serious infections was 2.3 percent in each group. CONCLUSIONS: Abatacept produced significant clinical and functional benefits in patients who had had an inadequate response to anti-TNF-alpha therapy.

Treatment of rheumatoid arthritis by selective inhibition of T-cell activation with fusion protein CTLA4Ig.

BACKGROUND: Effective new therapies are needed for rheumatoid arthritis. Current therapies target the products of activated macrophages; however, T cells also have an important role in rheumatoid arthritis. A fusion protein--cytotoxic T-lymphocyte-associated antigen 4-IgG1 (CTLA4Ig)--is the first in a new class of drugs known as costimulation blockers being evaluated for the treatment of rheumatoid arthritis. CTLA4Ig binds to CD80 and CD86 on antigen-presenting cells, blocking the engagement of CD28 on T cells and preventing T-cell activation. A preliminary study showed that CTLA4Ig may be effective for the treatment of rheumatoid arthritis. METHODS: We randomly assigned patients with active rheumatoid arthritis despite methotrexate therapy to receive 2 mg of CTLA4Ig per kilogram of body weight (105 patients), 10 mg of CTLA4Ig per kilogram (115 patients), or placebo (119 patients) for six months. All patients also received methotrexate therapy during the study. The clinical response was assessed at six months with use of the criteria of the American College of Rheumatology (ACR), which define the response according to its extent: 20 percent (ACR 20), 50 percent (ACR 50), or 70 percent (ACR 70). Additional end points included measures of the health-related quality of life. RESULTS: Patients treated with 10 mg of CTLA4Ig per kilogram were more likely to have an ACR 20 than were patients who received placebo (60 percent vs. 35 percent, P<0.001). Significantly higher rates of ACR 50 and ACR 70 responses were seen in both CTLA4Ig groups than in the placebo group. The group given 10 mg of CTLA4Ig per kilogram had clinically meaningful and statistically significant improvements in all eight subscales of the Medical Outcomes 36-Item Short-Form General Health Survey. CTLA4Ig was well tolerated, with an overall safety profile similar to that of placebo. CONCLUSIONS: In patients with active rheumatoid arthritis who were receiving methotrexate, treatment with CTLA4Ig significantly improved the signs and symptoms of rheumatoid arthritis and the health-related quality of life. CTLA4Ig is a promising new therapy for rheumatoid arthritis.

Effects of abatacept in patients with methotrexate-resistant active rheumatoid arthritis: a randomized trial.

BACKGROUND: The selective co-stimulation modulator abatacept demonstrated efficacy for treating rheumatoid arthritis in early clinical studies. OBJECTIVE: To evaluate the effects of abatacept in patients with persistent, active rheumatoid arthritis despite methotrexate treatment. DESIGN: One-year, multicenter, randomized, double-blind, placebo-controlled trial (November 2002 to October 2004). SETTING: 116 centers worldwide. PATIENTS: 652 patients with active rheumatoid arthritis despite methotrexate treatment. INTERVENTION: Once-monthly infusion of a fixed dose of abatacept, approximately 10 mg/kg of body weight, or placebo. MEASUREMENTS: Co-primary end points were a 20% improvement in American College of Rheumatology (ACR) response criteria (ACR 20) at 6 months, clinically meaningful improvements in physical function, and change from baseline in joint erosion score at 1 year. RESULTS: Four hundred thirty-three and 219 patients were randomly assigned to abatacept or placebo, respectively, and 385 (89%) and 162 (74%), respectively, completed 1 year of treatment. In a modified intention-to-treat analysis, 6-month ACR 20, ACR 50, and ACR 70 responses were 67.9% for abatacept versus 39.7% for placebo (difference, 28.2 percentage points [95% CI, 19.8 to 36.7 percentage points]), 39.9% for abatacept versus 16.8% for placebo (difference, 23.0 percentage points [CI, 15.0 to 31.1 percentage points]), and 19.8% for abatacept versus 6.5% for placebo (difference, 13.3 percentage points [CI, 7.0 to 19.5 percentage points]), respectively. At 1 year, the responses increased to 73.1% for abatacept versus 39.7% for placebo (difference, 33.4 percentage points [CI, 25.1 to 41.7 percentage points]), 48.3% for abatacept versus 18.2% for placebo (difference, 30.1 percentage points [CI, 21.8 to 38.5 percentage points]), and 28.8% for abatacept versus 6.1% for placebo (difference, 22.7 percentage points [CI, 15.6 to 29.8 percentage points]), respectively (P < 0.001 for all). Physical function significantly improved in 63.7% versus 39.3% of patients (P < 0.001). At 1 year, abatacept statistically significantly slowed the progression of structural joint damage compared with placebo. Abatacept-treated patients had a similar incidence of adverse events (87.3% vs. 84.0%; difference, 3.3 percentage points [CI, -2.5 to 9.1 percentage points]) and a higher incidence of prespecified serious infections (2.5% vs. 0.9%; difference, 1.6 percentage points [CI, -0.3 to 3.6 percentage points]) and infusion reactions (acute, 8.8% vs. 4.1%; difference, 4.7 percentage points [CI, 0.9 to 8.4 percentage points]; peri-infusional, 24.5% vs. 16.9%; difference, 7.6 percentage points [CI, 1.2 to 14.0 percentage points]) compared with placebo recipients. LIMITATIONS: The study involved only 1 group of patients over 1 year. CONCLUSIONS: Abatacept statistically significantly reduced disease activity in patients with rheumatoid arthritis and an inadequate response to methotrexate. Longer treatment in different patient populations is needed to establish its appropriate role in rheumatoid arthritis.

Longterm safety, efficacy, and inhibition of structural damage progression over 5 years of treatment with abatacept in patients with rheumatoid arthritis in the abatacept in inadequate responders to methotrexate trial.

OBJECTIVE: Evaluate the safety and efficacy of longterm abatacept (ABA) treatment over 5 years in methotrexate (MTX)-refractory patients with rheumatoid arthritis (RA). METHODS: Patients from the 1-year, double-blind Abatacept in Inadequate Responders to Methotrexate (AIM) study (NCT00048568) received open-label ABA (∼10 mg/kg) in the longterm extension (LTE). Safety was assessed for patients who received ≥ 1 ABA dose, and efficacy for patients randomized to ABA and treated in the LTE. Radiographs were evaluated for changes in Genant-modified Sharp scores. RESULTS: Out of 652 patients, 539 entered the LTE (ABA, n = 378; placebo, n = 161). At Year 5, 72.4% were ongoing; discontinuation rates declined over time. Incidence rates of serious adverse events, serious infections, malignancies, and autoimmune events were 13.87, 2.84, 1.45, and 0.99 events/100 patient-years exposure, respectively. American College of Rheumatology 20 response was 82.3% (n = 373) and 83.6% (n = 268) at years 1 and 5, respectively. Disease Activity Score 28 C-reactive protein (DAS28-CRP) < 2.6 and ≤ 3.2 were achieved by 25.4% and 44.1% of patients at Year 1 (n = 370), and 33.7% and 54.7% at Year 5 (n = 267), respectively. Mean changes in DAS28-CRP and Health Assessment Questionnaire-Disability Index at Year 1 [-2.83 (n = 365) and -0.68 (n = 369)] were maintained at Year 5 [-3.14 (n = 264) and -0.77 (n = 271)] for patients continuing treatment. Of them, 59.5% (n = 291) and 45.1% (n = 235) remained free from radiographic progression at years 1 and 5, respectively. CONCLUSION: In MTX-refractory patients with RA, longterm ABA treatment was well tolerated and provided consistent safety and sustained efficacy, with high patient retention. Radiographic progression continued to be inhibited with ongoing treatment.

Abatacept plus methotrexate provides incremental clinical benefits versus methotrexate alone in methotrexate-naive patients with early rheumatoid arthritis who achieve radiographic nonprogression.

OBJECTIVE: This article reports 1-year clinical outcomes in the subgroup of patients with rheumatoid arthritis in the Abatacept study to Gauge Remission and joint damage progression in methotrexate-naive patients with Early Erosive rheumatoid arthritis (AGREE) who achieved radiographic nonprogression at the end of the double-blind phase. METHODS: Patients who achieved radiographic nonprogression (change from baseline in total Sharp score ≤ 0 at 12 months) with abatacept plus methotrexate (MTX) or MTX alone were eligible for this analysis. Clinical outcomes were remission, defined by 28-joint Disease Activity Score (DAS28) using C-reactive protein (CRP), low Disease Activity Score (LDAS), American College of Rheumatology (ACR) scores, physical function (Health Assessment Questionnaire), and tender and swollen joint counts. Safety was assessed at each visit. RESULTS: Patients in the abatacept plus MTX and MTX monotherapy groups had similar baseline characteristics and were similar to the overall study population. The proportion of patients who achieved DAS28 (CRP) remission or LDAS was greater with abatacept plus MTX vs MTX alone [43.2% vs 22.7% (p < 0.001) and 57.4% vs 40.6% (p = 0.008), respectively]. More patients receiving abatacept plus MTX achieved key ACR responses, including major clinical response (27.3% vs 11.9%; p < 0.001). Safety profiles were similar in both treatment groups. CONCLUSION: More MTX-naive patients with early RA who achieved radiographic nonprogression taking abatacept plus MTX also achieved DAS28 (CRP)-defined remission and LDAS compared with patients who received MTX alone, supporting the use of abatacept as a first-line biologic in combination with disease-modifying antirheumatic drugs.

Safety and efficacy of the selective costimulation modulator abatacept in patients with rheumatoid arthritis receiving background methotrexate: a 5-year extended phase IIB study.

OBJECTIVE: To evaluate the safety and efficacy of abatacept plus methotrexate (MTX) over 5 years in patients with rheumatoid arthritis. METHODS: Patients were randomized to abatacept 10 or 2 mg/kg or placebo, plus MTX. Patients completing the 1-year, double-blind period entered the longterm extension, where all patients received a fixed dose of abatacept ~10 mg/kg. We describe safety analyses for all patients who received at least 1 dose of abatacept and efficacy analyses for the original ~10 mg/kg abatacept-treated group, over 5 years. RESULTS: Of the 235 abatacept- or placebo-treated patients completing the double-blind period, 219 entered the longterm extension; 130 (59.4%) were continuing at Year 5. No unexpected safety events were observed during the longterm extension compared with the double-blind period. Incidence rates of adverse events (AE) and serious AE were 489.7 and 20.0/100 patient-years in Year 1 versus 374.9 and 18.9/100 patient-years in the cumulative period, respectively. Using exploratory analyses, improvements observed at Year 1 in the 10 mg/kg group were maintained at Year 5, as assessed by ACR responses (ACR20=77.1% vs 82.7%; ACR50=53.0% vs 65.4%; ACR70=28.9% vs 40.4% at Years 1 and 5, respectively) and disease activity (Low Disease Activity State=48.2% vs 58.5%; Disease Activity Score-28-defined remission=25.3% vs 45.3% at Years 1 and 5, respectively). CONCLUSION: Abatacept maintained the efficacy observed at Year 1 over 5 years of treatment, and demonstrated consistent safety and tolerability. These data, along with relatively high retention rates, support the longterm clinical benefit provided by selective T cell costimulation modulation. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov; clinical trial registration number: NCT00254293.

Results of a two-year followup study of patients with rheumatoid arthritis who received a combination of abatacept and methotrexate.

OBJECTIVE: To evaluate the efficacy, radiographic changes, and safety of abatacept and methotrexate therapy through 2 years in a long-term extension of a previously published 1-year study. METHODS: Patients who received placebo during year 1 were switched to abatacept. Patients taking abatacept continued to take it. Efficacy and safety were assessed through 2 years. RESULTS: Of 539 patients enrolled in the initial 1-year study, 488 completed 1 year of the long-term extension (2% discontinued for lack of efficacy). At 2 years, patients taking abatacept had maintained their responses on the American College of Rheumatology (ACR) improvement criteria and the Disease Activity Score in 28 joints (DAS28; using the C-reactive protein [CRP] level), as well as their physical function (according to the Health Assessment Questionnaire [HAQ] disability index [DI]) and health-related quality of life (HRQOL; assessed with the Short Form 36 [SF-36] health survey), that were observed at the end of the double-blind period (year 1 versus year 2 values were 81.9% versus 80.3% for ACR 20% improvement, 25.4% versus 30.9% for a DAS28 [CRP] of <2.6, 71.8% versus 66.8% for the HAQ DI, and 9.7 versus 10.6 and 7.3 versus 7.2, respectively, for the mean change in the physical and mental components summary scores of the SF-36). In the abatacept group, post hoc analysis demonstrated further inhibition of radiographic progression during year 2 (57% reduction in mean change of total score in year 2 versus year 1; P<0.0001), and minimal radiographic progression was observed (mean change in total score from baseline was 1.1 and 1.6 at year 1 and 2, respectively). Rates of adverse events (AEs) and severe AEs were consistent throughout the cumulative period. CONCLUSION: The improvements in signs and symptoms, physical function, and HRQOL observed after 1 year of abatacept treatment were maintained through 2 years of treatment. This durability was accompanied by a safety profile consistent with that in the double-blind portion of the study. Radiographic progression was further inhibited in year 2 compared with year 1, suggesting an increasing effect of abatacept on the inhibition of structural damage in year 2.

Selective costimulation modulation using abatacept in patients with active rheumatoid arthritis while receiving etanercept: a randomised clinical trial.

OBJECTIVE: To investigate the efficacy and safety of abatacept in combination with etanercept in patients with active rheumatoid arthritis during a 1-year, randomised, placebo-controlled, double-blind phase, followed by an open-label, long-term extension (LTE). METHODS: Patients continued etanercept (25 mg twice weekly) and were randomised to receive abatacept 2 mg/kg (n = 85) or placebo (n = 36). As the effective dose of abatacept was established as 10 mg/kg in a separate trial, all patients received abatacept 10 mg/kg and etanercept during the LTE. RESULTS: A total of 121 patients were randomised; 80 completed double-blind treatment and entered the LTE. During double-blind treatment, the difference in the percentage of patients achieving the primary end point (modified American College of Rheumatology (ACR) 20 response at 6 months) was not significant between groups (48.2% v 30.6%; p = 0.072). At 1 year, no notable changes in modified ACR responses were observed. Subsequent to the dosing change, similar modified ACR responses were seen during the LTE. Significant improvements in quality of life were observed with abatacept and etanercept versus placebo and etanercept in five of the eight short-form 36 subscales at 1 year. More abatacept and etanercept-treated patients experienced serious adverse events (SAEs) at 1 year than patients receiving placebo and etanercept (16.5% v 2.8%), with 3.5% v 0% experiencing serious infections. CONCLUSION: The combination of abatacept (at a dose of 2 mg/kg during the double-blind phase and 10 mg/kg during the LTE) and etanercept was associated with an increase in SAEs, including serious infections, with limited clinical effect. On the basis of the limited efficacy findings and safety concerns, abatacept in combination with etanercept should not be used for rheumatoid arthritis treatment.

Reduction of inflammatory biomarker response by abatacept in treatment of rheumatoid arthritis.

OBJECTIVE: Abatacept, a soluble selective costimulation modulator, selectively modulates T cell activation via the CD80/CD86:CD28 costimulation pathway. Data from a Phase II trial showed efficacy in patients with active rheumatoid arthritis (RA) and inadequate response to methotrexate when treated with abatacept (10 mg/kg or 2 mg/kg). To determine the mechanism of action of abatacept, we analyzed changes in the serum levels of inflammatory biomarkers in the patients enrolled in this trial. RESULTS: Following 12 months' treatment, serum levels of interleukin 6 (IL-6), soluble IL-2 receptor, C-reactive protein, soluble E-selectin, and soluble intercellular adhesion molecule-1 were significantly lower in patients receiving abatacept 10 mg/kg versus placebo. Smaller reductions in tumor necrosis factor-a and rheumatoid factor were also observed in the abatacept 10 mg/kg group compared with the placebo group. Although there was no evidence for efficacy of the 2 mg/kg dose, small reductions in inflammatory biomarkers at this dosage support the biologic effect of this therapy. CONCLUSION: These findings reveal the antiinflammatory and immunomodulatory effects of abatacept in patients with RA, and are consistent with the concept that modulating T cell activation improves clinical signs and symptoms and inhibits the progression of structural damage. These data suggest that selective modulation of the CD80/CD86:CD28 pathway with abatacept may affect several inflammatory cell types and cytokines that are involved in the proinflammatory cascade.

Treatment of rheumatoid arthritis patients with abatacept and methotrexate significantly improved health-related quality of life.

OBJECTIVE: This study examined the effect of abatacept, a costimulation modulator, on the health-related quality of life (HRQOL) of patients with rheumatoid arthritis (RA). METHODS: Three hundred thirty-nine patients with RA on a background of methotrexate (MTX), who participated in a multicenter, double-blind, placebo-controlled trial, were randomized to abatacept 2 mg/kg, abatacept 10 mg/kg, or placebo. HRQOL was assessed at pretreatment, and at 3, 6, and 12 months posttreatment using the SF-36 Health Survey (SF-36). Changes in SF-36 scores from baseline to 12 months were compared across treatment and placebo groups to examine HRQOL benefits of abatacept. A link between American College of Rheumatology improvement and changes in SF-36 scores was established to demonstrate the association between HRQOL outcomes and clinical response. RESULTS: After 12 months of treatment, patients randomized to abatacept 10 mg/kg showed significantly better HRQOL outcomes overall versus patients randomized to placebo (MANOVA F = 4.71, p < 0.001) or to abatacept 2 mg/kg (MANOVA F = 1.97, p = 0.05). Differences in SF-36 change scores between abatacept 10 mg/kg and placebo groups reached statistical significance on all 8 domain scales, the 2 summary measures, and the SF-36 utility index (SF-6D). Differences in SF-36 change scores between abatacept 10 mg/kg and abatacept 2 mg/kg reached statistical significance on 5 of the 8 domain scales, the physical summary measure, and the SF-6D. Improvement in HRQOL was highly related to clinical response. CONCLUSION Abatacept 10 mg/kg plus MTX demonstrated a stronger HRQOL response than placebo plus MTX. The abatacept 2 mg/kg arm showed a very weak and transient response.

Treatment of rheumatoid arthritis with the selective costimulation modulator abatacept: twelve-month results of a phase iib, double-blind, randomized, placebo-controlled trial.

OBJECTIVE: To determine the clinical efficacy, safety, and immunogenicity of abatacept (CTLA-4Ig), a selective costimulation modulator, in patients with rheumatoid arthritis (RA) that has remained active despite methotrexate (MTX) therapy. METHODS: This was a 12-month, multicenter, randomized, double-blind, placebo-controlled study. A total of 339 patients with active RA despite MTX therapy were randomly assigned to receive 10 mg/kg abatacept (n = 115), 2 mg/kg abatacept (n = 105), or placebo (n = 119). This report focuses on the results observed at month 12 of a phase IIb trial. RESULTS: A significantly greater percentage of patients treated with 10 mg/kg abatacept met the American College of Rheumatology 20% improvement criteria (achieved an ACR20 response) at 1 year compared with patients who received placebo (62.6% versus 36.1%; P < 0.001). Greater percentages of patients treated with 10 mg/kg abatacept also achieved ACR50 responses (41.7% versus 20.2%; P < 0.001) and ACR70 responses (20.9% versus 7.6%; P = 0.003) compared with patients who received placebo. For patients treated with 10 mg/kg abatacept, there were also statistically significant and clinically important improvements in modified Health Assessment Questionnaire scores compared with patients who received placebo (49.6% versus 27.7%; P < 0.001). Abatacept at a dosage of 10 mg/kg elicited an increase in rates of remission (Disease Activity Score in 28 joints of <2.6) compared with placebo at 1 year (34.8% versus 10.1%; P < 0.001). The incidence of adverse events was comparable between the groups, and no significant formation of neutralizing antibodies was noted. CONCLUSION: Abatacept was associated with significant reductions in disease activity and improvements in physical function that were maintained over the course of 12 months in patients with RA that had remained active despite MTX treatment. Abatacept was found to be well tolerated and safe over the course of 1 year. Abatacept in combination with MTX has the potential to play an important role in future RA therapy.