Long-term safety of subcutaneous abatacept in rheumatoid arthritis: integrated analysis of clinical trial data representing more than four years of treatment.

OBJECTIVE: To investigate the safety of long-term subcutaneous (SC) abatacept treatment using integrated clinical trial data obtained in patients with rheumatoid arthritis refractory to traditional disease-modifying antirheumatic drugs. METHODS: Data from the double-blind and open-label phases of 5 clinical trials of SC abatacept were pooled. The overall and 6-month incidence rates were calculated as events per 100 patient-years of exposure. RESULTS: This analysis included 1,879 patients with 4,214.6 patient-years of exposure to SC abatacept. The mean ± SD length of exposure was 27.3 ± 9.1 months. The reported incidence rate of serious infections was 1.79 (95% confidence interval [95% CI] 1.42-2.24); the most frequent infections were pneumonia (incidence rate 0.36 [95% CI 0.22-0.59]), urinary tract infection (incidence rate 0.14 [95% CI 0.06-0.32]), and gastroenteritis (incidence rate 0.10 [95% CI 0.04-0.25]). Tuberculosis occurred rarely (incidence rate 0.09 [95% CI 0.04-0.25]). The reported incidence rate of malignancies was 1.32 (95% CI 1.01-1.72), and the most common was solid organ malignancy (incidence rate 0.69 [95% CI 0.48-0.99]). The incidence rate of autoimmune events was 1.37 (95% CI 1.06-1.78), and the most frequent events were psoriasis (incidence rate 0.33 [95% CI 0.20-0.56]) and Sjögren's syndrome (incidence rate 0.24 [95% CI 0.13-0.44]). The reported incidence rate of local injection site reactions was 1.72 (95% CI 1.36-2.17); these events occurred primarily during the first 6 months of treatment, and almost all were of mild or moderate intensity. The incidence rates of serious infections, malignancies, autoimmune events, and injection site reactions did not increase over time. CONCLUSION: Long-term treatment with SC abatacept was associated with low incidence rates of serious infections, malignancies, and autoimmune events and was well tolerated, with infrequent injection site reactions. These findings are consistent with those related to treatment with intravenous abatacept. Long-term treatment with SC abatacept did not lead to new safety signals over time.

Subcutaneous abatacept for the treatment of rheumatoid arthritis: longterm data from the ACQUIRE trial.

OBJECTIVE: Assess longterm tolerability, safety, and efficacy of subcutaneous (SC) abatacept (ABA) in methotrexate-refractory patients with rheumatoid arthritis (RA). METHODS: The phase III, multinational Abatacept Comparison of Sub[QU]cutaneous Versus Intravenous in Inadequate Responders to MethotrexatE (ACQUIRE) trial comprised a 6-month, randomized, double-blind (DB) period, in which patients received intravenous (IV) or SC ABA, plus MTX, followed by an open-label, longterm extension (LTE), in which patients received SC ABA, 125 mg/week. Safety and efficacy from the LTE (∼3.5 yrs of exposure) are reported. RESULTS: Patients who completed the DB period (1372/1385, 99.1%) entered the LTE; 1134 patients (82.7%) kept taking the treatment at time of reporting. Mean (SD) was 31.9 months (6.8); median (range) exposure was 33.0 (8-44) months. Patients entering the LTE had longstanding, moderate-to-severe disease [mean 7.6 (7.9) yrs and DAS28 (C-reactive protein) 6.2 (0.9)]. Incidence rates (events/100 patient-yrs) were reported for serious adverse events (8.76, 95% CI 7.71, 9.95), infections (44.80, 95% CI 41.76, 48.01), serious infections (1.72, 95% CI 1.30, 2.27), malignancies (1.19, 95% CI 0.86, 1.66), and autoimmune events (1.31, 95% CI 0.95, 1.79). Twenty-seven patients (2%) experienced injection-site reactions; all except 1 were mild. American College of Rheumatology 20, 50, and 70 responses achieved during the DB period were maintained through the LTE, and on Day 981 were 80.2% (95% CI 77.2, 83.2), 63.5% (95% CI 58.2, 68.9), and 39.5% (95% CI 34.0, 44.9) for patients who kept taking SC ABA, and 80.0% (95% CI 77.0, 83.0), 63.2% (95% CI 57.8, 68.7), and 39.2% (95% CI 33.7, 44.7) for those who switched from IV to SC ABA. CONCLUSION: These findings support SC ABA as a well-tolerated and efficacious longterm treatment for patients with RA and inadequate response to MTX (ClinicalTrials.gov identifier NCT00559585).

Safety of abatacept administered intravenously in treatment of rheumatoid arthritis: integrated analyses of up to 8 years of treatment from the abatacept clinical trial program.

OBJECTIVE: To assess the overall safety, including rare events, of intravenous (IV) abatacept treatment in rheumatoid arthritis (RA). METHODS: Data from 8 clinical trials of IV abatacept in RA were pooled. Safety events were assessed during the short-term (duration ≤ 12 months) and cumulative (short-term plus longterm extensions) abatacept treatment periods. Incidence rates per 100 patient-years were calculated. Standardized incidence ratios (SIR) for hospitalized infections and malignancies were compared with external RA cohorts and, for malignancies, with the US general population. RESULTS: There were 3173 IV abatacept-treated patients with 2331 patient-years of exposure in the short-term periods, and 4149 IV abatacept-treated patients with 12,132 patient-years of exposure in the cumulative period. Incidence rates for serious infections were low and consistent over time (3.68 for abatacept vs 2.60 for placebo during the short-term, and 2.87 for abatacept during the cumulative period). Hospitalized infections were generally similar to external RA patient cohorts and were consistent over time. Incidence rates of malignancies were similar for abatacept- and placebo-treated patients during the short-term period (0.73 vs 0.59) and remained low during the abatacept cumulative period (0.73). SIR of some tissue-specific malignancies (e.g., colorectal and breast) in the cumulative period tended to be lower, while others (lymphoma and lung) tended to be higher, compared with the general population; however, incidence rates were comparable with RA cohorts. Autoimmune events were rare and infusion reactions uncommon. CONCLUSION: Longterm safety of IV abatacept was consistent with the short-term, with no unexpected events and low incidence rates of serious infections, malignancies, and autoimmune events.

Immunogenicity, safety, and efficacy of abatacept administered subcutaneously with or without background methotrexate in patients with rheumatoid arthritis: results from a phase III, international, multicenter, parallel-arm, open-label study.

OBJECTIVE: To evaluate the impact of concomitant methotrexate (MTX) on subcutaneous (SC) abatacept immunogenicity, and to assess safety and efficacy. METHODS: This phase III, open-label study had a 4-month short-term (ST) period and an ongoing long-term extension (LTE) period. Rheumatoid arthritis patients were stratified to receive SC abatacept (125 mg/week) with (combination) or without MTX (monotherapy), with no intravenous loading dose; patients receiving monotherapy could add MTX in the LTE period. Immunogenicity (percentage of anti-abatacept antibody-positive patients) was assessed. ST and LTE period data are reported, including efficacy through LTE month 14 and safety through LTE month 20. RESULTS: Ninety-six of 100 enrolled patients completed the ST period; 3.9% (combination) and 4.1% of patients (monotherapy) developed transient immunogenicity, and no patients were antibody positive at month 4. Serious adverse events (SAEs) were reported in 3.9% (combination) and 6.1% of patients (monotherapy); 5.9% (combination) and 8.2% of patients (monotherapy) experienced SC injection reactions, and all were mild in intensity. Mean 28-joint Disease Activity Score (DAS28) changes were -1.67 (95% confidence interval [95% CI] -2.06, -1.28; combination) and -1.94 (95% CI -2.46, -1.42; monotherapy) at month 4. Ninety patients entered and were treated in the LTE period; 83.3% (75 of 90) remained ongoing at month 24. One LTE-treated patient (1.1%) developed immunogenicity, 14.4% of patients experienced SAEs, and no SC injection reactions were reported. For patients entering the LTE period, mean DAS28 changes from baseline were -1.84 (95% CI -2.23, -1.34; combination) and -2.86 (95% CI -3.46, -2.27; monotherapy) at month 18. CONCLUSION: SC abatacept did not elicit immunogenicity associated with loss of safety or efficacy, either with or without MTX.

Abatacept in subjects who switch from intravenous to subcutaneous therapy: results from the phase IIIb ATTUNE study.

OBJECTIVE: To assess safety, immunogenicity and efficacy in rheumatoid arthritis (RA) patients switched from long-term intravenous to subcutaneous (SC) abatacept. METHODS: In this phase IIIb, open-label, single-arm trial, patients who completed ≥4 years of intravenous abatacept (in long-term extensions of two phase III studies) were enrolled to receive SC abatacept (125 mg/week). The primary objective was safety during the first 3 months after switching from intravenous therapy. RESULTS: 123 patients entered the study (mean Disease Activity Score 28 (based on C reactive protein) and HAQ-DI of 3.4 and 0.94, respectively). At month 3, 120 (97.6%) patients were continuing to receive SC abatacept; no patients discontinued due to lack of efficacy. Adverse events (AEs) were reported in 49 (39.8%) patients through month 3. One patient (0.8%) discontinued due to an AE and one patient (0.8%) experienced a serious AE. Two (1.6%) patients had SC injection site reactions (erythema, pain), both with mild intensity. Clinical efficacy was maintained throughout. Limited impact on immunogenicity was observed when switching routes of administration. CONCLUSION: These data demonstrate that patients can switch from long-term monthly intravenous abatacept to a weekly fixed dose of 125 mg SC abatacept with no increased safety concerns. This study further supports SC abatacept as an alternative treatment option for patients with RA.

Evaluation of abatacept administered subcutaneously in adults with active rheumatoid arthritis: impact of withdrawal and reintroduction on immunogenicity, efficacy and safety (phase Iiib ALLOW study).

OBJECTIVES: To assess the effect of a temporary interruption in subcutaneous (SC) abatacept on immunogenicity, safety and efficacy in patients with active rheumatoid arthritis despite methotrexate in a phase III trial. METHODS: Following a 12-week open-label introduction (period I; intravenous abatacept loading dose and weekly fixed-dose SC abatacept 125 mg), patients were randomised 2:1 to double-blind SC placebo or SC abatacept for 12 weeks (period II). At the end of period II, patients receiving SC abatacept continued treatment and patients on placebo were reintroduced to SC abatacept (12-week open-label period III). The co-primary end points were ELISA-detected immunogenicity rate and safety at the end of period II. Efficacy was also monitored. RESULTS: Of 167 patients entering period I, 72% qualified for period II; during periods II and III, three patients discontinued treatment. Mean (SD) disease duration was 6.6 (6.5) years and Disease Activity Score 28 was 4.8 (0.8). The primary end point was met, with a non-significant increase in immunogenicity upon withdrawal (7/73 placebo vs 0/38 abatacept in period II; p=0.119) which was reversed upon reintroduction of SC abatacept (2/73 vs 1/38, end period III). Safety was comparable regardless of withdrawal, with no unexpected events upon reintroduction. Two patients experienced reactions at the SC injection site. On withdrawal, patients experienced slight worsening in efficacy which improved following reintroduction. CONCLUSIONS: Overall immunogenicity to SC abatacept is low, consistent with intravenous abatacept, and is not significantly affected by a 3-month interruption and reintroduction. This stop-start schedule was well tolerated, with little impact on safety and efficacy. These are important considerations for the clinical use of SC abatacept. CLINICALTRIALS: gov Identifier NCT00533897.