Tolerability and efficacy of abatacept in Japanese patients with rheumatoid arthritis: a phase I study

Abatacept in combination with methotrexate in Japanese biologic-naive patients with active rheumatoid arthritis: a randomised placebo-controlled phase IV study

Objectives

To evaluate efficacy and safety of abatacept+methotrexate (MTX) in biologic-naive, anticitrullinated protein antibody (ACPA)-positive Japanese patients with active rheumatoid arthritis (RA) and early erosion versus placebo+MTX.

Methods

In this phase IV, multicentre, double-blind study (NCT01758198), patients were randomised (1:1) to receive intravenous abatacept (~10 mg/kg) or placebo, plus MTX (≥6 mg/week). Primary efficacy objectives were to compare American College of Rheumatology 20 (ACR20) response rates at week 16 and mean change from baseline in van der Heijde-modified total Sharp score (vdH-mTSS) at week 24 between abatacept+MTX and placebo+MTX groups.

Results

Overall, 203 and 202 patients received abatacept+MTX and placebo+MTX, respectively. At week 16, ACR20 response rates were higher in the abatacept (75.4%) versus placebo group (27.7%; p<0.001). Mean change from baseline in vdH-mTSS at week 24 was 0.84 in the abatacept and 1.26 in the placebo group (p=0.017). Radiographic non-progression rates (change in vdH-mTSS≤smallest detectable change (1.9)) were 88.1% and 75.4% in abatacept and placebo groups, respectively. Adjusted mean change from baseline in Disease Activity Score 28 (C-reactive protein) (DAS28 (CRP)) at week 16 demonstrated a numerically greater reduction in the abatacept versus placebo group. Proportions of patients with DAS28 (CRP), Simplified Disease Activity Index and Clinical Disease Activity Index remission up to week 52 were higher in the abatacept versus placebo group. The abatacept safety profile was consistent with previous observations.

Conclusions

Compared with MTX alone, abatacept+MTX improved clinical symptoms and inhibited structural damage progression in ACPA-positive, Japanese patients with RA, early erosion and inadequate response to MTX.

Long-term safety and efficacy of treatment with subcutaneous abatacept in Japanese patients with rheumatoid arthritis who are methotrexate inadequate responders

OBJECTIVE

To assess the long-term safety, immunogenicity, and efficacy of subcutaneous (SC) abatacept in combination with methotrexate (MTX) in Japanese patients with rheumatoid arthritis who were MTX inadequate responders, in a long-term extension (LTE) to a double-dummy, double-blind study (NCT01001832).

METHODS

Patients, who had previously received SC or intravenous (IV) abatacept with MTX (6-8 mg/week) for 24 weeks, received SC abatacept (125 mg/week) with MTX for an additional 52 weeks. Safety, immunogenicity, and efficacy were assessed.

RESULTS

The LTE included 112 patients. SC abatacept was generally well tolerated in the LTE, with no new safety signals. American College of Rheumatology 20, 50, and 70 response rates, disease activity score 28 (C-reactive protein) remission rates (< 2.6), and Health Assessment Questionnaire-Disability Index response rates (≥ 0.3 improvement from baseline) achieved at the end of the double-blind period were maintained over the LTE and were comparable in patients who received SC or IV abatacept in the double-blind period. Seropositivity for immunogenicity occurred in 4 (3.6%) patients. Self-injection of SC abatacept was well controlled and not associated with additional safety events.

CONCLUSIONS

SC abatacept had acceptable safety and was well tolerated and effective over the LTE (76 weeks in total), with low rates of immunogenicity in Japanese patients.

Differential gene expression in human abdominal aortic aneurysm and aortic occlusive disease

Abdominal aortic aneurysm (AAA) and aortic occlusive disease (AOD) represent common causes of morbidity and mortality in elderly populations which were previously believed to have common aetiologies. The aim of this study was to assess the gene expression in human AAA and AOD. We performed microarrays using aortic specimen obtained from 20 patients with small AAAs (≤ 55mm), 29 patients with large AAAs (> 55mm), 9 AOD patients, and 10 control aortic specimens obtained from organ donors. Some differentially expressed genes were validated by quantitative-PCR (qRT-PCR)/immunohistochemistry. We identified 840 and 1,014 differentially expressed genes in small and large AAAs, respectively. Immune-related pathways including cytokine-cytokine receptor interaction and T-cell-receptor signalling were upregulated in both small and large AAAs. Examples of validated genes included CTLA4 (2.01-fold upregulated in small AAA, P = 0.002), NKTR (2.37-and 2.66-fold upregulated in small and large AAA with P = 0.041 and P = 0.015, respectively), and CD8A (2.57-fold upregulated in large AAA, P = 0.004). 1,765 differentially expressed genes were identified in AOD. Pathways upregulated in AOD included metabolic and oxidative phosphorylation categories. The UCP2 gene was downregulated in AOD (3.73-fold downregulated, validated P = 0.017). In conclusion, the AAA and AOD transcriptomes were very different suggesting that AAA and AOD have distinct pathogenic mechanisms.

Biologic-free remission of established rheumatoid arthritis after discontinuation of abatacept: a prospective, multicentre, observational study in Japan

Objective. The aim of this study was to determine whether biologic-free remission of RA is possible with discontinuation of abatacept.

Methods. Japanese RA patients in 28-joint DAS with CRP (DAS28-CRP) remission (<2.3) after >2 years of abatacept treatment in a phase II study and its long-term extension entered this 52 week, multicentre, non-blinded, prospective, observational study. At enrolment, the patients were offered the option to continue abatacept or not. The primary endpoint was the proportion of patients who remained biologic-free at 52 weeks after discontinuation. Clinical, functional and structural outcomes were compared between those who continued and those who discontinued abatacept.

Results. Of 51 patients enrolled, 34 discontinued and 17 continued abatacept treatment. After 52 weeks, 22 of the 34 patients (64.7%) remained biologic-free. Compared with the continuation group, the discontinuation group had a similar remission rate (41.2% vs 64.7%, P = 0.144) although they had a significantly higher mean DAS28-CRP score at week 52 (2.9 vs 2.0, P = 0.012). The two groups were also similar with regard to mean HAQ Disability Index (HAQ-DI) score (0.6 for both, P = 0.920), mean change in total Sharp score (ΔTSS; 0.80 vs 0.32, P = 0.374) and proportion of patients in radiographic remission (ΔTSS ≤ 0.5) at the endpoint (64.3% vs 70.6%, P = 0.752). Those attaining DAS28-CRP < 2.3 or < 2.7 without abatacept at the endpoint had significantly lower HAQ-DI score and/or CRP at enrolment. Non-serious adverse events occurred in three patients who continued or resumed abatacept.

Conclusion. Biologic-free remission of RA is possible in some patients after attaining clinical remission with abatacept. Lower baseline HAQ-DI or CRP may predict maintenance of remission or low disease activity after discontinuation of abatacept.

Trial registration: UMIN Clinical Trials Registry, http://www.umin.ac.jp/ctr/ (UMIN000004137).

Efficacy, safety, pharmacokinetics and immunogenicity of abatacept administered subcutaneously or intravenously in Japanese patients with rheumatoid arthritis and inadequate response to methotrexate: a Phase II/III, randomized study

OBJECTIVE

To evaluate efficacy and safety of subcutaneous (SC) and intravenous (IV) abatacept and background methotrexate (MTX) in Japanese patients with rheumatoid arthritis (RA) and inadequate response to MTX (MTX-IR).

METHODS

Double-dummy, double-blind study (NCT01001832); 118 adults with ≥ 10 swollen joints, ≥ 12 tender joints and C-reactive protein (CRP) ≥ 0.8 mg/dL randomized 1:1 to SC abatacept (125 mg weekly) with IV loading (∼10 mg/kg on Day 1), or IV abatacept (∼10 mg/kg monthly) for 169 days, both also receiving MTX (6-8 mg/week). Primary endpoint was Day 169 American College of Rheumatology (ACR)20 response; other efficacy endpoints, safety and immunogenicity were assessed.

RESULTS

Similar proportions of patients achieved ACR20 responses at Day 169 with SC (91.5% [95% CI 81.3, 97.2]) and IV abatacept (83.1% [71.0, 91.6]). ACR50/70 responses, adjusted mean changes from baseline in Health Assessment Questionnaire-Disability Index scores and remission rates (28-joint Disease Activity Score [CRP] < 2.6) were also comparable between groups. Serious adverse event frequencies (5.1% vs. 3.4%) were similar with both formulations. One patient per group tested seropositive for immunogenicity. Weekly SC abatacept dosing achieved mean serum concentrations > 10 μg/mL (minimum therapeutic target).

CONCLUSIONS

SC abatacept demonstrated comparable efficacy and safety to IV abatacept, with low immunogenicity rates, in MTX-IR Japanese patients with RA.