Eisuke Shono

Longterm Safety and Efficacy of Subcutaneous Tocilizumab Monotherapy: Results from the 2-year Open-label Extension of the MUSASHI Study

Objective. To evaluate the longterm safety and efficacy of subcutaneous tocilizumab (TCZ-SC) as monotherapy in patients with rheumatoid arthritis (RA). Methods. Of 346 patients who received 24 weeks of double-blind treatment with either TCZ-SC monotherapy, 162 mg every 2 weeks (q2w); or intravenous TCZ (TCZ-IV) monotherapy, 8 mg/kg every 4 weeks; 319 patients continued to receive TCZ-SC q2w in the 84-week open-label extension (OLE) of the MUSASHI study (JAPICCTI-101117). Efficacy, safety, and immunogenicity were evaluated for all patients treated with TCZ during 108 weeks. Results. The proportions of patients who achieved American College of Rheumatology 20/50/70 responses, low disease activity [28-joint Disease Activity Score (DAS28) ≤ 3.2], or remission (DAS28 < 2.6) at Week 24 were maintained until Week 108. The incidences of adverse events and serious adverse events were 498.3 and 16.9 per 100 patient-years (PY), respectively. The overall safety of TCZ-SC monotherapy was similar to that of TCZ-IV monotherapy. Rates of injection site reactions (ISR) through 108 weeks remained similar to rates through 24 weeks. ISR were mild and did not cause any patient withdrawals. No serious hypersensitivity events (including anaphylactic reactions) occurred. Anti-TCZ antibodies were present in 2.1% of patients treated with TCZ-SC monotherapy. Conclusion. TCZ-SC monotherapy maintained a favorable safety profile and consistent efficacy throughout the 108-week study. Like TCZ-IV, TCZ-SC could provide an additional treatment option for patients with RA.

Mechanism‐based approach using a biomarker response to evaluate tocilizumab subcutaneous injection in patients with rheumatoid arthritis with an inadequate response to synthetic DMARDs (MATSURI study)

A multicenter, open‐label, dose‐escalation phase 1/2 study was undertaken to evaluate the optimal subcutaneous tocilizumab dose that would result in exposure comparable to the intravenous tocilizumab 8‐mg/kg approved dose in patients with rheumatoid arthritis. A pharmacokinetic and biomarker approach was used to estimate the clinical optimal dose regimen of subcutaneous tocilizumab. Safety and efficacy of subcutaneous tocilizumab were assessed as secondary end points. Patients received subcutaneous tocilizumab at 81 mg every 2 weeks (q2w) (n = 8), 162 mg q2w (n = 12), or 162 mg weekly (qw) (n = 12) for 24 weeks. 88% of 162‐mg q2w patients and 100% of 162‐mg qw patients maintained mean serum trough tocilizumab concentrations of ≥1 µg/mL, and had exposure comparable with the approved intravenous tocilizumab dose of 8 mg/kg; this resulted in normalized C‐reactive protein levels and improvement in ACR20/50/70 responses. The most common adverse events were abnormal laboratory results, which were mild in severity. Anti‐tocilizumab antibodies were detected in a few patients in the 81‐mg q2w and 162‐mg qw groups. In conclusion, coupled with efficacy and tolerability results, the appropriate dose of subcutaneous tocilizumab was determined to be 162 mg q2w for Japanese patients.

Hereditary angioedema in Japan: Genetic analysis of 13 unrelated cases

Introduction:The molecular bases and clinical features of hereditary angioedema (HAE) have not been systematically documented in Japan or in other Asian countries. Thus, the authors researched the genetic and clinical characteristics of Japanese patients with HAE. Methods:The authors analyzed the CIINH gene for mutations in 13 unrelated Japanese patients with HAE by means of the polymerase chain reaction and nucleotide sequencing. In addition, the authors searched the literature from January 1969 to October 2010 on Japanese patients with HAE. Results:Seven of the mutations found were novel, including 4 missense mutations (8728T>G, 8831C>A, 16661T>G and 16885C>A), 2 frameshift mutations (2281_2350del70, 14158delT) and 1 large deletion (at least 1 kb-length deletion including exon 4), whereas 6 mutations had previously been reported in European populations. Conclusions:The genetic and clinical characteristics in Japanese patients with HAE may be similar to those in Western patients although our sample size is small and the authors identified 7 novel mutations.

Impact of methotrexate dose on efficacy of adalimumab in Japanese patients with rheumatoid arthritis: Results from registered data analyses

Abstract Objective: Upper limit of methotrexate (MTX) for patients with rheumatoid arthritis (RA) was recently increased from 8 to 16 mg/week in Japan. We therefore examined the effect of concomitant MTX dose on the efficacy of adalimumab (ADA) in clinical practice. Method: Sixty-one consecutive RA patients treated with ADA were followed for minimum 52 weeks and retrospectively compared by MTX dose; patients receiving concomitant MTX of 10 mg/week or more (MTX ≥10 mg group) and <10 mg/week (MTX <10 mg group). Disease activity and remission were evaluated by the disease activity score 28 (DAS28) criteria. Results: The MTX ≥10 mg group consistently showed better improvement in DAS28 and resulted in more patients (52.8%) with DAS28-remission compared with the MTX <10 mg group (26.1%). Multivariate analysis showed that MTX ≥10 mg had a significant effect on DAS28 remission with odds ratio of 5.12. ADA retention rate was 72.2% in MTX ≥10 mg group compared with 52.0% in MTX <10 mg group. Discontinuation of ADA due to adverse events were comparable in the MTX ≥10 mg and MTX <10 mg groups (11.1% vs. 12.0%). Conclusions: These findings support the critical role of concomitant MTX in the efficacy of ADA, and recommend use of MTX ≥10 mg in Japanese RA patients.