Elevation of KL-6 serum levels in clinical trials of tumor necrosis factor inhibitors in patients with rheumatoid arthritis: a report from the Japan College of Rheumatology Ad Hoc Committee for Safety of Biological DMARDs

Safety and effectiveness of certolizumab pegol in Japanese patients with rheumatoid arthritis: Up to 3-year results from a postmarketing surveillance study

OBJECTIVES

To report up to 3-year safety and effectiveness of certolizumab pegol (CZP) in Japanese patients with rheumatoid arthritis from a postmarketing surveillance study.

METHODS

Patients enrolled previously completed 24 weeks of CZP in the 24-week postmarketing surveillance study. Adverse drug reactions (ADRs) were recorded for patients who received ≥1 CZP dose. Effectiveness outcomes were 28-joint Disease Activity Score with erythrocyte sedimentation rate and European Alliance of Associations for Rheumatology response. Week 24-156 safety and Week 0-52 effectiveness data are reported here.

RESULTS

A total of 781 patients were enrolled, with 735 and 376 patients evaluated for safety and effectiveness, respectively. Within the safety set, 17.8% (131/735) of patients reported ADRs; 9.4% (69/735) reported serious ADRs. Among patients with history of respiratory, thoracic, and mediastinal disorders, 38.4% (28/73) reported ADRs. The most frequent ADRs were infections and infestations (11.8%; 87/735); skin and subcutaneous tissue disorders (1.9%; 14/735); respiratory, thoracic, and mediastinal disorders (1.6%; 12/735). Mean 28-joint Disease Activity Score with erythrocyte sedimentation rate reduced from 4.6 (Week 0) to 2.8 (Week 52). At Week 52, 51.8% (161/311) of patients achieved European Alliance of Associations for Rheumatology Good response.

CONCLUSIONS

The long-term safety and effectiveness of CZP in the real-world setting in Japan were consistent with previously reported data; no new safety signals were identified.

Biomarkers for interstitial lung disease and acute-onset diffuse interstitial lung disease in rheumatoid arthritis

Interstitial lung disease (ILD) is frequently a complication of rheumatoid arthritis (RA) as an extra-articular manifestation which has a poor prognosis. Acute-onset diffuse ILD (AoDILD) occasionally occurs in RA and includes acute exacerbation of ILD, drug-induced ILD, and Pneumocystis pneumonia. AoDILD also confers a poor prognosis in RA. Previously-established biomarkers for ILD include Krebs von den lungen-6 and surfactant protein-D originally defined in patients with idiopathic pulmonary fibrosis; the sensitivity of these markers for RA-associated ILD (RA-ILD) is low. Although many studies on ILD markers have been performed in idiopathic pulmonary fibrosis, only a few validation studies in RA-ILD or AoDILD have been reported. Biomarkers for RA-ILD and AoDILD are thus still required. Recently, genomic, cytokine, antibody, and metabolomic profiles of RA-ILD or AoDILD have been investigated with the aim of improving biomarkers. In this review, we summarize current preliminary data on these potential biomarkers for RA-ILD or AoDILD. The development of biomarkers on RA-ILD has only just begun. When validated, such candidate biomarkers will provide valuable information on pathogenesis, prognosis, and drug responses in RA-ILD in future.

Serum Krebs von den Lungen-6 levels in psoriatic patients under treatment with biologics

During biologic treatments, attention should be paid to adverse reactions, particularly infectious diseases. Furthermore, drug-induced interstitial lung disease is also known to be associated with biologic therapies. We retrospectively reviewed serum Krebs von den Lungen-6 (KL-6) levels in psoriatic patients who underwent treatment with seven different biologics. A total of 67 patients who received 80 biologic treatments were evaluated. The 31 anti-tumor necrosis factor (TNF)-α treatments consisted of 17 infliximab (IFX) and 14 adalimumab. The 23 anti-interleukin (IL)-23 treatments consisted of 14 ustekinumab and nine guselkumab. The 26 anti-IL-17 treatments consisted of nine secukinumab, six ixekizumab and 11 brodalumab. The IFX showed significantly increased mean serum KL-6 (170.9%), but none of the other treatments showed significant increases. Thirteen of the 17 (75.6%) patients in the IFX and 17 of the 31 (54.8%) patients in the total anti-TNF-α group demonstrated at least a 25% increase in serum KL-6. Levels exceeding the cut-off (500 U/mL) were detected in three patients before treatment and in seven patients after treatment. This study showed that anti-IL-17 and anti-IL-23 treatments have no significant impact on serum KL-6 level. In addition to the influence of IFX, a significantly large number of patients in the IFX group had a history of methotrexate administration associated with psoriatic arthritis, which might have influenced the KL-6 level. None of the patients with elevated serum KL-6 showed pulmonary changes by computed tomography and/or X ray.

Serum KL-6 elevation in a uveitis patient with Behçet's disease treated with adalimumab

Purpose

To report a case of uveitis with Behçet's disease in which serum levels of Krebs von den Lungen (KL)-6, a marker of interstitial lung disease, were elevated during treatment with adalimumab and returned to baseline after discontinuation of the agent.

Observations

A 67-year-old man complaining of vision disturbance was referred to our hospital. The patient had a history of recurrent episodes of bilateral uveitis and oral ulcers, and had been diagnosed with Behçet's disease. While uveitis activity was not well controlled under administration of oral prednisolone and cyclosporin, cataract of the right eye developed and required surgery. Biweekly administration of adalimumab 40 mg was therefore initiated with prednisolone at 15 mg/day. Uveitis became well controlled and cataract surgery was successfully carried out for the right eye. However, serum KL-6 gradually elevated to 1002 U/ml by 6 months after adalimumab initiation and 1277 U/ml at 9 months. Because serum KL-6 >1000 U/ml has been reported to predict interstitial lung disease, we discontinued adalimumab and started cyclosporine at 100 mg/day. Serum KL-6 gradually decreased and returned to baseline levels, no interstitial lung disease developed and exacerbation of uveitis was avoided.

Conclusions and importance

This case implies the clinical importance of monitoring serum KL-6 in patents with non-infectious uveitis being treated with adalimumab.

A Patient with KL-6 Elevation with Anti-TNFα Who Could Receive Long-Term Use without Interstitial Pneumonia after Class Switch of Anti-TNFα

A 40-year-old man with refractory ulcerative colitis (UC) was treated with tumor necrosis factor α inhibitor (anti-TNFα), infliximab. One month later, the chest computed tomography and laboratory test showed noninfectious interstitial lung disease (ILD) and elevation of serum Krebs von den Lungen-6 (KL-6). Fortunately, ILD disappeared after the discontinuation with anti-TNFα. Two and a half years after his first UC treatment, he was treated again with another anti-TNFα, adalimumab, for relapse and he had a second ILD. This course suggested anti-TNFα induced ILD. The characteristics of anti-TNFα-induced ILD in inflammatory bowel disease (IBD) are not well understood. We summarized and investigated the characteristics of such patients based on a literature review including 15 cases. It suggested that anti-TNFα-induced ILD in IBD might be rare and tends to have a better outcome compared with ILD in rheumatoid arthritis.

Interleukin-18 is associated with the presence of interstitial lung disease in rheumatoid arthritis: a cross-sectional study

OBJECTIVE

Serum interleukin-18 (IL-18) levels are increased in patients with interstitial lung disease (ILD). In addition, IL-18 levels are increased in patients with rheumatoid arthritis (RA) and are associated with arthritis activity. We determined whether increased IL-18 levels are associated with ILD in RA.

METHOD

RA patients were enrolled using an RA cohort database. Plasma IL-18 levels were measured by enzyme-linked immunosorbent assay. ILD was determined by a pulmonologist and a radiologist based on chest radiography and computed tomography findings. IL-18 levels for RA with ILD and RA without ILD were compared. Associations between ILD and various markers including IL-18 and confounding factors (e.g. smoking history) were investigated by logistic regression analysis. Diagnostic values of IL-18 for the presence of ILD were investigated using receiver operating characteristics curve analysis.

RESULTS

ILD was complicated in 8.2% (n = 26) of the study population (N = 312). Plasma IL-18 levels were higher for RA patients with ILD than for RA patients without ILD (721.0 ± 481.4 vs 436.8 ± 438.9 pg/mL, p < 0.001). IL-18, Krebs von den Lungen-6, and anti-cyclic citrullinated peptide antibody titre and glucocorticoid doses were independently associated with the presence of ILD during multivariate logistic regression analysis. Sensitivity and specificity of IL-18 levels for the detection of ILD in RA patients were 65.3% and 76.3%, respectively (area under the curve = 0.73).

CONCLUSION

Plasma IL-18 levels were higher for RA patients with ILD than for those without ILD. Increased IL-18 levels were associated with the presence of ILD.

Phase III study of the efficacy and safety of subcutaneous versus intravenous tocilizumab monotherapy in patients with rheumatoid arthritis

Objective

To evaluate the efficacious noninferiority of subcutaneous tocilizumab injection (TCZ-SC) monotherapy to intravenous TCZ infusion (TCZ-IV) monotherapy in Japanese patients with rheumatoid arthritis (RA) with an inadequate response to synthetic and/or biologic disease-modifying antirheumatic drugs (DMARDs).

Methods

This study had a double-blind, parallel-group, double-dummy, comparative phase III design. Patients were randomized to receive TCZ-SC 162 mg every 2 weeks or TCZ-IV 8 mg/kg every 4 weeks; no DMARDs were allowed during the study. The primary end point was to evaluate the noninferiority of TCZ-SC to TCZ-IV regarding the American College of Rheumatology criteria for 20% improvement in disease activity (ACR20) response rates at week 24 using an 18% noninferiority margin. Additional efficacy, safety, pharmacokinetic, and immunogenicity parameters were assessed.

Results

At week 24, ACR20 response was achieved in 79.2% (95% confidence interval [95% CI] 72.9, 85.5) of the TCZ-SC group and in 88.5% (95% CI 83.4, 93.5) of the TCZ-IV group; the weighted difference was −9.4% (95% CI −17.6, −1.2), confirming the noninferiority of TCZ-SC to TCZ-IV. Remission rates of the Disease Activity Score in 28 joints using the erythrocyte sedimentation rate and the Clinical Disease Activity Index at week 24 were 49.7% and 16.4% in the TCZ-SC group and 62.2% and 23.1% in the TCZ-IV group, respectively. Serum trough TCZ concentrations were similar between the groups over time. Incidences of all adverse events and serious adverse events were 89.0% and 7.5% in the TCZ-SC group and 90.8% and 5.8% in the TCZ-IV group, respectively. Anti-TCZ antibodies were detected in 3.5% of the TCZ-SC group; no serious hypersensitivity was reported in these patients.

Conclusion

TCZ-SC monotherapy demonstrated comparable efficacy and safety to TCZ-IV monotherapy. TCZ-SC could provide additional treatment options for patients with RA.