Comparative effectiveness of tofacitinib and tumour necrosis factor inhibitors in patients with rheumatoid arthritis in real-world practice: a prospective observational study.

OBJECTIVE: To assess the effectiveness of tofacitinib vs tumour necrosis factor inhibitors (TNFi) in Korean patients with rheumatoid arthritis (RA). METHODS: The study used data from a single academic referral hospital's registries of biologic disease-modifying anti-rheumatic drugs (bDMARDs) and tofacitinib and examined remission rates based on the disease activity score (DAS)28-erythrocyte sedimentation rate (ESR) after 12 months. Multivariable logistic regression analysis was used to estimate the odds ratio (OR) for achieving remission with tofacitinib compared with TNFi, adjusting for potential confounders. RESULTS: This analysis included 665 patients (200 on tofacitinib and 455 on TNFi) who were followed up for at least 12 months. Of these, 96 patients in the tofacitinib group (48.0%) and 409 patients in the TNFi group (89.9%) were treatment-naïve to bDMARDs. Intention-to-treat analysis revealed no significant difference in the remission rates between the two groups (18.0% vs 19.6%, p = 0.640). Multivariable analysis demonstrated comparable remission rates with tofacitinib and TNFi (OR 1.204, 95% confidence interval [CI] 0.720-2.013). In the subpopulation naïve to JAKi and bDMARD, tofacitinib showed better remission rates than TNFi (OR 1.867, 95% CI 1.033-3.377). Tofacitinib had more adverse events (AEs) but similar rates of serious AEs (SAEs) to TNFi. CONCLUSION: In real-world settings, there was no significant difference in remission rates at 12 months between the tofacitinib and TNFi groups. In terms of safety, tofacitinib exhibited a higher incidence of AEs compared with TNFi, while the occurrence of SAEs was comparable between the groups. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02602704.

Comparative effectiveness of JAK inhibitors and biologic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis.

BACKGROUND/AIMS: We aimed to compare the effectiveness and safety of Janus kinase inhibitors (JAKi) vs. biologic disease- modifying antirheumatic drugs (bDMARD) in Korean patients with rheumatoid arthritis (RA) who had an inadequate response to conventional synthetic DMARDs. METHODS: A quasi-experimental, multi-center, prospective, non-randomized study was conducted to compare response rates between JAKi and bDMARDs in patients with RA naïve to targeted therapy. An interim analysis was performed to estimate the proportion of patients achieving low disease activity (LDA) based on disease activity score (DAS)-28- erythroid sedimentation rate (ESR) (DAS28-ESR) at 24 weeks after treatment initiation and to evaluate the development of adverse events (AEs). RESULTS: Among 506 patients enrolled from 17 institutions between April 2020 and August 2022, 346 (196 JAKi group and 150 bDMARD group) were included in the analysis. After 24 weeks of treatment, 49.0% of JAKi users and 48.7% of bDMARD users achieved LDA (p = 0.954). DAS28-ESR remission rates were also comparable between JAKi and bDMARD users (30.1% and 31.3%, respectively; p = 0.806). The frequency of AEs reported in the JAKi group was numerically higher than that in the bDMARDs group, but the frequencies of serious and severe AEs were comparable between the groups. CONCLUSION: Our interim findings reveal JAKi have comparable effectiveness and safety to bDMARDs at 24 weeks after treatment initiation.

Increased risk of herpes zoster with tofacitinib treatment in Korean patients with rheumatoid arthritis: a single-center prospective study.

We aimed to determine the risk of herpes zoster (HZ) in Korean rheumatoid arthritis (RA) patients on tofacitinib compared with tumor necrosis factor inhibitor (TNFi) treatment. From the prospective cohorts of RA patients who started tofacitinib or TNFi in an academic referral hospital in Korea, patients who started tofacitinib between March 2017 and May 2021 and those who started TNFi between July 2011 and May 2021 were included. Baseline characteristics of tofacitinib and TNFi users were balanced through inverse probability of treatment weighting (IPTW) using the propensity score including age, disease activity of RA and medication use. The incidence rate of HZ in each group and incidence rate ratio (IRR) were calculated. A total of 912 patients were included: 200 tofacitinib and 712 TNFi users. There were 20 cases of HZ among tofacitinib users and 36 among TNFi users during observation period of 331.4 person-years (PYs) and 1950.7 PYs, respectively. In IPTW analysis with a balanced sample, IRR of HZ was 8.33 (95% confidence interval 3.05-22.76). Tofacitinib use increased the risk of HZ compared with TNFi in Korean patients with RA, but the rate of serious HZ or permanent discontinuation of tofacitinib due to HZ event was low.

Risk of venous thromboembolism in Korean patients with rheumatoid arthritis treated with Janus kinase inhibitors: A nationwide population-based study.

OBJECTIVE: There was a safety concern about an increased risk of thromboembolic events in patients with rheumatoid arthritis (RA) treated with Janus kinase inhibitors (JAKis). This study aimed to determine the risk of venous thromboembolism (VTE) in Korean patients with RA treated with JAKis compared with tumour necrosis factor (TNF) inhibitors. METHODS: Using the National Health Insurance Service database between 2015 and 2019, patients with prevalent RA who started JAKi or TNF inhibitor were selected as the study population. All participants were naïve to targeted therapy. Patients that had experienced any VTE event or used anticoagulant agents within 30 days were excluded. Demographic and clinical characteristics were all balanced by stabilised inverse probability of treatment weighting (sIPTW) using propensity score. The Cox proportional hazard model considering death as a competing risk was used to evaluate the risk of VTE in JAKi users compared with TNF inhibitor users. RESULTS: A total of 4,178 patients were included: 871 JAKi users and 3,307 TNF inhibitor users were followed up for 1,029.2 person-years (PYs) and 5,940.3 PYs, respectively. With a balanced sample after sIPTW, the incidence rates (IR) of VTE were 0.06 per 100 PYs (95% confidence interval [CI] 0.00-1.23) in JAKi users and 0.38 per 100 PYs (95% CI 0.25-0.58) in TNF inhibitor users. The hazard ratio was 0.18 (95% CI 0.01-3.47) after adjusting for unbalanced variables after performing sIPTW. CONCLUSION: There is no increased risk of VTE in RA patients treated with JAKis compared with TNF inhibitors in Korea.

Clinical characteristics of rheumatoid arthritis patients with interstitial lung disease: baseline data of a single-center prospective cohort.

BACKGROUND: To introduce a prospective cohort for rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) and to identify their clinical features in comparison with RA patients without ILD. METHODS: Using a multidisciplinary collaborative approach, a single-center cohort for RA patients with ILD (RA-ILD) was established in May 2017, and enrolment data from May 2017 to March 2021 were used to compare the clinical features of RA patients without ILD (RA-non ILD). Multivariable logistic regression analysis was used to identify factors associated with ILD in RA patients. RESULTS: Among 148 RA-ILD and 410 RA-non ILD patients, participants in the RA-ILD group were older (65.8 ± 9.9 vs. 58.0 ± 10.4 years, P < 0.001) and included more males (35.8% vs. 14.6%, P < 0.001) than in the RA-non ILD group. The RA-ILD group had a higher proportion of late-onset RA patients (age ≥ 60 years) than in the comparator group (43.9% vs. 14.2%, P < 0.001). Multivariable logistic regression analysis showed that higher age at RA onset (OR 1.056, 95% CI 1.021-1.091), higher body mass index (BMI; OR 1.65, 95% CI 1.036-2.629), smoking history (OR 2.484, 95% CI 1.071-5.764), and oral glucocorticoid use (OR 3.562, 95% CI 2.160-5.874) were associated with ILD in RA patients, whereas methotrexate use was less likely to be associated with ILD (OR 0.253, 95% CI 0.155-0.412). CONCLUSIONS: Higher age at RA onset, smoking history, and higher BMI were associated with the presence of ILD among RA patients. Oral glucocorticoids were more frequently used whereas methotrexate was less likely to be used in RA-ILD patients.

Factors associated with selection of targeted therapy in patients with rheumatoid arthritis.

OBJECTIVE: Deciding which drug to choose for targeted therapy is an important step in sequential treatment for rheumatoid arthritis (RA). This study aimed to identify factors for selecting Janus kinase inhibitors (JAKis) rather than biologic disease-modifying antirheumatic drugs (bDMARDs) in patients with RA in real-world practice. METHODS: We selected RA patients starting JAKis or bDMARDs from single-center prospective cohorts in Korea. Patients were divided into JAKi, tumor necrosis factor (TNF) inhibitor, and non-TNF inhibitor groups. We performed multinomial logistic regression analyses to identify factors associated with selecting JAKis. RESULTS: 145, 205, and 89 patients were included in the JAKi, TNF inhibitor, and non-TNF inhibitor groups. In multinomial regression analysis, the JAKi group was older than the TNF inhibitor group (OR 1.03, 95% confidence interval [CI] 1.01-1.05) but younger than the non-TNF inhibitor group (OR 0.97, CI 0.95-1.00). The JAKi group was less likely to have chronic pulmonary diseases compared with the TNF inhibitor group (OR 0.07, CI 0.01-0.56) or the non-TNF inhibitor group (OR 0.06, CI 0.01-0.50). Higher disease activity assessed by physician (OR 1.80, CI 1.51-2.38) and previous tacrolimus use (OR 2.05, CI 1.20-3.51) were factors suggesting selection of JAKis than TNF inhibitors. CONCLUSION: Age, pulmonary comorbidities, previous tacrolimus use, and high disease activity assessed by physician were factors influencing the selection of JAKis for RA patients in Korea.

Association between malignancy risk and Janus kinase inhibitors versus tumour necrosis factor inhibitors in Korean patients with rheumatoid arthritis: a nationwide population-based study.

OBJECTIVE: To determine the risk of malignancy in Korean patients with rheumatoid arthritis (RA) receiving Janus kinase inhibitors (JAKis) compared with tumour necrosis factor inhibitors (TNFis). METHODS: A retrospective cohort of patients with RA initiating their first JAKi or TNFi was established using the Korean National Health Insurance database between 2015 and 2019. They were followed up from treatment initiation to the occurrence of malignancy, drug discontinuation, death or until December 2019. Baseline features of the patients were balanced through inverse probability of treatment weighting (IPTW) using a propensity score. A Cox proportional hazard model was established to estimate the HR for malignancy risk in JAKi users compared with TNFi users. RESULTS: A total of 4929 patients (1064 JAKi-treated and 3865 TNFi-treated patients) were included, and the observation periods were 1288.6 person-years (PYs) for JAKi users and 6823.8 PYs for TNFi users. The incidence rates of overall malignancy were 0.54 per 100 PYs (95% CI 0.26 to 1.14) in JAKi users and 0.85 per 100 PYs (95% CI 0.66 to 1.10) in TNFi users. In IPTW analysis with a balanced sample (4101 JAKi-treated and 5131 TNFi-treated patients), HR was 0.83 (95% CI 0.55 to 1.27) for overall malignancy: 0.77 (95% CI 0.50 to 1.19) for solid malignancy and 2.86 (95% CI 0.41 to 20.00) for haematological malignancy. CONCLUSION: Malignancy risk in Korean patients with RA was not increased with JAKi use compared with TNFi use.

Uptake of Biosimilars and Its Economic Implication for the Treatment of Patients with Rheumatoid Arthritis in Korea.

BACKGROUND: We aimed to examine the uptake of infliximab and etanercept biosimilars in patients with rheumatoid arthritis (RA) and its economic implication for healthcare expenditure. METHODS: Using Korean Health Insurance Review and Assessment Service National Patient Samples, we extracted RA patients who used biologic disease modifying anti-rheumatic drugs (bDMARDs) between 2009 and 2018. Descriptive statistics were used to explain the basic features of the data. We calculated the proportion of users of each bDMARD among total patients with bDMARDs half-yearly. We assessed changes in the utilization proportions of bDMARDs including 4 tumor necrosis factor inhibitors (TNFis) and 2 non-TNFis, which have been approved for RA in Korea: etanercept, infliximab, adalimumab, golimumab, tocilizumab, and abatacept, and analyzed the changes in market share of biosimilars among the bDMARDs after their introduction. Overall trends of medical costs for each bDMARD were presented over the 10-year period. RESULTS: Since the introduction of the biosimilar TNFis in 2012, the proportion of their use among bDMARDs steadily increased to 15.8% in 2018. While there has been a gradual increase in the use of biosimilar TNFis, the use of the corresponding originators has been decreasing. The introduction of biosimilar TNFis has resulted in a decrease in the medical costs of patients using either originator or biosimilar TNFis. CONCLUSION: In Korea, the proportional use of biosimilar TNFis has gradually increased since their introduction. The availability of less expensive biosimilar TNFis seems to have brought about a decrease in the medical costs of users of the originators.

Risk of Tuberculosis Development in Patients with Rheumatoid Arthritis Receiving Targeted Therapy: a Prospective Single Center Cohort Study.

BACKGROUND: Patients with rheumatoid arthritis (RA) undergoing targeted therapy have a higher risk of developing tuberculosis (TB). This requires diagnosis and treatment of latent tuberculosis infection (LTBI). We aimed to evaluate whether diagnosis and treatment of LTBI in RA are effective in Korea, and to estimate the risk of TB development by calculating the incidence rate of active TB among RA patients receiving targeted therapy. METHODS: We analyzed data from two prospective cohort studies of RA patients who received biologic disease-modifying antirheumatic drugs (bDMARDs) or Janus kinase (JAK) inhibitor. We selected new starters of targeted therapy and classified them into three groups receiving tumor necrosis factor (TNF) inhibitor, non-TNF inhibitor, and JAK inhibitor, respectively. We then compared LTBI prevalence, treatments, and active TB incidence during first-line therapy in each group. RESULTS: A total of 765 RA patients (574 TNF inhibitor users, 132 non-TNF inhibitor users, and 59 JAK inhibitor users) were included in this study. Observation periods were 1,255.2 person-years (PYs), 264.7 PYs, and 53.3 PYs, respectively. All 765 patients underwent LTBI screening, and the positivity rate was 26.5% (n = 203). Of the 203 LTBI-positive patients, 189 (93.1%) received treatment. Only one patient, who was in the TNF inhibitor group, and was negative for the interferon gamma release assay (IGRA), did not receive LTBI treatment and developed active TB during follow-up. CONCLUSION: Although the prevalence of LTBI in RA patients who started targeted therapy was slightly elevated, the Korean guidelines specifying LTBI screening and treatment were effective in preventing latent TB from becoming active.

Excess mortality persists in patients with rheumatoid arthritis.

OBJECTIVES: To investigate the causes and risk of death in a large cohort of Korean patients with rheumatoid arthritis (RA). METHODS: Patients in the Hanyang BAE (Bae registry of Autoimmune diseases for Epidemiology) RA cohort who fulfilled the American College of Rheumatology criteria were analyzed. A total of 2355 patients were enrolled from October 2001 to December 2015. Mortality data were derived by linking with data from the Korean National Statistical Office. Standardized mortality ratio was estimated by dividing observed deaths by expected number of deaths in the general population. RESULTS: Over the observation period, 225 deaths were reported. Total age- and sex-adjusted standardized mortality ratio was 1.65 (95% confidence interval 1.44-1.87). The most common cause of death was malignancy (40 cases; 17.8%), followed by respiratory disease (38 cases; 16.9%) and cardiovascular disease (32 cases; 14.2%). Mortality rate and causes of death differed according to year and age of RA onset. Compared with survivors, individuals who died were more likely to be male, smokers, diagnosed with RA at an older age, and to have long disease duration, higher erythrocyte sedimentation rate and C-reactive protein, higher rheumatoid factor positivity rate, more severe radiographic damage, and more comorbidities. CONCLUSION: The mortality rate of patients with RA remains higher than that of the general population. Therefore, to improve the survival of patients with RA, attention should be paid to the management of comorbidities as well as to the RA itself.

Clinical and Genetic Risk Factors Associated With the Presence of Lupus Nephritis.

Objective: To elucidate whether clinical features and the weighted genetic risk score (wGRS) were associated with the presence of lupus nephritis (LN). Methods: We retrospectively divided patients with systemic lupus erythematosus (SLE, n=1,078) into biopsy-proven LN (n=507) and non-LN groups (non-LN, n=571) Baseline clinical features, serologic markers, and the wGRS were collected The wGRS was calculated from 112 non-human leukocyte antigen (non-HLA) loci and HLA-DRß1 amino acid haplotypes for SLE Associations among clinical features, wGRS, and the presence of LN were identified. Results: In the multivariate analysis, patients with LN were younger at diagnosis (odds ratio [OR]=0.97, p<0.001), had more pleuritis (OR=2.44, p<0.001) and pericarditis (OR=1.62, p=0.029), had a higher detection rate of anti-double stranded deoxyribonucleic acid (anti-dsDNA antibodies, OR=2.22, p<0.001), anti-Smith antibodies (anti-Sm antibodies, OR=1.70, p=0.002), low level of complement (OR=1.37, p=0.043) and absence of antiphospholipid antibodies (aPL antibodies, OR=1.60, p=0.002), and had higher wGRS (OR=1.16, p=0.012) Mediation analysis suggested that anti-Sm antibodies and low complement could be mediators in the relationship between high wGRS and the presence of LN. Conclusion: Onset age, pleuritis, pericarditis, several serologic markers, and wGRS were associated with the presence of LN Anti-Sm antibodies and low complement appeared to mediate the indirect relationship between wGRS and the presence of LN.