Risk factors for herpes zoster in Korean patients with rheumatoid arthritis treated with JAK inhibitor: a nested case-control study

Systematic Literature Review of Real-World Evidence on Baricitinib for the Treatment of Rheumatoid Arthritis

INTRODUCTION

Baricitinib, an orally available small-molecule inhibitor of Janus kinase (JAK)1 and JAK2, is indicated to treat active moderate-to-severe rheumatoid arthritis (RA).

OBJECTIVE

This systematic review described the real-world clinical characteristics of baricitinib-treated patients with RA, prescription patterns, effectiveness, drug persistence, patient-reported outcomes (PROs; physical function, pain, health-related quality of life [HRQoL]), patient global assessment (PGA), and safety of baricitinib.

METHODS

A PRISMA systematic review of real-world studies was conducted to identify relevant literature published between January 2016 and September 2022 using MEDLINE®, EMBASE®, and evidence-based medicine review databases. Websites or online repositories of the American College of Rheumatology and the European Alliance of Associations for Rheumatology were searched manually to include relevant abstracts from conferences held between January 2016 and November 2022.

RESULTS

A total of 11,472 records were identified by searching online databases. Seventy studies were included in the study, of which 40 were abstracts. Most patients were older (51-71 years), female, and with mean RA duration of 4-19 years. Baricitinib was mostly used after the failure of one or more bDMARDs, and 4 mg dosing was prevalent in patients with RA (range 22-100%). Clinical effectiveness of baricitinib was reported in real-world settings regardless of prior biologic/targeted synthetic disease-modifying antirheumatic drug (DMARD) use and concomitant conventional synthetic DMARD use. Achievement of Clinical Disease Activity Index (CDAI) remission was reported in 8.7-60% of patients at week 12 and CDAI low disease activity (LDA) in 20.2-81.6% at week 24. The proportion of patients attaining Simple Disease Activity Index (SDAI) remission was reported in 12% at week 4 to 45.4% at 24 weeks. Drug persistence was high, similar, or equal to anti-tumor necrosis factor drugs. No new safety signals were identified.

CONCLUSION

Baricitinib demonstrated effectiveness in the real-world setting with a consistent safety profile observed in clinical studies. Better persistence rates for baricitinib compared to bDMARDs with improvement in PROs were reported, although baricitinib-treated patients had RA with poor prognostic characteristics.

Burden of Herpes Zoster in Individuals with Immunocompromised Conditions and Autoimmune Diseases in the Republic of Korea: A Nationwide Population-Based Database Study

INTRODUCTION

To estimate herpes zoster (HZ) incidence rate (IR) and economic burden in individuals with immunocompromised conditions and autoimmune diseases (IC/AID) in the Republic of Korea (ROK).

METHODS

The nationwide Health Insurance Review and Assessment Service database was used to identify HZ cases from 2016 to 2020 in ROK. HZ and non-HZ IC/AID cases were matched 1:3 using age, sex, institution, Charlson comorbidity index, IC/AID, and index date. Annual HZ IRs/1000 persons and 1-year HZ-associated all-cause direct medical costs for IC/AID cases were calculated.

RESULTS

Among 65,976 individuals with IC/AID (mean age 57.14 years [standard deviation 14.1]; 64.94% female), annual HZ IR (95% confidence interval) fluctuated from 2016 to 2020, averaging 23.41/1000 persons (22.21-24.62) and was higher in women (26.85 [25.40-28.31]) than men (18.96 [18.03-19.89]). IRs were highest in individuals aged ≥ 50 years, and in those with transplants (including solid organ and hematopoietic stem cell transplants; 37.12 [35.45-38.79]) and hemato-oncology conditions (35.5 [31.6-39.3]). Mean 12-month all-cause direct medical costs were higher in individuals with IC/AID and HZ (4,759,671 Korean Republic won [KRW]; approximately 4046 United States dollar [USD; according to the 2020 conversion rate from UNCTAD; 1 KRW = 0.00085 USD]) than those without HZ (3,786,658 KRW; 3219 USD).

CONCLUSION

Individuals with IC/AID have a substantial disease and economic burden from HZ in ROK, highlighting the need for appropriate HZ prevention measures in the IC/AID population.

The Emerging Safety Profile of JAK Inhibitors in Rheumatic Diseases

Janus kinase inhibitor (JAKi) medications are small-molecule drugs that affect intracellular signal transduction. They are highly effective oral medications that have been approved for the treatment of various rheumatic diseases, with rheumatoid arthritis being a key example of an autoimmune rheumatic disease. JAKi are oral-route medications that are alternatives to injectable biologic therapies, launched in the late 1990s. While most safety concerns with JAKi are similar to the biologics, there are many differences. New data on comparative safety of JAKi versus tumor necrosis factor inhibitors (TNFi) were recently published that led to new black box warnings by the US Food and Drug Administration (FDA) about cardiovascular and cancer risks and a label change for JAKi. This review summarizes the current published data with regards to the safety of JAKi, focused on rheumatic diseases. Specifically, any risk differences between agents or across different indications are discussed, as well as the risk factors for these adverse outcomes.

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.

Herpes zoster in patients with inflammatory arthritides or ulcerative colitis treated with tofacitinib, baricitinib or upadacitinib: a systematic review of clinical trials and real-world studies

JAK inhibitors (JAKi) are new targeted-synthetic drugs, approved for various immune-mediated inflammatory diseases (IMIDs), including inflammatory arthritides (rheumatoid arthritis-RA, psoriatic arthritis-PsA, ankylosing spondylitis-AS) and ulcerative colitis (UC). JAKi have been associated with increased risk for herpes zoster (HZ), but the relative risk among different JAKi in these IMIDs remains unclear. We aimed to systematically review the incidence of HZ among RA, PsA, AS and UC patients treated with the approved doses of tofacitinib (TOFA), baricitinib (BARI) or upadacitinib (UPA). PubMed, Embase, Scopus, Cochrane and Web-of-Science were searched up to 30 March 2022. Clinical trials and real-world studies (RWS) were included. Outcomes assessed were the incidence rate (/100 patient-years) or/and cumulative incidence of HZ. From 1710 records, 53 clinical trials and 25 RWS were included (RA: 54, PsA: 8, AS: 4, and UC: 12). In clinical trials, the HZ-incidence was higher in TOFA-treated patients with RA (2.2-7.1/100 patient-years) or UC (1.3-7.6/100 patient-years) compared to PsA (1.7/100 patient-years), and with higher doses of TOFA in UC (10 mg/twice daily: 3.2-7.6/100 patient-years vs. 5 mg/twice daily: 1.3-2.3/100 patient-years). Evidence for HZ-risk in JAKi-treated patients with AS and in UPA-treated patients was limited. The HZ-incidence between TOFA and BARI groups in 2 RA RWS did not differ significantly. Concomitant glucocorticoid, but not methotrexate, use in RA increased the HZ-risk. This systematic review showed higher HZ-risk in RA or UC than PsA patients treated with TOFA, in those treated with higher TOFA doses or with concomitant glucocorticoids. Preventive measures and monitoring of JAKi-treated patients with IMIDs are essential in daily practice.

Randomized, double-blinded, placebo-controlled phase I study of the pharmacokinetics, pharmacodynamics, and safety of KL130008, a novel oral JAK inhibitor, in healthy subjects

BACKGROUND AND OBJECTIVES

KL130008 is a novel selective inhibitor of Janus kinase (JAK) 1/2 that may have therapeutic benefit against rheumatoid arthritis (RA) and other autoimmune diseases. Here, we developed a first-in-human trial of KL130008 to evaluate its pharmacokinetics (PK), pharmacodynamics (PD), and safety in healthy subjects.

METHODS

Randomized, double-blinded, placebo-controlled phase I study was designed. Healthy Chinese subjects received KL130008 in single-ascending doses (1-20 mg) or multiple-ascending doses (2-6 mg) once daily for seven days, and data on PK, PD, and safety data including QT interval were evaluated.

RESULTS

A total of 79 subjects were enrolled, of whom 77 completed the study. After oral administration following at least a 10-h fast, KL130008 was rapidly absorbed and reached a maximum concentration (C_max) in 0.6-1.5 h. KL130008 exposure was approximately linear and dose-proportional. The drug showed exponential elimination with t_1/2 = 14-18 h, and 8-20% of KL130008 was excreted in the urine. Dose-dependent inhibition of the phosphorylated signal transduction and transcriptional activator 3 (p-STAT3) was observed in subjects who received single KL130008 doses of 4-20 mg, while multiple dosing of KL130008 at 2, 4, or 6 mg once daily for seven consecutive days sustainably inhibited p-STAT3. The rates of treatment-emergent adverse events were 88.7% with KL130008 and 81.3% with placebo. All such events were grade 1 or 2 and disappeared or resolved by the end of the study. The most frequent such events were a decrease in neutrophil percentage, which occurred in 30.6% of subjects on KL130008; a decrease in neutrophil count, which occurred in 29.0% of subjects on KL130008; and an increase in lymphocyte percentage, which occurred in 25.8% of subjects on KL130008. None of these three events occurred while subjects were on placebo.

CONCLUSION

Our results support that KL130008 is a safe and well-tolerated oral JAK1/2 inhibitor. The present study may help optimize the KL130008 dosing regimen for a phase II study.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR1800018743 (chictr.org); registered on October 7, 2018.