Peficitinib for the treatment of rheumatoid arthritis: an overview from clinical trials

Safety and effectiveness of peficitinib 100 mg/day in patients achieving clinical remission from a long-term open-label extension study in Japan, Korea, and Taiwan (RAJ2)

OBJECTIVES

This post hoc analysis of the RAJ2 study assessed long-term safety and effectiveness of peficitinib 100 mg/day for treatment of rheumatoid arthritis.

METHODS

Eligible patients previously completed two Phase 3 (RAJ3 and RAJ4) studies of peficitinib in Asia. All patients received peficitinib 100 mg/day at RAJ2 Week (W)0; dose change to 50 mg/day or 150 mg/day was permitted. Safety endpoints included treatment-emergent adverse events and laboratory test results. Effectiveness endpoints included peficitinib exposure pattern, achievement of Clinical Disease Activity Index (CDAI) remission by peficitinib exposure pattern at W0 and W48, and association of demographics/characteristics with CDAI remission at W0 and W48.

RESULTS

Overall, no new safety findings were reported at W48, and renal function was unaffected. Of patients included in effectiveness analyses at W48, 70.9% (451/636) had maintained peficitinib 100 mg/day since W0. Of patients who achieved CDAI remission at W0 and maintained peficitinib 100 mg/day to W48, 50.3% (79/157) maintained CDAI remission to W48. Low disease activity and a lower number of prior disease-modifying antirheumatic drugs were significantly associated with CDAI remission at W48.

CONCLUSIONS

Long-term peficitinib treatment at a dose of 100 mg/day was generally well tolerated and, following induction therapy, maintained effectiveness through to W48.

JAK Inhibitors in Rheumatoid Arthritis: Immunomodulatory Properties and Clinical Efficacy

Rheumatoid arthritis (RA) is a highly prevalent autoimmune disorder. The pathogenesis of the disease is complex and involves various cellular populations, including fibroblast-like synoviocytes, macrophages, and T cells, among others. Identification of signalling pathways and molecules that actively contribute to the development of the disease is crucial to understanding the mechanisms involved in the chronic inflammatory environment present in affected joints. Recent studies have demonstrated that the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway regulates the behaviour of immune cells and contributes to the progression of RA. Several JAK inhibitors, such as tofacitinib, baricitinib, upadacitinib, and filgocitinib, have been developed, and their efficacy and safety in patients with RA have been comprehensively investigated in a number of clinical trials. Consequently, JAK inhibitors have been approved and registered as a treatment for patients with RA. In this review, we discuss the involvement of JAK/STAT signalling in the pathogenesis of RA and summarise the potential beneficial effects of JAK inhibitors in cells implicated in the pathogenesis of the disease. Moreover, we present the most important phase 3 clinical trials that evaluated the use of these agents in patients.

Pharmacokinetic review of janus kinase inhibitors and its clinical implications for the management of rheumatoid arthritis

INTRODUCTION

In the realm of autoimmune rheumatic diseases, understanding JAK inhibitors (JAKi) nuances is vital. Baricitinib, tofacitinib, upaacitinib, filgotinib, and peficitinib exhibit subtle yet impactful pharmacokinetic (PK) and pharmacodynamic (PD) variations.

AREAS COVERED

This narrative review critically assesses PK and PD distinctions among globally approved JAKi for rheumatoid arthritis, which primarily guide clinical decisions in autoimmune diseases, particularly rheumatoid arthritis. It explores the intricate JAK-STAT signaling pathway, offering insights into JAKs' roles in inflammation, hematopoiesis, and immune homeostasis. Emphasis on PK parameters, including absorption, distribution, metabolism, and excretion, along with CYP3A4 drug interactions, is highlighted. The review underscores integrating PK and PD properties, considering patient-specific factors like hepatic and renal clearance, for judicious JAKi selection in RA and related autoimmune conditions. The literature has been collected from all available databases based on the review question.

EXPERT OPINION

Integrating PK and PD properties with patient-specific factors is pivotal for judicious JAKi selection. Recognizing disparities in PK and PD across diseases, ethnicities, and environmental factors is crucial for personalized JAKi choices. This expert opinion underscores the significance of a second compartment analysis, elucidating the interplay between PK and PD and its impact on JAKi efficacy.

Discovery of selective TYK2 inhibitors: Design, synthesis, in vitro and in silico studies of promising hits with triazolopyrimidinone scaffold

The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway mediates many cytokine and growth factor signals. Tyrosine kinase 2 (TYK2), one of the members of this pathway and the first described member of the JAK family. TYK2 associates with inflammatory and autoimmune diseases, cancer and diabetes. Here, we present novel compounds as selective inhibitors of the canonical kinase domain of TYK2 enzyme. These compounds were rationally designed and synthesized with appropriate reactions. Molecular modeling techniques were used to design and optimize the candidates for TYK2 inhibition and to determine the estimated binding orientations of them inside JAKs. Designed compounds potently inhibited TYK2 with good selectivity against other JAKs as determined by in vitro assays. In order to verify its selectivity properties, compound A8 was tested against 58 human kinases (KinaseProfiler™ assay). The effects of the selected seven compounds on the protein levels of members of the JAK/STAT family were also detected in THP-1 monocytes although the basal level of these proteins is poorly detectable. Therefore, their expression was induced by lipopolysaccharide treatment and compounds A8, A15, A18, and A19 were found to be potent inhibitors of the TYK2 enzyme, (9.7 nM, 6.0 nM, 5.0 nM and 10.3 nM, respectively), and have high selectivity index for the JAK1, JAK2, and JAK3 enzymes. These findings suggest that triazolo[1,5-a]pyrimidinone derivatives may be lead compounds for developing potent TYK2-selective inhibitors targeting enzymes' active site.

FDA-Approved Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) Inhibitors for Managing Rheumatoid Arthritis: A Narrative Review of the Literature

Rheumatoid arthritis (RA) is a complex autoimmune disease causing chronic joint inflammation and, in more serious cases, organ involvement. RA typically affects people between the ages of 35 and 60; however, it can also afflict children younger than the age of 16 years and can also demonstrate a pattern of remission later in the disease course. Non-steroidal anti-inflammatory drugs, glucocorticoids, exercise, and patient education are all used in the management of RA, which is divided into symptomatic management and disease-modifying management (disease-modifying antirheumatic drugs) to reduce pain and inflammation, thereby preserving joint function. Janus kinase inhibitors (JAKis) have led to a substantial improvement in the management of RA. By specifically targeting the JAK-signal transducer and activator of transcription pathway, which is essential for immunological modulation, these inhibitors also demonstrate promise in treating various autoimmune illnesses, including inflammatory bowel diseases, giant cell arteritis, ankylosing spondylitis, and psoriatic arthritis. Tofacitinib, baricitinib, upadacitinib, peficitinib, delgocitinib, and filgotinib are examples of FDA-approved JAKis that have distinct properties and indications for treating a range of autoimmune illnesses. JAKis demonstrate a promising treatment approach for managing RA and other autoimmune diseases while enhancing patient outcomes and quality of life. However, due to major safety concerns and the need for long-term success, meticulous patient monitoring is essential.

Post hoc analysis of patients with rheumatoid arthritis under clinical remission in two Japanese Phase 3 trials of peficitinib treatment (RAJ3 and RAJ4)

OBJECTIVE

We evaluated remission rates and their relationship with baseline characteristics in patients with rheumatoid arthritis treated with the oral Janus kinase inhibitor peficitinib.

METHODS

This post hoc analysis of data from two Phase 3 studies (RAJ3 and RAJ4) of peficitinib (100 and 150 mg/day) in Asian rheumatoid arthritis patients investigated clinical disease activity index (CDAI) remission and low disease activity rates from baseline to Week 52. CDAI, Health Assessment Questionnaire-Disability Index, and van der Heijde-modified total Sharp score remission/low disease activity rates at Week 52 were evaluated among patients achieving CDAI remission at Weeks 12/28. Logistic regression analyses explored the relationship between baseline characteristics and CDAI remission/low disease activity rates.

RESULTS

CDAI remission rates increased over time in a dose-dependent manner in both peficitinib-treated groups. Most patients achieving CDAI remission at Weeks 12/28 also achieved remission at Week 52. Following the multivariate analysis of demographic and baseline characteristics, factors associated with the achievement of CDAI remission at Week 28 included male sex, low baseline prednisone dose (RAJ3 only), and low baseline Disease Activity Score 28-C-reactive protein (RAJ4 only).

CONCLUSIONS

Peficitinib demonstrated persistent efficacy in clinical remission to Week 52. Baseline characteristics associated with CDAI remission were mostly consistent with previous studies using other disease-modifying antirheumatic drugs.

Differential properties of Janus kinase inhibitors in the treatment of immune-mediated inflammatory diseases

Janus kinases (JAKs) are a family of cytosolic tyrosine kinases that regulate cytokine signal transduction, including cytokines involved in a range of inflammatory diseases, such as RA, psoriasis, atopic dermatitis and IBD. Several small-molecule JAK inhibitors (JAKis) are now approved for the treatment of various immune-mediated inflammatory diseases. There are, however, key differences between these agents that could potentially translate into unique clinical profiles. Each JAKi has a unique chemical structure, resulting in a distinctive mode of binding within the catalytic cleft of the target JAK, and giving rise to distinct pharmacological characteristics. In addition, the available agents have differing selectivity for JAK isoforms, as well as off-target effects against non-JAKs. Other differences include effects on haematological parameters, DNA damage repair, reproductive toxicity and metabolism/elimination. Here we review the pharmacological profiles of the JAKis abrocitinib, baricitinib, filgotinib, peficitinib, tofacitinib and upadacitinib.

Safety and efficacy of peficitinib in Asian patients with rheumatoid arthritis who had an inadequate response or intolerance to methotrexate: results of a multicenter, randomized, double-blind, placebo-controlled phase 3 study

Background

The efficacy and safety of the oral Janus kinase inhibitor peficitinib were investigated in Asian patients with rheumatoid arthritis (RA).

Methods

In this double-blind, phase 3 study, patients from mainland China, Korea, and Taiwan with RA and an inadequate response/intolerance to methotrexate were randomized (1:1:1) to once-daily placebo (N = 128), peficitinib 100 mg (N = 129), or 150 mg (N = 128) in combination with non-biologic DMARDs. At Week 24, patients receiving placebo switched to peficitinib 100 mg or 150 mg. American College of Rheumatology (ACR) 20 response at Week 24/early termination (ET) was the primary endpoint. Adverse events (AEs) were assessed. The study was registered at ClinicalTrials (NCT03660059).

Findings

385 patients were included in the analysis. ACR20 responses were statistically significantly higher in both peficitinib 100 mg (56.6%) and 150 mg (56.3%) groups versus placebo (24.2%); Odds Ratio (95% confidence interval, CI) 4.14 (2.42, 7.08) and 4.07 (2.38, 6.96), respectively (both P < 0.001) at Week 24/ET. The incidence rate of herpes zoster related disease (herpes zoster and varicella) was higher in patients who received peficitinib versus placebo, but no dose dependency was observed (incidence rate/100 patient-years (95% CI): peficitinib 6.7 (4.32, 10.37); placebo 3.7 (0.93, 14.88).

Interpretation

In Asian patients with RA and an inadequate response/intolerance to methotrexate, peficitinib 100 mg and 150 mg demonstrated superiority to placebo in the reduction of RA symptoms and was well tolerated. No additional benefit was observed with use of the higher peficitinib dose in this study population of predominantly Chinese patients.

Funding

Astellas Pharma.

The prevalence and impact of polypharmacy in rheumatology

Polypharmacy is increasingly common in rheumatology due to the complex nature of managing chronic autoimmune diseases. To date there has been limited research into the impact of polypharmacy on rheumatology patients. In this article we reviewed the literature to characterize the prevalence of polypharmacy and its effect on patients. In addition, we have highlighted some key drug-drug interactions to consider involving DMARDs as well as complementary and alternative medicines. There is emerging evidence demonstrating that polypharmacy contributes to adverse outcomes and alters treatment response. This association is best described in RA and is less clear in other patient cohorts. It is also unclear whether polypharmacy is directly harmful or just a surrogate marker for other factors affecting outcomes. Rheumatologists should be aware of the risk of polypharmacy as well as specific drug-drug interactions that can occur in managing chronic autoimmune disease.

Signaling pathways in rheumatoid arthritis: implications for targeted therapy

Rheumatoid arthritis (RA) is an incurable systemic autoimmune disease. Disease progression leads to joint deformity and associated loss of function, which significantly impacts the quality of life for sufferers and adds to losses in the labor force. In the past few decades, RA has attracted increased attention from researchers, the abnormal signaling pathways in RA are a very important research field in the diagnosis and treatment of RA, which provides important evidence for understanding this complex disease and developing novel RA-linked intervention targets. The current review intends to provide a comprehensive overview of RA, including a general introduction to the disease, historical events, epidemiology, risk factors, and pathological process, highlight the primary research progress of the disease and various signaling pathways and molecular mechanisms, including genetic factors, epigenetic factors, summarize the most recent developments in identifying novel signaling pathways in RA and new inhibitors for treating RA. therapeutic interventions including approved drugs, clinical drugs, pre-clinical drugs, and cutting-edge therapeutic technologies. These developments will hopefully drive progress in new strategically targeted therapies and hope to provide novel ideas for RA treatment options in the future.

Opportunistic infections associated with Janus kinase inhibitor treatment for rheumatoid arthritis: A structured literature review

BACKGROUND

The availability of Janus kinase (JAK) inhibitors has transformed the management of rheumatoid arthritis (RA), helping patients achieve clinical remission. However, the emergence of opportunistic infections (OIs) associated with the use of JAK inhibitors has been reported. This structured literature review was conducted to summarize reports of OIs associated with JAK inhibitor treatment for RA in clinical trials.

METHODS

Structured searches were performed in MEDLINE® and Embase® to identify relevant clinical trial data through March 2021. Bibliographic searches of recent reviews were also conducted, and gray literature searches were used to supplement key gap areas. Publications were screened, extracted, and quality assessed. Data were narratively synthesized.

RESULTS

Following screening, 105 publications describing 62 unique clinical trials reporting the rates of OIs in RA patients treated with JAK inhibitors were included. Overall, the highest exposure-adjusted incidence rate was reported for herpes zoster (HZ) infection (any form), followed by OI (any) and tuberculosis based on limited data from clinical trials with approved doses of JAK inhibitors. Lack of head-to-head trials and differences in trial design preclude direct comparison across JAK inhibitors. Higher rates of OIs were noted in the Asian and Australian populations compared with the global population. Higher rates of OIs were also noted with increasing dose of JAK inhibitors in most clinical trial data.

CONCLUSIONS

HZ was the most common OI reported among RA patients using all currently approved JAK inhibitors in clinical trials, although tuberculosis and other OIs were also reported. More long-term safety studies in the real-world setting are needed to compare the risk of OIs between various JAK inhibitors.

Post hoc analysis of clinical characteristics of patients with radiographic progression in a Japanese phase 3 trial of peficitinib and methotrexate treatment (RAJ4)

OBJECTIVE

To determine the efficacy of peficitinib in reducing joint damage and predictive factors affecting treatment response in Japanese patients with rheumatoid arthritis.

METHODS

This post hoc analysis used data from a placebo-controlled, phase 3 trial (RAJ4) of peficitinib in patients with rheumatoid arthritis and inadequate response to methotrexate. Erosion and joint space narrowing (JSN) were assessed at baseline and at Week 28/early termination of treatment using the van der Heijde-modified Sharp method. A univariate logistic regression analysis of change from baseline in a modified total Sharp score identified predictive factors with significant treatment interaction; the effects of these factors on treatment response were further evaluated using a multivariate model.

RESULTS

The analyses included 481 patients. For most joint groups, peficitinib demonstrated a reduced change from baseline at Week 28/early termination in erosion and JSN scores versus placebo; a numerically greater effect was observed with peficitinib 150 mg versus 100 mg. Baseline C-reactive protein (CRP) and prednisolone dose were identified as clinically significant negative predictive factors: the treatment effect decreased as CRP or prednisolone dose increased for both peficitinib doses.

CONCLUSIONS

Peficitinib 100 mg and 150 mg reduced joint damage versus placebo, across almost all joint groups. Higher baseline CRP and/or prednisolone dose were associated with reduced peficitinib efficacy.

CLINICALTRIALS.GOV IDENTIFIER

NCT02305849.

Anti-rheumatoid drugs advancements: New insights into the molecular treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is one of more than 100 types of arthritis. This chronic autoimmune disorder affects the lining of synovial joints in about 0.5% of people and may induce severe joints deformity and disability. RA impacts health life of people from all sexes and ages with more prevalence in elderly and women people. Significant improvement has been noted in the last two decades revealing the mechanisms of the development of RA, the improvement of the early diagnosis and the development of new treatment options. Non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying antirheumatic drugs (DMARDs) remain the most known treatments used against RA. However, not all patients respond well to these drugs and therefore, new solutions are of immense need to improve the disease outcomes. In the present review, we discuss and highlight the recent findings concerning the different classes of RA therapies including the conventional and modern drug therapies, as well as the recent emerging options including the phyto-cannabinoid and cell- and RNA-based therapies. A better understanding of their mechanisms and pathways might help find a specific target against inflammation, cartilage damage, and reduce side effects in arthritis.

A Retrospective, Longitudinal Study of Rheumatoid Arthritis Treatment Patterns with Janus Kinase Inhibitors and Other Disease-Modifying Antirheumatic Drugs in Japan

OBJECTIVES

There is limited information on the clinical use of Janus kinase inhibitors (JAKis) for rheumatoid arthritis (RA) treatment in Japan. The aim of this study was to identify disease-modifying antirheumatic drug (DMARD) treatment patterns in Japan.

METHODS

This retrospective, longitudinal study extracted data from the Japan Medical Data Center database. Patients with RA diagnosis were enrolled 2016-2019, during which patients had a first prescription of a major DMARD, split into six mutually exclusive classes: methotrexate (MTX); other conventional synthetic (cs)DMARDs; tumor necrosis factor alpha (TNFα) inhibitors; cytotoxic T-lymphocyte-associated antigen-4-immunoglobulin; anti-interleukin-6 receptor therapies; and JAKis. The primary objective was to describe DMARD treatment patterns, especially for JAKis.

RESULTS

Overall, 10,399 patients were included in the analysis. The most common treatments were MTX, other csDMARDs, and TNFα inhibitors. The total number of JAKi prescriptions increased approximately eight-fold during 2016-2019. Most (61.1%) patients who received JAKis had prior MTX or TNFα inhibitor treatment. JAKi treatment duration was longer than for biologics and other csDMARDs, and comparable to that of MTX.

CONCLUSIONS

The sequence of drug class prescriptions for RA in Japan during 2016-2019 followed clinical guidelines. Over this period, JAKis were increasingly used as second-line treatment following MTX.

A Comprehensive Overview of Globally Approved JAK Inhibitors

Janus kinase (JAK) is a family of cytoplasmic non-receptor tyrosine kinases that includes four members, namely JAK1, JAK2, JAK3, and TYK2. The JAKs transduce cytokine signaling through the JAK-STAT pathway, which regulates the transcription of several genes involved in inflammatory, immune, and cancer conditions. Targeting the JAK family kinases with small-molecule inhibitors has proved to be effective in the treatment of different types of diseases. In the current review, eleven of the JAK inhibitors that received approval for clinical use have been discussed. These drugs are abrocitinib, baricitinib, delgocitinib, fedratinib, filgotinib, oclacitinib, pacritinib, peficitinib, ruxolitinib, tofacitinib, and upadacitinib. The aim of the current review was to provide an integrated overview of the chemical and pharmacological data of the globally approved JAK inhibitors. The synthetic routes of the eleven drugs were described. In addition, their inhibitory activities against different kinases and their pharmacological uses have also been explained. Moreover, their crystal structures with different kinases were summarized, with a primary focus on their binding modes and interactions. The proposed metabolic pathways and metabolites of these drugs were also illustrated. To sum up, the data in the current review could help in the design of new JAK inhibitors with potential therapeutic benefits in inflammatory and autoimmune diseases.

A pooled analysis of serious infections and herpes zoster-related disease in Asian patients with rheumatoid arthritis treated with peficitinib (ASP015K) over a median of 3 years

OBJECTIVE

To analyse serious infection (SI) and herpes zoster-related disease (HZD) during long-term treatment of rheumatoid arthritis with the oral Janus kinase inhibitor, peficitinib (ASP015K).

METHODS

This was a post hoc analysis of pooled data from one Phase 2b study and two Phase 3 studies and final data from a long-term extension study of peficitinib in Asian rheumatoid arthritis patients. Two pooled datasets were analysed (Phase 3 studies and Phase 2/3 studies). Univariate and multivariate Cox regression analyses explored relationships between exposure-adjusted incidence rate of SI and HZD, peficitinib dose, and baseline factors.

RESULTS

Total peficitinib exposure for 1052 patients receiving once-daily peficitinib in the pooled Phase 2/3 Asian studies was 2998.9 patient-years. Exposure-adjusted incidence rates (95% confidence interval) of SI and HZD were 2.7 (2.2, 3.4) and 6.9 (6.0, 8.0) per 100 patient-years, respectively, in pooled Phase 2/3 studies. Advanced age was prognostic for SI and HZD, while baseline prednisolone dose was prognostic for SI. There was no temporal relationship between either adverse event and prolonged peficitinib administration.

CONCLUSIONS

As expected in this peficitinib-treated population, older patients had increased risk of SI and HZD, and those receiving higher prednisolone doses had increased risk of SI.

Impact of age on the efficacy and safety of peficitinib (ASP015K) for the treatment of rheumatoid arthritis

OBJECTIVES

To evaluate peficitinib efficacy and safety in Asian patients with rheumatoid arthritis (RA), stratified by age (≥20-<50, ≥50-<65, and ≥65 years).

METHODS

Efficacy data from two Phase 3 studies were analysed. Safety data from one Phase 2, two Phase 3, and one open-label extension study were pooled. Incidence rates per 100 patient-years of adverse events of special interest were calculated, and Cox proportional hazard analysis was conducted.

RESULTS

1052 patients received peficitinib for 2 years (median). Peficitinib demonstrated efficacy improvements versus placebo across all age categories. Incidence rates (95% confidence interval) per 100 patient-years for ≥20-<50, ≥50-<65, and ≥65 years were 0.8 (0.4, 1.9), 2.6 (1.8, 3.7), and 4.7 (3.1, 7.0) for serious infections and 3.7 (2.5, 5.4), 6.4 (5.0, 8.2), and 11.2 (8.5, 14.7) for herpes zoster-related disease, respectively. Twenty patients reported malignancies in pooled Phase 2/3 studies. Incidences of serious infections and herpes zoster-related disease increased significantly with age, but there was no association with baseline estimated glomerular filtration rate.

CONCLUSIONS

Peficitinib was efficacious in adult Asian RA patients of all ages. Age, but not estimated glomerular filtration rate, was associated with serious infections and herpes zoster-related disease, demonstrating the importance of an appropriate RA treatment strategy in older patients.

Patient- and physician-reported outcomes from two phase 3 randomized studies (RAJ3 and RAJ4) of peficitinib (ASP015K) in Asian patients with rheumatoid arthritis

BACKGROUND

Peficitinib (ASP015K), a novel oral Janus kinase inhibitor, has demonstrated efficacy and safety in the treatment of patients with rheumatoid arthritis (RA). This study evaluated the effect of peficitinib on patient- and physician-reported outcomes in Asian patients with RA and an inadequate response to prior disease-modifying antirheumatic drugs (DMARDs).

METHODS

Patients from two randomized, placebo-controlled, double-blind, phase 3 trials (RAJ3 and RAJ4) received once-daily peficitinib 100 mg, peficitinib 150 mg, or placebo, alone or in combination with DMARDs (RAJ3), or in combination with methotrexate (RAJ4). Mean changes in Work Productivity and Activity Impairment (WPAI) questionnaire domain scores from baseline, and percentages of patients achieving minimal clinically important differences (MCIDs) for patient- and physician-reported outcomes (WPAI, Health Assessment Questionnaire - Disability Index [HAQ-DI], and Subject's Global Assessment of Pain [SGAP]), and Physician's Global Assessment of disease activity (PGA) were evaluated at weeks 4, 8, 12, and 12/early termination (ET).

RESULTS

Data from 1025 patients were analyzed. At week 12/ET in both studies, patients who received peficitinib 100 mg or 150 mg reported significantly improved WPAI domain scores from baseline (except for absenteeism in RAJ4) compared with placebo (both doses, p<0.05). A higher proportion of peficitinib- versus placebo-treated patients achieved MCID in WPAI, HAQ-DI, SGAP, and PGA in studies RAJ3 and RAJ4. Significant differences with peficitinib versus placebo were evident in both studies as early as week 4 in HAQ-DI (peficitinib 150 mg only), SGAP, and PGA, and week 8 in WPAI loss of work productivity and daily activity impairment. At week 12/ET, significantly higher proportions of patients receiving peficitinib versus placebo achieved MCID in HAQ-DI, SGAP, PGA, and WPAI domains of presenteeism (RAJ3 only), loss of work productivity (RAJ3 only), and daily activity impairment (p<0.05 for all comparisons).

CONCLUSIONS

Peficitinib 100 mg or 150 mg administered daily over 12 weeks resulted in clinically meaningful improvements in outcomes that are important to RA patients, including pain, physical function, and work productivity and activity. These observations were reinforced through similar improvements in physicians' rating of disease activity.

TRIAL REGISTRATION

RAJ3: ClinicalTrials.gov, NCT02308163 , registered 4 December 2014. RAJ4: ClinicalTrials.gov, NCT02305849 , registered 3 December 2014.

Impact of Different JAK Inhibitors and Methotrexate on Lymphocyte Proliferation and DNA Damage

Janus kinase inhibitors (JAKis) represent a new strategy in rheumatoid arthritis (RA) therapy. Still, data directly comparing different JAKis are rare. In the present in vitro study, we investigated the immunomodulatory potential of four JAKis (tofacitinib, baricitinib, upadacitinib, and filgotinib) currently approved for RA treatment by the European Medicines Agency. Increasing concentrations of JAKi or methotrexate, conventionally used in RA therapy, were either added to freshly mitogen-stimulated or preactivated peripheral blood mononuclear cells (PBMC), isolated from healthy volunteers. A comparable, dose-dependent inhibition of lymphocyte proliferation was observed in samples treated with tofacitinib, baricitinib, and upadacitinib, while dosage of filgotinib had to be two orders of magnitude higher. In contrast, antiproliferative effects were strongly attenuated when JAKi were added to preactivated PBMCs. High dosage of upadacitinib and filgotinib also affected cell viability. Further, analyses of DNA double-strand break markers γH2AX and 53BP1 indicated an enhanced level of DNA damage in cells incubated with high concentrations of filgotinib and a dose-dependent reduction in clearance of radiation-induced γH2AX foci in the presence of tofacitinib or baricitinib. Thereby, our study demonstrated a broad comparability of immunomodulatory effects induced by different JAKi and provided first indications, that (pan)JAKi may impair DNA damage repair in irradiated PBMCs.

Comparative Efficacy and Safety of Peficitinib Versus Tofacitinib and Baricitinib for Treatment of Rheumatoid Arthritis: A Systematic Review and Network Meta-Analysis

INTRODUCTION

Peficitinib, a Janus kinase (JAK) inhibitor, is approved for clinical use in Japan, Korea, and Taiwan, but head-to-head comparisons versus other JAK inhibitors are lacking. We indirectly compared peficitinib, tofacitinib, and baricitinib for rheumatoid arthritis treatment.

METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and congress archives up until February 12, 2019, for randomized controlled trials of peficitinib, tofacitinib, and baricitinib. Efficacy (American College of Rheumatology responses, disease activity scores, modified total Sharp score, Simplified Disease Activity Index [SDAI]) and safety outcomes were compared using a Bayesian network meta-analysis. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) consensus was followed for reporting results. A network meta-regression assessed the impact on outcomes of proportions of patients receiving concomitant methotrexate or of Asian ethnicity.

RESULTS

The network meta-analysis included 21 randomized controlled trials. At 12 weeks, all evaluable efficacy outcomes were comparable or improved with peficitinib 150 mg and 100 mg once daily, versus baricitinib 2 and 4 mg once daily and tofacitinib 5 mg twice daily. At 24 weeks, efficacy outcomes were comparable or improved for each peficitinib dose versus baricitinib and tofacitinib. Risk of adverse events and serious adverse events at 12 weeks were similar with peficitinib 100 and 150 mg versus baricitinib and tofacitinib. The proportion of patients receiving concomitant methotrexate had no effect on any outcome analyzed, but Asian ethnicity had a positive effect on multiple efficacy outcomes.

CONCLUSIONS

Peficitinib had comparable efficacy versus tofacitinib and baricitinib for reduction in disease activity as measured by SDAI, and for reduction in progression of joint damage as measured radiographically. No notable differences in safety outcomes were observed. Further studies are required to better characterize the impact of ethnicity on the efficacy of JAK inhibitors.

Safety and Effectiveness of Peficitinib (ASP015K) in Patients with Rheumatoid Arthritis: Final Results (32 Months of Mean Peficitinib Treatment) From a Long-Term, Open-Label Extension Study in Japan, Korea, and Taiwan

INTRODUCTION

This final analysis of a long-term extension (LTE) study assessed the safety, tolerability, and effectiveness of peficitinib (ASP015K), a pan-Janus kinase inhibitor, in Asian patients with rheumatoid arthritis (RA).

METHODS

Patients had previously completed the 12-week phase 2b (RAJ1), or 52-week phase 3 (RAJ3 and RAJ4) peficitinib studies in Japan, Korea, and Taiwan, and received oral peficitinib 50 or 100 mg/day. Dose increase to 150 mg/day or reduction to 50 mg/day was permitted. Efficacy endpoints included American College of Rheumatology (ACR)20/50/70 response rates, 28-joint Disease Activity Score with C-reactive protein (DAS28-CRP), and ACR components. Safety endpoints included treatment-emergent adverse events (TEAEs), and incidence rates (IRs) of adverse events of special interest per 100 patient-years (PY).

RESULTS

Overall, 843 patients received peficitinib for a mean 32.0 months (maximum 85.2 months), and most (64.4%) received peficitinib 100 mg/day as a maximum dose. Respective ACR20/50/70 response rates were maintained from baseline (week 0 of LTE; 71.6, 52.1, and 34.7%) to end of treatment (78.7, 63.3, and 44.1%); continuous improvements in ACR components and DAS28-CRP were observed from the baselines of preceding studies and throughout the LTE. Overall, 796/843 (94.4%) patients experienced TEAEs; most were severity grade 1/2. Most common TEAEs were nasopharyngitis (47.0%) and herpes zoster (17.3%). Drug-related TEAEs leading to permanent discontinuation occurred in 140 (16.6%) patients, and IRs (95% confidence interval) per 100 PY of serious infections, herpes zoster-related disease, and malignancies were 2.7 (2.1, 3.4), 7.3 (6.2, 8.6), and 1.2 (0.9, 1.8), respectively. Two deaths occurred during the study; one each from diffuse large B cell lymphoma and pneumonia, which were, respectively considered probably and possibly related to study drug.

CONCLUSIONS

Improvements in effectiveness variables were maintained during this long-term study of peficitinib in Asian patients with RA; peficitinib was generally well tolerated over a mean 32 months' duration.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT01638013, retrospectively registered on 11 July 2012 https://clinicaltrials.gov/ct2/show/NCT01638013 .

The optimal dosage of pefcitinib for the treatment of active rheumatoid arthritis: A protocol for an updated network meta-analysis

BACKGROUND

Previous meta-analyses have indicated that peficitinib was the promising agent for the treatment of rheumatoid arthritis (RA). Meanwhile, a recent network meta-analysis has further investigated the comparative efficacy of different peficitinib regimes. However, pooled results from previous network meta-analysis must be cautiously interpreted because 2 eligible studies were missed. Therefore, we designed this updated network meta-analysis to further establish the optimal dosage of peficitinib in treating RA.

METHODS

We will carry out a network meta-analysis of randomized controlled trials (RCTs) with Markov Chain Monte Carlo method in order to merge direct and indirect evidence. We will identify potentially eligible studies through searching 4 databases including PubMed, Embase, Cochrane Library, and China National Knowledgement Infrastructure (CNKI) until to December 2020. We will make this network meta-analysis following the process recommended by the Cochrane Handbook.

DISCUSSION

As a systematic and chronic autoimmune disease, RA primarily was characterized by persistent synovitis, progressive joint injury, and deformity. Patients who were identified as RA will experience a series of adverse consequences such as disability and poor quality of life (QoL). Peficitinib, one of the Janus kinases (JAKs) inhibitors, has been suggested to be effective in treating active RA by numerous clinical studies and meta-analyses. Although a recent meta-analysis investigated the comparative efficacy of different dosages of peficitinib, reliable results cannot be obtained because it missed 2 critical eligible studies. We designed this updated network meta-analysis through including all eligible studies to further ask which dosages may be the preferred option for treating active RA.

ETHICS AND DISSEMINATION

No ethics approval and informed consent will be required in our meta-analysis. Our findings in this updated network meta-analysis will be disseminated via conferences and academic journal.

OPEN SCIENCE FRAMEWORK OSF REGISTRATION DOI NUMBER

This protocol of updated network meta-analysis has been registered in Open Science Framework (OSF) system on January 8, 2021. The unique registration DOI number of 10.17605/OSF.IO/YSPM6 has been approved for our protocol (accessible at: https://osf.io/yspm6).

JAK Inhibitors and Modulation of B Cell Immune Responses in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic immune-mediated inflammatory disease that can lead to joint destruction, functional disability and substantial comorbidity due to the involvement of multiple organs and systems. B cells have several important roles in RA pathogenesis, namely through autoantibody production, antigen presentation, T cell activation, cytokine release and ectopic lymphoid neogenesis. The success of B cell depletion therapy with rituximab, a monoclonal antibody directed against CD20 expressed by B cells, has further supported B cell intervention in RA development. Despite the efficacy of synthetic and biologic disease modifying anti-rheumatic drugs (DMARDs) in the treatment of RA, few patients reach sustained remission and refractory disease is a concern that needs critical evaluation and close monitoring. Janus kinase (JAK) inhibitors or JAKi are a new class of oral medications recently approved for the treatment of RA. JAK inhibitors suppress the activity of one or more of the JAK family of tyrosine kinases, thus interfering with the JAK-Signal Transducer and Activator of Transcription (STAT) signaling pathway. To date, there are five JAK inhibitors (tofacitinib, baricitinib, upadacitinib, peficitinib and filgotinib) approved in the USA, Europe and/ or Japan for RA treatment. Evidence from the literature indicates that JAK inhibitors interfere with B cell functions. In this review, the main results obtained in clinical trials, pharmacokinetic, in vitro and in vivo studies concerning the effects of JAK inhibitors on B cell immune responses in RA are summarized.

A Matching-Adjusted Indirect Comparison of Upadacitinib Versus Tofacitinib in Adults with Moderate-to-Severe Rheumatoid Arthritis

Introduction

Upadacitinib and tofacitinib are Janus kinase inhibitors approved for moderate-to-severe rheumatoid arthritis (RA). In the absence of head-to-head trials comparing their effectiveness, this study assessed the efficacy of upadacitinib 15 mg once-daily monotherapy/combination therapy against tofacitinib 5 mg twice-daily combination therapy among patients with RA using matching-adjusted indirect comparisons (MAICs).

Methods

The first of two MAICs used individual patient data (IPD) from the 14-week SELECT-MONOTHERAPY trial (upadacitinib [n = 217] vs. methotrexate [n = 216]) and published data from the ORAL Standard trial (tofacitinib + methotrexate [n = 204] vs. methotrexate [n = 108]). The second MAIC used IPD from the 26-week SELECT-COMPARE trial (upadacitinib + methotrexate [n = 647] vs. adalimumab + methotrexate [n = 324]) and published data from ORAL Strategy (tofacitinib + methotrexate [n = 376] vs. adalimumab + methotrexate [n = 386]). Data from patients in the upadacitinib trials were re-weighted based on age, sex, race, swollen joint count 66/28, tender joint count 68/28, C-reactive protein (CRP), and patients’ global assessments to match the patient characteristics in tofacitinib trials. After matching, ACR20/50/70 and clinical remission (SDAI[CRP] ≤ 3.3, CDAI ≤ 2.8, DAS28-ESR/CRP < 2.6) were compared for upadacitinib vs. tofacitinib + methotrexate at month 3 and upadacitinib + methotrexate vs. tofacitinib + methotrexate at months 3 and 6 using Wald tests.

Results

At month 3, upadacitinib monotherapy patients experienced significantly larger improvement in ACR70 compared to tofacitinib + methotrexate (mean difference in difference [DID]: 9.9%; p = 0.019), while upadacitinib + methotrexate was associated with higher ACR50 compared to tofacitinib + methotrexate (DID: 12.9%; p = 0.011). At month 6, upadacitinib + methotrexate patients experienced significantly larger improvement in SDAI/CDAI/DAS28-ESR clinical remission compared to tofacitinib + methotrexate, with DIDs of 9.1% (p = 0.011), 7.5% (p = 0.038), and 11.3% (p = 0.002), respectively.

Conclusions

Compared to tofacitinib combination therapy, treatment with upadacitinib monotherapy and combination therapy were associated with improved outcomes at 3/6 months (monotherapy: ACR70; combination: ACR50, SDAI, CDAI, and DAS28-ESR remission).

Electronic supplementary material

The online version of this article (10.1007/s40744-020-00257-w) contains supplementary material, which is available to authorized users.