Baricitinib, Methotrexate, or Combination in Patients With Rheumatoid Arthritis and No or Limited Prior Disease-Modifying Antirheumatic Drug Treatment

Novel Therapeutic Approaches in Rheumatoid Arthritis: Role of Janus Kinases Inhibitors

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Rheumatoid Arthritis (RA) is a chronic inflammatory disease characterized by synovial inflammation and hyperplasia, autoantibody production, cartilage and bone destruction and several systemic features. Cardiovascular, pulmonary, psychological, and muscle involvement are the main comorbidities of RA and are responsible for the severity of the disease and long-term prognosis.

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Pharmacological treatment of rheumatic diseases has evolved remarkably over the past years. In addition, the widespread adoption of treat to target and tight control strategies has led to a substantial improvement of outcomes, so that drug-free remission is nowadays a realistic goal in the treatment of RA. However, despite the availability of multiple therapeutic options, up to 40% of patients do not respond to current treatments, including biologics. Small-molecule therapies offer an alternative to biological therapies for the treatment of inflammatory diseases. In the past 5 years, a number of small-molecule compounds targeting Janus Kinases (JAKs) have been developed. Since JAKs are essential for cell signaling in immune cells, in particular controlling the response to many cytokines, their inhibitors quickly became a promising class of oral therapeutics that proved effective in the treatment of RA.

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ofacitinib is the first Janus Kinase (JAK) inhibitor approved for the treatment of RA, followed more recently by baricitinib. Several other JAK inhibitors, are currently being tested in phase II and III trials for the treatment of a different autoimmune diseases. Most of these compounds exhibit an overall acceptable safety profile similar to that of biologic agents, with infections being the most frequent adverse event. Apart from tofacitinib, safety data on other JAK inhibitors are still limited. Long-term follow-up and further research are needed to evaluate the general safety profile and the global risk of malignancy of these small molecules, although no clear association with malignancy has been reported to date.

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Here, we will review the main characteristics of JAK inhibitors, including details on their molecular targets and on the clinical evidences obtained so far in the treatment of RA.

Low rates of remission with methotrexate monotherapy in rheumatoid arthritis: review of randomised controlled trials could point towards a paradigm shift

Treatment of rheumatoid arthritis (RA) has improved substantially during the last decades, mainly due to the development and introduction in everyday practice of new, highly efficacious, disease-modifying antirheumatic drugs (DMARDs), more optimal usage of them, earlier diagnosis and tighter control of disease activity targeting at remission. Methotrexate is still today the anchor drug and the first-line treatment after diagnosis. However, numerous studies comparing methotrexate and biologic DMARDs, as well as new targeted synthetic DMARDs, both in early as in more established disease, have shown consistently better efficacy of the latter compared with methotrexate, with methotrexate yielding remission to maximum half of patients. This could suggest a new paradigm shift with earlier start of a biologic or a targeted synthetic DMARD, with the possibility of subsequent discontinuation in case of achievement of stable remission. Several strategy trials, however, have shown that there might be a clinical and structural benefit of initial, aggressive therapy, possibly even associated with higher chance of remaining in remission, after cessation of the biologic DMARD and continuing with methotrexate alone, but they have failed to show a clear advantage of such an aggressive treatment strategy. This might become a valuable option for the future treatment algorithm of RA, especially for a subgroup of patients with RA, but further confirmation from future research is needed. The crucial role of glucocorticoid use as part of the combination strategy should be acknowledged, and strategy trials should include this combination as an active comparator.

Fifty-Two-Week Results of Clinical and Imaging Assessments of a Patient with Rheumatoid Arthritis Complicated by Systemic Sclerosis with Interstitial Pneumonia and Type 1 Diabetes despite Multiple Disease-Modifying Antirheumatic Drug Therapy That Was Successfully Treated with Baricitinib: A Novel Case Report

Baricitinib is a Janus kinase 1/2 (JAK1/2) inhibitor used in the treatment of rheumatoid arthritis. A 71-year-old woman with rheumatoid arthritis complicated by systemic sclerosis and type 1 diabetes that were resistant to multiple disease-modifying antirheumatic drugs started treatment with baricitinib. After baricitinib administration, the disease activity of her rheumatoid arthritis was attenuated from the early stage of treatment, and the effect was maintained for up to 52 weeks. In addition, the skin sclerosis in systemic sclerosis showed an improvement. Regarding the influence on type 1 diabetes, the required daily dose of insulin and hemoglobin A1c (HbA1c) levels decreased. To date, no studies have demonstrated the effectiveness of baricitinib on systemic sclerosis or type 1 diabetes. We report that baricitinib was effective for systemic sclerosis and type 1 diabetes, as well as for rheumatoid arthritis, for up to 52 weeks.

Does Triple Conventional Synthetic Disease-Modifying Antirheumatic Drug Therapy Improve upon Methotrexate as the Initial Treatment of Choice for a Rheumatoid Arthritis Patient?

Although many treatment options exist for the initial management of rheumatoid arthritis, there has long been discussion about whether initial treatment should be with methotrexate (MTX) as monotherapy or in combination with other conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Although studies initially showed additional benefit from combining MTX with other csDMARDs, this benefit disappears when glucocorticoids are added to MTX, a strategy recommended in current guidelines as a short-term bridging approach until MTX therapy exhibits its full efficacy. Also concomitant use of glucocorticoids, with MTX may not be inferior to combination therapy of MTX with TNF-inhibitors.

Cardiovascular Safety During Treatment With Baricitinib in Rheumatoid Arthritis

OBJECTIVE

To assess the frequency of cardiovascular and venous thromboembolic events in clinical studies of baricitinib, an oral, selective JAK1 and JAK2 inhibitor approved in more than 50 countries for the treatment of moderately-to-severely active rheumatoid arthritis (RA).

METHODS

Data were pooled from 9 RA studies. Placebo comparison up to 24 weeks included data from 6 studies. Randomized dose comparison between baricitinib doses of 2 mg and 4 mg used data from 4 studies and from the associated long-term extension study. The data analysis set designated "All-bari-RA" included all baricitinib exposures at any dose.

RESULTS

Overall, 3,492 RA patients received baricitinib (7,860 patient-years of exposure). No imbalance compared to the placebo group was seen in the incidence of major adverse cardiovascular events (MACE) (incidence rates [IRs] of 0.5 per 100 patient-years for placebo and 0.8 per 100 patient-years for 4 mg baricitinib), arterial thrombotic events (ATE) (IRs of 0.5 per 100 patient-years for placebo and 0.5 per 100 patient-years for 4 mg baricitinib), or congestive heart failure (CHF) broad term (IRs of 4.3 per 100 patient-years for placebo and 2.4 per 100 patient-years for 4 mg baricitinib). Deep vein thrombosis (DVT)/pulmonary embolism (PE) were reported in 0 of 1,070 patients treated with placebo and 6 of 997 patients treated with 4 mg baricitinib during the placebo-controlled period; these events were serious in 2 of 6 patients, while all 6 had risk factors and 1 patient developed DVT/PE after discontinuation of the study drug. In the 2 mg-4 mg-extended data analysis set, IRs of DVT/PE were comparable between the doses across event types (IRs of 0.5 per 100 patient-years in those receiving 2 mg baricitinib and 0.6 per 100 patient-years in those receiving 4 mg baricitinib). In the All-bari-RA data analysis set, the rates were stable over time, with an IR of DVT/PE of 0.5 per 100 patient-years.

CONCLUSION

In RA clinical trials, no association was found between baricitinib treatment and the incidence of MACE, ATE, or CHF. With regard to incidence of DVT/PE, 6 events occurred in patients treated with 4 mg baricitinib, but no cases of DVT/PE were reported in the placebo group. During longer-term evaluation, the incidence of DVT/PE was similar between the baricitinib dose groups, with consistent IR values over time, and this was similar to the rates previously reported in patients with RA.

Current Therapeutic Options in the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of the joints. Untreated RA leads to a destruction of joints through the erosion of cartilage and bone. The loss of physical function is the consequence. Early treatment is important to control disease activity and to prevent joint destruction. Nowadays, different classes of drugs with different modes of action are available to control the inflammation and to achieve remission. In this review, we want to discuss differences and similarities of these different drugs.

[Pharmacological treatment of rheumatoid arthritis and its comorbidities]

Due to therapeutic advances, rheumatoid arthritis (RA) today has developed into a satisfactorily treatable disease in most cases, with remission being the target of treatment. Early diagnosis with immediate treatment initiation following treat-to-target strategy is the key to a favorable long-term outcome. A guideline-directed treatment algorithm determines the use of conventional synthetic disease-modifying anti-rheumatic drugs (DMARD; e.g., methotrexate), biological DMARD, and targeted oral DMARD (Janus kinase inhibitors). Comorbidities-in particular cardiovascular and interstitial lung disease-affect 80% of RA patients and represent the leading causes for mortality. The choice of drug treatment is influenced by the presence of comorbidities.

Impact of Janus kinase inhibitors on risk of cardiovascular events in patients with rheumatoid arthritis: systematic review and meta-analysis of randomised controlled trials

Objectives

To investigate the effect of Janus kinase inhibitors (Jakinibs) on cardiovascular risk in adult patients with rheumatoid arthritis (RA) via a meta-analysis of randomised controlled trials (RCTs).

Methods

PubMed, Embase and Cochrane library were thoroughly searched for RCTs reporting safety issues in patients with RA receiving Jakinibs, from inception to October 2018. The primary and secondary outcomes were all cardiovascular events (CVEs) and major adverse cardiovascular events (MACEs)/venous thromboembolism events (VTEs). OR and 95% CI were calculated using the Mantel-Haenszel fixed-effect method.

Results

26 RCTs randomising 11 799 patients were included. No significant difference was observed regarding all CVEs risk following Jakinibs usage in general (OR 1.04 (0.61 to 1.76), p = 0.89), tofacitinib (OR 0.63 (0.26 to 1.54), p = 0.31), baricitinib (OR 1.21 (0.51 to 2.83), p = 0.66), upadacitinib (OR 3.29 (0.59 to 18.44), p = 0.18), peficitinib (OR 0.43 (0.07 to 2.54), p = 0.35) or decernotinib (OR 1.12 (0.13 to 10.11), p = 0.92). Likewise, there was no significant difference for Jakinibs treatment overall regarding occurrence of MACEs (OR 0.80 (0.36 to 1.75), p = 0.57) or VTEs (OR 1.16 (0.48 to 2.81), p = 0.74). Dose-dependent impact of Jakinibs on the risks of all CVEs, MACEs and VTEs was not observed in tofacitinib (5 mg vs 10 mg), upadacitinib (15 mg vs 30 mg), whereas baricitinib at 2 mg was found to be safer than 4 mg in all CVEs incidence (OR 0.19 (0.04 to 0.88), p = 0.03).

Conclusion

The existing evidence from RCTs indicated no significant change in cardiovascular risk for Jakinib-treated patients with RA in a short-term perspective, but postmarketing data are sorely needed to ascertain their cardiovascular safety, especially at the higher dose, due to increased risk of thromboembolism events for both tofacitinib and baricitinib at higher dosage.

Low rates of radiographic progression of structural joint damage over 2 years of baricitinib treatment in patients with rheumatoid arthritis

Objectives

To evaluate radiographic progression of structural joint damage over 2 years in patients with rheumatoid arthritis from baricitinib clinical trials who were disease-modifying antirheumatic drug (DMARD)–naïve or had an inadequate response to conventional synthetic DMARDs (csDMARD-IR).

Methods

Patients had completed one of three phase III studies and entered a long-term extension (LTE) study, continuing on the same baricitinib dose as at originating study completion. At 52 weeks, DMARD-naïve patients receiving methotrexate (MTX) or combination therapy (baricitinib 4 mg+MTX) were switched to baricitinib 4 mg monotherapy (±MTX per investigator opinion); MTX-IR patients receiving adalimumab were switched to baricitinib 4 mg on background MTX. At 24 weeks, csDMARD-IR patients receiving placebo were switched to baricitinib 4 mg on background csDMARD. Radiographs at baseline, year 1 and year 2 were scored using the van der Heijde modified Total Sharp Score. Linear extrapolation was used for missing data.

Results

Of 2573 randomised patients, 2125 (82.6%) entered the LTE, of whom 1893 (89.1%) entered this analysis. At year 2, progression was significantly lower with initial baricitinib (monotherapy or combination therapy) versus initial MTX in DMARD-naïve patients (proportion with non-progression defined by ≤smallest detectable change (SDC): 87.3% baricitinib 4 mg+MTX; 70.6% MTX; p≤ 0.001). In MTX-IR patients, progression with initial baricitinib was significantly lower than with initial placebo and similar to initial adalimumab (≤SDC: 82.7% baricitinib 4 mg; 83.5% adalimumab; 70.6% placebo; p≤0.001). In csDMARD-IR patients, significant benefit was seen with baricitinib 4 mg (≤SDC: 87.2% vs 73.2% placebo; p≤0.01).

Conclusions

Treatment with once-daily baricitinib resulted in low rates of radiographic progression for up to 2 years.

Baricitinib for the treatment of rheumatoid arthritis and systemic lupus erythematosus: a 2019 update

Introduction: JAK, which constitutively binds to some cytokine receptors, plays an important role in cytokine signaling. While JAK is comprised of JAK1, JAK2, JAK3, and Tyk2, more than 40 types of cytokines transmit signals through JAK. Baricitinib is reported to be highly effective in the treatment of rheumatoid arthritis (RA) and is the second drug launched as a JAK inhibitor for RA. Area covered: We provide an overview of the mechanisms of action of baricitinib and its clinical implications in RA and other autoimmune diseases based on recent reports. This review outlines the mechanisms of action of baricitinib on human immune cells, the results of Phase III trials for RA, and the results of Phase II trials on SLE. Expert opinion: Baricitinib has potential to fine-tune various immune networks through a variety of mechanisms. Precision medicine is required in order to achieve maximum effects of targeted synthetic DMARDs including baricitinib and biological DMARDs in the future.

Evaluation of pneumococcal and tetanus vaccine responses in patients with rheumatoid arthritis receiving baricitinib: results from a long-term extension trial substudy

Background

Clinical guidelines recommend pneumococcal and tetanus vaccinations in patients with rheumatoid arthritis (RA). Baricitinib is an oral, selective Janus kinase (JAK) 1/JAK 2 inhibitor and is approved for the treatment of moderately to severely active RA in adults in over 50 countries including European countries, the USA, and Japan. This substudy evaluated pneumococcal conjugate and tetanus toxoid vaccine (TTV) responses in patients with RA receiving baricitinib. These vaccines elucidate predominantly T cell-dependent humoral antibody response.

Methods

Eligible RA patients receiving baricitinib 2 mg or 4 mg with or without concomitant methotrexate (MTX) were enrolled in a phase 3 long-term extension trial (RA-BEYOND; ClinicalTrials.gov, NCT01885078) in USA/Puerto Rico. Patients were vaccinated with 13-serotype pneumococcal conjugate vaccine (PCV-13) and TTV. Primary endpoints were the proportion of patients achieving a satisfactory humoral response for PCV-13 (≥ 2-fold increase in anti-pneumococcal antibody concentrations in ≥ 6 serotypes) and TTV (≥ 4-fold increase in anti-tetanus concentrations) at 5 weeks post-vaccination. Secondary endpoints included humoral responses at 12 weeks and functional responses of serotypes 4, 6B, 14, and 23F (twofold and fourfold increases in opsonic indexes at 5 and 12 weeks).

Results

Of 106 patients with a mean duration of RA of approximately 12 years, 80% were female, 30% were taking corticosteroids, and 89% (N = 94) were taking baricitinib plus MTX; most patients (97% PCV-13/96% TTV) completed the evaluations. Overall, 68% (95% CI 58.4, 76.2) of patients achieved a satisfactory response to PCV-13, 43% (34.0, 52.8) achieved a ≥ 4-fold increase in anti-tetanus concentrations, and 74% (64.2, 81.1) achieved a ≥ 2-fold increase. PCV-13 response was similar for patients taking corticosteroids (71%; 53.4, 83.9) vs those not (67%; 55.2, 76.5). The percentage of sera with a ≥ 2-fold increase in post-vaccination opsonic indexes at week 5 ranged from 47% (serotype 14) to 76% (serotype 6B). Through 12 weeks post-vaccination, seven patients (6.6%) reported injection-site events. There were no deaths during the substudy, and three patients experienced a serious adverse event.

Conclusions

Approximately two thirds of patients on long-term baricitinib achieved satisfactory humoral and functional responses to PCV-13 vaccination, while TTV responses were less robust. PCV-13 response was not diminished in those taking concomitant corticosteroids.

Trial registration

ClinicalTrials.gov, NCT01885078. Registered on 24 June 2013.

Comparison of Janus kinase inhibitors in the treatment of rheumatoid arthritis: a systemic literature review

Several Janus kinase (JAK) inhibitors, oral targeted disease-modifying drugs, will be approved for the treatment of rheumatoid arthritis (RA) and other diseases. This review compares and contrasts the efficacy of JAK inhibitors (tofacitinib, baricitinib, upadacitinib, filgotinib, peficitinib and decernotinib) in RA including: early RA methotrexate-naive patients, post methotrexate failure and post biologics. Trials in monotherapy, combination with disease modifying drugs such as methotrexate, and comparing with adalimumab in biologic-naive patients were studied. The efficacy is superior to methotrexate in naive patients and equal or superior to adalimumab depending on the drug and dose. There is a class effect of adverse events. Serious infections occur at a rate similar to other advanced therapies in RA, although more reactivation of herpes zoster occurs.

JAK Inhibitors for Atopic Dermatitis: An Update

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases. AD is driven by barrier dysfunction and abnormal immune activation of T helper (Th) 2, Th22, and varying degrees of Th1 and Th17 among various subtypes. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and spleen tyrosine kinase (SYK) pathways are involved in signaling of several AD-related cytokines, such as IFN-γ, IL-4, IL-13, IL-31, IL-33, IL-23, IL-22, and IL-17, mediating downstream inflammation and barrier alterations. While AD is primarily Th2-driven, the clinical and molecular heterogeneity of AD endotypes highlights the unmet need for effective therapeutic options that target more than one immune axis and are safe for long-term use. The JAK inhibitors, which target different combinations of kinases, have overlapping but distinct mechanisms of action and safety profiles. Several topical and oral JAK inhibitors have been shown to decrease AD severity and symptoms. A review of the JAK and SYK inhibitors that are currently undergoing evaluation for efficacy and safety in the treatment of AD summarizes available data on a promising area of therapeutics and further elucidates the complex molecular interactions that drive AD.

Baricitinib: The Second FDA-Approved JAK Inhibitor for the Treatment of Rheumatoid Arthritis

Objective: To review the pharmacology, pharmacokinetics, safety, and efficacy of baricitinib, a recently approved selective Janus Kinase (JAK) inhibitor for the treatment of rheumatoid arthritis (RA), and explore its potential role in therapy. Data Sources: Articles were identified using a PubMed search from inception through January 2019 using the terms rheumatoid arthritis, Olumiant, baricitinib, and LY3009104, its molecular name. Study Selection and Data Extraction: Articles relating to randomized clinical trials, pharmacology, pharmacokinetics, efficacy, and safety of baricitinib were evaluated. Data Synthesis: Baricitinib exerts its effects by inhibiting JAK1 and JAK2 enzymes, targeting cytokine and growth factor receptor stimulation, thus reducing downstream immune cell function. Four trials have demonstrated the efficacy of baricitinib with or without methotrexate in patients naïve to disease-modifying antirheumatic drugs (DMARDs) and those who had an inadequate response to or intolerance to both conventional and biological DMARDs. Furthermore, baricitinib was associated with delayed radiographic progression. Despite baricitinib 4 mg often demonstrating greater efficacy compared with the 2 mg dose, only the 2 mg dose is Food and Drug Administration approved because of safety concerns with the 4 mg dose, primarily thromboembolism. Relevance to Patient Care and Clinical Practice: Baricitinib provides an oral treatment option for patients failing tumor necrosis factor inhibitors (TNFis). Safety, cost, and comparative effectiveness to tofacitinib should be considered prior to prescribing baricitinib. Conclusion: Baricitinib is the second medication in its class and has been proven efficacious for the treatment of RA. Given concerns for adverse effects associated with baricitinib, it should be reserved for patients who have failed one or more TNFis.

The Use of Janus Kinase Inhibitors in Vitiligo: A Review of the Literature

Vitiligo is a common acquired depigmenting disorder characterized by the development of white macules and patches due to the loss of melanocytes. Patients with vitiligo can be stigmatized by society, making the disease a source of psychological stress that can considerably affect quality of life. The goal of vitiligo treatment is to obtain skin repigmentation in the majority of cases, and less commonly to depigment the remaining normal skin. There is no consistent, long-term, durable therapy for vitiligo for all patients, highlighting the unmet need for new safe and effective therapies to control this disease. Recently, JAK inhibitors have been explored as a promising novel treatment option in vitiligo. The JAK and signal transducers and activators of transcription (STAT) pathway is an attractive therapeutic target because IFN-γ-dependent cytokines produced through this pathway have been implicated in the pathogenesis of disease. This literature review describes vitiligo pathophysiology, explains the usefulness of the JAK inhibitors for treatment, and summarizes published case reports, case series, and open-label studies. Research outlined here shows JAK inhibitors in patients with vitiligo have a favorable safety profile and effectively produce repigmentation of lesions, especially with concomitant ultraviolet exposure. Additional studies are required to confirm efficacy, establish safety, and investigate durability of repigmentation.

Safety profile of baricitinib in Japanese patients with active rheumatoid arthritis with over 1.6 years median time in treatment: An integrated analysis of Phases 2 and 3 trials

Objectives: Baricitinib is a selective oral inhibitor of JAK1/JAK2 for patients with moderately-to-severely active rheumatoid arthritis (RA). Baricitinib's safety profile in Japanese patients was evaluated using six studies (five Ph2/Ph3 trials, one long-term extension study through 01 September 2016) from an integrated database (nine RA studies).Methods: Incidence rates (IRs) or exposure-adjusted IRs (EAIRs) of adverse events (AEs) per 100 patient-years (PY) were calculated using data which included RA patients exposed to any baricitinib dose.Results: Five hundred and fourteen Japanese patients received baricitinib for 851.5 total PY of exposure (median 1.7 years, maximum 3.2). The EAIR of treatment-emergent AEs was 57.4/100PY. There were no deaths; 31 patients had serious infections (IR: 3.6/100PY), 55 herpes zoster (6.5), 0 tuberculosis, 10 malignancies (1.1) including two lymphomas, two major cardiovascular AEs (0.3), one gastrointestinal perforation (0.1), and four deep vein thrombosis (0.5). In Japanese patients, herpes zoster was more frequent than that of patients overall in the integrated database, but the events were considered manageable.Conclusion: In this analysis, baricitinib had acceptable safety profile in Japanese RA patients in the context of demonstrated efficacy. Aside from herpes zoster, baricitinib safety was not notably different between Japanese RA patients and those RA patients in the integrated database.Trial registration: NCT01185353, NCT00902486, NCT01469013, NCT01710358, NCT01721044, NCT01721057, NCT01711359, and NCT01885078 at https://clinicaltrials.gov/.

Baricitinib induces LDL-C and HDL-C increases in rheumatoid arthritis: a meta-analysis of randomized controlled trials

Background

Baricitinib, an oral-administrated selective inhibitor of the JAK1 and JAK2, is recently approved for rheumatoid arthritis (RA) treatment. With the aim to provide some insights on the clinical safety, the current study mainly focused on the effect of baricitinib on low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels and cardiovascular risk.

Methods

The net change scores [least squares mean (LSM) and mean change] of LDL-C and HDL-C levels from baseline with the comparison of baricitinib versus placebo were pooled, respectively. Risk rations (RR) of major cardiovascular events (MACEs) and differences of cardiovascular risk scores at the end of treatment across groups were compared.

Results

Six trials with randomized 3552 patients were finally included in summary analysis. Results showed that baricitinib significantly increased LDL-C levels, the net mean change was 13.15 mg/dl with 95% CI 8.89~17.42 (I² = 0) and the net LSM was 11.94 mg/dl with 95% CI 7.52~16.37 (I² = 84%). HDL-C also increased obviously with the net LSM change was 7.19 mg/dl (95% CI, 6.05~8.33, I² = 47%) and net mean change was 5.40 mg/dl (95% CI, 3.07~7.74, I² = 10%). Subgroup and meta-regression analysis demonstrated baricitinib induced LDL-C and HDL-C increases in a dose-response manner. However, both the pooled RRs of MACEs and differences of cardiovascular risk scores were not statistically significant across groups.

Conclusion

This study confirmed that baricitinib induced a stable dose-response increase in LDL-C and HDL-C levels. Since the causality association between altered lipids and cardiovascular risk was not identified yet, this issue cannot be completely dismissed. Future research is needed to fully dissect the implications of these lipid changes.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-0994-7) contains supplementary material, which is available to authorized users.

New alternative in the treatment of rheumatoid arthritis: clinical utility of baricitinib

Baricitinib is an innovative small-molecule drug that reversibly inhibits continuous activation of JAK/STAT pathway, thus reducing joint inflammation. The drug was approved for use as monotherapy or in combination with methotrexate (MTX) in the treatment of adults with moderately to severely active rheumatoid arthritis (RA). The aim of this paper was to review the studies on pharmacology, mode of action, pharmacokinetics, efficacy, and safety of baricitinib in patients with RA. Baricitinib provides an innovative approach to modulating the immune and inflammatory response in patients with RA, which is especially important in individuals who do not respond to disease-modifying antirheumatic drugs or standard biologic drugs (tumor necrosis factor inhibitors) or who lose response over time. Baricitinib therapy reduces symptoms of RA and improves the quality of life. Moreover, it has shown high efficacy and an acceptable safety profile in Phase III randomized controlled trials (RCTs) and become another JAK inhibitor approved for RA treatment, providing a useful alternative option. RCTs have revealed a significant benefit of baricitinib over placebo, MTX, and adalimumab in terms of standard efficacy outcomes, especially the American College of Rheumatology ACR20, ACR50, and ACR70 response rates. Additionally, a clinically meaningful improvement in patient-reported outcomes, including the quality of life, compared with placebo has been reported. The safety profile seems acceptable, although some rare but potentially severe adverse events have been observed, such as serious infections, opportunistic infections (eg, herpes zoster), malignancies, and cardiac or hepatic disorders. Baricitinib administered at an approved dose of 2 or 4 mg once daily offers a novel and promising alternative to parenterally administered biologic drugs used in RA treatment.

Clinical efficacy of launched JAK inhibitors in rheumatoid arthritis

Tofacitinib and baricitinib are the first orally available, small-molecule inhibitors of Janus kinase (JAK) enzymes to be approved for the treatment of RA. Tofacitinib is a selective JAK1, 3 inhibitor with less activity against JAK2 and TYK2 and baricitinib is a selective, oral JAK1, 2 inhibitor with moderate activity against TYK2 and significantly less activity against JAK3. Both drugs have undergone extensive phase III clinical trials in RA and demonstrated rapid improvements in disease activity, function and patient-reported outcomes as well as disease modification. Tofacitinib 5 mg bd, was approved by the Federal Drug Administration in 2012 for the treatment of RA in patients who are intolerant or unresponsive to MTX. An extended release formulation for the treatment of RA was approved by Federal Drug Administration in 2016. In 2017 the European Medicines Agency approved tofacitinib 5 mg bd in combination with MTX and baricitinib 4 mg and 2 mg once daily for the treatment of moderate to severe active RA in adult patients who are intolerant or unresponsive to one or more conventional synthetic DMARDs.

Selective JAKinibs: Prospects in Inflammatory and Autoimmune Diseases

Cytokines, many of which signal through the JAK-STAT (Janus kinase-Signal Transducers and Activators of Transcription) pathway, play a central role in the pathogenesis of inflammatory and autoimmune diseases. Currently three JAK inhibitors have been approved for clinical use in USA and/or Europe: tofacitinib for rheumatoid arthritis, psoriatic arthritis and ulcerative colitis, baricitinib for rheumatoid arthritis, and ruxolitinib for myeloproliferative neoplasms. The clinical JAK inhibitors target multiple JAKs at high potency and current research has focused on more selective JAK inhibitors, almost a dozen of which currently are being evaluated in clinical trials. In this narrative review, we summarize the status of the pan-JAK and selective JAK inhibitors approved or in clinical trials, and discuss the rationale for selective targeting of JAKs in inflammatory and autoimmune diseases.

MRI and Dose Selection in a Phase II Trial of Baricitinib with Conventional Synthetic Disease-modifying Antirheumatic Drugs in Rheumatoid Arthritis

OBJECTIVE

Magnetic resonance imaging (MRI) was used in a phase IIb study of baricitinib in patients with RA to support dose selection for the phase III program.

METHODS

Three hundred one patients with active RA who were taking stable methotrexate were randomized 2:1:1:1:1 to placebo or once-daily baricitinib (1, 2, 4, or 8 mg) for up to 24 weeks. One hundred fifty-four patients with definitive radiographic erosion had MRI of the hand/wrist at baseline and at weeks 12 and 24. Two expert radiologists, blinded to treatment and visit order, scored images for synovitis, osteitis, bone erosion, and cartilage loss. Combined inflammation (osteitis + 3× synovitis score) and total joint damage (erosion + 2.5× cartilage loss score) scores were calculated. Treatment groups were compared using ANCOVA adjusting for baseline scores.

RESULTS

Mean changes from baseline to Week 12 for synovitis were -0.10, -1.50, and -1.60 for patients treated with placebo, baricitinib 4 mg, and baricitinib 8 mg, respectively (p = 0.003 vs placebo for baricitinib 4 and 8 mg). Mean changes for osteitis were 0.00, -3.20, and -2.10 (p = 0.001 vs placebo for baricitinib 4 mg and p = 0.037 for 8 mg), respectively. Mean changes for bone erosion were 0.90, 0.10, and 0.40 (p = 0.089 for 4 mg and p = 0.275 for 8 mg), respectively, in these treatment groups.

CONCLUSION

MRI findings in this subgroup of patients suggest suppression of synovitis, osteitis, and combined inflammation by baricitinib 4 and 8 mg. This corroborates previously demonstrated clinical efficacy of baricitinib and increases confidence that baricitinib 4 mg could reduce the radiographic progression in phase III studies. [Clinical trial registration number (www.ClinicalTrials.gov): NCT01185353].

A Bayesian mixed treatment comparison of efficacy of biologics and small molecules in early rheumatoid arthritis

The current paradigm in the management of rheumatoid arthritis (RA) is to treat patients in the early stage of the disease (ERA). Previous meta-analysis-based mixed treatment comparisons (MTCs), aimed to identify the most effective drugs in ERA, are biased by the wide "window" of early definition, ranging from 6 months to 2 years. The aim of this study was to estimate through a Bayesian Network Meta-Analysis which biologics or small molecules are more likely to achieve a 1-year good clinical response in ERA patients with disease duration < 1 year. According to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement, randomized controlled trials (RCTs) of biologic agents and small molecules in combination with MTX to treat patients affected with ERA lasting < 1 year were searched through MEDLINE, EMBASE, Cochrane Library, and Clinicaltrials.gov between 1990 and September 2017. The outcome of interest was the achievement of American College of Rheumatology (ACR) 50 and ACR 70 response at 1 year. WinBUGS 1.4 software (MRC Biostatistics Unit, Cambridge, UK) was used to perform the analyses, using a fixed effect model. Fourteen studies were included in the analysis. Tofacitinib (64.83%) followed by Etanercept (23.26%) were the drugs with the highest probability of achieving ACR50 response. Rituximab showed the highest probability of inducing ACR70 response (52.81%) followed by Etanercept (26.85%). This is the first MTC involving only RCTs on ERA patients with disease duration < 1 year. Tofacitinib and rituximab were the drugs ranked first in inducing 1-year ACR50 and ACR70 response, respectively.

Characterization and Changes of Lymphocyte Subsets in Baricitinib-Treated Patients With Rheumatoid Arthritis: An Integrated Analysis

OBJECTIVE

Baricitinib is an orally administered inhibitor of JAK1 and JAK2 that has been shown to be effective in treating rheumatoid arthritis (RA). This study was undertaken to analyze changes in lymphocyte cell subsets during baricitinib treatment and to correlate these changes with clinical outcomes.

METHODS

An integrated analysis was conducted by pooling data from 3 completed phase III trials comparing placebo with baricitinib treatment (RA-BEAM, RA-BUILD, and RA-BEACON) and 1 ongoing long-term extension study (RA-BEYOND) in patients with active RA (n = 2,186).

RESULTS

Baricitinib treatment was associated with an early transient increase in total lymphocyte count at week 4, which returned to baseline by week 12. Transient changes within normal reference ranges in T cells and subsets were observed with baricitinib treatment, up to week 104. B cells and relevant subpopulations increased after 4 weeks of baricitinib treatment, with no further increases noted through 104 weeks of treatment. Natural killer (NK) cells temporarily increased after 4 weeks of baricitinib treatment, before decreasing below baseline levels and then stabilizing over time. With baricitinib treatment, few correlations were observed between changes in lymphocyte subsets and clinical end points, and most correlations were also observed within the placebo group. A modest potential association between low NK cell numbers and treatment-emergent infections was observed in the baricitinib 4 mg/day treatment group, but not for serious infections or herpes zoster.

CONCLUSION

Overall, these findings demonstrate that changes in lymphocyte subsets were largely within normal reference ranges across the baricitinib phase III RA clinical program and were not associated with increased risk of serious infections.

Added value of combining methotrexate with a biological agent compared to biological monotherapy in rheumatoid arthritis patients: A systematic review and meta-analysis of randomised trials

OBJECTIVES

To assess the efficacy and safety of methotrexate (MTX) in combination with an approved biological agent compared to biological monotherapy, in the management of patients with rheumatoid arthritis (RA).

METHODS

MEDLINE, EMBASE, CENTRAL and other sources were searched for randomised trials evaluating a biological agent plus MTX versus the same biological agent in monotherapy. Co-primary outcomes were ACR50 and the number of patients who discontinued due to adverse events (AEs). Random-effects models were applied for meta-analyses with risk ratio and 95% confidence intervals and the GRADE approach was used to assess confidence in the estimates.

RESULTS

The analysis comprised 16 trials (4965 patients), including all biological agents approved for RA except anakinra and certolizumab. The overall likelihood of responding to therapy (i.e. ACR50) after 6 months was 32% better when MTX was given concomitantly with biological agents (1.32 [1.20-1.45]; P < 0.001) corresponding to 11 more out of 100 patients (7-16 more); Moderate Quality Evidence. Discontinuing due to AEs from concomitant use of MTX was potentially 20% increased (1.21 [0.97-1.50]; P = 0.09) compared to biological monotherapy corresponding to 1 more out of 100 patients (0-3 more); Moderate Quality Evidence.

CONCLUSIONS

Randomised trials provide Moderate Quality Evidence for a favourable benefit-harm balance supporting concomitant use of MTX rather than monotherapy when prescribing a biological agent in patients with RA although in absolute terms only 7-16 more out of 100 patients will achieve an ACR50 response after 6 months of this combination therapy.

[Biologics and further new drugs for rheumatic diseases since 2000]

BACKGROUND

Rheumatoid arthritis (RA), psoriatic arthritis and axial spondyloarthritis are severe diseases, which without adequate treatment lead to extremely reduced mobility, functional status and quality of life.

OBJECTIVE

The effects of biologics and further new antirheumatic drugs on the burden of disease.

METHODS

Evaluation of study results and register data dealing with the efficacy and safety of these drugs.

RESULTS

Biologics have been proven to dramatically improve the outcome of all three diseases and contributed to the fact that remission is a realistic target today. In addition, the cardiovascular risk and mortality in RA have been reduced and structural damage is considerably blocked by biologics. Recently Janus kinase (JAK) inhibitors contributed to the treatment possibilities in the same way. Biologics as well as JAK inhibitors offer an excellent safety profile and tolerability with infections being the most important risk.

CONCLUSION

With the availability of biologics and additional new drugs all three diseases have lost the status of difficult to treat diseases. Their usage according to the guidelines ensures that the burden of disease can been minimalized in most cases. The benefit-risk profile of these drugs has been shown to be excellent.

Efficacy of Monotherapy with Biologics and JAK Inhibitors for the Treatment of Rheumatoid Arthritis: A Systematic Review

Despite recommendations suggesting that biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) should be used in combination with methotrexate in the treatment of rheumatoid arthritis (RA), up to one-third of patients with RA are treated with monotherapy. The objective of the systematic literature review reported here was to evaluate the clinical evidence regarding the efficacy of b/tsDMARDs as monotherapy in the treatment of RA. MEDLINE®, Embase®, and the Cochrane Central Trials Register (to April 11, 2017) and the American College of Rheumatology and European League Against Rheumatism conference proceedings (2010-2016) were searched for randomized controlled trials evaluating the efficacy of b/tsDMARDs as monotherapy for RA in adults. Forty-four monotherapy studies of abatacept, adalimumab, baricitinib, certolizumab pegol, etanercept, sarilumab, sirukumab, tocilizumab, and tofacitinib reported in 71 publications were identified. Tocilizumab had the most studies (14), followed by etanercept (10) and adalimumab (9). These b/tsDMARDs were consistently shown to be efficacious treatments, regardless of whether patients were intolerant of or had never used conventional synthetic (cs) DMARDs. However, better treatment outcomes were usually achieved with combination therapy, and this was observed for all b/tsDMARDs assessed by this review. Only a few studies provided a head-to-head comparison between b/tsDMARD treatments or between b/tsDMARD monotherapy and combination therapy, and as many were initial RA treatments they were not generalizable to usual care. In conclusion, evidence from randomized trials suggests that the b/tsDMARDs studied are effective as monotherapy. In general, some patient responses seem better with combination therapy and the durability of monotherapy is less than combination therapy. There is, however, a need for longer-term head-to-head trials to establish positioning of these interventions in the treatment algorithm for RA.

FUNDING

Pfizer.Plain Language Summary: Plain language summary available on the journal website.

Safety Profile of Baricitinib in Patients with Active Rheumatoid Arthritis with over 2 Years Median Time in Treatment

OBJECTIVE

Baricitinib is an oral, once-daily selective Janus kinase (JAK1/JAK2) inhibitor for adults with moderately to severely active rheumatoid arthritis (RA). We evaluated baricitinib's safety profile through 288 weeks (up to September 1, 2016) with an integrated database [8 phase III/II/Ib trials, 1 longterm extension (LTE)].

METHODS

The "all-bari-RA" group included patients who received any baricitinib dose. Placebo comparison was based on the 6 studies with 4 mg and placebo up to Week 24 ("placebo-4 mg" dataset). Dose response assessment was based on 4 studies with 2 mg and 4 mg including LTE data ("2 mg-4 mg-extended"). The uncommon events description used the non-controlled all-bari-RA.

RESULTS

There were 3492 patients who received baricitinib for 6637 total patient-years (PY) of exposure (median 2.1 yrs, maximum 5.5 yrs). No differences in rates of death, adverse events leading to drug discontinuation, malignancies, major adverse cardiovascular event (MACE), or serious infections were seen for 4 mg versus placebo or for 4 mg versus 2 mg. Infections including herpes zoster were significantly more frequent for 4 mg versus placebo. Deep vein thrombosis/pulmonary embolism were reported with 4 mg but not placebo [all-bari-RA incidence rate (IR) 0.5/100 PY]; the IR did not differ between doses (0.5 vs 0.6/100 PY, 2 mg vs 4 mg, respectively) or compared to published RA rates. All-bari-RA had 6 cases of lymphoma (IR 0.09/100 PY), 3 gastrointestinal perforations (0.05/100 PY), 10 cases of tuberculosis (all in endemic areas; 0.15/100 PY), and 22 all-cause deaths (0.33/100 PY). IR for malignancies (0.8/100 PY) and MACE (0.5/100 PY) were low and did not increase with prolonged exposure.

CONCLUSION

In this integrated analysis of patients with moderate to severe active RA with exposure up to 5.5 years, baricitinib has an acceptable safety profile in the context of demonstrated efficacy. Trial registration numbers: NCT01185353, NCT00902486, NCT01469013, NCT01710358, NCT01721044, NCT01721057, NCT01711359, and NCT01885078 at clinicaltrials.gov.

Dose reduction of baricitinib in patients with rheumatoid arthritis achieving sustained disease control: results of a prospective study

Objectives

This study investigated the effects of dose step-down in patients with rheumatoid arthritis (RA) who achieved sustained disease control with baricitinib 4 mg once a day.

Methods

Patients who completed a baricitinib phase 3 study could enter a long-term extension (LTE). In the LTE, patients who received baricitinib 4 mg for ≥15 months and maintained CDAI low disease activity (LDA) or remission (REM) were blindly randomised to continue 4 mg or taper to 2 mg. Patients could rescue (to 4 mg) if needed. Efficacy and safety were assessed through 48 weeks.

Results

Patients in both groups maintained LDA (80% 4 mg; 67% 2 mg) or REM (40% 4 mg; 33% 2 mg) over 48 weeks. However, dose reduction resulted in small, statistically significant increases in disease activity at 12, 24 and 48 weeks. Dose reduction also produced earlier and more frequent relapse (loss of step-down criteria) over 48 weeks compared with 4 mg maintenance (23% 4 mg vs 37% 2 mg, p=0.001). Rescue rates were 10% for baricitinib 4 mg and 18% for baricitinib 2 mg. Dose reduction was associated with a numerically lower rate of non-serious infections (30.6 for baricitinib 4 mg vs 24.9 for 2 mg). Rates of serious adverse events and adverse events leading to discontinuation were similar across groups.

Conclusions

In a large randomised, blinded phase 3 study, maintenance of RA control following induction of sustained LDA/REM with baricitinib 4 mg was greater with continued 4 mg than after taper to 2 mg. Nonetheless, most patients tapered to 2 mg could maintain LDA/REM or recapture with return to 4 mg if needed.

Increased Binding of Specificity Protein 1 to the IL21R Promoter in B Cells Results in Enhanced B Cell Responses in Rheumatoid Arthritis

B cells are implicated in rheumatoid arthritis (RA) based on the presence of autoantibodies and the therapeutic response to B cell depletion. IL-21 has a significant role in B cell development and function. Here we assess B cell responses to IL-21 and the mechanisms responsible for altered IL-21R expression in RA. Flow cytometry of PBMC and cultured B cells was used to quantify protein and mRNA levels of IL-21R, IL-21 signaling through pSTAT3, specificity protein 1 (SP1) and to determine cytokine production (IL-6) and maturation status of B cells in RA and healthy control subjects. SP1 binding to the IL21R promoter region in B cells was assessed with ChIP-qPCR. We demonstrate an increase in IL-21R expression in total and memory B cells from RA subjects, which correlated with responsiveness to IL-21 stimulation. Stimulation of naïve RA B cells with IL-21 and CD40L resulted in an increase in differentiation into plasmablasts and an increase in IL-6 production in comparison to healthy controls, which was dose dependent on IL-21 stimulation. IL-21R expression on memory B cells in RA synovial fluid was comparable to peripheral blood making our study pertinent to understanding B cell responses in the joint and site of inflammation. We identified an increase in SP1 protein and mRNA in RA B cells and demonstrate an increase in binding of SP1 to the IL21R promoter region, which suggests a mechanism by which IL-21R expression is enhanced on B cells in RA. Taken together, our results indicate a mechanism by which IL-21 enhances B cell development and function in RA through an SP1 mediated increase in IL-21R expression on B cells.

Structural damage progression in patients with early rheumatoid arthritis treated with methotrexate, baricitinib, or baricitinib plus methotrexate based on clinical response in the phase 3 RA-BEGIN study

The objective of this study was to evaluate structural damage progression based on clinical response in rheumatoid arthritis patients with no or limited prior disease-modifying anti-rheumatic drug treatment receiving the Janus kinase (JAK)1/JAK2 inhibitor baricitinib 4 mg, methotrexate (MTX), or the combination. Data from the phase 3 RA-BEGIN study were analysed post hoc. Proportions of patients with structural damage progression (change from baseline greater than the smallest detectable change in modified total Sharp score) at week 52 were evaluated based on sustained Disease Activity Score for 28-joint count with serum high-sensitivity C-reactive protein (DAS28-hsCRP) ≤ 3.2 or Simplified Disease Activity Index (SDAI) score ≤ 11; no formal statistical comparisons between treatments were performed to test these proportions. Baseline factors associated with risk of structural damage progression, including Clinical Disease Activity Index (CDAI) score, were identified using multivariate analysis. Patients achieving versus not achieving sustained DAS28-hsCRP ≤ 3.2 or SDAI score ≤ 11 were less likely to experience structural damage progression at week 52. In patients achieving these responses, structural damage progression was less likely with baricitinib monotherapy or plus MTX than with MTX monotherapy. In patients not achieving these sustained clinical thresholds, structural damage progression was less likely with baricitinib plus MTX than with either monotherapy. Independent of treatment, baseline factors significantly associated with increased risk of structural damage progression included higher hsCRP and CDAI score, smoking, female sex, and lower body mass index. In conclusion, patients achieving versus not achieving sustained DAS28-hsCRP ≤ 3.2 or SDAI score ≤ 11 were less likely to show structural damage progression, irrespective of treatment.

Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 2 trial

BACKGROUND

Patients with systemic lupus erythematosus have substantial unmet medical need. Baricitinib is an oral selective Janus kinase (JAK)1 and JAK2 inhibitor that we hypothesised might have therapeutic benefit in patients with systemic lupus erythematosus.

METHODS

In this double-blind, multicentre, randomised, placebo-controlled, 24-week phase 2 study, patients were recruited from 78 centres in 11 countries. Eligible patients were aged 18 years or older, had a diagnosis of systemic lupus erythematosus, and had active disease involving skin or joints. We randomly assigned patients (1:1:1) to receive once-daily baricitinib 2 mg, baricitinib 4 mg, or placebo for 24 weeks. The primary endpoint was the proportion of patients achieving resolution of arthritis or rash at week 24, as defined by Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2K). Efficacy and safety analyses included all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT02708095.

FINDINGS

Between March 24, 2016, and April 27, 2017, 314 patients were randomly assigned to receive placebo (n=105), baricitinib 2 mg (n=105), or baricitinib 4 mg (n=104). At week 24, resolution of SLEDAI-2K arthritis or rash was achieved by 70 (67%) of 104 patients receiving baricitinib 4 mg (odds ratio [OR] vs placebo 1·8, 95% CI 1·0-3·3; p=0·0414) and 61 (58%) of 105 patients receiving baricitinib 2 mg (OR 1·3, 0·7-2·3; p=0·39). Adverse events were reported in 68 (65%) patients in the placebo group, 75 (71%) patients in the baricitinib 2 mg group, and 76 (73%) patients in the baricitinib 4 mg group. Serious adverse events were reported in ten (10%) patients receiving baricitinib 4 mg, 11 (10%) receiving baricitinib 2 mg, and five (5%) receiving placebo; no deaths were reported. Serious infections were reported in six (6%) patients with baricitinib 4 mg, two (2%) with baricitinib 2 mg, and one (1%) with placebo.

INTERPRETATION

The baricitinib 4 mg dose, but not the 2 mg dose, significantly improved the signs and symptoms of active systemic lupus erythematosus in patients who were not adequately controlled despite standard of care therapy, with a safety profile consistent with previous studies of baricitinib. This study provides the foundation for future phase 3 trials of JAK1/2 inhibition with baricitinib as a new potential oral therapy for systemic lupus erythematosus.

FUNDING

Eli Lilly and Company.

Efficacy and safety of baricitinib for active rheumatoid arthritis in patients with an inadequate response to conventional synthetic or biological disease-modifying anti-rheumatic drugs: A meta-analysis of randomized controlled trials

The purpose of the present meta-analysis was to assess the efficacy and safety of baricitinib for active rheumatoid arthritis (RA) in patients with an inadequate response or intolerance to conventional synthetic or biological disease-modifying anti-rheumatic drugs (DMARDs). A total of 7 randomized controlled trials (RCTs) were included. The primary effective outcome was the RA improvement to reach an American College of Rheumatology 20% (ACR20) response rate. The safety outcomes were composed of clinical laboratory parameters. All patients included received 4 mg baricitinib once daily to treat RA for 12 or 24 weeks. The ACR20 response rate in the baricitinib group was significantly higher compared with that in the control group at 12 weeks [relative risk (RR), 1.77; 95% confidence interval (CI), 1.62-1.94; P<0.00001] and 24 weeks (RR, 1.76; 95% CI, 1.48-2.10; P<0.00001). Similarly, other effective outcome measures also exhibited significant improvements in the baricitinib group compared with those in the placebo group. Regarding the safety outcomes, no significant difference in adverse events (AEs) was identified at 12 weeks (P=0.14), but AEs were significantly higher in the baricitinib group compared with those in the control group at 24 weeks (P=0.03). Most laboratory values were significantly different between the baricitinib and placebo groups; however, the clinical significance of these changes remains to be determined. In summary, the present meta-analysis demonstrated that 4 mg baricitinib once daily was beneficial in patients with active RA with an inadequate response or intolerance to conventional synthetic or biological DMARDs. More high-quality RCTs are required to determine the sustained efficacy and the safety of baricitinib.

Translational and clinical advances in JAK-STAT biology: The present and future of jakinibs

In this era, it is axiomatic that cytokines have critical roles in cellular development and differentiation, immune homeostasis, and host defense. Equally, dysregulation of cytokines is known to contribute to diverse inflammatory and immune-mediated disorders. In fact, the past 20 years have witnessed the rapid translation of basic discoveries in cytokine biology to multiple successful biological agents (mAbs and recombinant fusion proteins) that target cytokines. These targeted therapies have not only fundamentally changed the face of multiple immune-mediated diseases but have also unequivocally established the role of specific cytokines in human disease; cytokine biologists have many times over provided remarkable basic advances with direct clinical benefit. Numerous cytokines rely on the JAK-STAT pathway for signaling, and new, safe, and effective small molecule inhibitors have been developed for a range of disorders. In this review, we will briefly summarize basic discoveries in cytokine signaling and briefly comment on some major unresolved issues. We will review clinical data pertaining to the first generation of JAK inhibitors and their clinical indications, discuss additional opportunities for targeting this pathway, and lay out some of the challenges that lie ahead.

Janus Kinase Inhibitor Baricitinib Modulates Human Innate and Adaptive Immune System

The purpose of this study was to elucidate the mechanism of action of baricitinib on Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling, which involves in human innate and adaptive immune system. The effects of baricitinib were evaluated using human monocyte-derived dendritic cells (MoDCs), plasmacytoid dendritic cells (pDCs), B cells, and T cells. Baricitinib concentration-dependently suppressed the expression of CD80/CD86 on MoDCs and the production of type-I interferon (IFN) by pDCs. Baricitinib also suppressed the differentiation of human B cells into plasmablasts by B cell receptor and type-I IFN stimuli and inhibited the production of interleukin (IL)-6 from B cells. Human CD4⁺ T cells proliferated after T cell receptor stimulation with anti-CD3 and anti-CD28 antibody; however, such proliferation was suppressed by baricitinib in a concentration-dependent manner. In addition, baricitinib inhibited Th1 differentiation after IL-12 stimulation and Th17 differentiation by TGF-β1, IL-6, IL-1β, and IL-23 stimulation. Tofacitinib showed similar effects in these experiments. In naive CD4⁺ T cells, IFN-α and IFN-γ induced phosphorylation of STAT1, which was inhibited by baricitinib and tofacitinib. Furthermore, IL-6-induced phosphorylation of STAT1 and STAT3 was also inhibited by JAK inhibitors. In conclusion, the results indicated that baricitinib suppresses the differentiation of plasmablasts, Th1 and Th17 cells, as well as innate immunity, such as the T cell stimulatory capacity of dendritic cells. Thus, JAK inhibitors can be potentially clinically effective not only in rheumatoid arthritis but other immune-related diseases.

The role of concomitant methotrexate dosage and maintenance over time in the therapy of rheumatoid arthritis patients treated with adalimumab or etanercept: retrospective analysis of a local registry

OBJECTIVE

To evaluate the pattern of prescription and maintenance over time of concomitant methotrexate (MTX), and its impact on a 2-year clinical response in a cohort of rheumatoid arthritis (RA) patients treated with a first-line tumor necrosis factor alpha inhibitor (TNFi).

PATIENTS AND METHODS

The study population included all RA patients receiving adalimumab or etanercept a as first-line biologic drug, extracted from a local registry. Enrolled patients were stratified into 3 subgroups according to baseline concomitant MTX: no MTX, low-dose MTX (≤10 mg/wk), and high-dose MTX (≥12.5 mg/wk). The 2-year persistence of the initial MTX regimen was computed by the Kaplan-Meier method, and a Cox proportional hazard model was developed to examine potential predictors of MTX withdrawal/change of dosage. European League Against Rheumatism remission and good-to-moderate response were evaluated according to baseline MTX regimen and MTX maintenance over time.

RESULTS

A total of 330 patients (163 treated with adalimumab and 167 with etanercept) were included; 141 were prescribed TNFi without MTX and 112 received low-dose and 77 high-dose concomitant MTX. Male sex, younger age, and shorter mean disease duration were predictors of high-dose MTX use. Among MTX users (76.2% parenteral and 23.8% oral), initial MTX dose persisted over time in 79.9% at 1 year and 70.2% at 2 years. Fifty-one patients (27%) underwent MTX dose de-escalation/discontinuation because of intolerance/adverse events. The 2-year EULAR remission rate was higher in the patients receiving and maintaining high-dose MTX than in those receiving low-dose or no MTX (46.2% vs 29.5% and 23.4%, respectively; p=0.009). The same was true for good-to-moderate response rate (71.2% vs 52.6% and 50.4%, respectively; p=0.031).

CONCLUSION

In a real-life setting, about one-third of RA patients treated with TNFis experienced dose reduction/discontinuation of concomitant MTX because of intolerance/adverse events over a 2-year follow-up period. Initial high-dose MTX and its maintenance over time are associated with better 2-year clinical response.

Are Janus Kinase Inhibitors Superior over Classic Biologic Agents in RA Patients?

The Janus Kinases (JAKs) are a family of intracellular tyrosine kinases that provide transmission signals from cytokine, interferons, and many hormones receptors to the nucleus resulting in synthesis of many biologically active compounds and changing cell metabolism and function. That was theoretical background to synthetize the JAK inhibitors (Jakinibs). In recent years a substantial battery of evidence has been collected indicating the potential role of Jakinibs to interact with the specific elements of the immune system, therefore changing the inflammatory response. JAK kinase blockade offers a unique opportunity to block most of the key cytokines enabling the deep interaction into immune system functioning. Following discovery first Jakinibs were intensively studied in various forms of autoimmune diseases, including rheumatoid arthritis, and finally two Jakinibs tofacitinib and Baricitinib have been approved for the treatment of rheumatoid arthritis. Some clinical data indicated that under special circumstances Jakinibs may be even superior to biologics in the treatment of RA; however this suggestion should be verified in large clinical and observational studies.

Effects of baricitinib on radiographic progression of structural joint damage at 1 year in patients with rheumatoid arthritis and an inadequate response to conventional synthetic disease-modifying antirheumatic drugs

BACKGROUND

Baricitinib was efficacious in a 24-week phase III study in patients with rheumatoid arthritis (RA) and an inadequate response to conventional synthetic disease-modifying anti rheumatic drugs (DMARDs) (csDMARDs) (RA-BUILD).

OBJECTIVES

To evaluate radiographic progression of structural joint damage in RA-BUILD patients over 48 weeks of baricitinib treatment in the long-term extension study, RA-BEYOND.

METHODS

In RA-BUILD, patients were randomised to placebo, baricitinib 2 mg or 4 mg once daily, with rescue possible from week 16. Patients completing RA-BUILD and entering RA-BEYOND continued to receive the baricitinib dose received at the end of RA-BUILD. Patients receiving placebo were switched to baricitinib 4 mg in RA-BEYOND. Joint damage was measured using the van der Heijde modified total Sharp score. To account for missing scores and scores obtained after rescue, switch or discontinuation of study drug, data were analysed using (1) linear extrapolation (LE) and (2) observed/last observation carried forward (LOCF). The observed/LOCF method used all available observed data, including after rescue or switch, with patients analysed according to original treatment assignment.

RESULTS

Using LE, radiographic progression at 24 and 48 weeks was statistically significantly lower for both baricitinib 2 or 4 mg compared with placebo. Only baricitinib 4 mg demonstrated statistically significant inhibition of progressive radiographic joint damage compared with patients initially randomised to placebo using observed/LOCF at week 48.

CONCLUSIONS

Once daily oral baricitinib inhibited radiographic progression of structural joint damage in patients with an inadequate response or intolerance to csDMARDs over 48 weeks. The most robust benefit was seen for the 4 mg dose.

Interleukin-6: designing specific therapeutics for a complex cytokine

Interleukin-6 (IL-6) is a pivotal cytokine with a diverse repertoire of physiological functions that include regulation of immune cell proliferation and differentiation. Dysregulation of IL-6 signalling is associated with inflammatory and lymphoproliferative disorders such as rheumatoid arthritis and Castleman disease, and several classes of therapeutics have been developed that target components of the IL-6 signalling pathway. So far, monoclonal antibodies against IL-6 or IL-6 receptor (IL-6R) and Janus kinases (JAK) inhibitors have been successfully developed for the treatment of autoimmune diseases such as rheumatoid arthritis. However, clinical trials of agents targeting IL-6 signalling have also raised questions about the diseases and patient populations for which such agents have an appropriate benefit-risk profile. Knowledge from clinical trials and advances in our understanding of the complexities of IL-6 signalling, including the potential to target an IL-6 trans-signalling pathway, are now indicating novel opportunities for therapeutic intervention. In this Review, we overview the roles of IL-6 in health and disease and analyse progress with several approaches of inhibiting IL-6-signalling, with the aim of illuminating when and how to apply IL-6 blockade.