Comparative Efficacy of JAK Inhibitors for Moderate-To-Severe Rheumatoid Arthritis: A Network Meta-Analysis.
ABSTRACT: INTRODUCTION:Janus kinase (JAK) inhibitors are a class of targeted therapies for rheumatoid arthritis (RA) with established clinical efficacy. However, little is known about their efficacy compared with each other. This network meta-analysis (NMA) estimated the comparative efficacy of JAK inhibitors currently approved for RA. METHODS:A targeted literature review was conducted for phase III randomized controlled trials (RCTs) evaluating the efficacy of three approved JAK inhibitors (tofacitinib, baricitinib, and upadacitinib) as monotherapy or combination therapy among patients with moderate-to-severe RA who had inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARD-IR). Using Bayesian NMA, American College of Rheumatology (ACR) 20/50/70 responses and clinical remission (defined as DAS28-CRP?
Project description:BACKGROUND:Innate immune cells play a crucial role in the pathophysiology of rheumatoid arthritis (RA) via release of cytokines. Small-molecule inhibitors of Janus kinases (JAKi) are clinically efficacious in patients with RA. However, the isoform-specific action of each JAKi is difficult to assess, since JAKs form heterodimeric complexes with cytokine receptors. We assessed the effects of several JAKi on GM-CSF-primed human innate immune cells. RESULTS:Treatment with JAKi (tofacitinib, baricitinib, upadacitinib) prevented GM-CSF-induced JAK2/STAT5 phosphorylation at higher concentrations (400?nM) in THP-1 cells. Whereas compared with baricitinib or upadacitinib, the inhibitory effects of tofacitinib on the GM-CSF-induced JAK2/STAT5 phosphorylation were weak at lower concentrations (??100?nM). All JAKi inhibited GM-CSF-induced IL-1? production by human neutrophils. However, the inhibitory effects of baricitinib on IL-1? production were larger compared to those of tofacitinib or upadacitinib at lower concentrations (??100?nM). Similarly, all JAKi inhibited GM-CSF-induced caspase-1(p20) production by human neutrophils. CONCLUSION:We conclude that incubation with JAKi prevents GM-CSF-mediated JAK2/STAT5 activation in human innate immune cells. Although baricitinib and upadacitinib almost completely blocked GM-CSF-mediated JAK2/STAT5 signaling, the inhibitory effects of tofacitinib were weaker at lower concentrations suggesting that variation exists among these JAKi in the inhibition of JAK2 signaling pathways.
Project description:Janus kinase (JAK) inhibitors have emerged as an effective class of therapies for various inflammatory diseases such as rheumatoid arthritis (RA). JAK inhibitors function intracellularly by modulating the catalytic activity of JAKs and disrupting the receptor-mediated signaling of multiple cytokines and growth factors, including those with pro-inflammatory activity. Understanding the inhibition profiles of different JAK inhibitors, based on the associated cytokine receptors and downstream inflammatory pathways affected, is important to identify the potential mechanisms for observed differences in efficacy and safety. This study applied an integrated modeling approach, using in vitro whole blood cytokine inhibition potencies and plasma pharmacokinetics, to determine JAK-dependent cytokine receptor inhibition profiles, in the context of doses estimated to provide a similar clinical response in RA clinical trials. The calculated profiles of cytokine receptor inhibition for the JAK inhibitors tofacitinib, baricitinib, upadacitinib, and filgotinib and its metabolite, were generally similar when clinically efficacious doses for RA were considered. Only minor numerical differences in percentage cytokine receptor inhibition were observed, suggesting limited differentiation of these inhibitors based on JAK pharmacology, with each showing a differential selectivity for JAK1 heterodimer inhibition. Nevertheless, only robust clinical testing involving head-to-head studies will ultimately determine whether there are clinically meaningful differences between these JAK inhibitors. Furthermore, ongoing and future research into inhibitors with alternative JAK selectivity remains of clinical importance. Thus, all JAK inhibitors should be characterized via thorough preclinical, metabolic and pharmacological evaluation, adequate long-term clinical data, and when available, real-world experience.
Project description:Background:Anti-cytokine therapies such as adalimumab, tocilizumab, and the small molecule JAK inhibitor tofacitinib have proven that cytokines and their subsequent downstream signaling processes are important in the pathogenesis of rheumatoid arthritis. Tofacitinib, a pan-JAK inhibitor, is the first approved JAK inhibitor for the treatment of RA and has been shown to be effective in managing disease. However, in phase 2 dose-ranging studies tofacitinib was associated with dose-limiting tolerability and safety issues such as anemia. Upadacitinib (ABT-494) is a selective JAK1 inhibitor that was engineered to address the hypothesis that greater JAK1 selectivity over other JAK family members will translate into a more favorable benefit:risk profile. Upadacitinib selectively targets JAK1 dependent disease drivers such as IL-6 and IFN?, while reducing effects on reticulocytes and natural killer (NK) cells, which potentially contributed to the tolerability issues of tofacitinib. Methods:Structure-based hypotheses were used to design the JAK1 selective inhibitor upadacitinib. JAK family selectivity was defined with in vitro assays including biochemical assessments, engineered cell lines, and cytokine stimulation. In vivo selectivity was defined by the efficacy of upadacitinib and tofacitinib in a rat adjuvant induced arthritis model, activity on reticulocyte deployment, and effect on circulating NK cells. The translation of the preclinical JAK1 selectivity was assessed in healthy volunteers using ex vivo stimulation with JAK-dependent cytokines. Results:Here, we show the structural basis for the JAK1 selectivity of upadacitinib, along with the in vitro JAK family selectivity profile and subsequent in vivo physiological consequences. Upadacitinib is ~?60 fold selective for JAK1 over JAK2, and?>?100 fold selective over JAK3 in cellular assays. While both upadacitinib and tofacitinib demonstrated efficacy in a rat model of arthritis, the increased selectivity of upadacitinib for JAK1 resulted in a reduced effect on reticulocyte deployment and NK cell depletion relative to efficacy. Ex vivo pharmacodynamic data obtained from Phase I healthy volunteers confirmed the JAK1 selectivity of upadactinib in a clinical setting. Conclusions:The data presented here highlight the JAK1 selectivity of upadacinitinib and supports its use as an effective therapy for the treatment of RA with the potential for an improved benefit:risk profile.
Project description:BACKGROUND:The in vitro pharmacology of baricitinib, upadacitinib, and tofacitinib was evaluated to understand differences among these JAK inhibitors (JAKis) at the cellular level. METHODS:Peripheral blood mononuclear cells from healthy donors were incubated with different JAKis, levels of phosphorylated signal transducer and activator of transcription (pSTAT) were measured following cytokine stimulation, and half maximum inhibitory concentration (IC50) values were calculated in phenotypically gated leukocyte subpopulations. Therapeutic dose relevance of the in vitro analysis was assessed using calculated mean concentration-time profiles over 24 h obtained from JAKi-treated subjects. Time above IC50 and average daily percent inhibition of pSTAT formation were calculated for each JAKi, cytokine, and cell type. RESULTS:Distinct JAKis displayed different in vitro pharmacologic profiles. For example, tofacitinib and upadacitinib were the most potent inhibitors of the JAK1/3-dependent cytokines tested (interleukin [IL]-2, IL-4, IL-15, and IL-21) with lower IC50 values and increased time above IC50 translating to a greater overall inhibition of STAT signaling during the dosing interval. All JAKis tested inhibited JAK1/2-dependent cytokines (e.g., IL-6 and interferon [IFN]-γ), the JAK1/tyrosine kinase 2 (TYK2)-dependent cytokines IL-10 and IFN-α, the JAK2/2-dependent cytokines IL-3 and granulocyte-macrophage colony-stimulating factor (GM-CSF), and the JAK2/TYK2-dependent cytokine granulocyte colony-stimulating factor (G-CSF), but often to significantly differing degrees. CONCLUSIONS:Different JAKis modulated distinct cytokine pathways to varying degrees, and no agent potently or continuously inhibited an individual cytokine signaling pathway throughout the dosing interval. Notably, baricitinib inhibited JAK1/3 signaling to a lesser extent than upadacitinib and tofacitinib, while upadacitinib, baricitinib, and tofacitinib inhibited the signaling of JAK2/2-dependent cytokines, including GM-CSF and IL-3, as well as the signaling of the JAK2/TYK2-dependent cytokine G-CSF.
Project description:BACKGROUND/OBJECTIVE:Baricitinib is a selective and reversible Janus kinase (JAK) inhibitor indicated for the treatment of adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to one or more tumor necrosis factor inhibitors (TNFis) and has been shown to improve multiple clinical and patient-reported outcomes. However, it is unclear what the budgetary impact would be for US commercial payers to add baricitinib to their formulary and how the efficacy of baricitinib compares to other disease-modifying antirheumatic drugs (DMARDs) with a similar indication. METHODS:A budget impact model (BIM) was developed for a hypothetical population of 1 million plan members that compared a world without and with baricitinib. A retrospective observational study was carried out to estimate market utilization of advanced therapies. Number needed to treat (NNT) and cost per additional responder were calculated for American College of Rheumatology (ACR) 20%/50%/70% improvement criteria (ACR20/50/70) response outcomes combining cost estimates from the BIM and efficacy values from a network meta-analysis (NMA). The model included costs related to drug acquisition and monitoring costs. RESULTS:Adding baricitinib would save a commercial payer $US169,742 for second-line therapy and $US135,471 for third-line therapy over a 2-year time horizon (all costs correspond to 2019 US dollars). Cost savings were driven by baricitinib drawing market share away from more expensive comparators. The NMA, based on nine studies, found no statistically significant differences in the median treatment difference between baricitinib and comparators except for versus a conventional synthetic DMARD (csDMARD), and thus NNT versus a csDMARD was similar. The cost per additional responder for baricitinib in patients with inadequate response to a TNFi was substantially lower than all other treatments for all three ACR response criteria at 12 weeks (ACR20: $US129,672; ACR50: $US237,732; ACR70: $US475,464), and among the lowest at 24 weeks (ACR20: $US167,811; ACR50: $US259,344; ACR70: $US570,557). CONCLUSIONS:Baricitinib, compared to other DMARDs, was a less expensive option (-?$US0.01 incremental cost per member per month in second- and third-line therapy over a 2-year time horizon) with comparable efficacy in patients with inadequate response to TNFi. Adding baricitinib to formulary would likely be cost saving for US payers and expands treatment options for these patients.
Project description:The past decade has witnessed an explosion in trial data on JAK inhibitors (JAKi). These small molecules target the Janus kinase - signal transducer and activator of transcription (JAK-STAT) pathway, blocking crucial cytokines across a septum of rheumatic diseases. As a class, JAKi are beginning to demonstrate efficacy on par, if not superior to biologics. Two first generation JAKi are licensed for use in inflammatory arthritis; tofacitinib and baricitinib. Next-generation JAKi have been designed with selective affinity for one JAK enzymes, the aim to reduce unwanted adverse effects without declining clinical efficacy. Emerging data with selective JAK1 inhibitors upadacitinib and filgotinib looks very promising. Despite differences in selectivity between JAKi, an overlap exists in their safety profiles. Across the class, a characteristic safety signal is emerging with viral opportunistic infections, particularly herpes zoster. Post marketing drug surveillance will be essential in evaluating the long-term risk with these agents.
Project description:Janus kinase (JAK) Inhibitors are the latest drug class of disease-modifying medication to emerge for the treatment of rheumatoid arthritis (RA). They are a small molecule-targeted treatment and are the first oral option to compare favourably to existing biologic disease-modifying anti-rheumatic drugs (DMARDs). Tofacitinib, baricitinib and upadacitinib are the first 3 JAK inhibitors to become commercially available in the field and are the core focus of this review. To date, they have demonstrated comparable efficacy to tumour necrosis factor (TNF) inhibitors in terms of American College of Rheumatology (ACR) response rates and disease activity (DAS28) scores with similar cost to the benchmark adalimumab. This narrative review article aims to synthesise and distil the key available trial data on JAK inhibitor efficacy and safety, along with their place in the ACR and European League Against Rheumatism (EULAR) guidelines for RA. The novel mechanism of action of the JAK/STAT pathway is highlighted along with the potential effects of modulating each pathway. The rapid onset of action, role in attenuation of central pain processing and effect on structural damage and radiographic progression are also all examined in detail. We also explore the latest meta-analyses and comparative performance of each of the 3 available JAKs in an effort to determine which is most efficacious and which has the most favourable safety profile. Post marketing concerns regarding thromboembolism risk and herpes zoster infection are also discussed. Additionally, we review the cost-benefit analyses of the available JAK inhibitors and address some of the pharmacoeconomic considerations for real-world practice in the UK and US by detailing the raw acquisition cost and the value they provide in comparison to the benchmark biologic adalimumab and the anchor DMARD methotrexate.
Project description:The pathogenesis of SpA is multifactorial and involves a range of immune cell types and cytokines, many of which utilize Janus kinase (JAK) pathways for signaling. In this review, we summarize the animal and pre-clinical data that have demonstrated the effects of JAK blockade on the underlying molecular mechanisms of SpA and provide a rationale for JAK inhibition for the treatment of SpA. We also review the available clinical trial data evaluating JAK inhibitors tofacitinib, baricitinib, peficitinib, filgotinib and upadacitinib in PsA, AS and related inflammatory diseases, which have demonstrated the efficacy of these agents across a range of SpA-associated disease manifestations. The available clinical trial data, supported by pre-clinical animal model studies demonstrate that JAK inhibition is a promising therapeutic strategy for the treatment of SpA and may offer the potential for improvements in multiple articular and extra-articular disease manifestations of PsA and AS.
Project description:This article evaluates the efficacy and safety of baricitinib 4 mg versus placebo in United States including Puerto Rico (US) and rest of the world (ROW) subpopulations using data pooled from RA-BEAM and RA-BUILD, which enrolled patients with moderate-to-severe adult-onset rheumatoid arthritis (RA).In RA-BEAM, patients with an inadequate response (IR) to methotrexate, at least one X-ray erosion, and high sensitivity C-reactive protein (hsCRP) ≥ 6 mg/L were randomized to placebo or orally administered baricitinib 4 mg daily or subcutaneously administered adalimumab 40 mg every other week. In RA-BUILD, patients with an IR to at least one conventional synthetic disease-modifying antirheumatic drug (csDMARD) and with hsCRP ≥ 3.6 mg/L were randomized to placebo or baricitinib 2 or 4 mg daily. Patients in both trials were biologic naive. In this post hoc analysis, data from both studies were pooled (714 baricitinib 4 mg-treated, 716 placebo-treated patients).Overall, 188 US and 1242 ROW patients were included. Subgroups differed in baseline characteristics including race, weight, age, time since RA diagnosis, current corticosteroid use, and previous csDMARD use. At weeks 12 and 24, baricitinib-treated patients had larger responses compared to placebo-treated patients for multiple efficacy outcomes: American College of Rheumatology 20/50/70 response, low disease activity, remission, Disease Activity Score 28-C-reactive protein, and Health Assessment Questionnaire-Disability Index. Overall, similar efficacy was observed in US and ROW subgroups with no notable safety differences between subgroups at weeks 12 or 24.Baricitinib 4 mg was efficacious compared to placebo in US and ROW subpopulations. Safety was similar between subgroups.Eli Lilly & Company and Incyte Corporation.ClinicalTrials.gov identifiers, NCT01721057; NCT01710358.
Project description:Janus kinase inhibitors (JAKi) belong to a new class of oral targeted disease-modifying drugs which have recently revolutionized the therapeutic panorama of rheumatoid arthritis (RA) and other immune-mediated diseases, placing alongside or even replacing conventional and biological drugs. JAKi are characterized by a novel mechanism of action, consisting of the intracellular interruption of the JAK-STAT pathway crucially involved in the immune response. The aim of this narrative review is to globally report the most relevant pharmacological features and clinical outcomes of the developed and incoming JAKi for RA, based on the available preclinical and clinical evidence. A total of 219 papers, including narrative and systematic reviews, randomized controlled trials (RCTs), observational studies, case reports, guidelines, and drug factsheets, were selected. The efficacy and safety profile of both the first generation JAKi (baricitinib and tofacitinib) and the second generation JAKi (upadacitinib, filgotinib, peficitinib, decernotinib and itacitinib) were compared and discussed. Results from RCTs and real-life data are encouraging and outline a rapid onset of the pharmacologic effects, which are maintained during the time. Their efficacy and safety profile are comparable or superior to those of biologic agents and JAKi proved to be efficacious when given as monotherapy. Finally, the manufacturing of JAKi is relatively easier and cheaper than that of biologics, thus increasing the number of compounds being formulated and tested for clinical use.