Preferential Inhibition of JAK1 Relative to JAK3 by Upadacitinib: Exposure-Response Analyses of Ex Vivo Data From 2 Phase 1 Clinical Trials and Comparison to Tofacitinib

Ovarian cancer ascites confers platinum chemoresistance to ovarian cancer cells

Ovarian cancer (OC), the second most common form of gynecologic malignancy, has a poor prognosis and is often discovered in the late stages. Platinum-based chemotherapy is the first line of therapy. Nevertheless, treatment OC has proven challenging due to toxicity and the development of acquired resistance to therapy. Tumor microenvironment (TME) has been associated with platinum chemoresistance. Malignant ascites has been used as OC tumor microenvironment and its ability to induce platinum chemoresistance has been investigated. Our results suggest that exposure to OC ascites induces platinum chemoresistance in 11 of 13 cases (85 %) on OC cells. In contrast, 75 % of cirrhotic ascites (3 of 4) failed to confer platinum chemoresistance to OC cells. Cytokine array analysis revealed that IL -6 and to a lesser extent HGF were enriched in OC ascites, whereas IL -22 was enriched in cirrhotic ascites. Pharmaceutical inhibitors targeting the IL -6/ JAK pathway were mildly effective in overcoming platinum chemoresistance induced by malignant ascites. In contrast, crizotinib, an HGF/c- MET inhibitor, and 2-hydroxyestradiol (2HE2) were effective in restoring platinum chemosensitivity to OC. Our results demonstrate the importance of OC ascites in supporting platinum chemoresistance and the potential of combination therapy to restore chemosensitivity of OC cells.

Effectiveness of Dose Increase in Upadacitinib from 15 mg to 30 mg for Patients with Moderate-to-Severe Atopic Dermatitis: A Real-World Clinical Practice in Japan

BACKGROUND

Atopic dermatitis is characterized by persistent eczema and pruritus. Janus kinase inhibitors, including upadacitinib, are effective treatments for moderate-to-severe atopic dermatitis. If patients do not respond well to a certain dose of a Janus kinase inhibitor, increasing the dose may improve their treatment responsiveness.

OBJECTIVES

We assessed the outcomes of a dose increase in upadacitinib from 15 mg to 30 mg for Japanese patients with moderate-to-severe atopic dermatitis.

METHODS

In 23 patients who showed insufficient responses to upadacitinib 15-mg treatment, the dose of upadacitinib was increased to 30 mg. We evaluated total Eczema Area and Severity Index (EASI), EASI on the head and neck, trunk, upper, or lower limbs, EASI of erythema, edema/papulation, excoriation, or lichenification, and Peak Pruritus Numerical-Rating Scale at baseline (onset of upadactinib 15 mg), week 0 (time of increase), and weeks 4 and 12 after the increase.

RESULTS

Total EASI, EASI on each anatomical site, EASI of each clinical sign, and Peak Pruritus Numerical-Rating Scale were markedly reduced at weeks 4 or 12 compared with week 0. After the dose increase, the achievement rates of EASI 75 and EASI 90 significantly improved; EASI 75 4.3%, 68.2%, and 66.7%; EASI 90 0%, 18.2%, and 38.1% at weeks 0, 4, and 12, respectively.

CONCLUSIONS

These results suggest that upadacitinib 30 mg can ameliorate rash and pruritus insufficiently improved by upadacitinib 15 mg, and that the dose increase to 30 mg may be considered as a treatment option for patients with atopic dermatitis with a limited response to upadacitinib 15 mg.

Selectivity, efficacy and safety of JAKinibs: new evidence for a still evolving story

Fundamental insight gained over the last decades led to the discovery of cytokines as pivotal drivers of inflammatory diseases such as rheumatoid arthritis, psoriasis/psoriasis arthritis, inflammatory bowel diseases, atopic dermatitis and spondylarthritis. A deeper understanding of the pro-inflammatory and anti-inflammatory effects of various cytokines has prompted new cytokine-targeting therapies, which revolutionised the treatment options in the last years for patients with inflammatory disorders. Disease-associated immune responses typically involve a complex interplay of multiple cytokines. Therefore, blockade of one single cytokine does not necessarily lead to a persistent remission in all patients with inflammatory disorders and fostered new therapeutic strategies targeting intracellular pathways shared by multiple cytokines. By inhibiting JAK-STAT signalling pathways common to families of cytokines, JAK-inhibitors (JAKinibs) have created a new paradigm for the treatment of inflammatory diseases. Multiple agents have been approved for various disorders and more are being investigated for several new indications. Second-generation selective JAKinibs have been devised with the aim to achieve an increased selectivity and a possible reduced risk of side effects. In the current review, we will summarise the current body of evidence of pan versus selective JAKinibs and the most recent insights on new side effects and indications, including COVID-19.

Upadacitinib: Mechanism of action, clinical, and translational science

Upadacitinib is a selective Janus kinase (JAK) inhibitor which is approved by the US Food and Drug Administration, the European Medicines Agency, as well as other agencies around the world for the treatment of several chronic inflammatory diseases, including rheumatic, dermatologic, and gastrointestinal diseases. Through inhibition of JAK, upadacitinib inhibits phosphorylation of downstream effector proteins, which consequently inhibits cytokine signaling for key pathways involved in inflammatory diseases. Upadacitinib more potently inhibits JAK1 than other JAK isoforms. The pharmacokinetics, pharmacodynamics, efficacy, and safety of upadacitinib were characterized in many clinical trials, which demonstrated the superiority of upadacitinib treatment over placebo or an active comparator in rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, non-radiographic axial spondyloarthritis, atopic dermatitis, Crohn's disease, and ulcerative colitis. The safety profile of upadacitinib supported a favorable benefit-risk profile across all the approved indications. In this article, we review the mechanism of action of upadacitinib and describe how the JAK-STAT (Janus kinase-signal transducers and activators of transcription) pathway is involved in the pathogenesis of several chronic and progressive immune-mediated inflammatory diseases. In addition, this review also provides an overview of key clinical trials that were conducted as well as relevant data which supported the clinical development of upadacitinib and informed the recommended dose(s) in each of the approved indications.

Upadacitinib Plus Intensive Granulocyte and Monocyte Adsorptive Apheresis for Ulcerative Colitis Achieved Ulcer Healing for Pyoderma Gangrenosum

A 44-year-old woman who had been diagnosed with ulcerative colitis (UC) at 22 years old was diagnosed with severe flare-up of UC based on endoscopic findings associated with new-onset active pyoderma gangrenosum (PG) on both lower legs after she decided to discontinue UC treatment. Systemic treatment with intravenous prednisolone at 30 mg/day had achieved insufficient response to UC and PG, resulting in a diagnosis of corticosteroid-refractory UC and PG. Combination therapy with upadacitinib at 45 mg/day plus intensive granulocyte and monocyte adsorptive apheresis (GMA) was started to achieve clinical remission of UC. Ten weeks after starting this combination therapy, clinical improvement of UC was achieved with PG ulcer healing on both lower legs. A combination of upadacitinib plus intensive GMA may offer an effective therapeutic option for patients with active PG in addition to UC but has yet to be approved for induction or maintenance treatment of PG worldwide. PG is a dermatological involvement in UC patients that requires attention.

The Therapeutic Values of IL-7/IL-7R and the Recombinant Derivatives in Glioma: A Narrative Review

Interleukin-7 (IL-7) is essential for maintaining the immune system's defense functions by regulating the development and homeostasis of lymphocytes. Findings have shown the high efficacy of IL-7/IL-7 receptor (IL-7R)-based immunotherapy on various malignancies, with confirmation in both animal models and humans. In recent years, the progression-free survival and overall survival of patients suffering from gliomas significantly increased by introducing C7R-expressing chimeric antigen receptor (CAR)-T cells and long-acting IL-7 agonists such as NT-I7 (rhIL-7-hyFc, Efineptakin alfa). However, the effect of IL-7-based immunotherapies on the resistance of tumor cells to chemotherapy (when used simultaneously with chemotherapy agents) is still ambiguous and requires further studies. This article first reviews the pathophysiological roles of IL-7/IL-7R in tumors, focusing on gliomas. Subsequently, it discusses the therapeutic values of IL-7/IL-7R and the recombinant derivatives in gliomas.

The evolving role of JAK inhibitors in the treatment of inflammatory bowel disease

INTRODUCTION

Janus Kinase inhibitors (JAKi) are a new class of oral therapies for the treatment of moderate-severe ulcerative colitis with additional potential for the treatment of moderate-severe Crohn's disease. In contrast to biologic therapies JAKi provide the opportunity for non-immunogenic once or twice daily oral therapies.

AREAS COVERED

Janus Kinase inhibitors for the treatment of ulcerative colitis and Crohn's disease based on mechanism of action, pharmacokinetics, clinical trial and real-world data regarding safety and efficacy; focusing on regulatory approvals in the U.S. and Europe.

EXPERT OPINION

Janus Kinase inhibitors are considered among the 'advanced therapies' for IBD and are approved for the treatment of moderate to severe ulcerative colitis in adults with pending approvals for Crohn's disease in the U.S. JAKi offer non-immunogenic, oral options for patient not responding to other conventional agents but, have been 'restricted' by the FDA to patients with inadequate response to TNF blockers. JAKi offer rapidly acting oral alternatives to biologic agents for moderate-severe ulcerative colitis where the risks of cardiovascular and thrombotic events noted in rheumatoid arthritis have not been observed in IBD clinical trials. Nevertheless, monitoring of infections (primarily herpes zoster) and risk factors for cardiovascular and thrombotic complications is appropriate.

Upadacitinib Induction and Maintenance Therapy for Crohn's Disease

BACKGROUND

Upadacitinib, an oral selective Janus kinase (JAK) inhibitor, is under investigation for the treatment of Crohn's disease.

METHODS

In two phase 3 induction trials (U-EXCEL and U-EXCEED), we randomly assigned patients with moderate-to-severe Crohn's disease to receive 45 mg of upadacitinib or placebo (2:1 ratio) once daily for 12 weeks. Patients who had a clinical response to upadacitinib induction therapy were randomly assigned in the U-ENDURE maintenance trial to receive 15 mg of upadacitinib, 30 mg of upadacitinib, or placebo (1:1:1 ratio) once daily for 52 weeks. The primary end points for induction (week 12) and maintenance (week 52) were clinical remission (defined as a Crohn's Disease Activity Index score of <150 [range, 0 to 600, with higher scores indicating more severe disease activity]) and endoscopic response (defined as a decrease in the Simple Endoscopic Score for Crohn's Disease [SES-CD; range, 0 to 56, with higher scores indicating more severe disease] of >50% from baseline of the induction trial [or for patients with an SES-CD of 4 at baseline, a decrease of ≥2 points from baseline]).

RESULTS

A total of 526 patients underwent randomization in U-EXCEL, 495 in U-EXCEED, and 502 in U-ENDURE. A significantly higher percentage of patients who received 45-mg upadacitinib than those who received placebo had clinical remission (in U-EXCEL, 49.5% vs. 29.1%; in U-EXCEED, 38.9% vs. 21.1%) and an endoscopic response (in U-EXCEL, 45.5% vs. 13.1%; in U-EXCEED, 34.6% vs. 3.5%) (P<0.001 for all comparisons). At week 52 in U-ENDURE, a higher percentage of patients had clinical remission with 15-mg upadacitinib (37.3%) or 30-mg upadacitinib (47.6%) than with placebo (15.1%), and a higher percentage had an endoscopic response with 15-mg upadacitinib (27.6%) or 30-mg upadacitinib (40.1%) than with placebo (7.3%) (P<0.001 for all comparisons). Herpes zoster infections occurred more frequently in the 45-mg and 30-mg upadacitinib groups than in the respective placebo groups, and hepatic disorders and neutropenia were more frequent in the 30-mg upadacitinib group than in the other maintenance groups. Gastrointestinal perforations developed in 4 patients who received 45-mg upadacitinib and in 1 patient each who received 30-mg or 15-mg upadacitinib.

CONCLUSIONS

Upadacitinib induction and maintenance treatment was superior to placebo in patients with moderate-to-severe Crohn's disease. (Funded by AbbVie; U-EXCEL, U-EXCEED, and U-ENDURE ClinicalTrials.gov numbers, NCT03345849, NCT03345836, and NCT03345823.).

Upadacitinib for the Treatment of Rheumatoid Arthritis: An Extensive Review

OBJECTIVES

To review the characteristics, efficacy, safety, pharmacoeconomics, and place in therapy of upadacitinib, a Janus kinase (JAK) inhibitor, in the treatment of rheumatoid arthritis (RA).

DATA SOURCES

PubMed (January 2003-May 2022) was searched using upadacitinib and ABT-494.

STUDY SELECTION AND DATA EXTRACTION

Human studies published in peer-reviewed publications in English were the primary sources for efficacy and safety data.

DATA SYNTHESIS

In randomized, double-blind, controlled clinical studies, upadacitinib demonstrated statistically significant improvement in RA symptoms as monotherapy and in combination with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) when compared with csDMARD monotherapy or to adalimumab or abatacept in combination with csDMARD therapy in patients with RA. American College of Rheumatology 20% response rates were 68% to 79% for upadacitinib monotherapy and 64% to 84% for upadacitinib plus csDMARD therapy, compared with 28% to 59% for csDMARD-only therapy and 63% to 74% for biologic DMARD (bDMARD) plus csDMARD therapy. Long-term extension studies demonstrated similar findings. Upadacitinib had similar rates of serious infections, herpes zoster, major cardiovascular events, and venous thromboembolic events as other JAK inhibitors. Upadacitinib was similar in cost to tofacitinib and twice as high as baricitinib based on current estimated costs to patients, but actual costs may vary.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Upadacitinib is an alternative therapy to other JAK inhibitors and bDMARDs in patients with moderate to severe RA who have had an inadequate response to a tumor necrosis factor inhibitor alone or in combination with a csDMARD.

CONCLUSIONS

Upadacitinib is an effective JAK inhibitor for use in RA.

Histone deacetylase inhibitors as a potential new treatment for psoriatic disease and other inflammatory conditions

Collectively known as psoriatic disease, psoriasis and psoriatic arthritis (PsA) are immune-mediated inflammatory diseases in which patients present with cutaneous and musculoskeletal inflammation. Affecting roughly 2-3% of the world's total population, there remains unmet therapeutic needs in both psoriasis and PsA despite the availability of current immunomodulatory treatments. As a result, patients with psoriatic disease often experience reduced quality of life. Recently, a class of small molecules, commonly investigated as anti-cancer agents, called histone deacetylase (HDAC) inhibitors, have been proposed as a new promising anti-inflammatory treatment for immune- and inflammatory-related diseases. In inflammatory diseases, current evidence is derived from studies on diseases like rheumatoid arthritis (RA) and systematic lupus erythematosus (SLE), and while there are some reports studying psoriasis, data on PsA patients are not yet available. In this review, we provide a brief overview of psoriatic disease, psoriasis, and PsA, as well as HDACs, and discuss the rationale behind the potential use of HDAC inhibitors in the management of persistent inflammation to suggest its possible use in psoriatic disease.

IL-7: A promising adjuvant ensuring effective T cell responses and memory in combination with cancer vaccines?

Cancer vaccines exhibit specificity, effectiveness, and safety as an alternative immunotherapeutic strategy to struggle against malignant diseases, especially with the rapid development of mRNA cancer vaccines in recent years. However, how to maintain long-term immune memory after vaccination, especially T cells memory, to fulfill lasting surveillance against cancers, is still a challenging issue for researchers all over the world. IL-7 is critical for the development, maintenance, and proliferation of T lymphocytes, highlighting its potential role as an adjuvant in the development of cancer vaccines. Here, we summarized the IL-7/IL-7 receptor signaling in the development of T lymphocytes, the biological function of IL-7 in the maintenance and survival of T lymphocytes, the performance of IL-7 in pre-clinical and clinical trials of cancer vaccines, and the rationale to apply IL-7 as an adjuvant in cancer vaccine-based therapeutic strategy.

Targeting Janus Kinase (JAK) for Fighting Diseases: The Research of JAK Inhibitor Drugs

Janus Kinase (JAK), a nonreceptor protein tyrosine kinase, has emerged as an excellent target through research and development since its discovery in the 1990s. As novel small-molecule targeted drugs, JAK inhibitor drugs have been successfully used in the treatment of rheumatoid arthritis (RA), myofibrosis (MF) and ulcerative colitis (UC). With the gradual development of JAK targets in the market, JAK inhibitors have also received very considerable feedback in the treatment of autoimmune diseases such as atopic dermatitis (AD), Crohn's disease (CD) and graft-versus host disease (GVHD). This article reviews the research progress of JAK inhibitor drugs: introducing the existing JAK inhibitors on the market and some JAK inhibitors in clinical trials currently. In addition, the synthesis of various types of JAK inhibitors were summarized, and the effects of different drug structures on drug inhibition and selectivity.

Phase 1 and Scintigraphy Studies to Evaluate Safety, Tolerability, Pharmacokinetics, and Lung Deposition of Inhaled GDC-0214 in Healthy Volunteers

Several inflammatory cytokines that promote inflammation and pathogenesis in asthma signal through the Janus kinase 1 (JAK1) pathway. This phase I, randomized, placebo‐controlled trial assessed the pharmacokinetics and safety of single and multiple ascending doses up to 15 mg twice daily for 14 days of a JAK1 inhibitor, GDC‐0214, in healthy volunteers (HVs; n = 66). Doses were administered with a dry powder, capsule‐based inhaler. An accompanying open‐label gamma scintigraphy study in HVs examined the lung deposition of a single dose of inhaled Technetium‐99m (^99mTc)‐radiolabeled GDC‐0214. GDC‐0214 plasma concentrations were linear and approximately dose‐proportional after both single and multiple doses. Peak plasma concentrations occurred at 15–30 min after dosing. The mean apparent elimination half‐life ranged from 32 to 56 h across all single and multiple dose cohorts. After single and multiple doses, all adverse events were mild or moderate, and none led to treatment withdrawal. There was no clear evidence of systemic toxicity due to JAK1 inhibition, and systemic exposure was low, with plasma concentrations at least 15‐fold less than the plasma protein binding‐corrected IC50 of JAK1 at the highest dose. Scintigraphy showed that approximately 50% of the emitted dose of radiolabeled GDC‐0214 was deposited in the lungs and was distributed well to the peripheral airways. ^99mTc‐radiolabeled GDC‐0214 (1 mg) exhibited a mean plasma C_max similar to that observed in phase I at the same dose level. Overall, inhaled GDC‐0214 exhibited pharmacokinetic properties favorable for inhaled administration.

Benefit-Risk Analysis of Upadacitinib Compared with Adalimumab in the Treatment of Patients with Moderate-to-Severe Rheumatoid Arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic autoimmune disease requiring long-term treatment. Upadacitinib (UPA), a Janus kinase (JAK) inhibitor, is a new treatment for RA. The benefit-risk profile of a medication is best understood by evaluating the number needed to treat (NNT) and the number needed to harm (NNH). This analysis evaluated the comparative risk-benefit of UPA versus adalimumab (ADA).

METHODS

Post-hoc analyses were performed using data from the SELECT-COMPARE trial of UPA versus placebo (PBO) and UPA versus ADA among patients with active RA who remained on stable methotrexate (MTX) treatment and had an inadequate response; patients who failed to achieve response were rescued by predefined criteria-PBO or ADA switch to UPA, and UPA switch to ADA (all patients on PBO were switched to UPA at week 26). This analysis assessed efficacy and adverse events of special interest (AESIs) at week 26, 48, and 156 (3 years). NNT and NNH (95% confidence intervals) values were calculated between UPA versus ADA for all time points, and between UPA versus PBO for week 26. NNT and NNH values were applied to a hypothetical cohort of 100 patients to estimate the comparative efficacy and safety profiles.

RESULTS

UPA consistently showed greater efficacy than ADA, as evidenced by NNT values < 10 for achievement of Disease Activity Score in 28 joints based on C-reactive protein (DAS28-CRP) of < 2.6 and ≤ 3.2, respectively, and functional improvement. Based on indices for disease assessment other than the DAS28-CRP, remission outcomes were higher with UPA versus ADA over 26 weeks (NNTs: 7-12), 48 weeks (NNTs: 9-16), and 156 weeks (NNTs: 9-15). With the exception of herpes zoster, other AESIs demonstrated a similar risk with UPA versus ADA.

CONCLUSION

In patients with active RA despite MTX use, UPA demonstrated an incremental achievement of clinical outcomes compared to ADA together with a similar profile of AESIs with ADA (with the exception of herpes zoster).

Evaluating upadacitinib for the treatment of psoriatic arthritis

INTRODUCTION

Psoriatic arthritis is an extra-cutaneous manifestation affecting up to 40% of psoriasis patients with multiple therapies recommended by international guidelines including conventional and targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs) as well as biologics. Janus kinase inhibitors (JAKis) have emerged as a unique therapeutic target with tofacitinib the first to gain FDA approval in 2017. The non-selectivity of older JAKis increases the risk of off-target effects such as suppression of hemopoiesis hence the rationale for more selective alternatives.

AREAS COVERED

This paper explores the use of upadacitinib (a selective JAK1 inhibitor) for the treatment of psoriatic arthritis. It covers its chemical properties, pharmacokinetics, pharmacodynamics, efficacy, safety and regulation.

EXPERT OPINION

In our opinion, upadacitinib is set to play an important role in the treatment of psoriatic arthritis as demonstrated by the SELECT-PsA trials especially in patients with poor or non-response to current first-line therapies. It's JAK1 receptor selectivity promises a lower side effect profile compared to the older nonselective JAKis but this will require confirmation with long-term clinical trial data.

The Broad Immunomodulatory Effects of IL-7 and Its Application In Vaccines

Interleukin-7 (IL-7) is produced by stromal cells, keratinocytes, and epithelial cells in host tissues or tumors and exerts a wide range of immune effects mediated by the IL-7 receptor (IL-7R). IL-7 is primarily involved in regulating the development of B cells, T cells, natural killer cells, and dendritic cells via the JAK-STAT, PI3K-Akt, and MAPK pathways. This cytokine participates in the early generation of lymphocyte subsets and maintain the survival of all lymphocyte subsets; in particular, IL-7 is essential for orchestrating the rearrangement of immunoglobulin genes and T-cell receptor genes in precursor B and T cells, respectively. In addition, IL-7 can aid the activation of immune cells in anti-virus and anti-tumor immunity and plays important roles in the restoration of immune function. These biological functions of IL-7 make it an important molecular adjuvant to improve vaccine efficacy as it can promote and extend systemic immune responses against pathogens by prolonging lymphocyte survival, enhancing effector cell activity, and increasing antigen-specific memory cell production. This review focuses on the biological function and mechanism of IL-7 and summarizes its contribution towards improved vaccine efficacy. We hope to provide a thorough overview of this cytokine and provide strategies for the development of the future vaccines.

Selectivity Profile of the Tyrosine Kinase 2 Inhibitor Deucravacitinib Compared with Janus Kinase 1/2/3 Inhibitors

INTRODUCTION

Deucravacitinib, a novel, oral, selective inhibitor of tyrosine kinase 2 (TYK2) signaling, acts via an allosteric mechanism by binding to the enzyme's regulatory domain instead of the catalytic domain. This unique binding provides high functional selectivity for TYK2 versus the closely related Janus kinases (JAKs) 1/2/3. Deucravacitinib was efficacious in phase 2 and 3 psoriasis trials, without clinical or laboratory parameters indicative of JAK 1/2/3 inhibition being observed. This analysis compared the kinase specificities of deucravacitinib versus JAK 1/2/3 inhibitors at therapeutic exposures.

METHODS

Signaling via JAK 1/3, JAK 2/2, and TYK2/JAK 2 dimers was measured in in vitro whole blood assays. Concentrations providing half-maximal inhibition (IC₅₀) in these assays were determined for deucravacitinib and the JAK 1/2/3 inhibitors tofacitinib, upadacitinib, and baricitinib. Newly derived whole blood IC₅₀ values were plotted against available pharmacokinetic profiles using doses evaluated in phase 2/3 trials. Simulated average daily inhibition and durations over which concentrations exceeded IC₅₀ were evaluated.

RESULTS

At clinically relevant exposures, projected steady-state deucravacitinib plasma concentrations were higher than TYK2 IC₅₀ for approximately 9-18 h. Maximal plasma concentrations (C_max) of deucravacitinib were 8- to 17-fold lower than JAK 1/3 IC₅₀ and > 48- to > 102-fold lower than JAK 2/2 IC₅₀. Simulated daily average TYK2 inhibition by deucravacitinib ranged from 50% to 69%. Simulations indicated that tofacitinib, upadacitinib, and baricitinib at steady state exhibited varying degrees of JAK 1/3 (daily average inhibition, 70-94%) and JAK 2/2 (23%-67%) inhibition at therapeutic concentrations, with C_max values 17- to 33-fold lower than their TYK2 IC₅₀ levels.

CONCLUSION

At clinically relevant doses and exposures, deucravacitinib demonstrates highly selective inhibition of TYK2 and not JAK 1/2/3. Tofacitinib, upadacitinib, and baricitinib variably inhibit JAK 1/2/3 but not TYK2. These results indicate that deucravacitinib is a distinct class of kinase inhibitor compared with JAK 1/2/3 inhibitors.

Upadacitinib pharmacokinetics and exposure-response analyses of efficacy and safety in psoriatic arthritis patients - Analyses of phase III clinical trials

Upadacitinib is an oral Janus kinase inhibitor approved for the treatment of rheumatoid arthritis (RA) and recently approved by the European Medicines Agency for the treatment of psoriatic arthritis (PsA). The efficacy and safety profile of upadacitinib in PsA have been established in the SELECT‐PsA program in two global phase III studies, which evaluated upadacitinib 15 and 30 mg q.d. The analyses described here characterized upadacitinib pharmacokinetics and exposure‐response relationships for efficacy and safety endpoints using data from the SELECT‐PsA studies. Upadacitinib pharmacokinetics in patients with PsA were characterized through a Bayesian population analysis approach and were comparable to pharmacokinetics in patients with RA. Exposure‐response relationships for key efficacy and safety endpoints were characterized using data from 1916 patients with PsA. The percentage of patients achieving efficacy endpoints at week 12 (American College of Rheumatology [ACR]50 and ACR70), 16 and 24 (sIGA0/1) increased with increasing upadacitinib average plasma concentration over a dosing interval, whereas no clear exposure‐response trend was observed for ACR20 at week 12 or ACR20/50/70 at week 24 within the range of plasma exposures evaluated in the phase III PsA studies. No clear trends for exposure‐response relationships were identified for experiencing pneumonia, herpes zoster infection, hemoglobin less than 8 g/dl, lymphopenia (grade ≥ 3), or neutropenia (grade ≥ 3) after 24 weeks of treatment. Shallow relationships with plasma exposures were observed for serious infections and hemoglobin decrease greater than 2 g/dl from baseline at week 24. Based on exposure‐response analyses, the upadacitinib 15 mg q.d. regimen is predicted to achieve robust efficacy in patients with PsA and to be associated with limited incidences of reductions in hemoglobin or occurrence of serious infections.

Recent advances on signaling pathways and their inhibitors in rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by systemic synovitis leading to joint destruction in which imbalances in pro-inflammatory and anti-inflammatory cytokines promote the induction of autoimmunity. Some pro-inflammatory cytokines can trigger the signaling pathways which responsible for immune-mediated inflammation in RA, and the activated signaling pathways produce pro-inflammatory cytokines, resulting in aggravation of RA. Hence, understanding of the signaling pathways and their inhibitors might be advantageous in the development of therapeutic targets and new drugs for RA. In the current review, we summarize the signaling pathways involved in the pathogenesis of RA as well as the potential role of specific inhibitors in its management. We hope this paper may serve a reference for future studies on signaling pathways implicated in the pathogenesis of RA and benefit the treatment of RA.

Switching between Janus kinase inhibitor upadacitinib and adalimumab following insufficient response: efficacy and safety in patients with rheumatoid arthritis

Objectives

To evaluate efficacy and safety of immediate switch from upadacitinib to adalimumab, or vice versa, in patients with rheumatoid arthritis with non-response or incomplete-response to the initial therapy.

Methods

SELECT-COMPARE randomised patients to upadacitinib 15 mg once daily (n=651), placebo (n=651) or adalimumab 40 mg every other week (n=327). A treat-to-target study design was implemented, with blinded rescue occurring prior to week 26 for patients who did not achieve at least 20% improvement in both tender and swollen joint counts (‘non-responders’) and at week 26 based on Clinical Disease Activity Index (CDAI) >10 (‘incomplete-responders’) without washout.

Results

A total of 39% (252/651) and 49% (159/327) of patients originally randomised to upadacitinib and adalimumab were rescued to the alternate therapy. In both switch groups (adalimumab to upadacitinib and vice versa) and in non-responders and incomplete-responders, improvements in disease activity were observed at 3 and 6 months following rescue. CDAI low disease activity was achieved by 36% and 47% of non-responders and 45% and 58% of incomplete-responders switched to adalimumab and upadacitinib, respectively, 6 months following switch. Overall, approximately 5% of rescued patients experienced worsening in disease activity at 6 months postswitch. The frequency of adverse events was similar between switch groups.

Conclusions

These observations support a treat-to-target strategy, in which patients who fail to respond initially (or do not achieve sufficient response) are switched to a therapy with an alternate mechanism of action and experience improved outcomes. No new safety findings were observed despite immediate switch without washout.

Clinical Pharmacology of Janus Kinase Inhibitors in Inflammatory Bowel Disease

Inflammatory bowel disease, including ulcerative colitis and Crohn's disease, are chronic inflammatory disorders of the gastrointestinal tract which are characterised, in part, by an imbalance in the production of several pro- and anti-inflammatory cytokines. Although various agents are effective for inducing and maintaining remission, approximately 20% of patients are treatment-refractory and require surgery. Parenterally administered monoclonal antibody-based biologics are associated with adverse effects resulting in treatment discontinuation and/or immunogenicity, leading to loss of response to therapy. Approximately 50% of patients who initially respond to treatment with tumour necrosis factor antagonists lose response to therapy within the 1st year of treatment. Incidence of immunogenicity tends to decrease over time, but once present can persist for years, even after treatment discontinuation. Nonimmunogenic oral small molecule therapies, including Janus kinase inhibitors, are currently being developed and have demonstrated efficacy in early phase clinical trials, which has already led to regulatory approval of tofacitinib for the treatment of patients with moderate-to-severe ulcerative colitis. Differentiation of T cells into T helper cells, which are mediators of the inflammatory response in inflammatory bowel disease, is mediated by the Janus kinase signal transducer and activator of the transcription signalling pathway. Absorption and distribution of Janus kinase inhibitors occurs at the site of action in the gastrointestinal tract, and newer compounds are being developed with limited systemic absorption, potentially reducing the risk of adverse effects. The current review describes the clinical pharmacology of approved Janus kinase inhibitors, as well as those in clinical development for the treatment of inflammatory bowel disease.

Molecular Structure and Function of Janus Kinases: Implications for the Development of Inhibitors

Cytokines can trigger multiple signalling pathways, including Janus tyrosine kinases [JAK] and signal transducers and activators of transcription [STATS] pathways. JAKs are cytoplasmic proteins that, following the binding of cytokines to their receptors, transduce the signal by phosphorylating STAT proteins which enter the nuclei and rapidly target gene promoters to regulate gene transcription. Due to the critical involvement of JAK proteins in mediating innate and adaptive immune responses, these family of kinases have become desirable pharmacological targets in inflammatory diseases, including ulcerative colitis and Crohn's disease. In this review we provide an overview of the main cytokines that signal through the JAK/STAT pathway and the available in vivo evidence on mutant or deleted JAK proteins, and discuss the implications of pharmacologically targeting this kinase family in the context of inflammatory diseases.

Evaluating upadacitinib for the treatment of rheumatoid arthritis

INTRODUCTION

The introduction of JAKs inhibitors for the treatment of rheumatoid arthritis represents a promising new era in the management of the disease. New compounds under investigation, like upadacitinib, with greater selectivity for JAK1 inhibition have recently been approved for the treatment of adults with moderately to severely active rheumatoid arthritis who have had an inadequate response or intolerance to conventional synthetic disease-modifying antirheumatic drugs.

AREAS COVERED

Herein, the authors review the pharmacological data, the therapeutic efficacy, and safety data of upadacitinib before providing the reader with their critical evaluation and future perspectives.

EXPERT OPINION

Upadacitinib was able to accomplish all the primary and secondary end points in most of the trials, with a safety profile that is similar to the other JAK inhibitors. It has also demonstrated superiority over a tumor necrosis factor inhibitor and data on new indications is also favorable. Upadacitinib is a promising new drug for the treatment of rheumatoid arthritis.

GLOSSARY

Adalimumab: ADA; American College of Rheumatology: ACR; Assessment of Spondylarthritis International Society 40: ASAS40; Ankylosis Spondylitis: AS; Area under the Curve: AUC; Biological Disease-modifying arthritis drugs: bDMARDs; Clinical disease activity index: CDAI; C Reactive Protein: CRP; Conventional Synthetic Disease-modifying arthritis drugs: csDMARDs; Deep Venous Thrombosis: DVT; Disease arthritis score: DAS.

Exposure-Response Analyses of Upadacitinib Efficacy and Safety in Phase II and III Studies to Support Benefit-Risk Assessment in Rheumatoid Arthritis

Exposure–response analyses of upadacitinib (UPA) key efficacy and safety end points (3,685 and 4,577 subjects for efficacy and safety, respectively) using data from phase II and phase III rheumatoid arthritis (RA) studies were conducted to support benefit–risk assessment. Percentage of subjects achieving American College of Rheumatology (ACR)20/50/70, disease activity score 28 (C‐reactive protein) (DAS28‐CRP) ≤ 3.2, and DAS28‐CRP < 2.6 increased with increasing UPA plasma exposures. With the small number of observed safety events, no clear trends for exposure–response relationships were identified for pneumonia, herpes zoster infection, changes in platelet count, lymphopenia (Grade ≥ 4), or neutropenia (Grade ≥ 3) up to Week 26. Shallow exposure–response relationships were observed for > 2 g/dL decrease in hemoglobin, lymphopenia Grade ≥ 3 at Week 12/14, and serious infections at Week 24/26. Exposure–efficacy analyses demonstrate that UPA 15 mg q.d. (once daily) dose provided the optimal benefit–risk in RA through maximizing efficacy with only small incremental benefit with 30 mg q.d.; and with consistency across RA subpopulations and with UPA monotherapy or combination with conventional synthetic disease‐modifying antirheumatic drugs.