Clinical Pharmacokinetics of Upadacitinib: Review of Data Relevant to the Rheumatoid Arthritis Indication

Upadacitinib Optimization in a Patient With Protein-Losing Enteropathy Secondary to (Transient) Nonocclusive Mesenteric Ischemia, Idiopathic Myointimal Hyperplasia, and Hemodialysis: Grand Round

BACKGROUND

We report a case of a 19-year-old man with severe total parenteral nutrition-dependent protein-losing enteropathy who was treated with upadacitinib. Treatment was complicated by renal failure requiring hemodialysis and severe diarrhea, which possibly hindered absorption.

METHODS

Therapeutic drug monitoring (TDM) and pharmacokinetic analyses were compared with published population pharmacokinetic data to determine the dose adjustments for each patient.

RESULTS

Based on TDM results, the dose was gradually increased from 30 mg once daily to 45 mg twice daily. Repeated sampling was performed to estimate the area under the curve (AUC)6.5 (402.5 mcg*h/L), which was higher than data reported in the literature (AUC24 525, SD ± 123 mcg*h/L dosing 30 mg extended release once daily). No AUC24 could be calculated because of the absence of concentrations in the descending part of the concentration-time curve. Clinical improvement was achieved at a higher dose, and no major signs and/or symptoms of drug-related toxicity occurred.

CONCLUSIONS

Although TDM for Janus-kinase inhibitors is not yet a part of current clinical practice, in this case, the measurement of upadacitinib serum concentrations aided individualized dosing based on TDM.

Sequential rescue therapy with JAK inhibitors in corticosteroid and infliximab-refractory acute severe ulcerative colitis: a case series

Acute severe ulcerative colitis (ASUC) is a life-threatening medical emergency affecting over 20% of patients with ulcerative colitis (UC). Up to 40% of patients are refractory to intravenous corticosteroids (IVCS) and require rescue medical therapy or immediate colectomy. The potent Janus kinase (JAK) inhibitors, upadacitinib and tofacitinib, have proven efficacy in a randomised control trial setting for moderate-to-severe UC, but not ASUC. We describe a case series of sequential rescue therapy with JAK inhibitors following the failure of dose-intensified infliximab in corticosteroid-refractory ASUC. Six adult (>16 years old) patients received sequential rescue therapy with a JAK inhibitor (upadacitinib n = 5, tofacitinib n = 1) following failure of IVCS and dose-intensified infliximab at the Royal Brisbane and Women's Hospital (QLD, Australia) between October 2023 and April 2024. All patients met the Truelove and Witts criteria for ASUC on admission. Data were captured during admission and at 90-days post-discharge. Co-primary outcomes were 90-day colectomy-free survival and inpatient clinical response (<4 non-bloody stools per day) 72 h after JAK-inhibitor initiation. Secondary outcomes included 90-day clinical (PRO-2 score < 1) and biochemical (faecal calprotectin (FCP) < 150 µg/g and C-reactive protein (CRP) < 5 mg/L) corticosteroid-free remission and adverse events. Median CRP on admission was 100 mg/L (interquartile range (IQR) 58-105), median FCP 3400 µg/g (IQR 910-4950) and median Mayo Endoscopic Score 3. Four out of six patients had a clinical response within 72 h of sequential JAK-inhibitor rescue therapy. Two patients underwent emergent inpatient colectomy for refractory disease - one of whom developed post-operative sepsis. Among the four JAK-responders at 90 days, all achieved corticosteroid-free clinical remission and three achieved biochemical remission. No other adverse events were recorded. There is a promising role for JAK inhibitors as sequential rescue therapy following the failure of dose-intensified infliximab in select patients with corticosteroid-refractory ASUC.

Development and validation of a sensitive LC-MS/MS assay for determination of upadacitinib in human plasma and its application in patients with inflammatory bowel disease

BACKGROUND

Upadacitinib is a selective Janus kinase (JAK) 1 inhibitor approved by the Food and Drug Administration for the treatment of moderate-to-severe inflammatory bowel disease (IBD). We aimed to establish and validate a method for determining Upadacitinib in patients with IBD by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method.

METHODS

The mobile phase was 0.1 % formic acid: acetonitrile (35:65, v/v) at a flow rate of 0.40 mL/min. Upadacitinib and its internal standard Upadacitinib 15N, d2 were separated by a Waters Xbridge BEH C18 column (4.6 × 100 mm, 2.5 μm) and subjected to mass analysis using positive electrospray ionization (ESI).

RESULTS

The calibration range of Upadacitinib was 0.5-200 ng/mL with the correlation coefficient r2 ≥ 0.99. Accuracies ranged from -9.48 % ∼ 8.27 % and the inter- and intra-day precisions were less than 15 % for all analytes in quality control samples. There was no significant matrix effect. The range of extraction recoveries was 87.53-93.47 % for all analytes. Twenty-one plasma samples were obtained from the sixth affiliated hospital of Sun Yat-sen University. The median plasma concentration of Upadacitinib was 7.32 (0.56-26.78) ng/mL.

CONCLUSION

This newly developed method is sensitive, simple, and successfully applied in determining Upadacitinib in IBD patients to provide reference for safe and effective drug administration in clinical practice.

The Cell-Specific Effects of JAK1 Inhibitors in Ulcerative Colitis

JAK1 inhibitors have become an important addition to the therapeutic options for ulcerative colitis (UC), targeting key inflammatory pathways mediated by cytokines such as the IL-6 family, interferons, IL-2 family, IL-10 family, and G-CSF. However, not all patients respond equally, and chronic inflammation persists in a subset of individuals. The variability in treatment response may reflect the heterogeneity of UC. Immune cells, epithelial cells, and stromal cells may have distinct contributions to disease pathogenesis. While JAK inhibitors were originally designed to target immune cells, their impact on non-immune cell types, such as epithelial and stromal cells, remains poorly understood. Investigating the mechanisms through which JAK1 inhibitors affect these diverse cellular populations and identifying the factors underlying differential responses is crucial to optimizing outcomes. This review explores the roles of immune, epithelial, and stromal cells in response to JAK1 inhibition and discusses potential strategies to improve treatment precision, such as predicting responders and identifying complementary therapeutic targets.

Pharmacokinetics, Safety, Tolerability, and Exploratory Efficacy of Upadacitinib in Children with Severe Atopic Dermatitis

PURPOSE

This study aims to characterize the pharmacokinetics, safety, tolerability, and exploratory efficacy of upadacitinib, an oral Janus kinase inhibitor approved for treating moderate to severe atopic dermatitis (AD) in adults and adolescents, in children with severe AD.

METHODS

In an open-label, multiple-dose, Phase 1 study, pediatric patients with severe AD from two age groups (2 to <6 years and 6 to <12 years) received bodyweight-based dosing regimens of upadacitinib using either twice-daily immediate-release (IR) oral solution or once-daily extended-release (ER) tablets. A pharmacokinetic assessment was conducted on Day 7 of the study, which was followed by a long-term safety and exploratory efficacy evaluation for up to 108 weeks. The results reported here are based on an interim analysis when the study had completed enrollment and pharmacokinetic assessment.

FINDINGS

A total of 35 patients were enrolled and received upadacitinib. The maximum upadacitinib plasma concentration was attained within a median time of 0.5 to 2 hours and 2 to 2.5 hours for the IR oral solution and ER tablet formulations, respectively. Upadacitinib functional half-life was generally shorter with IR oral solution relative to ER tablets. Upadacitinib apparent oral clearance decreased with decreasing body weight in the pediatric patients enrolled in this study. Upadacitinib was generally safe and well tolerated. The most common (≥3 patients) adverse events were upper respiratory tract infection, COVID-19 infection, headache, abdominal discomfort, vomiting, asthma, and cough. No new safety risks were identified compared to the known safety profile for upadacitinib in adults and adolescents. In the 30 patients with available exploratory efficacy data at Week 12, 36.7% achieved validated Investigator's Global Assessment scale for AD score of 0 or 1 (Validated Investigator Global Assessment for AD 0/1), and 70.0% had Eczema Area and Severity Index (EASI) improvement of at least 75% (EASI 75).

IMPLICATIONS

The characterized pharmacokinetic profiles in this study, together with the observed safety and exploratory efficacy results, support further investigation of the current upadacitinib dosing regimen in future confirmatory Phase 3 clinical trials in children with AD.

CLINICAL TRIAL NUMBER

NCT03646604, registered 2018-08-23.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Upadacitinib for the treatment of adult patients with active psoriatic arthritis

INTRODUCTION

Psoriatic arthritis (PsA) is a rheumatic disorder that may be responsible for relevant articular impairment. The recently licensed Janus Kinase (JaK) inhibitors represent a new opportunity to improve PsA treatment. This review deals with the clinical usefulness of the selective JaK-1 inhibitor upadacitinib (UPA) in patients with PsA.

COVERED AREAS

Two phase-III studies are available: SELECT-PsA 1, performed in patients with an inadequate response to non-biological therapies, and SELECT-PsA 2, conducted in biologic-experienced patients. Long-term extension results and post-hoc analysis data of these two trials are also available.

EXPERT OPINION

The results provided by the trials indicate that UPA may be used to treat all of the clinical manifestations of PsA. Venous thromboembolism, cardiovascular events, and malignancy, the most feared adverse events associated with JaK inhibitor use, were not increased in the trial populations, yet long-term observational studies are needed to make sure that UPA is safe in this respect.

Evaluating the pharmacokinetics of upadacitinib for the treatment of moderate-to-severe Crohn's disease

INTRODUCTION

Janus kinases (JAK) are enzymes involved in signaling pathways that activate the immune system. Upadacitinib, an oral small molecule, is the first JAK inhibitor approved by FDA and EMA for the treatment of moderately to severely active Crohn's disease (CD), following successful phase II and III trials. Compared to other JAK inhibitors, upadacitinib has a high selectivity toward JAK1. This characteristic could improve its efficacy and safety.

AREAS COVERED

This review provides an overview of the available knowledge on the pharmacokinetics of upadacitinib as induction and maintenance therapy for CD.

EXPERT OPINION

The approval of newer targeted small molecules drug, including JAK inhibitors, marked a significant advancement in terms of effectiveness. In fact, the oral administration, the rapid absorption, the excellent bioavailability and the short serum time of maximum concentration are some of the advantages compared to biologics. The selective inhibition of JAK1 by upadacitinib allows for high efficacy while maintaining a reliable safety profile.

Upadacitinib for the treatment of moderate-to-severe Crohn's disease

Despite an increasing number of therapies for Crohn's disease (CD), half of patients do not respond to initial treatment or lose response over time, highlighting the need for novel therapies. Inhibition of Janus kinases (JAKs) has emerged as an important therapeutic target for CD. Upadacitinib is an orally administered selective JAK1 inhibitor, which is effective for the induction and maintenance of remission in moderately-to-severely active CD, including in patients with prior failure of biological therapy. Nonselective JAK inhibition has been associated with thromboembolic disease, cardiovascular events and malignancy in patients older than 50 years with rheumatoid arthritis and pre-existing cardiovascular risk factors, which should be considered upon prescription. Upadacitinib is the first and currently only oral advanced therapy for CD.

EIDD-1931 Treatment Tweaks CYP3A4 and CYP2C8 in Arthritic Rats to Expedite Drug Interaction: Implication in Oral Therapy of Molnupiravir

EIDD-1931 is the active form of molnupiravir, an orally effective drug approved by the United States Food and Drug Administration (USFDA) against COVID-19. Pharmacokinetic alteration can cause untoward drug interaction (drug-drug/disease-drug), but hardly any information is known about this recently approved drug. Therefore, we first investigated the impact of the arthritis state on the oral pharmacokinetics of EIDD-1931 using a widely accepted complete Freund's adjuvant (CFA)-induced rat model of rheumatoid arthritis (RA) after ascertaining the disease occurrence by paw swelling measurement and X-ray examination. Comparative oral pharmacokinetic assessment of EIDD-1931 (normal state vs arthritis state) showed that overall plasma exposure was augmented (1.7-fold) with reduced clearance (0.54-fold), suggesting its likelihood of dose adjustment in arthritis conditions. In order to elucidate the effect of EIDD-1931 treatment at a therapeutic regime (normal state vs arthritis state) on USFDA-recommended panel of cytochrome P450 (CYP) enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) for drug interaction using the same disease model, we monitored protein and mRNA expressions (rat homologs) in liver tissue by western blotting (WB) and real time-polymerase chain reaction (RT-PCR), respectively. Results reveal that EIDD-1931 treatment could strongly influence CYP3A4 and CYP2C8 among experimental proteins/mRNAs. Although CYP2C8 regulation upon EIDD-1931 treatment resembles similar behavior under the arthritis state, results dictate a potentially reverse phenomenon for CYP3A4. Moreover, the lack of any CYP inhibitory effect by EIDD-1931 in human/rat liver microsomes (HLM/RLM) helps to ascertain EIDD-1931 treatment-mediated disease-drug interaction and the possibility of drug-drug interaction with disease-modifying antirheumatic drugs (DMARDs) upon coadministration. As elevated proinflammatory cytokine levels are prevalent in RA and nuclear factor-kappa B (NF-kB) and nuclear receptors control CYP expressions, further studies should focus on understanding the regulation of affected CYPs to subside unexpected drug interaction.

Upadacitinib in Crohn's disease

INTRODUCTION

The small molecule and oral selective and reversible Janus kinase (JAK) inhibitor upadacitinib has been approved for the treatment of moderate to severe active Crohn's disease (CD) in adult patients since April 2023 by EMA/FDA.

AREAS COVERED

The approval is based on the two induction studies a maintenance study showing that upadacitinib induction and maintenance therapy was superior to placebo. The approval of upadacitinib in CD expands the therapeutic armamentarium for the management of inflammatory bowel diseases (IBD). Upadacitinib is the first and only JAK inhibitor approved in patients with CD and provides a novel mechanism of action and the first advanced oral treatment option for patients with CD. Upadacitinib is approved for the treatment of other immunologically mediated disorders, including ulcerative colitis, rheumatoid arthritis, psoriasis arthritis, axial spondylarthritis, ankylosing spondylitis, and atopic dermatitis. Treatment of atopic dermatitis has been approved from the age of 12 years.

EXPERT OPINION

Upadacitinib may cause relevant changes of our current treatment algorithms for Crohn's disease. Further real-world studies and head-to-head comparisons are needed to position upadacitinib in our current treatment algorithms for CD.

Population pharmacokinetics and exposure-response analyses for efficacy and safety of upadacitinib in patients with axial spondyloarthritis

Upadacitinib is an orally administered, selective, Janus kinase inhibitor that is approved for several auto-immune conditions, such as axial spondyloarthritis, an inflammatory rheumatic disease that includes ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). The approvals of upadacitinib for the treatment of AS and nr-axSpA were based on the safety and efficacy data for upadacitinib 15 mg once-daily compared to placebo from the SELECT-AXIS 1 and SELECT-AXIS 2 studies. Population pharmacokinetic analyses based on data from 244 patients with axSpA showed that the pharmacokinetics of upadacitinib were comparable in subjects with AS and nr-axSpA. Exposure-response relationships were characterized for key efficacy and safety end points using data from 482 patients with axSpA. The exposure-response analyses for efficacy based on Assessment of SpondyloArthritis International Society (ASAS)20 and ASAS40 responses at week 14, showed a clear differentiation from placebo with no evidence of increased responses with increasing upadacitinib plasma exposures. There were no clear exposure-response trends observed for safety end points that included serious infections, herpes zoster, pneumonia, lymphopenia (grade ≥3), neutropenia (grade ≥3), or a greater than 2 g/dL decrease in hemoglobin from baseline through week 14. The exposure-response analyses for efficacy and safety presented here supported the favorable benefit-risk profile with the use of upadacitinib 15 mg once-daily for the treatment of axSpA.

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.

Development and validation of a multiplex HPLC-MS/MS assay for the monitoring of JAK inhibitors in patient plasma

Janus kinase inhibitors (JAKi) are oral small molecules used in the treatment of a broad spectrum of autoimmune and myeloproliferative diseases. JAKi exhibit significant intra- and inter-individual pharmacokinetic variabilities, due to fluctuations in compliance with oral treatments and their metabolism essentially driven by cytochrome P450 enzymes. Intrinsically, JAKi have dose-response relationship and narrow therapeutic index: therapeutic drug monitoring (TDM) is expected to optimize and adapt their dosage regimen in order to resolve problems of efficacy and tolerance linked to dose and safety. A sensitive analytical method using multiplex high-performance liquid-chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was developed and validated for the simultaneous quantification in plasma of the 6 major currently used JAKi, namely abrocitinib, baricitinib, fedratinib, ruxolitinib, tofacitinib, and upadacitinib. Plasma samples are subjected to protein precipitation with MeOH, using stable isotopically labelled internal standards. The separation of JAKi in supernatants diluted 1:1 with ultrapure H2O was performed using a C18 column Xselect HSS T3 2.5 µm, 2.1x150 mm using a mobile phase composed of formic acid (FA) 0.2% and acetonitrile (+FA 0.1%) in gradient mode. The analytical run time for the multiplex assay was 7 min. JAKi drugs were monitored by electrospray ionization in the positive mode followed by triple-stage quadrupole MS/MS analysis. The method was validated according to SFSTP and ICH guidelines over the clinically relevant concentration ranges (0.5-200 ng/mL for abrocitinib, baricitinib and upadacitinib; 1-400 ng/mL for tofacitinib; 0.5-400 ng/mL for ruxolitinib, and 10-800 ng/mL for fedratinib). This multiplex HPLC-MS/MS assay achieved good performances in term of trueness (91.1-113.5%), repeatability (3.0-9.9%), and intermediate precision (4.5-11.3%). We developed and validated a highly sensitive method for the multiplex quantification of the JAKi abrocitinib, baricitinib, fedratinib, ruxolitinib, tofacitinib, and upadacitinib in human plasma. The method will be applied for prospective clinical pharmacokinetic studies to determine whether TDM programs for JAKi based on residual drug concentrations can be recommended using disease-specific therapeutic ranges.

JAK-STAT pathway inhibitors in dermatology

The JAK-STAT signaling pathway mediates important cellular processes such as immune response, carcinogenesis, cell differentiation, division and death. Therefore, drugs that interfere with different JAK-STAT signaling patterns have potential indications for various medical conditions. The main dermatological targets of JAK-STAT pathway inhibitors are inflammatory or autoimmune diseases such as psoriasis, vitiligo, atopic dermatitis and alopecia areata; however, several dermatoses are under investigation to expand this list of indications. As JAK-STAT pathway inhibitors should gradually occupy a relevant space in dermatological prescriptions, this review presents the main available drugs, their immunological effects, and their pharmacological characteristics, related to clinical efficacy and safety, aiming to validate the best dermatological practice.

Efficacy and Safety of Biological Therapies and JAK Inhibitors in Older Patients with Inflammatory Bowel Disease

With the introduction of more and more monoclonal antibodies selectively targeting various mediators of the immune system, together with Janus-Kinase (JAK)-inhibitors with variable affinities towards different JAK subtypes, the available therapeutic options for the treatment of inflammatory bowel diseases (IBD) have undergone an acceleration in the last five years. On the other hand, the prevalence of IBD patients over 65-years-old is steadily increasing, and, with this, there is a large population of patients that presents more comorbidities, polypharmacy, and, more frequently, frailty compared to younger patients, exposing them to potentially major risks for adverse events deriving from newer therapies, e.g., infections, cardiovascular risks, and malignancies. Unfortunately, pivotal trials for the commercialization of new therapies rarely include older IBD patients, and those with serious comorbidities are virtually excluded. In the present review, we focus on existing literature from pivotal trials and real-world studies, analyzing data on efficacy/effectiveness and safety of newer therapies in older IBD patients with special emphasis on comorbidities and frailty, two distinct but intercorrelated aspects of the older population since age by itself seems to be of minor importance.

Advances in pharmacotherapy for ulcerative colitis: a focus on JAK1 inhibitors

INTRODUCTION

Janus kinase (JAK) inhibitors are an emerging class of small-molecule drugs, providing targeted therapy for a variety of diseases, and have made their way into the treatment of armamentarium of ulcerative colitis (UC) in recent years.

AREAS COVERED

This review focuses on the pharmacokinetics, safety, and efficacy of selective JAK1 inhibitors in the treatment of moderate-to-severe UC. The PubMed database and clinicaltrials.gov were consulted using keywords - further expanded in the methods section. The search was focused on full-text publications in English. No publication date restrictions were imposed.

EXPERT OPINION

JAK1 inhibitors are small-molecule drugs used in the treatment of ulcerative colitis and other immune mediated inflammatory diseases. They are orally bioavailable and have a rapid mechanism of action and no immunogenicity. JAK inhibitors can be used for the management of both naïve patients and biological-experienced patients.Particular attention should be paid to elderly patients or those with cardiovascular or oncological risk factors, in whom JAK inhibitors should be recommended only if no alternatives are available. In addition, JAK inhibitors have the potential to be combined with other biological drugs or small molecules for the management of difficult-to-treat cases.

Update on the role of upadacitinib in the treatment of adults with moderately to severely active ulcerative colitis

With further knowledge of the pathogenesis of inflammatory bowel disease, small oral molecules have become available, including the Janus kinase (JAK) inhibitors. Upadacitinib (UPA) is a selective JAK1 inhibitor and has become the newest drug in this class, with recent approval for the management of moderate-to-severe ulcerative colitis. The large phase III program (including the U-ACHIEVE and U-ACCOMPLISH parallel induction trials and the U-ACHIEVE Maintenance trial) demonstrated superiority over placebo, for all primary and secondary endpoints including key clinical, endoscopic, and histological outcomes utilizing 45 mg orally (po) once daily (OD) during induction and either 30 mg or 15 mg po OD in maintenance. From a safety perspective, UPA has proven to be a safe and well-tolerated medication across immune-mediated diseases with manageable adverse risks such as an increase in herpes zoster. Proper discussion and patient profiling are essential when positioning UPA, considering efficacy and potential risks associated with this highly effective medication.

Clinical Evaluation of Upadacitinib in the Treatment of Adults with Moderately to Severely Active Ulcerative Colitis (UC): Patient Selection and Reported Outcomes

This review addresses appropriate patient selection for upadacitinib, a Janus kinase inhibitor approved by the FDA and EMA for treatment of moderately to severely active ulcerative colitis (UC). Janus kinase molecules can contribute to the inflammatory pathway, so inhibiting certain of them may prove efficacious in treating UC and may reduce safety concerns. Upadacitinib is the newest Janus kinase inhibitor to be approved for UC, so it is timely and relevant to review patient selection and when to consider this medication. We will discuss efficacy and safety data from the pivotal clinical trials on upadacitinib. These data can be shared with patients and can inform the use of these agents in clinical practice.

Management of Atopic Dermatitis During the COVID-19 Pandemic: Key Questions and Review of the Current Evidence

Since the outbreak of COVID-19, management of atopic dermatitis (AD) has been widely discussed. Key issues include the risk of COVID-19 infection and related outcomes in AD patients, the efficacy and safety of COVID-19 vaccination in AD populations, and management of AD in the COVID-19 pandemic. Recent studies have shown that patients with AD have a slightly increased risk of COVID-19 infection but are not associated with a worse outcome than the non-AD population. COVID-19 vaccination is generally effective and safe in patients with AD. However, temporary discontinuation of certain systemic immunomodulatory agents after vaccination is suggested. During the pandemic, continuation of all immunomodulating agents is suggested, but these agents should be paused when patients with AD are infected with COVID-19 until recovery. Further studies are warranted to investigate the long-term interaction between AD and COVID-19 to aid clinical decisions during the pandemic.

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Upadacitinib for Patients with Rheumatoid Arthritis: A Comprehensive Review

Upadacitinib is a selective and reversible Janus kinase (JAK) inhibitor recently approved by the European Medicine Agency and the Food and Drug Administration for the treatment of rheumatoid arthritis (RA) at a dose of 15 mg/day. We present the chemical structure and mechanism of action of upadacitinib together with a comprehensive review of the efficacy of this drug in RA based on the SELECT clinical trial program and its safety profile. Its role in the management and therapeutic strategy of RA is also discussed. Upadacitinib in the different clinical trials has shown similar rates of clinical response, including the remission rates, regardless of the population analyzed (methotrexate-naïve, methotrexate-failure or biologic failure). In a head-to-head randomized clinical trial, upadacitinib plus methotrexate was superior to adalimumab when given on background methotrexate (MTX) in patients who have experienced an inadequate response to MTX. Upadacitinib also demonstrated superiority over abatacept in patients with RA after failure to previous biologic drugs. The safety profile of upadacitinib is generally consistent with those observed with biological or other JAK inhibitors.

Upadacitinib Population Pharmacokinetics and Exposure-Response Relationships in Ulcerative Colitis Patients

BACKGROUND AND OBJECTIVE

Upadacitinib, an oral selective and reversible Janus kinase (JAK) inhibitor, showed favorable efficacy and safety in patients with moderate-to-severe ulcerative colitis (UC). The objective was to characterize upadacitinib pharmacokinetics in UC patients across Phase 2b and 3 trials and evaluate the relationships between upadacitinib plasma exposures and key efficacy or safety endpoints.

METHODS

Population pharmacokinetics and exposure-response analyses were performed to characterize upadacitinib pharmacokinetics in UC patients and evaluate the relationships between plasma exposures and key efficacy or safety endpoints at the end of 8-week induction and 52-week maintenance periods. Data from 1234 UC patients from Phase 2 and 3 induction trials and 449 UC patients from a Phase 3 maintenance trial were used for these analyses. Additionally, data from patients with rheumatoid arthritis, atopic dermatitis, Crohn's disease, and healthy volunteers were used in the pharmacokinetics analysis. Quartile plots and logistic regression models were used to evaluate the exposure-response relationships across upadacitinib doses of 7.5-45 mg once daily (QD) for induction and 15-30 mg QD for maintenance.

RESULTS

Upadacitinib plasma exposures were dose-proportional in UC patients across the evaluated dose range. Upadacitinib pharmacokinetics in UC were consistent between the induction and maintenance periods, and with other patient populations. Upadacitinib plasma exposures associated with the 45 mg QD induction dose maximized efficacy for Week 8 clinical and endoscopic endpoints. Plasma exposures associated with upadacitinib 30 mg maintenance dose provided additional incremental benefit compared to 15 mg QD for Week 52 key clinical and endoscopic endpoints. No trends were observed in the evaluated safety events with increasing plasma exposures at the end of induction or maintenance periods.

CONCLUSION

These analyses supported selection of upadacitinib UC induction and maintenance doses.

TRIAL REGISTRATION

Data from studies NCT02819635 and NCT03653026 were included in these analyses.

A Comprehensive Overview of Globally Approved JAK Inhibitors

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

Utility of Modeling and Simulation Approach to Support the Clinical Relevance of Dissolution Specifications: a Case Study from Upadacitinib Development

Dissolution specifications are often essential in assuring the quality and consistency of therapeutic benefits of drug lots released to the market as in vitro dissolution is often considered to be a surrogate for bioavailability. Despite the importance of demonstrating the clinical relevance of the dissolution specifications, it is often challenging to achieve this goal. In this case study, a modeling and simulation approach was utilized to support the clinical relevance of the dissolution specifications for upadacitinib extended-release tablets. A level A in vitro in vivo correlation was developed and utilized in predicting upadacitinib plasma exposures for formulations which correspond to the upper and lower dissolution limits. Exposure-response models for upadacitinib efficacy and safety in patients with moderate to severe rheumatoid arthritis (RA) were utilized to conduct clinical trial simulations to evaluate the efficacy and safety of formulations at the upper and lower dissolution boundaries. Each simulated clinical trial consisted of three treatment arms: (1) upadacitinib 15 mg QD using the target formulation, (2) upadacitinib 15 mg QD using a formulation at the lower dissolution boundary, and (3) upadacitinib 15 mg QD using a formulation at the upper dissolution boundary. Each simulated trial included 300 patients per arm and simulations were replicated 200 times. Results demonstrated that formulations at the lower and upper dissolution boundaries are predicted to have noninferior efficacy and comparable safety to the target 15 mg extended-release formulation. This approach was successfully utilized in demonstrating the clinical relevance of upadacitinib extended-release tablet dissolution specifications. Graphical Abstract.

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.

Toward Overcoming Treatment Failure in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by inflammation and bone erosion. The exact mechanism of RA is still unknown, but various immune cytokines, signaling pathways and effector cells are involved. Disease-modifying antirheumatic drugs (DMARDs) are commonly used in RA treatment and classified into different categories. Nevertheless, RA treatment is based on a "trial-and-error" approach, and a substantial proportion of patients show failed therapy for each DMARD. Over the past decades, great efforts have been made to overcome treatment failure, including identification of biomarkers, exploration of the reasons for loss of efficacy, development of sequential or combinational DMARDs strategies and approval of new DMARDs. Here, we summarize these efforts, which would provide valuable insights for accurate RA clinical medication. While gratifying, researchers realize that these efforts are still far from enough to recommend specific DMARDs for individual patients. Precision medicine is an emerging medical model that proposes a highly individualized and tailored approach for disease management. In this review, we also discuss the potential of precision medicine for overcoming RA treatment failure, with the introduction of various cutting-edge technologies and big data.

Quantification of the janus kinase 1 inhibitor upadacitinib in human plasma by LC-MS/MS

Upadacitinib is a selective janus-kinase-1 inhibitor effective in the treatment of autoimmune related diseases like rheumatoid arthritis or psoriatic arthritis. Here, we described a LC-MS/MS method for the quantification of upadacitinib in human plasma applicable for therapeutic drug monitoring. Pexidartinib was used as internal standard. Plasma samples were prepared by acidic protein precipitation and the analytes were separated on a C-18 reversed phase column. Detection took place by tandem mass spectroscopy after ionization in the positive mode and collision induced fragmentation at m/z 381 → 256, 213 for upadacitinib and m/z 418 → 258, 165 for pexidartinib. The calibration function was linear in the range of 0.15 - 150 ng/mL. Precisions and accuracies were better than 10% in intra- as well as inter-day evaluations. The method was applied in therapeutic drug monitoring of patients undergoing treatment for rheumatoid arthritis with the standard dose of 15 mg upadacitinib extended release formulation once daily. At steady state, we found trough levels of 4.13 (3.51 - 11.0) ng/mL, which is comparable to values found in healthy volunteers receiving the same dose (2.8 ± 1.2 ng/mL).

Development of an UPLC-MS/MS Method for the Quantitative Analysis of Upadacitinib in Beagle Dog Plasma and Pharmacokinetics Study

Background

Upadacitinib, a novel selective Janus kinase 1 (JAK1) inhibitor, has been recently approved by the US FDA for the treatment of adult patients with moderately to severely active rheumatoid arthritis (RA). An ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the quantitative analysis of upadacitinib in beagle dog plasma was developed and validated.

Methods

Upadacitinib and fedratinib (internal standard, IS) were extracted with ethyl acetate under alkaline condition and then separated and detected. The chromatographic column was Waters Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm), the mobile phase was acetonitrile and 0.1% formic acid in water with gradient elution procedure, and the flow rate was 0.40 mL/min. Under the positive ion mode, upadacitinib and IS were monitored by multiple reaction monitoring (MRM) as the following mass transition pairs: m/z 447.00 → 361.94 for upadacitinib and m/z 529.82 → 141.01 for IS.

Results

In the concentration range of 1–500 ng/mL, upadacitinib had good linearity, and the lower limit of quantification (LLOQ) was 1 ng/mL. The RSD of the intra- and inter-day precision was less than 10.03%, and the RE of accuracy was −3.79% to 2.58%. The extraction recovery of upadacitinib was more than 80%, the matrix effect was around 100%, and upadacitinib was found to be stable.

Conclusion

The novel optimized UPLC-MS/MS assay was an effective tool for the determination of upadacitinib and had been successfully applied to the pharmacokinetic study of upadacitinib in beagle dogs, and this method would also be used to study DDIs.

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.

Effect of Upadacitinib on the Pharmacokinetics of Rosuvastatin or Atorvastatin in Healthy Subjects

This phase 1, 2‐part, 2‐period, open‐label, drug‐drug interaction study evaluated the potential for pharmacokinetic interactions between upadacitinib and rosuvastatin, an organic anion transporting polypeptide (OATP) 1B1 and breast cancer resistance protein substrate, or atorvastatin, a cytochrome P450 3A, OATP1B1, and OATP1B3 substrate, in 36 healthy volunteers. During period 1, a single dose of rosuvastatin (5 mg; part 1) or atorvastatin (10 mg; part 2) was administered on day 1, followed by a washout period of 5 days. During period 2, once‐daily doses of upadacitinib extended‐release (30 mg) were administered on days 1 to 10, and a single dose of rosuvastatin (5 mg; part 1) or atorvastatin (10 mg; part 2) was administered 1 hour after the upadacitinib dose on day 7. Serial blood samples were collected for assays of drug concentrations. In Part 1, rosuvastatin maximum observed plasma concentration (C_max) and area under the plasma concentration–time curve from time 0 to infinity (AUC_inf) were 23% and 33% lower, respectively, when administered with upadacitinib relative to when administered alone. In part 2, atorvastatin C_max and AUC_inf was 11% and 23% lower, respectively, when administered with upadacitinib relative to when administered alone. The C_max and AUC_inf of the active metabolite ortho‐hydroxyatorvastatin remained unchanged. Administration of a single 5‐mg dose of rosuvastatin or a single 10‐mg dose of atorvastatin had no relevant effect on upadacitinib C_max or area under the plasma concentration–time curve. These results demonstrated that upadacitinib has no clinically relevant effect on the pharmacokinetics of rosuvastatin and atorvastatin or on substrates transported by OATP1B or breast cancer resistance protein.

JAK inhibitors, psoriatic arthritis, and axial spondyloarthritis: a critical review of clinical trials

INTRODUCTION

Psoriatic arthritis (PsA) and spondyloarthritis (SpA) are inflammatory arthritides associated with progressive damage, deformity and morbidity. Janus kinase (JAK) inhibitors block JAKs, cytoplasmic protein tyrosine kinases important in signal transduction and immune processes that are currently being studied as synthetic disease modifying anti-rheumatic drugs (tsDMARDs) in psoriatic arthritis and spondyloarthritis.

AREAS COVERED

This review evaluates published phase 2 and 3 clinical trial data for JAK kinase inhibitors for psoriatic arthritis and spondyloarthritis. A literature search using PubMed was conducted using the following keywords: 'psoriatic arthritis', 'ankylosing spondylitis', 'axial spondyloarthritis', 'non-radiographic axial spondyloarthritis', 'tofacitinib', 'baricitinib', 'filgotinib' and 'upadacitinib'. Mechanism of action, phase 2 and 3 clinical trial data, including efficacy and safety, are discussed.

EXPERT OPINION

JAK inhibitors are important orally administered agents conferring different degrees of selectivity toward JAK1, JAK2, and JAK3 which may have implications on efficacy and safety in PsA and SpA. Phase 2 and 3 clinical trials in PsA for tofacitinib and upadacitinib and phase 2 for filgotinib confirmed efficacy comparable to biologic DMARDs. In SpA, phase 2 and 2/3 studies confirmed significant efficacy of tofacitinib, filgotinib and upadacitinib compared to placebo. Safety was comparable to clinical trial, long-term extension, and registry data for rheumatoid arthritis.

Upadacitinib in Rheumatoid Arthritis: A Benefit-Risk Assessment Across a Phase III Program

Treating to a target of clinical remission or low disease activity is an important principle for managing rheumatoid arthritis (RA). Despite the availability of biologic disease-modifying antirheumatic drugs (bDMARDs), a substantial proportion of patients with RA do not achieve these treatment targets. Upadacitinib is a once-daily, oral Janus kinase (JAK) inhibitor with increased selectivity for JAK1 over JAK2, JAK3, and tyrosine kinase 2. The SELECT phase III upadacitinib clinical program comprised five pivotal trials of approximately 4400 patients with RA, including inadequate responders (IR) to conventional synthetic (cs)DMARDs or bDMARDs. This review aims to provide insights into the benefit-risk profile of upadacitinib in patients with RA. Upadacitinib 15 mg once daily, in combination with csDMARDs or as monotherapy, achieved all primary and ranked secondary endpoints in the five pivotal trials across csDMARD-naïve, csDMARD-IR, and bDMARD-IR populations. Upadacitinib 15 mg also demonstrated significantly higher rates of remission and low disease activity in all five pivotal trials, compared with placebo, methotrexate, or adalimumab. Labeled warnings of JAK inhibitors include serious infections, herpes zoster, malignancies, major cardiovascular events, and venous thromboembolic events. Short- and long-term integrated analyses showed that upadacitinib 15 mg was associated with increased risk of herpes zoster and creatine phosphokinase elevations compared with methotrexate and adalimumab but otherwise had comparable safety with these active comparators. This review suggests that upadacitinib 15 mg had a favorable benefit-risk profile. The safety of upadacitinib will continue to be monitored in long-term extensions and post-marketing studies.

Exposure-Response Analyses for Upadacitinib Efficacy in Subjects With Atopic Dermatitis-Analyses of Phase 2b Study to Support Selection of Phase 3 Doses

Upadacitinib is a selective Janus kinase 1 inhibitor that was recently approved for treatment of rheumatoid arthritis and is currently being evaluated for treatment of several other autoimmune diseases, including atopic dermatitis (AD). The relationships between upadacitinib plasma exposure and efficacy (assessed as Eczema Area Severity Index [EASI]-75, EASI-90, and Investigator Global Assessment [IGA] 0/1) in subjects with moderate to severe atopic dermatitis were characterized using the data from 167 subjects who were enrolled in a phase 2b dose-ranging study. Subjects were randomized to receive once daily doses of monotherapy treatment with upadacitinib extended-release 7.5, 15, or 30 mg or placebo for 16 weeks. Logistic regression models were developed and utilized to simulate efficacy for upadacitinib with an approximate phase 3 sample size. Based on exposure-response models, 15 mg once daily is predicted to achieve EASI-75, EASI-90, and IGA 0/1 responses in 48%, 26%, and 29% of subjects, respectively, compared with placebo responses of 9%, 2%, and 2%, respectively, whereas 30 mg once daily is predicted to provide an additional approximately 20% greater efficacy for these end points relative to 15 mg once daily. These analyses supported the selection of upadacitinib doses that are being evaluated in ongoing global phase 3 studies in atopic dermatitis.

Characterization of the Effect of Upadacitinib on the Pharmacokinetics of Bupropion, a Sensitive Cytochrome P450 2B6 Probe Substrate

This phase 1 study characterized the effect of multiple doses of upadacitinib, an oral Janus kinase 1 selective inhibitor, on the pharmacokinetics of the cytochrome P450 (CYP) 2B6 substrate bupropion. Healthy subjects (n = 22) received a single oral dose of bupropion 150 mg alone (study period 1) and on day 12 of a 16-day regimen of upadacitinib 30 mg once daily (study period 2). Serial blood samples for measurement of bupropion and hydroxybupropion plasma concentrations were collected in each study period. The central values (90% confidence intervals) for the ratios of change were 0.87 (0.79-0.96) for bupropion maximum plasma concentration (Cmax ), 0.92 (0.87-0.98) for bupropion area under the plasma-concentration time curve from time 0 to infinity (AUCinf ), 0.78 (0.72-0.85) for hydroxybupropion Cmax , and 0.72 (0.67-0.78) for hydroxybupropion AUCinf when administered with, relative to when administered without, upadacitinib. After multiple-dose administration of upadacitinib 30 mg once daily, upadacitinib mean ± SD AUC0-24 was 641 ± 177 ng·h/mL, and Cmax was 83.3 ± 30.7 ng/mL. These results confirm that upadacitinib has no relevant effect on pharmacokinetics of substrates metabolized by CYP2B6.

Spinal and paraspinal inflammatory reactions after epidural steroid injection in a patient taking disease-modifying antirheumatic drugs

BackgroundDisease-modifying anti-rheumatic drugs (DMARDs) are used in the management of rheumatoid arthritis (RA) and are classified as conventional DMARDs and biologic agents. A concern with DMARDs is the increased risk of infection after surgery. A practice advisory from the American Society of Anesthesiologists recommend alternatives to neuraxial injections in patients who are immunocompromized. We describe a patient who was on several DMARDs and developed inflammatory reactions in her bilateral paraspinal muscles and lumbar spine after an epidural steroid injection (ESI). CASE PRESENTATION: The patient was a 79-year-old woman; she was taking methotrexate, adalimumab and prednisone for her RA. She had a left L5-S1 paramedian ESI for her L5 radiculitis. After relief of her back and radicular pain for 5 weeks, she had an acute exacerbation of her back pain. MRI showed bilateral paraspinal fluid accumulations and enhancement in her ligamentum flavum. Cultures of the aspirated fluid and biopsy specimens were negative for fungal, aerobic and anaerobic organisms. A repeat MRI 2 months later showed diminution of the fluid collection but with a new fluid accumulation near the left L4-5 facet and left L4 pedicle. Repeat cultures and gram stain of the specimens taken from the pedicle and the paraspinal muscles were negative. The patient was followed by her rheumatologist and in the pain clinic until resolution of her symptoms. CONCLUSIONS: Several society guidelines recommend the continuation of methotrexate but stoppage of the biologic DMARDS before surgery. The occurrence of an intense inflammatory reaction after an ESI in our patient calls for additional research on the subject and shared decision-making between the pain physician, patient and rheumatologist especially in patients on several DMARDs.