Population Pharmacokinetics of Abrocitinib in Healthy Individuals and Patients with Psoriasis or Atopic Dermatitis

Meta-Analysis of Noncompartmental Pharmacokinetic Parameters to Evaluate the Impact of CYP2C19 and CYP2C9 Genetic Polymorphisms on Abrocitinib Exposure

Abrocitinib is a selective Janus kinase 1 inhibitor approved for the treatment of atopic dermatitis. It is metabolized primarily by cytochrome P450 (CYP) 2C19 (approximately 53%) and CYP2C9 (approximately 30%), which form 2 active metabolites. The pharmacologic activity of abrocitinib is attributable to the unbound exposures of abrocitinib and those metabolites with active moiety area under the plasma concentration-time curve (AUC) considered the best measure of the total pharmacological effect. The effect of CYP2C19 and/or CYP2C9 genotypes on abrocitinib and active moiety exposures were evaluated using a meta-analysis of the noncompartmental estimates of exposure pooled from 10 clinical studies. A linear mixed-effects model was developed on the basis of the power model to evaluate the effect of CYP2C19 and/or CYP2C9 genotypes on exposure (i.e., abrocitinib AUC and peak plasma concentration, active moiety AUC and peak plasma concentration). The genotypes were evaluated individually and as a combined phenotype effect. When evaluating the poor metabolizers of CYP2C19 or CYP2C9 individually, the estimated increases were 44.9% and 42.0% in active moiety AUC, respectively. The combined phenotype models showed a 0.6% decrease, and 25.1% and 10.5% increases in the active moiety AUC for "elevated," "mixed," and "reduced" metabolizers, respectively. Overall, the active moiety exposures did not appear to be affected to a clinically meaningful extent by different genotypes of CYP2C19 and/or CYP2C9.

Risk of Enzyme- and Transporter-mediated Drug Interactions With Drugs Approved by the US Food and Drug Administration in 2022: A Detailed Analysis of In Vitro and Clinical Data Available in New Drug Application Reviews

PURPOSE

This analysis aimed to provide mechanistic understanding and clinical relevance of pharmacokinetic drug-drug interactions (DDIs) associated with drugs approved by the Food and Drug Administration in 2022.

METHODS

Drug metabolism, transport, and DDI data available in New Drug Applications (NDAs) of small molecular drugs approved (n = 22) was analyzed. The mechanism and clinical magnitude of these interactions were characterized based on in vitro, in silico, and clinical data.

FINDINGS

As victims, 10 drugs were identified as clinical substrates. Of these, 7 drugs were substrates of CYP3A, including the sensitive substrates daridorexant and mitapivat. As perpetrators, 3 drugs (adagrasib, lenacapavir, and vonoprazan) were clinical inhibitors of CYP enzymes, and 2 drugs (mavacamten and mitapivat) showed induction. Regarding transporter data, abrocitinib and deucravacitinib were found to be substrates of OAT3 and P-gp/BCRP, respectively, and 4 drugs (abrocitinib, adagrasib, lenacapavir, and oteseconazole) were found to inhibit P-gp and/or BCRP. As expected, all clinical DDIs with AUC changes ≥ 2-fold triggered label recommendations. Over half of DDIs with an AUC change < 2 also had label recommendations, pertaining most often to the concomitant use of drugs with a narrow therapeutic index. Overall, CYP3A played a major role in the drug disposition of the drugs approved in 2022, mediating all strong drug interactions.

IMPLICATIONS

The mechanistic information obtained from studying these new therapeutics with marker compounds can be extrapolated to common concomitant medications sharing the same pharmacokinetic properties, enhancing the safe and effective administration of these products in situations of polytherapy.

Plant-based zinc nanoflowers assisted molecularly imprinted polymer for the design of an electrochemical sensor for selective determination of abrocitinib

The first electrochemical sensor application in the literature is described for the sensitive and selective determination of the selective Janus kinase (JAK)-1 inhibitor abrocitinib (ABR). ABR is approved by the U.S. Food and Drug Administration (FDA) for the treatment of atopic dermatitis. The molecularly imprinted polymer (MIP)-based sensor was designed to incorporate zinc nanoflower (ZnNFs)-graphene oxide (GO) conjugate (ZnNFs@GO), synthesized from the root methanolic extract (RME) of the species Alkanna cappadocica Boiss. et Bal. to improve the porosity and effective surface area of the glassy carbon electrode (GCE). Furthermore, the MIP structure was prepared using ABR as a template molecule, 4-aminobenzoic acid (4-ABA) as a functional monomer, and other additional components. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the surface and structure of the synthesized nanomaterial and MIP-based surface. Among the electrochemical methods, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were preferred for detailed electrochemical characterization, and differential pulse voltammetry (DPV) was preferred for all other electrochemical measurements using 5.0 mM [Fe(CN)6]3-/4- solution as the redox probe. The MIP-based sensor, which was the result of a detailed optimization phase, gave a linear response in the 1.0 × 10-13 - 1.0 × 10-12 M range in standard solution and serum sample. The obtained limit of detection (LOD) and limit of quantification (LOQ) values and recovery studies demonstrated the sensitivity, accuracy, and applicability of the sensor. Selectivity, the most important feature of the MIP-based sensor, was verified by imprinting factor calculations using ibrutinib, ruxolitinib, tofacitinib, zonisamide, and acetazolamide.

Case report: Treatment of psoriasiform dermatitis in patients with malignancy

Psoriasis and atopic dermatitis (AD) are prevalent inflammatory skin disorders, each stemming from diverse factors, and characterized by recurring episodes. In certain complex cases, the clinical and pathological features exhibit overlapping and atypical characteristics, making accurate clinical diagnosis and targeted treatment a challenge. Psoriasiform dermatitis is the term used to describe such cases. Moreover, when patients have a history of malignancy, the situation becomes even more intricate, resulting in limited treatment options. Biologic therapies have transformed the management of immune-mediated inflammatory diseases, including psoriasis and AD. Meanwhile, the safety of biologics in special populations, especially among patients with a history of malignancy, should be underlined. The selective Janus kinase 1 (JAK1) inhibitor abrocitinib has been approved for the treatment of AD and has showed satisfying efficacy and safety in the treatment of psoriasis in clinical trials. Although unreported, JAK1 inhibitors are thought to have the potential to increase the risk of potential tumors. Apremilast, an oral phosphodiesterase (PDE)-4 inhibitor, is approved for moderate to severe plaque psoriasis. It has been investigated for its efficacy in AD, and is not contraindicated in malignancy. This report presents three cases of psoriasiform dermatitis in patients with a history of malignancy, showcasing significant improvement following treatment with systemic glucocorticoid, abrocitinib, or apremilast.

Targeted Systemic Therapies for Adults with Atopic Dermatitis: Selecting from Biologics and JAK Inhibitors

Therapeutic options for people with moderate or severe atopic dermatitis refractory to topical therapy have rapidly expanded in recent years. These new targeted immunomodulatory agents-biologics and Janus kinase (JAK) inhibitors-have each demonstrated high levels of efficacy and acceptable safety in mostly placebo-controlled clinical trials for atopic dermatitis, but there is no universally applicable algorithm to help choose between them for a given patient. Hence, patients and physicians should utilize shared decision making, discussing efficacy, safety, mode of delivery, monitoring, costs, speed of onset, and other factors to reach individualized treatment decisions. In this review, we try to aid shared decision making by summarizing the efficacy, safety, and monitoring of biologics and oral JAK inhibitors for adults with atopic dermatitis. Network meta-analyses suggest that higher doses of abrocitinib and upadacitinib are more effective than biologics. They also show that, among biologics, dupilumab is likely more effective than tralokinumab and lebrikizumab. Biologics are generally considered safer than JAK inhibitors, although concerns about JAK inhibitors are mainly extrapolated from older generation JAK inhibitors used in higher-risk populations. We also outline evidence and considerations for choosing and using systemic immunomodulatory treatments for special populations including pregnant individuals, those with human immunodeficiency virus (HIV), hepatitis B and C, end stage kidney disease, and older adults.

Pharmacokinetics, safety, and efficacy of cedirogant from phase I studies in healthy participants and patients with chronic plaque psoriasis

Cedirogant is an inverse agonist of retinoic acid-related orphan receptor gamma thymus (RORγt) developed for the treatment of moderate to severe chronic plaque psoriasis. Here, we report the results from two phase I studies in which the pharmacokinetics (PK), safety, and efficacy of cedirogant in healthy participants and patients with moderate to severe chronic plaque psoriasis were evaluated. The studies consisted of single (20-750 mg) and multiple (75-375 mg once-daily [q.d.]) ascending dose designs, with effect of food and itraconazole on cedirogant exposure also evaluated. Safety and PK were evaluated for both healthy participants and psoriasis patients, and efficacy was assessed in psoriasis patients. Following single and multiple doses, cedirogant mean terminal half-life ranged from 16 to 28 h and median time to reach maximum plasma concentration ranged from 2 to 5 h across both populations. Cedirogant plasma exposures were dose-proportional after single doses and less than dose-proportional from 75 to 375 mg q.d. doses. Steady-state concentrations were achieved within 12 days. Accumulation ratios ranged from approximately 1.2 to 1.8 across tested doses. Food had minimal effect and itraconazole had limited impact on cedirogant exposure. No discontinuations or serious adverse events due to cedirogant were recorded. Psoriasis Area and Severity Index (PASI) and Self-Assessment of Psoriasis Symptoms (SAPS) assessments demonstrated numerical improvement with treatment of cedirogant 375 mg q.d. compared with placebo. The PK, safety, and efficacy profiles of cedirogant supported advancing it to phase II clinical trial in psoriasis patients.

Evolution of Ritlecitinib Population Pharmacokinetic Models During Clinical Drug Development

BACKGROUND

Ritlecitinib is an oral Janus kinase 3/tyrosine kinase expressed in hepatocellular carcinoma family inhibitor undergoing parallel clinical development for alopecia areata, vitiligo, ulcerative colitis, Crohn's disease, and rheumatoid arthritis.

OBJECTIVE

As studies read out simultaneously, strategic planning of population pharmacokinetic model development and evaluation is required to ensure timely decisions.

METHODS

Data from healthy participants and patients from 12 clinical trials between December 2014 and July 2021 were included: seven phase I studies in healthy participants and organ impairment, five phase II/III studies in patients with rheumatoid arthritis, ulcerative colitis, alopecia areata, and vitiligo. Population pharmacokinetic models consisted of stepwise procedures to accommodate data availability and the model's application to answering clinical development questions. At each iteration of the model update, parameters of the next model were re-estimated by leveraging previous information and new data.

RESULTS

Three model development lifecycle iterations of the ritlecitinib population pharmacokinetic model were conducted to support alopecia areata, vitiligo, and ulcerative colitis study readouts. Initial structural modeling based on healthy participant data (and some rheumatoid arthritis and alopecia areata data) in iteration 1 provided a platform for comprehensive covariate testing during iteration 2, and model evaluation and implementation of the frequentist prior approach in iteration 3. The final model was a two-compartment model with first-order absorption and direct-response non-stationary clearance and bioavailability driven by concentrations in the peripheral compartment.

CONCLUSIONS

The present approach demonstrated the evolution of three population pharmacokinetic models with accumulating data, addressed clinical drug development questions related to systemic exposures of ritlecitinib, and informed the approved product label.

CLINICAL TRIAL REGISTRATION

NCT02309827, NCT02684760, NCT02958865, NCT02969044, NCT03232905, NCT03732807, NCT04016077, NCT03715829, NCT04037865, NCT04004663, NCT04634565, NCT02974868.

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.

Abrocitinib for the Treatment of Moderate-to-Severe Atopic Dermatitis

BACKGROUND

Atopic dermatitis (AD) is ranked as the third most prevalent skin condition with a worldwide prevalence of 2.4%. Atopic dermatitis is a common form of eczema. It develops in infancy or childhood and continues into adulthood with symptoms ranging from mild to severe. Pruritis and inflammation are the hallmark symptoms of AD.

MECHANISM OF ACTION, PHARMACODYNAMICS, AND PHARMACOKINETICS

Abrocitinib is a JAK1 selective inhibitor; inhibition results in a decreased interleukin (IL) 4 activation and decreased pruritis in a patient with AD. Abrocitinib is hepatically metabolized by multiple cytochrome P450 enzymes, and dose modification may be required when administered with concurrent medications.

CLINICAL TRIALS

At least 6 JAK1 Atopic Dermatitis Efficacy and Safety (JADE) trials were conducted evaluating Investigator's Global Assessment and Eczema Area and Severity Index score for efficacy. All JADE trials showed abrocitinib 100 mg and 200 mg doses efficacious when compared with placebo. Common adverse reactions were related to gastrointestinal disturbances, headache, and acne. Serious adverse reactions to assess risk for include serious infections, malignancy, major adverse cardiovascular events, and venous thromboembolisms.

THERAPEUTIC ADVANCE

Abrocitinib provides a valuable treatment option for patients with moderate-to-severe AD unresponsive to other therapies for those candidates without a high risk for significant adverse reaction associated with its use.

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.

Collapse

Efficacy and Safety of JAK1 Inhibitor Abrocitinib in Atopic Dermatitis

Abrocitinib is a JAK1 selective inhibitor recently approved for the treatment of moderate-to-severe atopic dermatitis in adults. It has demonstrated efficacy and safety in several clinical trials, both in children and adults, in monotherapy, and compared with dupilumab. The expected EASI-75 response rate estimates at week 12 are 62.9% (95% CrI 42.5-79.9%) for abrocitinib 200 mg and 43.0% (95% CrI 24.8-64.0%) for abrocitinib 100 mg. Abrocitinib has shown a faster effect than dupilumab as regards early alleviation of itch. Because of the incomplete target selectivity of JAK inhibitors, when abrocitinib treatment is considered, laboratory screening is necessary, latent tuberculosis must be screened for, active infections are a contraindication, and special caution must be exerted in treating elderly patients and those predisposed to thromboembolic events. Even though recent meta-analyses of clinical trials have not shown that atopic dermatitis, or its treatment with JAK inhibitors or dupilumab, modify the risk of deep venous thrombosis or pulmonary embolism, long-term follow-up studies will better define the safety profile of abrocitinib.

Magnitude and Time Course of Response to Abrocitinib for Moderate-to-Severe Atopic Dermatitis

BACKGROUND

Emerging treatments for moderate-to-severe atopic dermatitis (AD) may provide greater and faster improvement in AD signs and symptoms than current therapies.

OBJECTIVE

To examine JADE COMPARE (NCT03720470) data using stringent efficacy end points.

METHODS

Adults with moderate-to-severe AD were randomly assigned 2:2:2:1 to receive oral abrocitinib 200 or 100 mg once daily, subcutaneous dupilumab 300 mg every 2 weeks (600-mg loading dose), or placebo, with medicated topical therapy for 16 weeks. Stringent response thresholds were applied for Eczema Area and Severity Index (EASI), Investigator's Global Assessment, Dermatology Life Quality Index, Peak Pruritus Numerical Rating Scale, and Night Time Itch Scale severity.

RESULTS

At week 16, 48.9%, 38.0%, and 38.8% of the abrocitinib 200-mg, 100-mg, and dupilumab groups, respectively, achieved greater than or equal to 90% improvement from baseline in EASI versus 11.3% placebo; 14.9%, 12.6%, and 6.5% achieved Investigator's Global Assessment 0 (clear) versus 4.8% placebo; 29.7%, 21.6%, and 24.0% achieved Dermatology Life Quality Index 0/1 (no/minimal impact on quality of life) versus 10.6% placebo; and 57.1%, 44.5%, and 46.1% achieved Night Time Itch Scale severity 0/1 (no/minimal night-time itch) versus 31.9% placebo. Kaplan-Meier median time to greater than or equal to 90% improvement from baseline in EASI was 59, 113, and 114 days in the abrocitinib 200-mg, 100-mg, and dupilumab groups, respectively, and was not evaluable for placebo; median time to Peak Pruritus Numerical Rating Scale 0/1 (no/very minimal itch) was 86 and 116 days for abrocitinib 200-mg and dupilumab groups, respectively, and was not evaluable for abrocitinib 100-mg and placebo groups.

CONCLUSIONS

A greater proportion of patients treated with abrocitinib than placebo had almost complete control of AD signs and symptoms.

An evaluation of abrocitinib for moderate-to-severe atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common itchy inflammatory skin condition that affects many individuals. For many years, the landscape of AD treatment remained unchanged; however, there has been developing therapies that directly target the underlying immunological mechanism of AD. Janus kinase (JAK) inhibitors are small molecules that have shown anti-inflammatory and anti-itch effects in AD. Recently, abrocitinib, an oral JAK 1 inhibitor, was approved by the Food and Drug Administration for atopic dermatitis.

AREAS COVERED

By downregulating the immune cascade, abrocitinib has demonstrated the ability to curb symptoms of AD, including rapidly reducing pruritus in 2-3 days, and is safe and well-tolerated overall despite a low increased risk in infection. The data discussed was obtained from a comprehensive literature review utilizing PubMed.

EXPERT OPINION

Abrocitinib has strong efficacy, likely due to its broader mechanism of action provided by the inhibition of key regulatory molecule, JAK. Results have demonstrated that it is more efficacious at curbing symptoms of AD than dupilumab, the current treatment of choice for refractory, moderate-to-severe AD. While abrocitinib provides a great alternative treatment, particularly for non-responders and AD subtypes, it also demonstrates a stronger side effect profile that must be considered.