Clinical Pharmacokinetic and Pharmacodynamic Considerations in the Treatment of Moderate-to-Severe Psoriasis

Psoriasis is a common inflammatory immune disorder due to chronic activation of the adaptive and innate immune responses. Therapies for psoriasis target reducing inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-17, and interleukin-22. Patients with inflammatory disorders have reduced metabolism by cytochrome P450 enzymes in the liver. The pharmacokinetic and pharmacodynamic changes due to psoriasis also have an impact on reaching therapeutic concentrations of the drug. Pharmacokinetic and pharmacodynamic data help determine the safety and clinical considerations necessary when utilizing drugs for plaque psoriasis. A literature search was performed on PubMed and Ovid MEDLINE for the pharmacokinetic and pharmacodynamic data of oral therapies and biologics utilized for moderate-to-severe plaque psoriasis. The findings from the literature search were organized into two sections: oral therapies and biologics. The pharmacokinetic and pharmacodynamic parameters in healthy patients, patients with psoriasis, and special populations are discussed in each section. The oral therapies described in this review include methotrexate, cyclosporine, apremilast, tofacitinib, and deucravacitinib. Biologics include tumor necrosis factor-alpha inhibitors, interleukin-17 inhibitors, ustekinumab, and interleukin-23 inhibitors. Clinical considerations for these therapies include drug toxicities, dosing frequency, and anti-drug antibodies. Methotrexate and cyclosporine have a risk for hepatoxicity and renal impairment, respectively. Moreover, drugs metabolized via cytochrome P450, including tofacitinib and apremilast have decreased clearance in patients with psoriasis, requiring dose adjustments. Patients treated with therapies such as adalimumab can develop anti-drug antibodies that reduce the long-term efficacy of the drug. Additionally, overweight patients benefit from more frequent dosing to achieve better psoriasis clearance.

Systemic treatment of psoriasis in special population

Psoriasis is a common skin disorder affecting approximately 1% of the general population. The treatment of psoriasis depends on the body surface area involvement, quality of life impairment and associated co-morbidities. Special population comprising of pregnant women, lactating mothers, elderly individuals and children, is more vulnerable. They are not included in drug trials; rendering the data for use of systemic treatment scant and is mainly based on anecdotal evidence. In this narrative review, we discuss systemic treatment options in this special population. Though couples planning a family are not considered a special population, they form a subset that require special therapeutic consideration and have also been included in this review.

Efficacy and safety of biologics and small molecules for psoriasis in pediatric and geriatric populations. Part I: focus on pediatric patients

INTRODUCTION

Psoriasis management is challenging, especially in pediatric age for different factors. The introduction of biologic drugs and oral small molecules (OSM) revolutionized the armamentarium of available weapons in psoriasis treatment. Despite the use of these drugs in adult patients has been widely investigated, pediatric patients have often been unconsidered in clinical trials and real-life studies. However, the high efficacy and speed of action, the safety profile and the ease-to-use administration make these innovative drugs an invaluable therapeutic opportunity.

AREAS COVERED

The aim of this manuscript is to perform a review of the current literature examining data on the effectiveness and safety of biologic drugs and OSM for the management of psoriasis in pediatric patients in order to put the basis for universally shared treatment algorithm following available evidence. PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines were used for the literature research.

EXPERT OPINION/COMMENTARY

Our review based on currently available evidence suggests biologics and OSM as an ideal treatment option for pediatric patients, with an excellent profile in terms of efficacy and safety as compared to traditional systemic drugs.

Safety of current systemic therapies for nail psoriasis

INTRODUCTION

A discussion of safety of systemic treatments for nail psoriasis is lacking, particularly in reference to approval of new therapies assessed for nail outcomes. A review of safety profiles for agents commonly utilized for treatment of nail psoriasis is warranted to help inform treatment choices. The PubMed database was searched on 5 April 20235 April 2023, with articles discussing safety of nail psoriasis systemic therapies identified and reviewed.

AREAS COVERED

Systemic treatments for nail psoriasis include biologic therapies (tumor necrosis factor-alpha inhibitors, interleukin-17 inhibitors, interleukin-23 inhibitors, interleukin-12/23 inhibitors), small molecule inhibitors (apremilast, tofacitinib), and oral systemic immunomodulators (methotrexate, cyclosporine, acitretin), each with unique safety profiles and considerations. Herein, we discuss adverse events, contraindications, drug-drug interactions, screening/monitoring guidelines, as well as utilization for special populations, including pregnant, older, and pediatric patients.

EXPERT OPINION

The advent of targeted therapies, including biologic treatments and small molecule inhibitors, has revolutionized outcomes for nail psoriasis patients, but warrant review and monitoring for potential adverse events. Oral systemic immunomodulators have demonstrated moderate efficacy for nail psoriasis treatment, but are notable for frequent contraindications and drug-drug interactions. Further study of these agents and their use in special populations is needed to elucidate safety profiles for long-term use.

A toddler with an unusually severe polyarticular arthritis and a lung involvement: a case report

Background

COPA syndrome is a rare hereditary inflammatory disease caused by mutations in the gene encoding the coatomer protein subunit alpha, causing excessive production of type I interferon.

This case is a reminder for the general paediatrician, highlighting the relevance of the association between arthritis and lung involvement in toddlers.

Case presentation

We report the case of a 2-year-old girl with intermittent limping and joint pain. Her family history was relevant for a Still disease with lung involvement in the mother. Physical examination showed moderate wrist swelling. Laboratory findings on admission showed an increase in inflammatory markers, positive rheumatoid factor, antibodies antinuclear antibody (ANA) and cyclic citrullinated peptide (anti-CCP). Wrists’ ultrasound documented synovial thickening, and chest X-rays showed an unexpected severe interstitial pneumopathy. Genetic testing confirmed the diagnosis of a heterozygous mutation of the COPA gene in c.841C > T (p.R281W). Janus kinase treatment was started (baricitinib, 4 mg daily per os) with a remarkable improvement in limping and joint pain after two weeks.

Conclusions

In cases of recurrent arthritis with family history and multiple involvement organs, a genetic disorder should be suspected and genetic testing should be performed. Furthermore, this case suggests that therapy with jak inhibitors may be effective and safe in interferonopathies.

Efficacy and safety of JAK inhibitors in the treatment of alopecia areata in children: a systematic review and meta-analysis

BACKGROUND

Alopecia areata (AA) is a non-scarring hair loss mediated by T lymphocytes. Recently, a growing number of studies have shown that Janus kinase inhibitors are effective in the treatment of AA in children.

METHODS

A systematic review and meta-analysis were performed according to the PRISMA guidelines. Good response was defined as more than 50% decrease in Severity of Alopecia Tool (SALT) score or complete regrowth or more than 50% regrowth. Partial response was defined as 5-50% decrease in SALT score. Any response to treatment was defined as more than 5% in SALT score decrease.

RESULTS

There were 81.9% responders, 68.5% good responders, and 7.7% partial responders among the 10 included studies. The treatment duration was longer in good responders than in partial responders (p = .009). Oral route was linked to a better response to topical medication, with an odds ratio of 7.8 (95%CI 1.655-36.76). In terms of toxicity, reported adverse events included only mild symptoms. Liver transaminase elevation, upper respiratory tract infection, and eosinophilia were the most common adverse events.

CONCLUSIONS

Janus kinase inhibitors demonstrated promise in the treatment of AA in children, with the most common side effects being minor and reversible.

[Recent research on tofacitinib in the treatment of pediatric rheumatic diseases]

Tofacitinib is a Janus kinase inhibitor and can block the Janus kinase-signal transducer and activator of transcription signal transduction pathway and reduce the production and release of a variety of cytokines. It has great potential in the treatment of various rheumatic diseases with a rapid onset of action and can reduce corticosteroid dependence and related adverse events. The therapeutic effect of tofacitinib in adult patients has been confirmed, and it has been increasingly used in pediatric patients in recent years. This article reviews the clinical application of tofacitinib in the treatment of pediatric autoimmune diseases.

Oral tofacitinib for the treatment of alopecia areata in pediatric patients

BACKGROUND

Alopecia areata (AA) is characterized by the loss of hair, often in well-demarcated areas. While the pathogenesis of AA is not entirely understood, it is known that CD8 T cell-mediated destruction of the hair follicle occurs. There are no curative therapies for AA, although several therapies have been utilized with variable results. Oral tofacitinib, a JAK inhibitor, has been demonstrated to be efficacious and well tolerated in the treatment of adult AA. However, few studies have examined the clinical efficacy and tolerability of oral tofacitinib in the treatment of pediatric AA.

OBJECTIVE

To summarize the clinical outcomes of pediatric patients with AA treated with oral tofacitinib at the University of Colorado Hospital Dermatology Clinic.

METHODS

This is a retrospective case series conducted at the University of Colorado Hospital Dermatology Clinic. We included patients with a diagnosis of AA who were 18 years old or younger at the initiation of tofacitinib therapy. Demographics, treatment response, and adverse events were collected from electronic medical records.

RESULTS

Eleven patients (seven females, four males) with AA presented to the University of Colorado Hospital Dermatology Clinic who were between the ages of 8 and 18 years. Eight patients (72.7%) experienced hair regrowth with oral tofacitinib, while three patients (27.3%) experienced minimal to no hair regrowth. There were no serious adverse events recorded in the study population during the observed treatment period.

CONCLUSIONS

Oral tofacitinib was clinically effective in the majority our of patients and well tolerated.

Tofacitinib Therapy in Children and Young Adults With Pediatric-onset Medically Refractory Inflammatory Bowel Disease

OBJECTIVES

Tofacitinib, a selective Janus kinase inhibitor, effectively induces and maintains remission in adults with inflammatory bowel disease (IBD), but data are limited in children. This study aimed to evaluate the efficacy and safety of tofacitinib for medically refractory pediatric-onset IBD.

METHODS

This single-center retrospective study included subjects ages 21 years and younger who started tofacitinib for medically refractory IBD. Clinical activity indices, clinical response, steroid-free remission, biochemical response, and adverse events (AEs) were evaluated over 52 weeks.

RESULTS

Twenty-one subjects, 18 with ulcerative colitis or indeterminate IBD, received tofacitinib. At the end of the 12-week induction period, 9 out of 21 (42.9%) subjects showed clinical response and 7 out of 21 (33.3%) were in steroid-free remission. Of evaluable subjects at 52 weeks, 7 out of 17 (41.2%) showed clinical response and were in steroid-free remission. Of those remaining on tofacitinib at 1 year, none required concomitant systemic corticosteroids. Tofacitinib was discontinued in 8 subjects because of refractory disease, including 8 who ultimately underwent colectomy, and in 1 subject who developed a sterile intra-abdominal abscess. There were no instances of thrombi, zoster reactivation, or clinically significant hyperlipidemia, all of which were AEs of interest.

CONCLUSIONS

There is limited experience with tofacitinib in pediatric IBD. In this cohort, tofacitinib induced rapid clinical response with sustained efficacy in nearly half of subjects. This study provides encouraging evidence for the efficacy and safety of tofacitinib as part of the treatment paradigm for young individuals with moderate-to-severe IBD. Larger, well-powered, prospective studies are warranted.

Pediatric Psoriasis: From New Insights into Pathogenesis to Updates on Treatment

Psoriasis is a chronic inflammatory systemic disease primarily affecting the skin, but which often involves considerable comorbidities as well. One-third of psoriasis cases start during childhood. In pediatric psoriasis, an association with several medical comorbidities is also indicated. Furthermore, because of its chronic nature and frequent relapses, psoriatic patients tend to require long-term treatment and experience negative impacts on their quality of life. Considering the different clinical characteristics of pediatric psoriasis, it has recently been presented that the pathogenesis of pediatric psoriasis is distinct from adult psoriasis. Treatment for pediatric psoriasis usually involves the same methods as for adults. However, most treatments in pediatric psoriasis are used off-label and research in this regard is still lacking. Targeted therapies involving newly developed biologics are also increasingly being applied to psoriasis in children. This review summarizes the clinical characteristics of pediatric psoriasis and focuses mainly on the updated concepts of pathogenesis and treatments in pediatric psoriasis. This was undertaken to widen the understanding of these relevant aspects and to provide better management of pediatric psoriasis by clinicians.

Therapeutic challenges in managing pediatric psoriasis

Background

Each year, 20,000 patients aged <10 years are diagnosed with psoriasis. Pediatric-onset psoriasis has many similarities to adult-onset disease, and previous studies suggest that the incidence might be increasing in both populations.

Objective

The challenges that arise when treating patients with psoriasis, especially those age <12 years, are summarized, as well as the limited available treatment options for treating pediatric patients with psoriasis and the evidence supporting each of them.

Methods

Recently published guidelines by the American Academy of Dermatology and the National Psoriasis Foundations, as well as guidelines published by the German Society of Dermatology, provide considerable insight in managing patients who have this condition. The latest studies on pediatric psoriasis treatment were reviewed, including recent and current clinical trials with U.S. Food and Drug Administration approved and nonapproved medications, case reports, case series, and reviews. The authors also reviewed American and European guidelines, as well as recommendations from expert panels.

Results

Currently, only six medications are approved by the U.S. Food and Drug Administration for the treatment of pediatric psoriasis: three biologics and three topical. Many off-label topical treatments have been used in pediatric psoriasis, with variable effectiveness and safety profiles. Data from adult clinical trials, as well as case reports and series from pediatric patients, suggest that other biologic medications are effective for pediatric psoriasis.

Conclusion

Many questions remain unanswered, leaving clinicians facing multiple challenges when encountering pediatric patients with psoriasis. This summation will help provide an overview of current on- and off-label medications for pediatric psoriasis. Pediatric clinical trials should be implemented to obtain data that can result in expanding the therapeutic spectrum for this population, parallel to their adult counterparts.