Pharmacokinetics, Safety, and Efficacy of Ixekizumab in Chinese Patients with Moderate-to-Severe Plaque Psoriasis: A Phase 1, Single- and Multiple-Dose Study

INTRODUCTION

We evaluated the pharmacokinetics (PK), safety, and efficacy of ixekizumab, a high-affinity monoclonal antibody that selectively targets interleukin-17A, in Chinese patients with moderate-to-severe psoriasis.

METHODS

In this phase 1, multicenter, open-label study, adults (≥ 18 years) diagnosed with moderate-to-severe plaque psoriasis for ≥ 6 months involving ≥ 10% of their body surface area received ixekizumab 80 mg by subcutaneous injection and were observed for 20 weeks (single-dose phase) and then an initial dose of 160 mg followed by randomization (1:1) to 80 mg ixekizumab every 2 weeks (IXE Q2W) or every 4 weeks (IXE Q4W) for an 8-week treatment period (multiple-dose phase).

RESULTS

The median time to maximum observed ixekizumab concentrations occurred 2-4 days after dosing and the geometric mean half-life was 15-16 days, after single (n = 12) and multiple (n = 29) doses. Approximately linear pharmacokinetics were observed between the 80 and 160 mg single doses. Steady-state systemic exposure to ixekizumab during a dosing interval was similar with the IXE Q2W and IXE Q4W regimens, with estimates of 224 µg·day/mL and 213 µg·day/mL for the area under the concentration-time curve from time 0 to 14 days post-dose and 0 to 28 days post-dose, respectively. Safety was consistent with the established safety profile of ixekizumab. At week 12 after multiple doses, the proportions of patients achieving a 75% or 90% improvement in Psoriasis Area and Severity Index score were 100% and 86% for IXE Q2W, respectively, and 93% and 80% for IXE Q4W, respectively. A Static Physician's Global Assessment score of 0 or 1 was achieved in 100% and 87% with IXE Q2W and IXE Q4W, respectively.

CONCLUSIONS

The PK of ixekizumab in Chinese patients with moderate-to-severe plaque psoriasis was comparable to findings in global populations. After IXE Q2W or IXE Q4W for 12 weeks, clinically relevant treatment responses and an acceptable safety profile were observed.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT03073213).

Blocking interleukin-17 in psoriasis: Real-world experience from the PsoPlus cohort

BACKGROUND

Real-world studies on the use of biologics in psoriasis (Pso) are increasing, but still scarce. Trough concentrations (C_t s) of interleukin-17 inhibitors (IL-17i) seem promising for clinical decision-making, but their value in daily practice has yet to be proven.

OBJECTIVES

To report on IL-17i effectiveness, treatment modifications and C_t use in our clinic.

METHODS

Data were collected from IL-17i-treated Pso patients followed up in the PsoPlus clinic at the Dermatology department, Ghent University Hospital, Belgium. Descriptive statistics and Kaplan-Meier analysis were performed.

RESULTS

A total of 111 patients were included, counting for 134 IL-17i courses (secukinumab, ixekizumab, and brodalumab). Fifty-five per cent of the patients were bio-naive prior to IL-17i initiation. During maintenance, merely 97.0% and 77% achieved near-complete and complete skin clearance, respectively. Major reasons for treatment modification were suboptimal response (63.0%) and safety issues (9.3%). Reported modifications were switch (25.4%), dose escalation (11.9%), dose de-escalation (6.7%), treatment association (6.0%) and IL-17i stop (3.0%). Overall drug survival was 69.0 months, without difference between the different IL-17i (p = 0.078). Ixekizumab tended to have the highest survival. Drug survival was higher in bio-naive subjects compared to bio-experienced subjects (p = 0.011). C_t was measured in 20 patients and interpreted post hoc. In 85%, the clinical decision was in accordance with the C_t (e.g. substantiated need for dose escalation). For the other cases, the C_t would have led to another clinical decision if known at that time.

CONCLUSIONS

This real-world study showed that IL-17i are very effective drugs for Pso, with ixekizumab as leading biologic. Prior bio-experience seemed to impact IL-17i drug survival. Treatment modifications were mainly performed in case of insufficient response, primarily via switch and dose escalation, and least frequently in ixekizumab patients. C_t might rationalize clinical decision-making; however, there is need for standardized algorithms to corroborate its use.

Efficacy of ixekizumab in patients with moderate-to-severe plaque psoriasis and prediabetes or type 2 diabetes

Objective

Patients with psoriasis have an increased prevalence of type 2 diabetes when compared to the general population. Research suggests that type 2 diabetes (T2D) as well as obesity may have an impact on patients' response to treatment. This post-hoc analysis reports the efficacy of ixekizumab in treating moderate-to-severe psoriasis in patients with prediabetes or T2D.

Method and materials

UNCOVER-1, UNCOVER-2, and UNCOVER-3 were three Phase 3, multicenter, randomized, double-blind, placebo-controlled trials that evaluated the efficacy and safety of ixekizumab in adult patients with moderate-to-severe psoriasis. Patients were aged ≥18 years with chronic moderate-to-severe psoriasis (defined as ≥10% body surface area affected, static Physician Global Assessment ≥3, and Psoriasis Area and Severity Index [PASI] ≥12 at screening and baseline) who were candidates for phototherapy or systemic therapy. UNCOVER-1, UNCOVER-2, and UNCOVER-3 participants received ixekizumab as per label (that is, an initial dose of two subcutaneous injections [160 mg in total] at Week 0, followed by 80 mg every 2 weeks through Week 12 and 80 mg every 4 weeks thereafter through Week 60).

Results

The proportions of patients with prediabetes, T2D and normoglycemia that achieved PASI75, PASI90, and PASI100 at Week 60 were similar. Results suggest that patients with T2D were slower to achieve PASI100 than patients with prediabetes or those with normoglycemia. Ixekizumab had no effect on any metabolic markers in patients receiving the treatment.

Conclusions

Despite the higher rate of obesity and extreme obesity in patients with prediabetes and T2D, ixekizumab was an efficacious treatment in treating patients with psoriasis.

Racial/ethnic differences in treatment efficacy and safety for moderate-to-severe plaque psoriasis: a systematic review

Biologic medications have revolutionized treatment of psoriasis; however, there remains uncertainty in which medications should be used to maximize efficacy based on race/ethnicity. The purpose was to determine if efficacy of biological medications differs based on race/ethnicity. A systematic review identified all clinical trials focused on biologic treatment outcomes from inception of database until March 5th, 2021. Included studies provided data on racial/ethnic differences in biologic skin clearance efficacy using the Psoriasis Area and Severity Index (PASI) and "clear/almost clear" scores. There were 1220 studies identified, and 24 included in the review. The races/ethnicities included were Asian (n = 2740), White (n = 9745), Black (n = 138), and Latino (n = 728). Ixekizumab provided the highest "clear/almost clear" score (90.7%, 89.4%) and PASI 75 (98.8%, 96.6%) for Asian and Latino patients, respectively. Guselkumab had the highest "clear/almost clear" score for White (86.8%) patients, while Black patients had highest "clear/almost clear" (75.0%) and PASI 75 (91.7%) scores to brodalumab. Limitations included lack of studies reporting outcome data based on race/ethnicity and lack of patients of color within psoriasis clinical trials. For treatment of plaque psoriasis, there is evidence of differences in efficacy of biologics improving clinical disease severity between different races or ethnicities.

Impact of Pharmacokinetic and Pharmacodynamic Properties of Monoclonal Antibodies in the Management of Psoriasis

The treatment of psoriasis has been revolutionized by the emergence of biological therapies. Monoclonal antibodies (mAb) generally have complex pharmacokinetic (PK) properties with nonlinear distribution and elimination. In recent years, several population pharmacokinetic/pharmacodynamic (PK/PD) models capable of describing different types of mAb have been published. This study aims to summarize the findings of a literature search about population PK/PD modeling and therapeutic drug monitoring (TDM) of mAb in psoriasis. A total of 22 articles corresponding to population PK/PD models of tumor necrosis factor (TNF)-α inhibitors (adalimumab and golimumab), interleukin (IL)-23 inhibitors (guselkumab, tildrakizumab, and risankizumab), IL-23/IL-12 inhibitor (ustekinumab), and IL-17 inhibitors (secukinumab, ixekizumab, and brodalumab) were collected. A summary of the clinical trials conducted so far in psoriasis was included, together with the current structural population PK and PD models. The most significant and clinical covariates were body weight (BW) and the presence of immunogenicity on clearance (CL). The lack of consensus on PK/PD relationships has prevented establishing an adequate dosage and, therefore, accentuates the need for TDM in psoriasis.

Population pharmacokinetic and exposure-efficacy analysis of ixekizumab in paediatric patients with moderate-to-severe plaque psoriasis (IXORA-PEDS)

AIMS

Ixekizumab is a high-affinity monoclonal antibody that selectively targets interleukin-17A used in the treatment of adult and paediatric patients with moderate-to-severe psoriasis. This analysis evaluated the pharmacokinetics (PK) of ixekizumab and the exposure-efficacy relationship in paediatric patients aged 6 to <18 years with psoriasis.

METHODS

Population PK and exposure-efficacy models were developed. The models used data from paediatric patients with psoriasis participating in the Phase 3 IXORA-PEDS trial in which patients were dosed according to weight categories. The exposure-efficacy model is a Psoriasis Area and Severity Index (PASI) time course model using data up to Week 12, a co-primary efficacy endpoint.

RESULTS

A 2-compartment population PK model describes the PK of ixekizumab in paediatric patients with the effect of body weight incorporated on clearance and volume terms using an allometric relationship. The weight category-based dosing ensured that ixekizumab mean trough serum concentrations in paediatric patients with psoriasis (3.20-3.33 μg/mL) were within the range of concentrations observed in adult patients with psoriasis (mean [standard deviation]: 3.48 [2.16] μg/mL) administered an efficacious dosing regimen. The observed PASI response rates at Week 12 in paediatric patients (91.9/81.8/52.5% for PASI75/90/100) are well predicted by the final exposure-efficacy model and response rates are similar or higher than those achieved in adults (86.2/66.6/35.0% for PASI75/90/100).

CONCLUSION

This analysis is the first to describe the PK and exposure-efficacy relationship of ixekizumab in paediatric patients with psoriasis. The analyses support the selection of the weight category-based ixekizumab dosing regimens approved for use in paediatric patients with psoriasis.

Therapeutic drug monitoring of biologics in inflammatory bowel disease: unmet needs and future perspectives

Therapeutic drug monitoring (TDM) has emerged as a useful tool for optimising the use of biologics, and in particular anti-tumour necrosis factor (anti-TNF) therapy, in inflammatory bowel disease (IBD). However, challenges remain and are hindering the widespread implementation of TDM in clinical practice. These barriers include identification of the optimal drug concentration to target, the lag time between sampling and results, and the proper interpretation of anti-drug antibody titres among different assays. Solutions to overcome these barriers include the harmonisation of TDM assays and the use of point-of-care testing. Other unmet needs include well designed prospective studies and randomised controlled trials focusing on proactive TDM, particularly during induction therapy. Future studies should also investigate the utility of TDM for biologics other than anti-TNF therapies in both IBD and other immune-mediated inflammatory diseases such as rheumatoid arthritis and psoriasis, and the use of pharmacokinetic modelling dashboards and pharmacogenetics towards individual personalised medicine.

Relationship between serum trough levels and efficacy of brodalumab from a post hoc exploratory analysis of a Japanese study in patients with plaque psoriasis

Previous clinical studies have shown that efficacy and serum brodalumab levels are dose dependent in patients with psoriasis receiving the same dose of brodalumab during the study. This study aimed to investigate the association between dosage, serum levels, and efficacy of brodalumab in Japanese patients with plaque psoriasis with dosage variations during the study. This was a post hoc exploratory analysis of a 108‐week, multicenter, open‐label extension study, which changed into a post‐marketing surveillance study following brodalumab approval in Japan. Eligible patients with plaque psoriasis (n = 129) received brodalumab 140 mg every 4 weeks on Day 1; dosage change at physician’s discretion from 140 mg every 8 weeks to 210 mg every 2 weeks was permitted; patients switched to 210 mg every 2 weeks during the post‐marketing surveillance study. Exploratory endpoints included serum brodalumab levels at Weeks 28 and 108, its association with Psoriasis Area and Severity Index score, and Psoriasis Area and Severity Index score in patients receiving brodalumab 210 mg every 2 weeks at end of study. Median brodalumab trough levels were significantly higher (P < 0.05) at higher vs. lower dosages at Weeks 28 (n = 126) and 108 (n = 111) except for 140 mg every 2 weeks vs. 210 mg every 2 weeks at Week 108 and higher in patients with lower Psoriasis Area and Severity Index scores—significantly different only for Psoriasis Area and Severity Index score 0 vs. >2 at Week 28 (P = 0.0153). Of 100 patients receiving 210 mg every 2 weeks at end of study, 89% had a Psoriasis Area and Severity Index score ≤2. In patients with plaque psoriasis, brodalumab efficacy may depend upon sustained serum trough levels and can be restored by using the approved dose.

Ixekizumab in the treatment of psoriatic arthritis

Psoriatic arthritis (PsA) is a heterogeneous chronic rheumatic disorder with numerous phenotypic facets. A better in deep understanding of the pathophysiologic mechanisms leading to psoriasis and PsA has contributed to the introduction of novel therapeutic agents. IL-17 is at the heart and a critical factor in the onset of PsA. Ixekizumab, a high-affinity monoclonal antibody against IL-17 A, has been approved by the US FDA in March 2016 for baseline psoriasis and Dec 2017 for PsA; by the EMA in April 2016 and January 2018, respectively. This article reviews the published data relating to ixekizumab efficacy and safety in the PsA treatment.

Dermatologists on the medical need for therapeutic drug monitoring of biologics in psoriasis: results of a structured survey

BACKGROUND

Therapeutic drug monitoring (TDM) may lead to more rational use of biologics. Still, TDM is largely underexplored in psoriasis. Little is known about the dosing behavior of biologics by dermatologists, and their attitude toward TDM.

OBJECTIVE

Exploration of the awareness and need for the concept of TDM in psoriasis amongst (inter)national dermatologists.

METHOD

A survey was distributed at the Belgian Dermatology Days 2019 and Skin Inflammation & Psoriasis International Network (SPIN) Congress 2019. Next, an online survey version was launched amongst the SPIN Scientific Committee members. We collected physician's characteristics, prescription behavior of biologics, data regarding clinical response to biologics and attitude toward TDM.

RESULTS

A total of 107 surveys were included for analysis. Most dermatologists were Belgium-based (54.2%), others from European (23.4%) or non-European countries (19.6%). Seventy percent performed either dose increase (64.8%), time interval shortening (74.6%), dose lowering (16.9%) or time interval extension (33.8%). The majority who performed dose adaptations acknowledged the need for TDM.

CONCLUSION

This study showed most dermatologists perform dose adaptations empirically. The need for TDM was indicated by the majority, implying the need for effective communication regarding availability, utility and implementation of TDM assays in daily dermatology practice.