Dupilumab pharmacokinetics in Chinese healthy subjects and patients with atopic dermatitis: Results of two randomized, double-blind, placebo-controlled studies

Development and validation of an enzyme-linked immunosorbent assay for the quantification of a recombinant humanized anti-IL-4Rα monoclonal antibody CM310 in serum and its application to pharmacokinetic study in Sprague-Dawley Rats

CM310 is a recombinant humanized monoclonal antibody targeting Interleukin (IL)-4 receptor alpha (IL-4Rα). IL-4Rα blockade prevents IL-4 and IL-13 from binding to their receptor, thereby inhibiting downstream signaling pathways that drive Type 2 helper T-cell (Th2) inflammation. CM310 holds potential for treating Th2-related inflammatory diseases, such as asthma, atopic dermatitis and chronic sinusitis with nasal polyposis. In this study, a direct enzyme-linked immunosorbent assay (ELISA) was developed to measure the concentrations of CM310 in rat serum. Seven calibration standards (ranging from 25 to 1600 ng/mL) and three quality controls (70, 500 and 1250 ng/mL) were defined. The limit of detection (LOD), lower limit of quantification (LLOQ) and upper limit of quantification (ULOQ) were 13, 25 and 1600 ng/mL, respectively. The method exhibited excellent precision and accuracy and successfully applied to in vitro serum stability and pharmacokinetic (PK) studies. In conclusion, we have developed and validated a highly sensitive and selective method for measuring CM310 in Sprague-Dawley rats. The development and validation ELISA method met the acceptable criteria, which suggested that these can be applied to quantify CM310, as well as in PK studies.

Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability of Stapokibart in Healthy Volunteers and Adult Subjects with Atopic Dermatitis

INTRODUCTION

Stapokibart, a novel humanized anti-interleukin (IL)-4 receptor alpha monoclonal antibody, inhibits the signaling of IL-4 and IL-13, which are key drivers of type 2 inflammation in atopic dermatitis (AD). This study aimed to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of stapokibart in a randomized, double-blind, placebo-controlled single ascending dose (SAD) study and a multiple ascending dose (MAD) study.

METHODS

The SAD study enrolled 33 healthy male adults aged 18-65 years at a single center. The MAD study enrolled 39 patients with moderate-to-severe AD aged 18-70 years at seven centers. Enrolled subjects were randomized to subcutaneous (SC) doses of stapokibart (75-600 mg) or placebo. Serum thymus and activation-regulated chemokine (TARC) and total immunoglobulin E (IgE) were measured as PD biomarkers for stapokibart.

RESULTS

Similar PK characteristics were observed in healthy volunteers and subjects with AD after the initial administration. Stapokibart exhibited non-linear pharmacokinetics in both types of subjects. Following single doses, the mean maximum serum concentration (Cmax) ranged from 5.3 to 63.0 μg/mL, median Tmax ranged from 3.0 to 7.0 days, mean terminal half-life (t1/2z) ranged from 2.39 to 7.43 days, and mean apparent volume (Vz/F) ranged from 3.64 to 6.73 L in healthy subjects. The mean AUC accumulation ratio was 2.29 in subjects with AD after three doses of stapokibart 300 mg administered every 2 weeks. The median serum total IgE and TARC levels on day 43 decreased from baseline by 14.9-25.2% and 48.6-77.0%, respectively, among subjects with AD receiving three doses of stapokibart. No subjects developed grade ≥ 3 adverse events (AEs) or serious AEs or discontinued the study because of AEs. The incidence of AEs was similar between stapokibart and placebo groups.

CONCLUSION

Stapokibart showed favorable pharmacokinetics, pharmacodynamics, safety, and tolerability in the SAD and MAD studies. Based on these results, phase II and phase III trials of stapokibart have been performed in subjects with moderate-to-severe AD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT06161090 (29 November, 2023), NCT04893941 (15 May, 2021).

Rademikibart (CBP-201), a next-generation monoclonal antibody targeting human IL-4Rα: Two phase I randomized trials, in healthy individuals and patients with atopic dermatitis

IL-4 and IL-13 signaling via IL-4Rα plays key roles in the pathogenesis of atopic dermatitis (AD) and asthma. Rademikibart (formerly CBP-201), a next-generation human IgG4 kappa monoclonal antibody, blocks IL-4Rα-mediated signal transduction. We performed two phase I, randomized, double-blind, placebo-controlled trials. In a single-ascending dose trial, 40 healthy adults were randomized 3:1 to rademikibart (75-600 mg s.c., 300 mg i.v.) or placebo, with 12 weeks of follow-up. In the multiple-ascending dose trial, 31 adults with moderate-to-severe AD were randomized 4:1 to once weekly rademikibart (75-300 mg s.c.) or placebo for 4 weeks, plus 7 weeks of follow-up. Most treatment-emergent adverse events (TEAEs) were mild; none were serious. Two s.c. injection site reactions and one TEAE of conjunctivitis were reported, all were mild. Rapid and sustained improvements were observed in AD severity and in quality of life (QoL), without plateauing. At week 4, efficacy scores improved by a maximum of -74.4% (Eczema Area and Severity Index), -62.7% (body surface area), -52.8% (Pruritus Numerical Rating Scale [PNRS] severity), -54.4% (PNRS frequency), and - 69.9% (Dermatology Life Quality Index). Thymus activation regulated chemokine inflammatory biomarker concentrations decreased in both trials (-55.4% in the pooled rademikibart arms vs. +18.0% with placebo, at week 5, in patients with AD). Exposure to rademikibart increased in a greater than dose-proportional manner, suggesting nonlinear clearance. In summary, rademikibart was well-tolerated and associated with rapid and sustained improvements in eczematous lesions, pruritus, QoL, and inflammatory biomarker concentrations during 4 weeks of treatment. Efficacy responses did not plateau and were generally dose dependent. These promising findings support further development of rademikibart in patients with AD.

Patient-centered dupilumab dosing regimen leads to successful dose reduction in persistently controlled atopic dermatitis

BACKGROUND

At present, no real-world studies are available on different dupilumab dosing regimens in controlled atopic dermatitis (AD). The aim of this study was to clinically evaluate a patient-centered dupilumab dosing regimen in patients with controlled AD and to relate this to serum drug levels and serum biomarkers.

METHODS

Ninety adult AD patients from the prospective BioDay registry were included based on their dupilumab administration interval according to a predefined patient-centered dosing regimen. Group A (n = 30) did not fulfill the criteria for interval prolongation and continued using the standard dupilumab dosage (300 mg/2 weeks), group B (n = 30) prolonged dupilumab interval with 50% (300 mg/4 weeks), and group C (n = 30) prolonged dupilumab interval with 66%-75% (300 mg/6-8 weeks). AD severity score, patient-reported outcomes, serum dupilumab levels, and serum biomarkers were analyzed over time.

RESULTS

Disease severity scores did not significantly change over time during the tapering period in any of the groups. In groups B and C, the Numeric Rating Scale (NRS)-pruritus temporarily significantly increased after interval prolongation but remained low (median NRS-pruritus≤4). Median dupilumab levels remained stable in group A (standard dosage), but significantly decreased in groups B and C (24.1 mg/L (IQR = 17.1-45.6); 12.5 mg/L (IQR = 1.7-22.3)) compared with the levels during the standard dosage (88.2 mg/L [IQR = 67.1-123.0, p < .001]). Disease severity biomarker levels (CCL17/CCL18) remained low in all study groups during the whole observation period.

CONCLUSIONS

This study showed that dose reduction was successful in a subgroup of patients with controlled AD by using a patient-centered dosing regimen. These patients showed stable low disease activity and low severity biomarkers over time.