Persistent expression of interleukin-17 and downstream effector cytokines in recalcitrant psoriatic lesions after ustekinumab treatment

Brodalumab Versus Guselkumab in Patients with Moderate-to-Severe Psoriasis with an Inadequate Response to Ustekinumab: A Randomized, Multicenter, Double-Blind Phase 4 Trial (COBRA)

INTRODUCTION

Despite improved treatment options for plaque psoriasis within the last decades, some patients still have an inadequate response to treatment. Direct clinical evaluation between therapies used after biologic failure could facilitate physicians' choice of treatment.

METHODS

COBRA (NCT04533737) was a randomized (1:1), blinded (patient and assessor), 28-week, active-comparator trial conducted in Europe from December 2020 to December 2022. The objective was to compare the efficacy and safety of brodalumab versus guselkumab in adults with moderate-to-severe plaque psoriasis and inadequate response to ustekinumab. Patients received either brodalumab 210 mg or guselkumab 100 mg. The primary [having Psoriasis Area and Severity Index (PASI)-100 response at week 16] and key secondary (time to PASI-100 response) endpoints were tested in a fixed sequence.

RESULTS

Due to delays and enrollment challenges, recruitment was terminated with 113 patients enrolled of 240 planned. The proportion of patients having PASI-100 at week 16 for brodalumab was 53.4% compared with 35.9% for guselkumab [odds ratio (OR) 2.05; 95% confidence interval (CI) 0.95, 4.44; p = 0.069]. As this was not statistically significant, the hierarchical testing procedure was stopped. All other secondary PASI endpoints had nominal p-values below 0.05 in favor of brodalumab. In the time to PASI response analyses, brodalumab separated from guselkumab in estimated cumulative incidence of patients achieving a response from week 2 onward, suggesting fast onset of action with brodalumab. Quality of life measures improved in both treatment groups. The safety findings were consistent with the known safety profiles.

CONCLUSIONS

Brodalumab showed a tendency toward better and earlier effect than guselkumab in patients who had failed ustekinumab. Thus, this trial provides important information in assisting physicians in their choice of therapy for patients who have failed their prior anti-interleukin (IL)-12/23 treatment.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04533737.

Epidermal Hyperproliferation With Less Prominent Dermal Inflammation Is the Unique Histopathological Feature of the Refractory Lesions in Psoriasis Treated With Ustekinumab

ABSTRACT

Although ustekinumab (UST) shows excellent efficacy in treating psoriasis, not all patients have a complete clearance rate. The purpose of this study was to investigate the histopathological characteristics of refractory psoriasis lesions in patients with excellent response to UST. Fifty-seven patients with newly diagnosed psoriasis and 66 patients with a 75% reduction in the Psoriasis Area and Severity Index score after UST treatment were included. Computer-aided image analysis was performed to measure the epidermal thickness, horny layer thickness, number of dermal vessels, and dermal inflammatory cell infiltration rate. Parakeratosis was scored using a 4-point scale. These measurements were compared between the refractory lesions of UST-treated patients and the untreated lesions of newly diagnosed patients after the adjustment for confounding factors. The dermal inflammatory cell infiltration rate was significantly lower in the refractory lesions (P = 0.022). Meanwhile, the epidermal thickness, horny layer thickness, grade of parakeratosis, and dermal vessel count did not differ between the groups (P = 0.125, 0.719, 0.542, and 0.758, respectively). Subgroup analyses were performed within the UST-treated group after dividing them into 2 groups according to the number of treatments or treatment response rates. None of these features were significantly different between the subgroups. This study suggests that the reduction of dermal inflammation by UST was not sufficient to ameliorate the epidermal changes and implies the role of the interleukin-23-independent downstream cytokine pathway in causing the refractory lesions among patients who responded well to UST. The continuation of UST treatment might not further improve epidermal alterations.

Interleukine-17 Modulates Neurogenesis and Behavior Following Exposure to Trauma in Mice

Post-traumatic stress disorder (PTSD) is a psychiatric disorder accompanied by deficits in cognitive and social skills. Adult hippocampal neurogenesis is a lifelong phenomenon, with new neurons being formed in the granular cell layer of the dentate gyrus. Impaired neurogenesis is associated with multiple behavioral disorders including Alzheimer's disease and schizophrenia. PTSD patients often present hippocampal atrophy and animal models clearly present impaired neurogenesis. Previous studies on PTSD patients demonstrated elevated levels of Th17 cells and plasma levels of the pro-inflammatory cytokine interleukin-17A (IL-17A). Since IL-17A can impair neurogenesis in mice, we thus hypothesized that decreasing the serum levels of IL-17A will increase hippocampal neurogenesis and alleviate symptoms in a murine model of PTSD. Surprisingly, our results showed that attempting to neutralize IL-17A with an antibody resulted in increased serum levels of IL-17A, while targeting IL-23, the upstream regulator of IL-17, did lower the levels of IL-17A in trauma-exposed mice. As expected, increased levels of serum IL-17A (in anti-IL-17A treated mice) resulted in impaired neurogenesis, reflected by reduced number of proliferating Ki67⁺ neural progenitors and newly formed DCX⁺ neurons, which was correlated with increased expression of Hes1. Nevertheless, increased maturation was noted by the expression of Slit2 and Ache. In contrast, treatment with anti-IL-23 indeed resulted in increased neurogenesis. Behaviorally, both treatments did not affect trauma-related freezing behavior but did affect trauma-related social deficits. Unexpectedly, increased levels of serum IL-17A (in anti-IL-17A treated mice) prevented social deficits in trauma-exposed mice while anti-IL-23 exacerbated these deficits. We thus conclude that IL-17 is involved in regulating neurogenesis following exposure to stress but may be important in maintaining social behavior.