From Messengers to Receptors in Psoriasis: The Role of IL-17RA in Disease and Treatment

Brodalumab: Six-Year US Pharmacovigilance Report

INTRODUCTION

Brodalumab is a human interleukin-17 receptor A antagonist indicated for the treatment of moderate-to-severe plaque psoriasis in adult patients who are candidates for systemic therapy or phototherapy and have failed to respond or have lost response to other systemic therapies. In the USA, brodalumab has a boxed warning regarding suicidal ideation and behavior and is only available under a Risk Evaluation and Mitigation Strategy, but no causal association has been established. To assess long-term safety of brodalumab, we summarize pharmacovigilance data from 6 years of real-world clinical practice.

METHODS

Crude adverse event (AE) reporting rates per 100 patients were calculated for common AEs and AEs of special interest reported to Ortho Dermatologics by US patients and healthcare providers from August 15, 2017 through August 14, 2023. Brodalumab exposure was estimated as time from the first to last prescription-dispensing authorization dates. Adverse events were defined by Medical Dictionary for Regulatory Activities v26.0 Preferred Terms and standardized MedDRA queries.

RESULTS

Data were collected from 5138 US patients (estimated exposure of 6900 patient-years). Over 6 years, 13 cases of adjudicated major adverse cardiovascular events were reported (0.25 events/100 patients). The rate of serious infections was 2.20 events/100 patients. Since the 5-year report, there was one new case of Candida infection and a serious fungal infection of the elbow. Among 57 reported malignancies affecting 49 patients, 4 were deemed possibly related to brodalumab. One new case of indeterminate inflammatory bowel disease unrelated to brodalumab was reported. No new suicide attempts were reported in year 6, and there were no completed suicides throughout 6 years.

CONCLUSION

Pharmacovigilance data throughout 6 years are consistent with the safety profile of brodalumab established in clinical trials and previous US pharmacovigilance reports, with no completed suicides and a low fungal infection rate.

Narciclasine induces colon carcinoma cell apoptosis by inhibiting the IL-17A/Act1/TRAF6/NF-κB signaling pathway

IL-17 A is a promoter of colorectal cancer initiation and progression. Narciclasine is a polyhydroxy alkaloid compound isolated from Narcissus plants, which has potent anti-inflammatory and antitumor actions. The effects of narciclasine on colorectal tumors were evaluated, with a focus on IL-17 A. Narciclasine reduced the growth of HCT-116 and SW-480 colon cancer cells in vitro and in vivo in murine xenografts. The results of flow cytometry on JC-1 and Annexin V/PI revealed that narciclasine significantly reduced the mitochondrial membrane potential and induced apoptosis, findings confirmed by western blotting results of reduced Bcl-2 and enhanced Bax expression, as well as accumulation of cleaved Caspase-3, Caspase-8, Caspase-9, and cytoplasmic Cytochrome-c. After narciclasine incubation, IL-17 A, Act1, and TRAF6 were down-regulated, while p-P65 (Ser536) accumulated in the cytoplasm, a finding confirmed by laser scanning confocal microscopy. IL17A substitution could partly reverse these narciclasine effects while they were elevated by IL17A silencing. Moreover, IL-17 A, Act1, and TRAF6 were significantly expressed to greater extents in human colorectal cancer compared to normal adjacent tissue specimens and were closely linked with a poor prognosis. This study provided evidence that narciclasine may be a useful therapeutic drug for colorectal cancer treatment through its actions in down-regulating the L-17A/Act1/TRAF6/NF-κB anti-apoptotic signaling pathway.

Interleukin 17F Gene Polymorphism as a Potential Protective Factor in the Immunopathology of Ocular Toxoplasmosis

Ocular toxoplasmosis (OT) is characterised by intraocular inflammation due to Toxoplasma gondii infection. Studies have found that interleukin 17 (IL-17) plays a central role in the pathology of OT. However, nucleotide variability in IL17 and interleukin 17 receptor (IL17R) genes has not been characterised in OT. As cytokine gene polymorphisms may influence the expression of these molecules, the aim of this study was to verify whether IL17A (rs2275913), IL17F (rs763780), IL17RA (rs4819554) and IL17RC (rs708567) polymorphisms are associated with OT in a Brazilian population. This study enrolled 214 patients seropositive for T. gondii (110 with OT and 104 without) and 107 controls. Polymorphisms were identified by PCR-restriction fragment length polymorphism analysis, validated by DNA sequencing with chi-square and multivariate analyses being used to assess possible associations between polymorphisms and OT. Logistic regression under the dominant model revealed a protection factor against OT of the C mutant allele of the IL17F (rs763780) polymorphism. The T/C-C/C genotypes were significantly more common in patients without OT compared to those with OT (p value = 0.0066) and controls (p value = 0.014). Findings from this study suggest that the IL17F polymorphism may have an influence in the immunopathology of OT in Brazilian individuals.

Interleukin inhibitors and the associated risk of candidiasis

Interleukins (ILs) are vital in regulating the immune system, enabling to combat fungal diseases like candidiasis effectively. Their inhibition may cause enhanced susceptibility to infection. IL inhibitors have been employed to control autoimmune diseases and inhibitors of IL-17 and IL-23, for example, have been associated with an elevated risk of Candida infection. Thus, applying IL inhibitors might impact an individual's susceptibility to Candida infections. Variations in the severity of Candida infections have been observed between individuals with different IL inhibitors, necessitating careful consideration of their specific risk profiles. IL-1 inhibitors (anakinra, canakinumab, and rilonacept), IL-2 inhibitors (daclizumab, and basiliximab), and IL-4 inhibitors (dupilumab) have rarely been associated with Candida infection. In contrast, tocilizumab, an inhibitor of IL-6, has demonstrated an elevated risk in the context of coronavirus disease 2019 (COVID-19) treatment, as evidenced by a 6.9% prevalence of candidemia among patients using the drug. Furthermore, the incidence of Candida infections appeared to be higher in patients exposed to IL-17 inhibitors than in those exposed to IL-23 inhibitors. Therefore, healthcare practitioners must maintain awareness of the risk of candidiasis associated with using of IL inhibitors before prescribing them. Future prospective studies need to exhaustively investigate candidiasis and its associated risk factors in patients receiving IL inhibitors. Implementing enduring surveillance methods is crucial to ensure IL inhibitors safe and efficient utilization of in clinical settings.

Safety, tolerability, pharmacokinetics and efficacy of HB0017, a humanized monoclonal antibody that targets interleukin-17A, in healthy participants and patients with moderate-to-severe plaque psoriasis

BACKGROUND

Several interleukin (IL)-17 inhibitors have been approved for the treatment of moderate-to-severe plaque psoriasis (PsO). There is still scope for the development of affordable treatments for PsO.

OBJECTIVES

To assess, in a phase Ia study, the safety, tolerability and pharmacokinetics (PK) of HB0017, a humanized monoclonal antibody that targets IL-17A, in healthy participants and patients with moderate-to-severe plaque PsO; and, in a phase Ib study, to assess the efficacy of HB0017 in patients with moderate-to-severe plaque PsO.

METHODS

The phase Ia study (NCT04505033) was a randomized double-blind placebo-controlled dose-escalation study in healthy participants. Each cohort of 10 volunteers was randomly assigned to receive either a single dose of HB0017 (50 mg, 150 mg, 300 mg or 450 mg) or the matching placebo at a ratio of 4 : 1. The phase Ib study (NCT05442788) was a randomized double-blind placebo-controlled dose-escalation study in enrolled patients with moderate-to-severe plaque PsO. Each cohort of 10 patients was randomly assigned to receive either multiple doses of HB0017 (150 mg, 300 mg or 450 mg) or the matching placebo at a ratio of 4 : 1.

RESULTS

HB0017 demonstrated dose-proportional linear PK and was tolerated across the dose range assessed. In the phase Ia and Ib studies, participants in both the HB0017 and placebo groups experienced treatment-emergent adverse events (69% vs. 87%, 96% vs. 100%, respectively). HB0017 demonstrated clinically meaningful effects in patients with moderate-to-severe plaque PsO. PASI 75 [≥ 75% improvement in Psoriasis Area and Severity Index (PASI)], PASI 90 (≥ 90% improvement in PASI) and static Physician Global Assessment (sPGA) 0/1 (i.e. 'clear' or 'almost clear') responses were 100% for the HB0017 300-mg group, with maximal improvements (100% or near 100% reductions from baseline) in PASI score observed at week 12, while the duration of effect was evident up to week 20. There was no clinical response in any participant in the placebo group in the phase Ib study.

CONCLUSIONS

Overall, HB0017 showed acceptable safety and tolerability in both healthy participants and patients with moderate-to-severe plaque PsO. An encouraging signal of efficacy with a longer half-life provides HB0017 with the potential to be added to the currently available range of biologics targeting IL-17A.

The IL-17 family in diseases: from bench to bedside

The interleukin-17 (IL-17) family comprises six members (IL-17A-17F), and recently, all of its related receptors have been discovered. IL-17 was first discovered approximately 30 years ago. Members of this family have various biological functions, including driving an inflammatory cascade during infections and autoimmune diseases, as well as boosting protective immunity against various pathogens. IL-17 is a highly versatile proinflammatory cytokine necessary for vital processes including host immune defenses, tissue repair, inflammatory disease pathogenesis, and cancer progression. However, how IL-17 performs these functions remains controversial. The multifunctional properties of IL-17 have attracted research interest, and emerging data have gradually improved our understanding of the IL-17 signaling pathway. However, a comprehensive review is required to understand its role in both host defense functions and pathogenesis in the body. This review can aid researchers in better understanding the mechanisms underlying IL-17's roles in vivo and provide a theoretical basis for future studies aiming to regulate IL-17 expression and function. This review discusses recent progress in understanding the IL-17 signaling pathway and its physiological roles. In addition, we present the mechanism underlying IL-17's role in various pathologies, particularly, in IL-17-induced systemic lupus erythematosus and IL-17-related tumor cell transformation and metastasis. In addition, we have briefly discussed promising developments in the diagnosis and treatment of autoimmune diseases and tumors.

Bimekizumab in the Treatment of Plaque Psoriasis: Focus on Patient Selection and Perspectives

Psoriasis is a chronic systemic inflammatory disease that significatively impairs patients' quality of life. Biological treatments are highly effective and safe and have led to breakthroughs in the management of patients with moderate-to-severe psoriasis. However, therapeutic response can be unsatisfactory or lost with time, leading to discontinuation of treatment. Bimekizumab is a humanized monoclonal antibody that specifically inhibits both interleukin (IL)-17A and IL-17F. The efficacy and safety of bimekizumab in moderate-to-severe plaque psoriasis has been demonstrated in Phase 2 and Phase 3 clinical trials. Bimekizumab may offer some advantages over other biological treatments, making it especially indicated for certain patients. This narrative review aims to summarize the latest published evidence on the use of bimekizumab for the treatment of moderate-severe plaque psoriasis, focusing on patient selection and therapeutic perspectives. Bimekizumab has been shown to be more efficacious than adalimumab, secukinumab and ustekinumab in clinical trials, with high estimated probabilities of achieving complete (approximately 60%) or almost complete clearance (approximately 85%) of psoriasis at weeks 10-16, and a good safety profile. Response to bimekizumab is usually fast and maintained in the long term for both biologic-naive patients and those resistant to previous biologic treatments. The usual maintenance dose of 320 mg every 8 weeks makes bimekizumab especially convenient for non-compliant patients. Moreover, the efficacy and safety of bimekizumab have also been demonstrated in psoriasis affecting challenging-to-treat areas, psoriatic arthritis and hidradenitis suppurativa. In conclusion, dual inhibition of IL-17A and IL-17F with bimekizumab is a good therapeutic option for moderate-to-severe psoriasis.

Interleukin 25 and its biological features and function in intestinal diseases

Interleukin 25 (IL-25), also known as IL-17E, is a member of the IL-17 cytokine family and an important regulator of the type 2 immune response. Accumulating evidence suggests that IL-25 interacts with diverse immune as well as non-immune cells and plays a rather complicated role in different backgrounds of multiple organs. IL-25 has been studied in the physiology and pathology of the intestine to some extent. With epithelial cells being an important source in the intestine, IL-25 plays a key role in intestinal immune responses and is associated with inappropriate allergic reactions, autoimmune diseases, and cancer tumorigenesis. In this review, we discuss the emerging comprehension of the biology of IL-25, as well as its cellular sources, targets, and signaling transduction. In particular, we discuss how IL-25 participates in the development of intestinal diseases including helminth infection, inflammatory bowel diseases, food allergy and colorectal cancer, as well as its underlying role in future therapy.

Secukinumab for the treatment of adult-onset pityriasis rubra pilaris: a single-arm clinical trial with transcriptomic analysis

BACKGROUND

The pathogenesis of pityriasis rubra pilaris (PRP) is not completely understood, but interleukin (IL)-17 has been shown to play a critical role. There are no reliable immunomodulatory agents to treat PRP. We conducted an open-label, single-arm clinical trial of secukinumab, a monoclonal antibody that inhibits IL-17A, for the treatment of PRP.

OBJECTIVES

To evaluate the clinical efficacy of secukinumab and define the transcriptomic landscape of PRP and its response to IL-17A blockade.

METHODS

Twelve patients with PRP were recruited for an open-label trial of secukinumab. Patients received a 24-week course of secukinumab. The primary endpoint was a ≥ 75% reduction in Psoriasis Area and Severity Index (PASI 75) from baseline to week 28. Secondary endpoints included PASI 90, change in Physician's Global Assessment (PGA), and change in Dermatology Life Quality Index (DLQI). RNA sequencing was performed on lesional and nonlesional skin biopsies obtained at baseline and week 2. Sample groups were compared to identify differential gene expression and pathway enrichment. This trial was registered with ClinicalTrials.gov: 'Cosentyx (secukinumab) for the treatment of adult onset pityriasis rubra pilaris' - NCT03342573.

RESULTS

At week 28, six of 11 patients (55%) achieved PASI 75, and three patients (27%) achieved PASI 90. PGA (P = 0.008) and DLQI scores (P = 0.010) showed significant improvement with treatment. No serious treatment-related adverse events were encountered. Treatment with secukinumab normalized transcriptional differences between lesional and nonlesional skin. Transcriptomic data from nonresponsive patients suggest that overactivity of innate immune pathways may be driving resistance to secukinumab.

CONCLUSIONS

Secukinumab appears to be an effective treatment for PRP and warrants further investigation. PRP is a transcriptionally heterogeneous disease, reflecting its variable response to therapy. Agents targeting other IL-17 isoforms and innate immune mediators should be considered for future clinical trials. What is already known about this topic? The pathogenesis of pityriasis rubra pilaris is incompletely understood. Successful treatment has been reported with a variety of immunomodulatory agents, but disease is often refractory to therapy. Interleukin (IL)-17 is thought to drive keratinocyte proliferation and vascular dysfunction in this disease. A previous trial demonstrated efficacy of the anti-IL-17A drug ixekizumab for pityriasis rubra pilaris. What does this study add? Herein we describe the findings of a clinical trial of secukinumab, an anti-IL-17A monoclonal antibody, for the treatment of pityriasis rubra pilaris. Secukinumab was effective in treating pityriasis rubra pilaris. Our transcriptomic data give new insight into the expressional changes that occur in response to secukinumab and suggest mechanisms of treatment resistance.

Discovery of an Oral, Rule of 5 Compliant, Interleukin 17A Protein-Protein Interaction Modulator for the Potential Treatment of Psoriasis and Other Inflammatory Diseases

Interleukin 17A (IL-17A) is an interleukin cytokine whose dysregulation is implicated in autoimmune disorders such as psoriasis, and monoclonal antibodies against the IL-17A pathway are now well-established and very effective treatments. This article outlines the work that led to the identification of 23 as an oral, small-molecule protein-protein interaction modulator (PPIm) clinical development candidate. Protein crystallography provided knowledge of the key binding interactions between small-molecule ligands and the IL-17A dimer, and this helped in the multiparameter optimization toward identifying an orally bioavailable, Rule of 5 compliant PPIm of IL-17A. Overlap of early ligands led to a series of benzhydrylglycine-containing compounds that allowed the identification of dimethylpyrazole as a key substituent that gave PPIm with oral bioavailability. Exploration of the amino acid portion of the structure then led to dicyclopropylalanine as a group that gave potent and metabolically stable compounds, including the development candidate 23.

Correction: Vidal et al. From Messengers to Receptors in Psoriasis: The Role of IL-17RA in Disease and Treatment. Int. J. Mol. Sci. 2021, 22, 6740

In the original publication [...].

The Role of Tumor Microenvironment in the Pathogenesis of Sézary Syndrome

Sézary syndrome is an aggressive leukemic variant of cutaneous T-cell lymphomas, characterized by erythroderma, lymphadenopathy, and peripheral blood involvement by CD4+ malignant T-cells. The pathogenesis of Sézary syndrome is not fully understood. However, the course of the disease is strongly influenced by the tumor microenvironment, which is altered by a combination of cytokines, chemokines, and growth factors. The crosstalk between malignant and reactive cells affects the immunologic response against tumor cells causing immune dysregulation. This review focuses on the interaction of malignant Sézary cells and the tumor microenvironment.

Recent Update on Immunopathogenesis of Psoriasis

Psoriasis is a chronic disabling complex inflammatory disorder prevalent worldwide with environmental and genetic components that involve predominantly skin in addition to nails and joints associated with various systemic comorbidities having periods of exacerbations and remissions. Psoriasis is characterized by hyper-proliferation as well as abnormal differentiation of epidermal keratinocytes and lymphocyte infiltration (mainly T cells) with resultant inflammatory cytokines and chemokines. Immunological and genetic studies over the last decade have identified genetic susceptibility risk alleles, molecular, cellular and immunological mechanisms involved in immunopathogenesis of psoriasis. The current disease model emphasizes the role of aberrant Th1 and Th17 responses regulated by a complex network of different cytokines, including TNF-α, IL-17 and IL-23; signal transduction pathways downstream to the cytokine receptors; and various activated transcription factors, including NF-κB, interferon regulatory factors and signal transducer and activator of transcriptions. Cytokines targeting biologics (IL-17, IL-23 and TNFα) therapies have revolutionized the management of severe skin disease having beneficial effects on joints and systemic inflammation of psoriasis as well. Further better understanding of immunopathogenesis of psoriasis will pave way for precision medicine based on specific immunopathogenic targets in a given phenotype of disease. Complex interplay of psoriasis with associated comorbidities is also a future area of research for overall better patient management and to improve their quality of life.