Discovery of Small Molecule Interleukin 17A Inhibitors with Novel Binding Mode and Stoichiometry: Optimization of DNA-Encoded Chemical Library Hits to In Vivo Active Compounds.

Dysregulation of IL17A drives numerous inflammatory and autoimmune disorders with inhibition of IL17A using antibodies proven as an effective treatment. Oral anti-IL17 therapies are an attractive alternative option, and several preclinical small molecule IL17 inhibitors have previously been described. Herein, we report the discovery of a novel class of small molecule IL17A inhibitors, identified via a DNA-encoded chemical library screen, and their subsequent optimization to provide in vivo efficacious inhibitors. These new protein-protein interaction (PPI) inhibitors bind in a previously undescribed mode in the IL17A protein with two copies binding symmetrically to the central cavities of the IL17A homodimer.

Bimekizumab in psoriasis: a monocentric study evaluating short- and mid-term effectiveness and safety profile in a real-world setting.

INTRODUCTION: Bimekizumab is a humanized monoclonal IgG1 antibody with a unique mechanism of action, as it inhibits both IL17A and IL17F molecules. This dual inhibition is thought to be responsible for its high efficacy in treating chronic plaque psoriasis with rapid onset of action in Randomized Controlled Trials (RCTs). Concerning safety, oral candidiasis was one of the most common drug-related adverse events, commonly mild-to-moderate in severity. Although data from RCTs supporting this efficacy and safety profile of bimekizumab is numerous, results from the real-world setting concerning short- and mid-term treatment effectiveness and safety profile are limited. MATERIALS AND METHODS: An observational, retrospective, monocentric study was conducted at the Psoriasis Outpatient Unit of "A. Sygros" Hospital for Skin and Venereal Diseases, in Athens, Greece, which included 61 adult patients with moderate-to-severe skin psoriasis, who received at least one dosage of bimekizumab. RESULTS: At week 4, 65.7% achieved PASI75, 45.7% PASI90, and 32.4% PASI100. After 16 weeks of treatment, 92.3/76.9/66.7% of the patients achieved PASI75/90/100, respectively. Increased BMI, previous treatment with another IL-17 inhibitor, or previous exposure to another biologic did not seem to influence the possibility of achieving PASI90 and PASI100 at week 16 of bimekizumab treatment in this cohort. Six (9.8%) cases of possibly drug-related AEs were reported, from which four incidences of oral candidiasis. CONCLUSION: Our results confirm that this IL17A/F inhibitor is highly effective, with a tolerability profile similar to the one expected from RCTs.

Changes in Inflammatory Cytokines in Responders and Non-Responders to TNFα Inhibitor and IL-17A Inhibitor: A Study Examining Psoriatic Arthritis Patients.

This study aimed to examine the changes in biomarker levels in responders and non-responders to tumor necrosis factor alpha inhibitor (TNFi) and interleukin-17A inhibitor (IL-17Ai) in psoriatic arthritis (PsA) patients over a 4-month period after treatment initiation. A total of 68 PsA patients initiating either TNFi, IL-17Ai, or methotrexate treatment were included. Blood plasma and clinical outcome measures were collected adjacent to treatment initiation and after four months. A commercially available multiplex immunoassay was included to evaluate 54 biomarkers. Mean changes were used to evaluate change over time. A statistically significant decrease in pro-inflammatory cytokines IL-6 (log-transformed mean change -0.97, 95%CI -4.30; 2.37, [p = 0.032]) and an increase in anti-inflammatory IL-10 (0.38, 95%CI 1.74; 2.50 [p = 0.010]) were seen in TNFi responders. Meanwhile, a statistically significant increase in the target cytokine IL-17A was seen in both IL-17Ai responders (2.49, 95%CI -1.84; 6.85 [p = 0.031]) and non-responders (2.48, 95%CI -1.46; 6.41 [p = 0.001]). This study demonstrated differing changes in cytokine levels when comparing treatment responders and non-responders, highlighting the need to improve the understanding of the different immune response mechanisms explaining different responses to medical treatment in PsA patients.

Celastrol regulates psoriatic inflammation and autophagy by targeting IL-17A.

Anti-IL-17A antibodies, such as secukinumab and ixekizumab, are effective proinflammatory cytokine inhibitors for autoimmune disorders, including psoriasis. However, anti-IL-17A small molecule treatments are yet to be commercialized. Celastrol, a natural compound extracted from the roots of traditional Chinese medicinal plants, has anti-inflammatory and antioxidant properties. However, the binding of celastrol to IL-17A and the associated anti-inflammatory mechanisms remain unclear. This study investigated whether celastrol could directly bind to IL-17A and regulate inflammation in psoriatic in vitro and in vivo models. The results showed that celastrol directly binds to IL-17A and inhibits its downstream signaling, including the NF-kB and MAPK pathways. Interestingly, celastrol restored autophagy dysfunction and reduced proinflammatory cytokine secretion in keratinocytes. In addition, celastrol increased autophagy in the epidermis of a mouse model of psoriasis. Celastrol decreased Th17 cell populations and proinflammatory cytokine levels in mice. Thus, IL-17A-targeting celastrol reduced inflammation by rescuing impaired autophagy in in vitro and in vivo models of psoriasis, demonstrating its potential as a substitute for anti-IL-17A antibodies for treating psoriasis.

Cedirogant Population Pharmacokinetics and Pharmacodynamic Analyses of Interleukin-17A Inhibition in Two Phase 1 Studies in Healthy Participants and Participants with Moderate to Severe Psoriasis.

Cedirogant (ABBV-157) is an orally bioavailable inverse agonist of retinoic acid-related orphan receptor gamma thymus. Data from 2 Phase 1 studies were used to characterize cedirogant pharmacokinetics and evaluate target engagement. Cedirogant plasma concentrations and ex vivo interleukin 17A (IL-17A) concentrations from healthy participants and participants with moderate to severe psoriasis (PsO) were analyzed in a population pharmacokinetic and pharmacodynamic modeling framework to characterize cedirogant pharmacokinetics following single and multiple doses and assess ex vivo IL-17A inhibition in relation to cedirogant exposure. Cedirogant population pharmacokinetics were best described by a 2-compartment pharmacokinetic model with delayed absorption and an enzyme turnover compartment to describe cytochrome P450 3A autoinduction. The pharmacokinetics of cedirogant were comparable between healthy participants and participants with PsO. Cedirogant steady-state average and maximum plasma concentrations were predicted to be 7.56 and 11.8 mg/L, respectively, for participants with PsO for the 375 mg once-daily regimen on Day 14. The apparent clearance and apparent volume of distribution for cedirogant were estimated to be 24.5 L/day and 28.2 L, respectively. A direct maximum inhibition model adequately characterized the exposure-response relationship of cedirogant and ex vivo IL-17A inhibition, indicating no temporal delay between exposure and response with a saturable inhibition of IL-17A. Model-estimated half-maximal inhibitory concentration and maximum inhibition values for cedirogant inhibition of ex vivo IL-17A were 0.56 mg/L and 0.76, respectively. The established relationship between cedirogant exposure and biomarker effect supported dose selection for the Phase 2 dose-ranging study in patients with PsO.

Incidence of Uveitis in Patients With Axial Spondylarthritis Treated With Biologics or Targeted Synthetics: A Systematic Review and Network Meta-Analysis.

OBJECTIVE: Anterior uveitis is a common extra-articular manifestation of axial spondyloarthritis (AxSpA). We set to evaluate the risk of anterior uveitis (AU) with biologics and synthetic disease-modifying drugs in AxSpA. METHODS: We conducted a systematic review and meta-analysis to identify phase II/III double-blinded randomized controlled trials of anti-tumor necrosis factor (TNF) monoclonal antibodies (mAb), anti-interleukin-17 (anti-IL-17), and Janus kinase inhibitors (JAKi) in AxSpA. Patient-exposure years (PEY) were calculated using the per-protocol approach. Incidence rate (IR) of AU/100 person-years were calculated by treatment group using the random effects approach. Network meta-analysis (NMA) was used to estimate risk of AU in treatment groups, expressed as IR ratios (IRRs). Bias was assessed using the Cochrane Risk of Bias-2 tool. RESULTS: Forty-four trials were included: 17 anti-TNF mAb (1,004 PEY), 9 etanercept (180 PEY), 13 anti-IL-17 (1,834 PEY), and 6 JAKi (331 PEY). The IR of AU were as follows for anti-TNF mAb: 4.1, 95% confidence interval (CI) 0-8.5; etanercept: 5.4, 95% CI 0-16.0; anti-IL-17: 2.8, 95% CI 1.6-4.1; JAKi: 1.5, 95% CI 0.0-3.0; and placebo: 10.8, 95% CI 7.4-14.1. In NMA, IRRs of treatments compared with placebo were as follows for anti-TNF mAb: 0.32, 95% CI 0.10-1.04; etanercept 0.42, 95% CI 0.08-2.38; anti-IL-17: 0.43, 95% CI 0.19-0.98; and JAKi: 0.32, 95% CI 0.06-1.67. Comparisons between anti-TNF mAb, anti-IL-17, and JAKi did not demonstrate any significant difference in AU risk. Using the surface under the cumulative ranking curve approach to rank AU risk, anti-TNF mAbs were associated with the lowest risk followed by JAKi, anti-IL-17, and etanercept. All treatments were ranked superior to placebo. CONCLUSION: Anti-TNF mAbs, JAKi, and anti-IL-17 appear protective against AU events in individuals with AxSpA, with no significant differences in risk of AU between treatments.

Short-term risk and long-term incidence rate of infection and malignancy with IL-17 and IL-23 inhibitors in adult patients with psoriasis and psoriatic arthritis: a systematic review and meta-analysis.

The risk of infection and malignancy may be a concern for patients with psoriasis receiving interleukin (IL)-17 and IL-23 inhibitors, particularly with long-term treatments. We aimed to estimate the short-term risks and long-term incidence rates of infection and malignancy with IL-17 or IL-23 antagonists in adult patients with psoriasis and psoriatic arthritis through this comprehensive meta-analysis (PROSPERO registration number: CRD42022363127). We searched PubMed, MEDLINE, Web of Science and ClinicalTrials.gov until May 17, 2023 for randomized placebo-controlled trials and long-term (≥ 52 weeks) open-label extension studies. The estimates of short-term risk ratios (RRs) and long-term exposure-adjusted incidence rates (EAIRs) were pooled using R software 4.1.1 and STATA 16.0. This review included 45 randomized placebo-controlled studies and 27 open-label extension studies. Short-term RRs of serious infection, overall infection and malignancy were 1.45 (95% confidence intervals, 95% CI: 0.81-2.59), 1.20 (95% CI: 1.06-1.35), 0.83 (95% CI: 0.41-1.71) with IL-17 inhibitors; and 0.68 (95% CI: 0.38-1.22), 1.13 (95% CI: 1.00-1.28), 0.87 (95% CI: 0.37-2.04) with IL-23 inhibitors. Increased short-term risks of nasopharyngitis and Candida infection with IL-17 inhibitors were found. Long-term EAIRs of serious infection, overall infection, nonmelanoma skin cancer (NMSC), malignancies excluding NMSC, nasopharyngitis and upper respiratory tract infection were 1.11/100 patient-years (PYs), 57.78/100PYs, 0.47/100PYs, 0.24/100PYs, 15.07/100PYs, 8.52/100PYs, 3.41/100PYs with IL-17 inhibitors; and 1.09/100PYs, 48.50/100PYs, 0.40/100PYs, 0.43/100PYs, 10.75/100PYs, 5.84/100PYs with IL-23 inhibitors. Long-term EAIR of Candida infection was 3.41/100PYs with IL-17 inhibitors. No active or reactivated tuberculosis was ever reported in all the trials, and only a few cases of latent tuberculosis, hepatitis, and herpes zoster were reported during the long-term extension periods. No evidence of increased EAIRs of infection and malignancy with longer durations was found. Our study suggested that short-term risk and long-term incidence of infections and malignancies in psoriasis patients receiving IL-17 inhibitors and IL-23 inhibitors are generally low. However, close monitoring is required for nasopharyngitis and Candida infection with IL-17 inhibitors. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022363127.

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.

Clues from planarians about interleukin-17A and stress that result from light avoidance: IL-17A antagonists reduce defensive responding in flatworms.

Emerging evidence links interleukin-17A (IL-17A) to anxiety and stress. Circulating levels of IL-17A are elevated in patients with anxiety disorders, and pharmacological blockade of IL-17 signaling or genetic deletion of IL-17 reduces anxiety-like behaviors in mice. Given that IL-17 is one of the most conserved cytokines among animal phyla, we tested the hypothesis that anti-IL-17 treatments reduce defensive responding in planarians, the simplest animal with bilateral symmetry and a CNS with cephalization. The endpoint selected was light avoidance, which is a common phenotype of planarians and rodents and an index of defensive responding that is reduced by anxiolytic compounds in both species. Planarians were placed at the midline of a Petri dish containing water or test solution that was equally split into light and dark halves. Planarians exposed to a selective IL-17A antibody (0.1, 1, 10 pM) over a 5-min interval spent more time in the light than water-exposed planarians. Cyanidin (0.01, 0.1 1, 10 µM), an anti-inflammatory flavonoid and non-selective IL-17A inhibitor, also increased time spent in the light. Motility was not affected by IL-17A antibody or cyanidin at concentrations that reduced light avoidance, although higher concentrations reduced motility (>10 µM). Our results show that IL-17A antagonists reduce defensive responding in planarians and suggest conservation of IL-17A effects on aspects of anxiety-related behaviors.

Efficacy of anti-IL-23 and anti-IL-17 after adalimumab failure in psoriatic patients.

BACKGROUND: Many national guidelines at the European level recommend first-line therapy based on the anti-TNF-alpha adalimumab for treatment of psoriasis and psoriatic arthritis, mainly for economic reasons. Consequently, patients being treated with newer IL-17 and IL-23 inhibitors underwent previous unsuccessful first-line adalimumab-based therapy. OBJECTIVES: Evaluate the efficacy and safety of IL-17 and IL-23 inhibitors after treatment with adalimumab compared to adalimumab-naive psoriatic patients. METHODS: We retrospectively analysed 1053 psoriatic patients treated with anti-IL17 and anti-IL23 agents, which included 68 and 24 adalimumab-experienced and 399 and 260 bio-naive patients. Efficacy was assessed with mean PASI, PASI90, PASI100, and <3. RESULTS: Concerning the achieving of PASI100, PASI90 and PASI < 3 in patients treated with anti-IL17 agents, no significant differences were observed between adalimumab-experienced and bio-naive patients. In patients treated with an anti-IL-23 agent, a faster response was observed in bio-naive patients, with PASI < 3 significantly higher than ADA-experienced patients at 16 weeks (77% vs. 58% p = 0.048). In a sub-analysis that evaluated the performance of anti-IL17 and anti-IL23 agents in adalimumab-experienced patients with a history of secondary failure, no significant differences were found. In multivariate analysis of PASI100, only anti-IL-17 therapy appeared to have a negative impact at 52 weeks (OR: 0.54 p = 0.04) independently of previous treatment. For PASI90, type of treatment and bio-naïve status did not seem to have an impact at any time point. CONCLUSIONS: Anti-IL 23 and anti-IL 17 agents are not significantly different in terms of efficacy in bio-naive patients or as second-line therapy after failure with a biosimilar or originator adalimumab.

Real-world treatment patterns and use of adjunctive pain and anti-inflammatory medications among patients with psoriatic arthritis treated with IL-17A inhibitors in the United States.

BACKGROUND: Much of the current research on treatment patterns and use of adjunctive pain and anti-inflammatory medications among patients living with psoriatic arthritis (PsA) predates the approval and uptake of IL (interleukin)-17A inhibitors. OBJECTIVE: To compare real-world treatment patterns and use of adjunctive pain and antiinflammatory medications between patients with PsA initiating the IL-17A inhibitors, ixekizumab and secukinumab, in a US-managed care population. METHODS: We conducted a retrospective cohort study using the HealthCore Integrated Research Database. Patients with a PsA diagnosis who initiated ixekizumab or secukinumab treatment between December 1, 2017, and November 30, 2019, were identified. Two cohorts were created based on which of the 2 medications was initiated (index date), and patients with prior use of either drug were excluded, as were patients with ankylosing spondylitis. Patients had to be continuously enrolled in the health plan for 6 months prior to (baseline) and 12 months after the index date (post-index). Inverse probability of treatment weighting was used to minimize confounding from baseline demographic and clinical differences between cohorts. Treatment patterns (dosing, persistence, discontinuation, and switching) and use of adjunctive pain/anti-inflammatory medications were assessed and compared between weighted cohorts using chi-square and t-tests. RESULTS: In total, 407 patients were identified in the ixekizumab cohort (mean age 51.6 years; 54% female) and 1,508 patients were identified in the secukinumab cohort (mean age 50.1 years; 59% female). Prior to weighting, presence of a psoriasis diagnosis code (ixekizumab: 60% vs secukinumab: 45%; standardized difference [std diff] = -0.30), specialty of the index prescriber (std diff = 0.38), and mean number of prior advanced therapies (2.0 vs 1.5; std diff = -0.33) were different between cohorts. Cohorts were well balanced after weighting. The majority of secukinumab patients (71%) received an index dose of 300 mg. Rates of persistence (ixekizumab: 40% vs secukinumab: 43%; P = 0.411) and switching (25% vs 20%; P = 0.072) were not statistically different between cohorts. Use of new adjunctive pain and anti-inflammatory medications was not statistically different between cohorts either (ixekizumab: 63% vs secukinumab: 58%; P = 0.187). CONCLUSIONS: Real-world treatment patterns and use of adjunctive pain and anti-inflammatory medications were similar in patients with PsA initiating ixekizumab and secukinumab in this US-managed care population. Further research examining reasons for discontinuation, switching, and use of adjunctive medications may help inform treatment decisions for patients living with PsA. DISCLOSURES: Ms Pizzicato, Ms Ketkar, and Dr Grabner are employees of HealthCore, Inc, which received funding from Eli Lilly and Company for the conduct of the study on which this manuscript is based. Ms Pepe was an employee of HealthCore, Inc., during the time the study was conducted. Dr Grabner is a shareholder of Elevance Health (legacy Anthem, Inc.). Dr Vadhariya, Dr Birt, and Ms Bolce are employees of Eli Lilly and Company, the manufacturer of ixekizumab (Taltz). Dr Birt and Ms Bolce are shareholders of Eli Lilly and Company. Dr Walsh is a paid consultant to Eli Lilly and Company and Novartis, the manufacturers of ixekizumab (Taltz) and secukinumab (Cosentyx), respectively. Additionally, Dr Walsh is a paid consultant for Pfizer, Janssen, AbbVie, and UCB and has contracts with Pfizer, AbbVie, and Merck.

Selection and characterization of a new human Interleukin-17A blocking DNA aptamer using protein-SELEX.

BACKGROUND: Interleukin-17A (IL-17A) is an important pro-inflammatory cytokine observed in the development of many disorders, such as psoriasis, rheumatoid arthritis, and multiple sclerosis. The anti-IL-17A biological drugs, including Secukinumab, Ixekizumab, and Brodalumab, are monoclonal antibodies approved for several disease treatments. Due to the disadvantages of biological therapies, including their immunogenicity, difficulties in scale generation, and high production costs and time, it is necessary to find new alternative anti- IL-17A agents for these monoclonal antibodies. Our study aimed to identify ssDNA aptamers that block IL-17A activity using the protein-SELEX procedure. METHODS: The hIL-17A was expressed in codon plus E. coli, and after 14 rounds of the SELEX process, monitoring of aptamer pools was done using the dot blot method. Three families of aptamers were obtained from the selected round 9 aptamer pool, and seven truncates were created. Inhibitory effects of aptamer truncate on IL-17-induced CCL20 expression in HaCaT keratinocytes were evaluated. RESULTS: All aptamer truncates had a significant inhibitory effect compared to the library, but the inhibitory effect of M2 and M7 truncates was more than 80%. Moreover, we evaluated the potential binding site of selected aptamers by ELISA. CONCLUSIONS: We introduced a new small 17-nucleotide DNA aptamer that efficiently binds and blocks hIL-17A with a 0.3 nM kd, a potential anti-IL-17A therapeutic agent.

Biological treatment for erythrodermic psoriasis.

INTRODUCTION: Erythrodermic psoriasis (EP) is an extreme and potentially life-threatening form of psoriasis in which most or all of the body surface area is affected by psoriasis. It occurs in 1-2% of patients with psoriasis and is less responsive to conventional therapies. Biologics have shown promise in the management of EP. AREAS COVERED: This review briefly discusses the pathophysiology of EP. Current evidence on established and emerging targeted therapies for EP is covered, including anti-TNF-α biologics, IL-12/23, IL-17, and IL-23 inhibitors. EXPERT OPINION: The need for rapidly acting, safe, and efficacious agents in EP has been met with advent of newer biologics, particularly IL-17 and IL-23 inhibitors. These targeted approaches warrant consideration as first-line management option for the management of EP; however, high-quality evidence regarding their long-term efficacy and safety in EP is lacking. Novel biologics such as bimekizumab and mirikizumab, and nanobodies such as netakimab and sonelokimab have shown promise in the management of plaque psoriasis, and potential of these molecules in management of EP should be explored. Management of patients with prior biologic failure remains a challenge. Guidelines for the management of EP need to be revisited in light of the recent advances.

Identification and structure-based drug design of cell-active inhibitors of interleukin 17A at a novel C-terminal site.

Anti-IL17A therapies have proven effective for numerous inflammatory diseases including psoriasis, axial spondylitis and psoriatic arthritis. Modulating and/or antagonizing protein-protein interactions of IL17A cytokine binding to its cell surface receptors with oral therapies offers the promise to bring forward biologics-like efficacy in a pill to patients. We used an NMR-based fragment screen of recombinant IL17A to uncover starting points for small molecule IL17A antagonist discovery. By examining chemical shift perturbations in 2D [1H, 13C-HSQC] spectra of isotopically labeled IL17A, we discovered fragments binding the cytokine at a previously undescribed site near the IL17A C-terminal region, albeit with weak affinity (> 250 µM). Importantly this binding location was distinct from previously known chemical matter modulating cytokine responses. Subsequently through analog screening, we identified related compounds that bound symmetrically in this novel site with two copies. From this observation we employed a linking strategy via structure-based drug design and obtained compounds with increased binding affinity (< 50 nM) and showed functional inhibition of IL17A-induced cellular signaling (IC50~1 µM). We also describe a fluorescence-based probe molecule suitable to discern/screen for additional molecules binding in this C-terminal site.

Time to Relapse After Discontinuing Systemic Treatment for Psoriasis: A Systematic Review.

BACKGROUND: The decision of when to discontinue systemic treatment after achieving remission in psoriasis is an important question. In this systematic review, we sought to evaluate time to relapse after the discontinuation of systemic treatment in psoriasis patients. METHODS: Systematic searches of PubMed, Cochrane Library, and Embase databases were performed for randomized controlled studies reporting time to relapse after discontinuation of systemic drugs in psoriasis patients. In addition, pharmaceutical companies were contacted by the authors regarding missing data from the identified publications. In each publication, the time to psoriasis relapse and the timing of drug discontinuation were carefully assessed. The level of psoriasis control at the time of drug discontinuation and the definition used for psoriasis relapse were taken into account. RESULTS: Thirty articles published before April 2021 were included in the systematic review. Four articles focused on conventional systemic treatments with methotrexate and/or cyclosporine, nine focused on tumor necrosis factor (TNF) antagonists, eight focused on interleukin-17 (IL-17) antagonists, eight focused on IL-12/23 or IL-23 antagonists, and one focused on tofacitinib and apremilast. Different definitions were used to define psoriasis treatment success at the time of drug discontinuation. Similarly, heterogeneous criteria were used to define psoriasis relapse. Comparison between drugs was performed indirectly (i.e. across studies) for most drugs. Considering time of 50% loss of maximum Psoriasis Area Severity Index (PASI) improvement, a shorter median time to psoriasis relapse was observed with traditional systemic treatment (~ 4 weeks) compared to biological agents (from 12 to ~ 34 weeks). When using stringent relapse criteria, such as loss of PASI 90, a longer time to relapse after treatment cessation was observed with IL-23 antagonists (21-42 weeks) versus IL-17 antagonists (7-24 weeks). CONCLUSION: Biological agents are associated with a longer time to relapse than oral systemic agents after drug discontinuation. Among biologicals, IL-23 antagonists are associated with the longest time to relapse. These findings may have clinical consequences for the selection of systemic agents when intermittent treatment is necessary.

The dark side of the moon: the immune-mediated adverse events of IL-17A/IL-17R inhibition.

As aberrant IL-17 signaling plays a critical role in the pathogenesis of psoriasis, biologic agents targeting this pathway have become an important weapon against this disease. Some biologic agents such as IL-17 inhibitors (secukinumab and ixekizumab) and the IL-17 receptor (IL17R) inhibitor (brodalumab) are relatively safe, tolerable and efficacious drugs. Nevertheless, side effects of IL-17 pathway inhibition occur. This review focuses on the dermatological manifestations linked to these treatments. Paradoxical psoriasis and atopic-like eczema may be the most common cutaneous adverse events, while manifestations such as neutrophilic dermatoses, hypersensitivity reactions, lichenoid eruptions, vasculitides, bullous diseases, lupus-like reactions, pigmentation disorders, adnexal diseases and granulomatous dermatoses have been described less frequently.

Dual Blockade of TNF and IL-17A Inhibits Inflammation and Structural Damage in a Rat Model of Spondyloarthritis.

The tumor necrosis factor (TNF) and IL-23/IL-17 axes are the main therapeutic targets in spondyloarthritis. Despite the clinical efficacy of blocking either pathway, monotherapy does not induce remission in all patients and its effect on new bone formation remains unclear. We aimed to study the effect of TNF and IL-17A dual inhibition on clinical disease and structural damage using the HLA-B27/human ß2-microglobulin transgenic rat model of SpA. Immunized rats were randomized according to arthritis severity, 1 week after arthritis incidence reached 50%, to be treated twice weekly for a period of 5 weeks with either a dual blockade therapy of an anti-TNF antibody and an anti-IL-17A antibody, a single therapy of either antibody, or PBS as vehicle control. Treatment-blinded observers assessed inflammation and structural damage clinically, histologically and by micro-CT imaging. Both single therapies as well as TNF and IL-17A dual blockade therapy reduced clinical spondylitis and peripheral arthritis effectively and similarly. Clinical improvement was confirmed for all treatments by a reduction of histological inflammation and pannus formation (p < 0.05) at the caudal spine. All treatments showed an improvement of structural changes at the axial and peripheral joints on micro-CT imaging, with a significant decrease for roughness (p < 0.05), which reflects both erosion and new bone formation, at the level of the caudal spine. The effect of dual blockade therapy on new bone formation was more prominent at the axial than the peripheral level. Collectively, our study showed that dual blockade therapy significantly reduces inflammation and structural changes, including new bone formation. However, we could not confirm a more pronounced effect of dual inhibition compared to single inhibition.