Efficacy of dimethyl fumarate treatment for moderate-to-severe plaque psoriasis: presentation extracts from the 29th EADV virtual congress, 29-31 October 2020

Autoreactive T-Cells in Psoriasis: Are They Spoiled Tregs and Can Therapies Restore Their Functions?

Psoriasis is a chronic inflammatory skin disease, which affects 2-4% of the population worldwide. T-cell derived factors such as Th17 and Th1 cytokines or cytokines such as IL-23, which favors Th17-expansion/differentiation, dominate in the disease. Therapies targeting these factors have been developed over the years. An autoimmune component is present, as autoreactive T-cells specific for keratins, the antimicrobial peptide LL37 and ADAMTSL5 have been described. Both autoreactive CD4 and CD8 T-cells exist, produce pathogenic cytokines, and correlate with disease activity. Along with the assumption that psoriasis is a T-cell-driven disease, Tregs have been studied extensively over the years, both in the skin and in circulation. This narrative review resumes the main findings about Tregs in psoriasis. We discuss how Tregs increase in psoriasis but are impaired in their regulatory/suppressive function. We debate the possibility that Tregs convert into T-effector cells under inflammatory conditions; for instance, they may turn into Th17-cells. We put particular emphasis on therapies that seem to counteract this conversion. We have enriched this review with an experimental section analyzing T-cells specific for the autoantigen LL37 in a healthy subject, suggesting that a shared specificity may exist between Tregs and autoreactive responder T-cells. This suggests that successful psoriasis treatments may, among other effects, restore Tregs numbers and functions.

New and Old Horizons for an Ancient Drug: Pharmacokinetics, Pharmacodynamics, and Clinical Perspectives of Dimethyl Fumarate

(1) Background: In their 60-year history, dimethyl fumarate and other salts of fumaric acid have been used for the treatment of psoriasis and other immune-mediated diseases for their immune-modulating properties. Over the years, new mechanisms of action have been discovered for this evergreen drug that remains a first-line treatment for several different inflammatory diseases. Due to its pleiotropic effects, this molecule is still of great interest in varied conditions, not exclusively inflammatory diseases. (2) Methods: The PubMed database was searched using combinations of the following keywords: dimethyl fumarate, pharmacokinetics, pharmacodynamics, adverse effects, psoriasis, multiple sclerosis, and clinical indications. This article reviews and updates the pharmacokinetics, mechanisms of action, and clinical indications of dimethyl fumarate. (3) Conclusions: The pharmacology of dimethyl fumarate is complex, fascinating, and not fully known. Progressive insights into the molecule's mechanisms of action will make it possible to maximize its clinical efficacy, reduce concerns about adverse effects, and find other possible areas of application.

Long-Term Treatment with Dimethyl Fumarate for Plaque Psoriasis in Routine Practice: Good Overall Effectiveness and Positive Effect on Impactful Areas

Introduction

Dimethyl fumarate (DMF) is an oral compound to treat plaque psoriasis. Data on the treatment of patients with psoriasis affecting impactful areas are scarce. In this interim analysis of the prospective, noninterventional SKILL study, we summarized results of DMF treatment regarding effectiveness (overall and in impactful areas) and safety.

Methods

Data from 676 patients suffering from moderate-to-severe plaque psoriasis were analyzed after 52 weeks of DMF treatment. Of these, 257 had data available after 52 weeks. The considered impactful areas were nails, palms, soles, and scalp. Data analysis included observed cases (OC) and last observation carried forward (LOCF).

Results

All effectiveness parameters improved after 52 weeks. The Psoriasis Area and Severity Index score was reduced by 79.5% (OC) and 65.7% (LOCF). Compared with baseline, improvements were shown for 70.2% of the patients in their nail psoriasis [nail-Physician Global Assessment (PGA)] and for 57.3% in palmoplantar disease (palmoplantar-PGA). The proportion of patients with scalp-PGA 0/1 (clear/almost clear) increased significantly to 79.8% (OC) and 69.3% (LOCF, both p < 0.001) (versus 37.5% and 36.6% at baseline, respectively). Significant reduction of pruritus (p < 0.001) was also observed. No unexpected adverse drug reactions were observed.

Conclusion

Long-term treatment with DMF in routine practice showed good overall effectiveness and safety, and a positive effect on plaque-psoriasis-affected impactful areas.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00714-0.

Dimethyl Fumarate's Effectiveness and Safety in Psoriasis: A Real-Life Experience During the COVID-19 Pandemic

Introduction

Dimethyl fumarate (DMF) is approved as oral systemic treatment for moderate-to-severe psoriasis. Scarce evidence is available for DMF treatment in psoriatic patients at the time of COVID-19 pandemic. The objective of this study was to assess the long-term effectiveness and safety of DMF monotherapy in moderate-to-severe psoriasis during the COVID-19 pandemic period.

Methods

This multicenter, retrospective study included patients with moderate-to-severe psoriasis who had received a 48-week DMF treatment during the COVID-19 pandemic. Selected outcomes were: variation of mean PASI, proportion of patients achieving PASI50 and PASI75, variation of mean PGA and face PGA, genital PGA, scalp PGA, mean itch VAS and mean DLQI.

Results

Forty-four patients were enrolled, and four patients became COVID-19 positive during the observation period but did not discontinue DMF therapy. DMF produced a significant improvement of signs and symptoms of psoriasis as expressed by mean PASI variation from 13.07 at baseline to 6.11 at week 48 (p < 0.0001), itch VAS from 3.22 at baseline to 1.18 at week 48 (p < 0.001), PGA from 2.84 at baseline to 1.30 at week 48 (p < 0.0001) and DLQI from 13.09 at baseline to 6.07 at week 48 (p < 0.0001). The percentage of patients who achieved PASI50 and PASI75 was 4.55% at week 4 and 59.09% at week 48 and 0% at week 4 and 22.73% at week 48, respectively. A clinical important decrease of mean PGA score was observed in all subgroups, face psoriasis, genital psoriasis and scalp psoriasis. Adverse events were predictable and manageable.

Conclusions

DMF monotherapy is an effective and safe treatment option in moderate-to-severe psoriasis also in patients who develop SARS-CoV-2 infection.

The Defect in Regulatory T Cells in Psoriasis and Therapeutic Approaches

Psoriasis is a chronic inflammatory skin disease characterized by accelerated tumor necrosis factor-α/interleukin (IL)-23/IL-17 axis. Patients with psoriasis manifest functional defects in CD4⁺CD25⁺ forkhead box protein 3 (Foxp3)⁺ regulatory T cells (Tregs), which suppress the excess immune response and mediate homeostasis. Defects in Tregs contribute to the pathogenesis of psoriasis and may attribute to enhanced inhibition and/or impaired stimulation of Tregs. IL-23 induces the conversion of Tregs into type 17 helper T (Th17) cells. IL-17A reduces transforming growth factor (TGF)-β1 production, Foxp3 expression, and suppresses Treg activity. Short-chain fatty acids (SCFAs), butyrate, propionate, and acetate are microbiota-derived fermentation products that promote Treg development and function by inducing Foxp3 expression or inducing dendritic cells or intestinal epithelial cells to produce retinoic acids or TGF-β1, respectively. The gut microbiome of patients with psoriasis revealed reduced SCFA-producing bacteria, Bacteroidetes, and Faecallibacterium, which may contribute to the defect in Tregs. Therapeutic agents currently used, viz., anti-IL-23p19 or anti-IL-17A antibodies, retinoids, vitamin D3, dimethyl fumarate, narrow-band ultraviolet B, or those under development for psoriasis, viz., signal transducer and activator of transcription 3 inhibitors, butyrate, histone deacetylase inhibitors, and probiotics/prebiotics restore the defected Tregs. Thus, restoration of Tregs is a promising therapeutic target for psoriasis.