Microbiome modulators for atopic eczema: a systematic review of experimental and investigational therapeutics

INTRODUCTION

Atopic dermatitis (AD) is a common inflammatory cutaneous disease that arises due to dysregulation of the Th2 immune response, impaired skin barrier integrity, and dysbiosis of the skin and gut microbiota. An abundance of Staphylococcus aureus biofilms in AD lesions increases the Th2 immune response, and gut bacteria release breakdown products such as Short Chain Fatty Acids that regulate the systemic immune response.

AREAS COVERED

We aim to evaluate therapies that modulate the microbiome in humans and discuss the clinical implications of these treatments. We performed a review of the literature in which 2,673 records were screened, and describe the findings of 108 studies that were included after full-text review. All included studies discussed the effects of therapies on the human microbiome and AD severity. Oral probiotics, topical probiotics, biologics, and investigational therapies were included in our analysis.

EXPERT OPINION

Oral probiotics demonstrate mixed efficacy at relieving AD symptoms. Topical probiotics reduce S. aureus abundance in AD lesional skin, yet for moderate-severe disease, these therapies may not reduce AD severity scores to the standard of biologics. Dupilumab and tralokinumab target key inflammatory pathways in AD and modulate the skin microbiome, further improving disease severity.

Clinical pharmacokinetics and pharmacodynamics of oral systemic nonbiologic therapies for psoriasis patients

INTRODUCTION

Psoriasis is a chronic inflammatory immune condition. Treatments for psoriasis vary with disease severity, ranging from topicals to systemic biologic agents. The pharmacokinetic (PK) and pharmacodynamic (PD) properties of these therapies establish drug efficacy, toxicity, and optimal dosing to ensure therapeutic drug levels are sustained and adverse effects are minimized.

AREAS COVERED

A literature search was performed on PubMed, Google Scholar, and Ovid MEDLINE for PK and PD, efficacy, and safety data regarding oral systemic nonbiologic therapies utilized for moderate-to-severe plaque psoriasis. The findings were organized into sections for each drug: oral acitretin, methotrexate, cyclosporine, apremilast, tofacitinib, and deucravacitinib.

EXPERT OPINION

Some psoriasis patients may not respond to initial therapy. Ongoing research is evaluating genetic polymorphisms that may predict an improved response to specific medications. However, financial and insurance barriers, as well as limited genetic polymorphisms correlated with treatment response, may restrict the implementation of genetic testing necessary to personalize treatments. How well psoriasis patients adhere to treatment may contribute greatly to variation in response. Therapeutic drug monitoring may help patients adhere to treatment, improve clinical response, and sustain disease control.

Clinical pharmacokinetics and pharmacodynamics of topical non-biological therapies for psoriasis patients

INTRODUCTION

Psoriasis is a chronic inflammatory cutaneous disease that causes patients psychosocial distress. Topical therapies are utilized for mild-to-moderate disease and for more severe disease in conjunction with systemic therapies. Topical corticosteroids are a cornerstone of treatment for psoriasis, but long-term use can cause stria and cutaneous atrophy and as well as systemic side effects such as topical steroid withdrawal. Non-steroidal topical therapies tend to be safer than topical corticosteroids for long-term use.

AREAS COVERED

We conducted a literature review on the pharmacokinetic (PK) and pharmacodynamic (PD) properties of topical therapies for psoriasis. We discuss how the PK and PD characteristics of these therapies inform clinicians on efficacy and toxicity when prescribing for patients.

EXPERT OPINION

Topical corticosteroids, used intermittently, are very safe and effective. Long-term, continuous use of topical corticosteroids can cause systemic side effects. Several generic and newly approved non-steroidal options are available, but no head-to-head studies compare the effectiveness of the generics (vitamin D analogs, tacrolimus, pimecrolimus) against the newer therapies (roflumilast, tapinarof). Patients often do not respond to topical therapies due to poor adherence to treatment regimens. For patients resistant to topical treatment, phototherapy or systemic therapy may be an option.

Discoidin Domain Receptor 1 is a therapeutic target for neurodegenerative diseases

The role of Discoidin Domain Receptors (DDRs) is poorly understood in neurodegeneration. DDRs are upregulated in Alzheimer's and Parkinson's disease (PD), and DDRs knockdown reduces neurotoxic protein levels. Here we show that potent and preferential DDR1 inhibitors reduce neurotoxic protein levels in vitro and in vivo. Partial or complete deletion or inhibition of DDR1 in a mouse model challenged with α-synuclein increases autophagy and reduces inflammation and neurotoxic proteins. Significant changes of cerebrospinal fluid microRNAs that control inflammation, neuronal injury, autophagy and vesicular transport genes are observed in PD with and without dementia and Lewy body dementia, but these changes are attenuated or reversed after treatment with the DDR1 inhibitor, nilotinib. Collectively, these data demonstrate that DDR1 regulates autophagy and reduces neurotoxic proteins and inflammation and is a therapeutic target in neurodegeneration.