Morphopathological aspects of healthy nails and nails affected by onychomycosis

Correlation of clinical characteristics, by calculation of SCIO index, with the laboratory diagnosis of onychomycosis

INTRODUCTION

Onychomycosis is a chronic fungal infection with increasing incidence and the global prevalence is estimated to be 5.5%. The aim of our study was to perceive objectively severity of onychomycosis by calculating Scoring Clinical Index for Onychomycosis and to correlate this index with accurate laboratory diagnosis in our patients.

MATERIALS AND METHODS

The study population comprised of 417 patients with laboratory confirmed onychomycosis. For each patient, we recorded basic demographic information, site of infection, the most affected nail with onychomycosis, clinical presentation, and type of onychomycosis. The evaluation of the disease severity was based on Scoring Clinical Index for Onychomycosis which was calculated for every patient separately. Mycological identification was done by microscopy and fungal culture.

RESULTS

The majority of patients had distal and lateral subungual onychomycosis (95.44%) that was localized on big toe (62.59%), with female to male ratio 1.24:1. Male patients had significantly more nails affected with onychomycosis compared with female patients (p = 0.011), while female had significantly more often onychomycosis on fingernails 2-5 (p < 0.05), and they reported significantly more often pain (p < 0.05) and esthetic problems (p < 0.05). Mean Scoring Clinical Index for Onychomycosis was 16.76. Dermatophytes were most frequently isolated (91.85%). In patients with onychomycosis caused by dermatophytes, Scoring Clinical Index for Onychomycosis had significantly higher values (p = 0.032).

CONCLUSION

Comprehensive understanding of disease characteristics will allow introduction of individualized treatment plan for each patient, based on proper fungal identification and standardized method of evaluating disease severity, which could help the patient achieve a complete cure.

NP213 (Novexatin®): A unique therapy candidate for onychomycosis with a differentiated safety and efficacy profile

NP213 (Novexatin®) is a novel antifungal peptide specifically designed for the topical treatment of onychomycosis. NP213 was designed using host defense peptides (HDP), essential components of the innate immune response to infection, as a template. NP213 is a water-soluble cyclic fungicidal peptide that effectively penetrates human nail. NP213 demonstrated a promising preclinical and clinical safety profile, with no evidence of systemic exposure following topical application to the skin and nails. NP213 was efficacious in two phase IIa human trials with 43.3% of patients having no fungi detectable by culture of fragments from NP213-treated nails after 180 days in the first study and likewise 56.5% of patients were culture negative for dermatophytes after 360 days in the second phase IIa study. In both trials, NP213 was applied daily for only 28 days in marked contrast to other topical onychomycosis treatments that require application for up to 52 weeks. Patient reported outcomes from the phase IIa studies were positive with participants recording an improved appearance of their nails after only 14 days of application. All fungi identified in these studies were Trichophyton spp. NP213 (Novexatin®) is a promising, highly differentiated peptide-based candidate for the topical treatment of onychomycosis, addressing the infectious cause and cosmetic issues of this very common condition.

Innate Inspiration: Antifungal Peptides and Other Immunotherapeutics From the Host Immune Response

The purpose of this review is to describe antifungal therapeutic candidates in preclinical and clinical development derived from, or directly influenced by, the immune system, with a specific focus on antimicrobial peptides (AMP). Although the focus of this review is AMP with direct antimicrobial effects on fungi, we will also discuss compounds with direct antifungal activity, including monoclonal antibodies (mAb), as well as immunomodulatory molecules that can enhance the immune response to fungal infection, including immunomodulatory AMP, vaccines, checkpoint inhibitors, interferon and colony stimulating factors as well as immune cell therapies. The focus of this manuscript will be a non-exhaustive review of antifungal compounds in preclinical and clinical development that are based on the principles of immunology and the authors acknowledge the incredible amount of in vitro and in vivo work that has been conducted to develop such therapeutic candidates.

Improved Methods for Assessing Therapeutic Potential of Antifungal Agents against Dermatophytes and Their Application in the Development of NP213, a Novel Onychomycosis Therapy Candidate

Onychomycosis is a common, difficult-to-treat nail infection that is mainly caused by dermatophytes. Current therapies are not wholly effective and are associated with manifold side effects.

Onychomycosis is a common, difficult-to-treat nail infection that is mainly caused by dermatophytes. Current therapies are not wholly effective and are associated with manifold side effects. The development of treatments for onychomycosis is challenging because standard in vitro tests are not predictive of antifungal efficacy within the nail. We have developed a new antifungal agent, NP213, for the treatment of onychomycosis. NP213 is based on endogenous host defense peptides produced within the nail. We compared the in vitro activity of NP213 and existing antifungal agents using conventional antimicrobial susceptibility test (AST) systems and more physiologically relevant models based on the human nail. We observed that the standard in vitro AST methodologies failed to predict the efficacy of antifungal agents within the nail. To address that, we present a more physiologically relevant modified AST method. This method, alongside other standard in vitro assessments of activity (including mechanism-of-action and time-of-kill studies), better reflected the activity of NP213 and other antifungal agents within the nail than standard in vitro AST methods. NP213 is a rapidly acting, fungicidal peptide that is superior to existing antifungal agents in vitro. It penetrated the nail more effectively than other antifungals, as confirmed by using an optimized in vitro nail infection model. The data presented here support the current clinical development status of NP213 as a novel agent for treating onychomycosis. We propose that the modified tests developed and applied for NP213 characterization are the most relevant to use for screening any potential therapeutic candidates for onychomycosis.