How do we measure efficacy of therapy in onychomycosis: Patient, physician, and regulatory perspectives

Nd:YAG 1064 nm laser treatment for onychomycosis - is it really effective? A prospective assessment for efficiency and factors contributing to response

Onychomycosis is a highly prevalent and persistent nail disorder primarily caused by dermatophytes. The effectiveness of current topical and systemic antifungals is limited by the extent and severity of the infection, patient demographics and health status, hepatic toxicity, drug interactions and low compliance. Laser therapy is a promising modality for safe and cost-effective removal of mycotic nail. This prospective study assessed the performance of a multi-series long-pulsed Nd:YAG 1064 nm regimen (30-40 J/cm2 , 1 Hz) in the treatment of 213 mycotic nails in 31 patients. Pain and discomfort were scored at each treatment session and mycological and clinical cure rates were determined 3 months after the last treatment session. Patients presented with mostly severe (mean SCIO score: 21.9 ± 8.9), T. rubrum-positive (87.1%) infections. Most (61%) had a family history of onychomycosis and a significant proportion had comorbidities, including hypertension (38.7%), hyperlipidemia (35.5%) and/or diabetes (12.9%). Treatment was well tolerated and there were no reports of nail deformity or burns. By 3 months post-treatment, mycological cure was achieved by 4 (12.9%) and visual improvements were noted for 10 (32.3%) patients, including 3 (9.7%) with moderate to significant improvements. Clinical response correlated with baseline SCIO ≤ 20 (OR: 0.9 [0.13-6.52]), family history of onychomycosis (OR: 0.27 [0.04-1.50]) and comorbidities (OR: 0.44 [0.05-3.74]). In conclusion, Nd:YAG 1064 nm laser is safe and effective for the management of mild-to-moderate onychomycosis in diverse populations. Further studies will be necessary to adjust treatment parameters to patient and nail profiles and to determine the impact of combined laser and topical therapies.

Promising onychomycosis treatment with hypericin-mediated photodynamic therapy: case reports

BACKGROUND

Onychomycosis (OM) is a common nail plate disorder caused by dermatophyte molds, yeasts, and non-dermatophyte molds, which use keratin in the nail plate as an energy source. OM is characterized by dyschromia, increased nail thickness, subungual hyperkeratosis, and onychodystrophy, and is typically treated with conventional antifungals despite frequent reports of toxicity, fungal resistance, and OM recurrence. Photodynamic therapy (PDT) with hypericin (Hyp) as a photosensitizer (PS) stands out as a promising therapeutic modality. When excited by a specific wavelength of light and in the presence of oxygen, to lead to photochemical and photobiological reactions on the selected targets.

METHODS

OM diagnosis was made in three suspected cases, and the causative agents were identified by classical and molecular methods, and confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Susceptibility of planktonic cells of the clinical isolates to conventional antifungals and PDT-Hyp was evaluated, and photoacoustic spectroscopy (PAS) of Hyp permeation in nail fragments ex vivo was analyzed. Furthermore, the patients opted to undergo PDT-Hyp treatment and were subsequently followed up. The protocol was approved by the human ethics committee (CAAE, number 14107419.4.0000.0104).

RESULTS

The etiological agents of OM in patients ID 01 and ID 02 belonged to the Fusarium solani species complex, being identified as Fusarium keratoplasticum (CMRP 5514) and Fusarium solani (CMRP 5515), respectively. For patient ID 03, the OM agent was identified as Trichophyton rubrum (CMRP 5516). PDT-Hyp demonstrated a fungicidal effect in vitro, with reductions of ≥3 log₁₀ (p<0.0051 and p<0.0001), and the PAS analyses indicated that Hyp could completely permeate through both healthy and OM-affected nails. After four sessions of PDT-Hyp, mycological cure was observed in all three cases, and after seventh months, clinical cure was confirmed. PDT-Hyp showed satisfactory results in terms of efficacy and safety, and thus can be considered a promising therapy for the clinical treatment of OM.

A multicentre, randomised, parallel-group, double-blind, vehicle-controlled and open label versus amorolfine 5% study, to evaluate the efficacy and safety of terbinafine 10% nail lacquer in the treatment of onychomycosis

BACKGROUND

Onychomycosis is a difficult-to-treat fungal nail infection whose treatment can involve systemic or topical antifungal approaches.

OBJECTIVES

To assess the efficacy and safety of terbinafine 10% nail lacquer in distal lateral subungual onychomycosis (DLSO).

PATIENTS/METHODS

Patients with mild-to-moderate DLSO were randomised (3:3:1) to receive double-blind topical terbinafine 10% (n = 406) or its vehicle (n = 410) administered once daily for 4 weeks and then once weekly for 44 weeks, or open-label topical amorolfine 5% (n = 137) for 48 weeks, with a 12-week follow-up period. The primary efficacy endpoint, complete cure rate at Week 60, was a composite of negative potassium hydroxide (KOH) microscopy, negative culture for dermatophytes and no residual clinical involvement of the target big toenail.

RESULTS

Complete cure rates at Week 60 in the terbinafine, vehicle and amorolfine groups were 5.67%, 2.20% and 2.92%, respectively (odds ratio (OR) vs vehicle = 2.68; 95% confidence intervals (CI): 1.22-5.86; p = .0138). Statistically significant differences in responder (negative KOH and negative culture and ≤10% residual clinical involvement) and mycological cure rates (negative KOH and negative culture) at Week 60 were obtained between terbinafine and vehicle. Terbinafine was well-tolerated with no systemic adverse reactions identified; the most common topical adverse reactions were erythema and skin irritation.

CONCLUSIONS

Terbinafine 10% nail lacquer was an effective treatment for mild-to-moderate onychomycosis improving both clinical and mycological criteria compared with vehicle. Furthermore, there may be some benefits compared to the currently available topical agent, amorolfine 5%. Treatment was well-tolerated and safe.

Inactivation of Dermatophytes Causing Onychomycosis and Its Therapy Using Non-Thermal Plasma

Onychomycosis is one of the most common nail disorders. Its current treatment is not satisfactorily effective and often causes adverse side effects. This study aims to determine the optimal conditions for non-thermal plasma (NTP) inactivation of the most common dermatophytes in vitro and to apply it in patient`s therapy. The in vitro exposure to NTP produced by negative DC corona discharge caused full inactivation of Trichophyton spp. if applied during the early growth phases. This effect decreased to negligible inactivation with the exposure applied six days after inoculation. In a group of 40 patients with onychomycosis, NTP therapy was combined with nail plate abrasion and refreshment (NPAR) or treatment with antimycotics. The cohort included 17 patients treated with NPAR combined with NTP, 11 patients treated with antimycotics and NTP, and 12 patients treated with NPAR alone. The combination of NPAR and NTP resulted in clinical cure in more than 70% of patients. The synergistic effect of NPAR and NTP caused 85.7% improvement of mycological cure confirmed by negative microscopy and culture of the affected nail plate. We conclude that NTP can significantly improve the treatment of onychomycosis.

A practical application of onychomycosis cure - combining patient, physician and regulatory body perspectives

Due to the high relapse rates and the rise of predisposing factors, the need for curing onychomycosis is paramount. To effectively address onychomycosis, the definition of cure used in a clinical setting should be agreed upon and applied homogeneously across therapies (e.g. oral, topical and laser treatments). In order to determine what is or what should be used to define cure in a clinical setting, a literature search was conducted to identify methods used to evaluate treatment success. The limitations, strengths, prevalence and utility of each outcome measure were investigated. Seven ways to measure treatment success were identified; mycological cure, patient/investigator assessments, complete cure, quality of life instruments, severity indexes, clinical cure and temporary clearance. Despite its shortcomings, mycological cure is the most objective and consistent outcome measure used across onychomycosis studies. It is suggested that diagnostic goals of onychomycosis should be used to define cure in a clinical setting. Modifications to outcome measures such as incorporating molecular-based techniques could be a future avenue to explore.

Onychomycosis: Treatment and prevention of recurrence

Onychomycosis is a fungal nail infection caused by dermatophytes, nondermatophytes, and yeast, and is the most common nail disorder seen in clinical practice. It is an important problem because it may cause local pain, paresthesias, difficulties performing activities of daily living, and impair social interactions. The epidemiology, risk factors, and clinical presentation and diagnosis of onychomycosis were discussed in the first article in this continuing medical education series. In this article, we review the prognosis and response to onychomycosis treatment, medications for onychomycosis that have been approved by the US Food and Drug Administration, and off-label therapies and devices. Methods to prevent onychomycosis recurrences and emerging therapies are also described.

Onychomycosis in the 21st Century: An Update on Diagnosis, Epidemiology, and Treatment

Onychomycosis accounts for 50% of all nail disease cases and is commonly caused by dermatophytes. Diabetes, human immunodeficiency virus, immunosuppression, obesity, smoking, and advancing age are predisposing factors of this fungal infection. Potassium hydroxide and culture are considered the current standard for diagnosing onychomycosis, revealing both fungal viability and species identification. Other diagnostic tests currently available include periodic acid-Schiff staining, polymerase chain reaction techniques, and fluorescent staining. Across 6 recently published epidemiology studies, the global prevalence of onychomycosis was estimated to be 5.5%, falling within the range of previously reported estimates (2%-8%). Newly approved onychomycosis treatments include efinaconazole, tavaborole, and laser therapy with lasers only approved to temporarily increase the amount of clear nail. Additional onychomycosis treatments being investigated include iontophoresis and photodynamic therapy with small open-label studies reported thus far. Preventative strategies, to help decrease recurrence and reinfection rates, include sanitisation of footwear and prophylactic topical antifungal agents.