An experimental investigation of a novel iron chelating protoporphyrin IX prodrug for the enhancement of photodynamic therapy.

OBJECTIVES: Non-melanoma skin cancers are the most frequently occurring type of cancer worldwide. They can be effectively treated using topical dermatological photodynamic therapy (PDT) employing protoporphyrin IX (PpIX) as the active photosensitising agent as long as the disease remains superficial. Novel iron chelating agents are being investigated to enhance the effectiveness and extend the applications of this treatment modality, as limiting free iron increases the accumulation of PpIX available for light activation and thus cell kill. METHODS: Human lung fibroblasts (MRC-5) and epithelial squamous carcinoma (A431) cells were treated with PpIX precursors (aminolaevulinic acid [ALA] or methyl-aminolevulinate [MAL]) with or without the separate hydroxypyridinone iron chelating agent (CP94) or alternatively, the new combined iron chelator and PpIX producing agent, AP2-18. PpIX fluorescence was monitored hourly for 6 hours prior to irradiation. PDT effectiveness was then assessed the following day using the lactate dehydrogenase and neutral red assays. RESULTS: Generally, iron chelation achieved via CP94 or AP2-18 administration significantly increased PpIX fluorescence. ALA was more effective as a PpIX-prodrug than MAL in A431 cells, corresponding with the lower PpIX accumulation observed with the latter congener in this cell type. Addition of either iron chelating agent consistently increased PpIX accumulation but did not always convey an extra beneficial effect on PpIX-PDT cell kill when using the already highly effective higher dose of ALA. However, these adjuvants were highly beneficial in the skin cancer cells when compared with MAL administration alone. AP2-18 was also at least as effective as CP94 + ALA/MAL co-administration throughout and significantly better than CP94 supplementation at increasing PpIX fluorescence in MRC5 cells as well as at lower doses where PpIX accumulation was observed to be more limited. CONCLUSIONS: PpIX fluorescence levels, as well as PDT cell kill effects on irradiation can be significantly increased by pyridinone iron chelation, either via the addition of CP94 to the administration of a PpIX precursor or alternatively via the newly synthesized combined PpIX prodrug and siderophore, AP2-18. The effect of the latter compound appears to be at least equivalent to, if not better than, the separate administration of its constituent parts, particularly when employing MAL to destroy skin cancer cells. AP2-18 therefore warrants further detailed analysis, as it may have the potential to improve dermatological PDT outcomes in applications currently requiring enhancement. Lasers Surg. Med. 50:552-565, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Observational study of chondrodermatitis nodularis helicis treated with methyl aminolevulinate photodynamic therapy.

BACKGROUND: Therapies used to treat chondrodermatitis nodularis helicis (CNH), such as surgical excision, pressure relief, or topical steroids report varying degrees of success. OBJECTIVE: We evaluated the response and safety of methyl aminolevulinate (MAL) photodynamic therapy (PDT) in CNH. METHODS: This retrospective, observational study performed at the University Hospital Ramon y Cajal (Madrid, Spain) and Hospital San Jorge (Huesca, Spain) included all patients diagnosed with CNH and treated with MAL-PDT from 2008 to 2015. Treatment sites were prepared and irradiated as per the conventional MAL-PDT procedure. RESULTS: Patients underwent a mean of 2.3 sessions with between-session intervals ranging from 15 days to 1 month. A complete response to PDT was observed in 33 patients (76.7%), who experienced pain relief and resolution of the inflammatory nodule. Lesion recurrence was recorded in 10 patients (23.3%) during the mean follow-up period of 20 months. Receiving ≥2 PDT sessions was significantly associated with a good response (26/28, 93% success rate, P = .003). LIMITATIONS: Some limitations of the study are the lack of an established between-session interval, the absence of evaluation of curettage effectiveness and the limited sample size. DISCUSSION: The results support the view that PDT is a promising treatment approach for CNH.

Daylight methyl-aminolevulinate photodynamic therapy versus ingenol mebutate for the treatment of actinic keratoses: an intraindividual comparative analysis.

Daylight-photodynamic therapy (D-PDT) and ingenol mebutate (IM) are novel therapies directed to actinic keratoses (AK). The purpose of our study was to compare effectiveness, tolerability, cosmetic outcome and patient preference of D-PDT versus IM in the treatment of grade I and II AK. Twenty-seven patients with AK on the face or scalp were enrolled. Each patient received, in a 25 cm(2) target area, D-PDT on right side and IM on left side. Overall 323 AK were treated. Both target areas achieved complete response in 40.47% of the cases and average AK clearance rate was similar for D-PDT and IM (p=0.74). In D-PDT areas mean grade II AK clearance rate was lower compared with that of grade I AK (p=0.015). In IM areas grade I and II AK average clearance rates were similar (p=0.28). At week 1 and month 1, mean local skin responses (LSR) score were higher in areas treated with IM. IM areas showed more severe pain and cosmetic sequelae. D-PDT had similar effectiveness to IM, even if IM demonstrated higher grade II AK clearance rate. Tolerability profile was superior for D-PDT in terms of LSR and pain. D-PDT was more cosmetically acceptable. Patients preferred D-PDT to IM in most cases.

MAL Daylight Photodynamic Therapy for Actinic Keratosis: Clinical and Imaging Evaluation by 3D Camera.

Non-melanoma skin cancer is the most common skin cancer with an incidence that varies widely worldwide. Among them, actinic keratosis (AK), considered by some authors as in situ squamous cell carcinoma (SCC), are the most common and reflect an abnormal multistep skin cell development due to the chronic ultraviolet (UV) light exposure. No ideal treatment exists, but the potential risk of their development in a more invasive form requires prompt treatment. As patients usually present with multiple AK on fields of actinic damage, there is a need for effective, safe, simple and short treatments which allow the treatment of large areas. To achieve this, daylight photodynamic therapy (DL-PDT) is an innovative treatment for multiple mild actinic keratosis, well tolerated by patients. Patients allocated to the PDT unit, affected by multiple mild-moderate and severe actinic keratosis on sun-exposed areas treated with DL-PDT, were clinically evaluated at baseline and every three months with an Antera 3D, Miravex(©) camera. Clinical and 3D images were performed at each clinical check almost every three months. In this retrospective study, 331 patients (56.7% male, 43.3% female) were treated with DL-PDT. We observed a full clearance in more than two-thirds of patients with one or two treatments. Different responses depend on the number of lesions and on their severity; for patients with 1-3 lesions and with grade I or II AK, a full clearance was reached in 85% of cases with a maximum of two treatments. DL-PDT in general improved skin tone and erased sun damage. Evaluating each Antera 3D images, hemoglobin concentration and pigmentation, a skin color and tone improvement in 310 patients was observed. DL-PDT appears as a promising, effective, simple, tolerable and practical treatment for actinic damage associated with AK, and even treatment of large areas can be with little or no pain. The 3D imaging allowed for quantifying in real time the aesthetic benefits of DL-PDT's increasing compliance.

Daylight photodynamic therapy with methyl-aminolevulinate for the treatment of actinic cheilitis.

Actinic cheilitis (AC) is a common premalignant condition that requires an effective treatment to reduce the risk of malignant transformation. Photodynamic therapy (PDT) has been recently added to the armamentarium available for AC treatment. Daylight PDT (D-PDT) is a novel PDT modality in which the activation of the topical photosensitizer is induced by the exposure to natural daylight instead of artificial light sources without preliminary occlusion. This simplified procedure was found to be more tolerated as compared to conventional PDT. We report our preliminary experience on the use of D-PDT using methyl-aminolevulinate cream in 10 patients with refractory AC of the lower lip. Patients received two consecutive D-PDT sessions with an interval of 7-14 days. At 3 months after therapy, a complete response was observed in seven patients, with sustained results in five patients over an observational period of 6-12 months. Treatment was well tolerated.

Usefulness of in vivo photodiagnosis for the identification of tumor margins in recurrent basal cell carcinoma of the face.

BACKGROUND: Basal cell carcinoma (BCC) is the most frequent malignant tumor of the skin. The high prevalence of BCC, the risk of local recurrence, and the difficult clinical identification of the excision margins emphasize the importance of studying new approaches, ensuring complete surgical excision that allows preservation of normal tissue, especially for BCCs located on cosmetically important areas such as the mid face. Photodiagnosis (PD) is a pre-operative technique that allows a more accurate distinction of neoplastic lesions from surrounding healthy skin in vivo. PURPOSE: The aim of this study is to assess the usefulness of PD for the evaluation of tumor margins in 10 patients with recurrent BCC of the face. METHODS: We study the red fluorescence emitted by neoplastic tissue under a Wood's lamp irradiation, after accumulation of methyl amino levulinate (MAL) cream in 10 patients with recurrent BCC. RESULTS: Our histologic analysis of perilesional skin by PD allowed to delineate more precise tumor margins, thus achieving radical excision in 90% of patients. CONCLUSION: PD represents a diagnostic method that helps to distinguish between tumor tissue and surrounding healthy tissue especially in case of recurrent BCC of the face when the clinical delimitation is not clear.

Efficacy of photodynamic therapy with laser pretreatment for actinic keratosis and photorejuvenation as evaluated by fluorescent imaging.

BACKGROUND: The Methylaminolevulinate-photodynamic therapy (MAL-PDT) has been reported to be effective in treating actinic keratosis (AK). Fluorescent images taken after topical MAL application have been used to diagnose cancerous lesions. OBJECTIVES: We evaluated therapeutic efficacy of MAL-PDT for multiple AK and defined value of fluorescent images in evaluating treatment response. We also investigated photorejuvenation effects of PDT. METHODS: Ten patients with multiple AK were enrolled. We did histological confirmation of the lesion by biopsy. After 3 h of MAL cream occlusion, red light was illuminated with 37 J/cm(2) on 0, 4, 16, and 20 weeks. At each visit, lesions were counted by inspection and fluorescent images were taken under ultraviolet A light. We repeated skin biopsy in 16 weeks. RESULTS: All patients showed significant improvement after three sessions of PDT. The average remission rate was 85.96%. Overall, patients showed significant improvement in photoaging such as erythema, coarse wrinkles, and skin roughness. Histological examination also showed improvement. There was meaningful agreement between lesion count by fluorescent imaging and inspection (coefficient = 0.9). CONCLUSIONS: PDT was found to be effective, well-tolerated, cosmetically acceptable for AK treatment and photorejuvenation, both clinically and histologically. In addition, fluorescent images taken after MAL application aided in evaluation of treatment response as well as diagnosis.

Cutaneous Alternariosis in Immunosuppressed Patients Treated with Photodynamic Therapy and Oral Antifungals, a Synergistic Strategy.

Cutaneous alternariosis is a rare condition, more frequently presented in immunocompromised patients, which usually requires long courses of systemic antifungals that may interact with other medications. The presented series shows three cases of cutaneous alternariosis in immunocompromised patients and organ transplant recipients that were successfully treated with photodynamic therapy and oral antifungals, allowing a reduction in the systemic treatment duration and therefore decreasing the risk of side effects and drug interactions.

Fractionated 5-aminolevulinic acid photodynamic therapy after partial debulking versus surgical excision for nodular basal cell carcinoma: a randomized controlled trial with at least 5-year follow-up.

BACKGROUND: Although effective in superficial basal cell carcinoma (BCC), the treatment effect of photodynamic therapy (PDT) in nodular BCC (nBCC) is still questionable. The relation between tumor thickness and PDT failure is unclear. OBJECTIVE: We sought to compare long-term effectiveness of fractionated 20% 5-aminolevulinic acid (ALA)-PDT with prior partial debulking versus surgical excision in nBCC. The effect of tumor thickness on ALA-PDT failure was analyzed. METHODS: 173 primary, histologically proven nBCCs in 151 patients were randomized to fractionated ALA-PDT (n = 85) or surgical excision (n = 88). Two PDT illuminations were performed with a 1-hour interval. Follow-up was at least 5 years posttreatment. Clinical recurrences were confirmed histologically. RESULTS: A total of 171 nBCCs were treated and had a median follow-up of 67 months (range 0-106). At 60 months, 23 tumors had recurred in the ALA-PDT group and 2 tumors in the surgical excision group. Cumulative recurrence probabilities 5 years posttreatment were 30.7% (95% confidence interval [CI] 21.5%-42.6%) for ALA-PDT and 2.3% (95% CI 0.6%-8.8%) for surgical excision (P < .0001). Two tumors in the ALA-PDT group recurred at 72 and 91 months posttreatment. Cumulative probability of recurrence-free survival post-PDT was 65.0% (95% CI 51%-76%) for nBCC measuring greater than 0.7 mm in thickness and 94.4% (95% CI 67%-99%, P = .018) for tumors less than or equal to 0.7 mm. LIMITATIONS: Tumor thickness on punch biopsy specimen might differ from the total lesion thickness. CONCLUSIONS: In nBCC, 5-year cumulative probability of recurrence after surgical excision is lower than after fractionated ALA-PDT with prior debulking. Although surgical excision remains the gold standard of treatment, PDT might be an alternative for inoperable patients with thin (≤0.7 mm) nBCC.

Photodynamic Therapy, a successful treatment for granular parakeratosis.

Granular parakeratosis is characterized by variably hyperkeratotic brownish papules or plaques, mostly found on flexures. Different treatments have been suggested with variable results. We present a series of 3 cases successfully treated with one session of methyl-aminolevulinate photodynamic therapy, showing resolution of the lesions and symptoms within less than 2 weeks, as a potentially new, safe and effective therapeutic option.

A 12-month follow-up split-scalp study comparing calcipotriol-assisted MAL-PDT with conventional MAL-PDT for the treatment of actinic keratosis: a randomized controlled trial.

To enhance the efficacy of photodynamic therapy (PDT) for actinic keratosis (AKs), physical and chemical pre-treatments, such as calcipotriol (CAL) have been suggested. To compare the long-term 12-month efficacy and safety between methylaminolevulinate (MAL)-PDT and prior application of topical CAL versus conventional MAL-PDT for AKs of the scalp. Twenty patients with multiple AKs on the scalp were randomized to receive conventional PDT on one side of the scalp and CAL-assisted PDT, in which CAL was applied daily for 15 days beforehand, on the other side. Patients were evaluated for AK clearance at three, six and 12 months thereafter. All 20 patients completed the study. At three months, overall AK clearance was 92.07% and 82.04% for CAL-PDT and conventional PDT, respectively (p < 0.001). Similar results were found at six and 12 months: 92.07% and 81.69% (p < 0.001), and 90.69% and 77.46% (p < 0.001) for CAL-PDT and conventional PDT, respectively. Grade I AKs showed a similar response rate for both sides (p = 0.055) at three months and significant differences were obtained at six (p = 0.001) and 12 months (p < 0.001) for CAL-PDT and conventional PDT. Grade II AKs showed greater improvement on the CAL-PDT side (89.55% vs 62.90%) (p < 0.001) at three months. No difference was found at six and 12 months. CAL-PDT proved to be safe and more effective than conventional PDT for the treatment of AKs on the scalp after 12 months. CAL pre-treatment may have enhanced the efficacy of PDT for AK treatment, however, larger trials are needed to corroborate our findings.

Fractionated illumination improves the treatment outcomes of photodynamic therapy for high grade cutaneous leishmaniasis.

Photodynamic therapy (PDT) has been widely used in dermatology to treat different skin diseases. Here, we aim to compare the efficacy of single versus multiple fraction light illumination PDT for high grade lesions of cutaneous leishmaniasis (CL). In particular, 60 patients (104 CL lesions) were randomly divided into two groups; 30 patients (46 CL lesions) in group I were treated with methylaminolevulinate (MAL)-based PDT in three sessions, with a light dose of 90 J/cm2 delivered in a single fraction in each session. The 30 patients (58 CL lesions) in group II received the same treatment, except the light dose in each session was delivered in three fractions. Patient assessment at nine months follow-up revealed complete response at 35 (76 %) for group I, compared to 53 (91.4 %) for group II. Moreover, partial response was observed in 11 (24 %) CL lesions for group I, as compared with 5 (8.6 %) CL lesions in group II. Pain and burning sensation in patients from group II was markedly less than patient from group I. In conclusion, fractionated illumination improves the treatment efficacy of PDT for high grade CL lesions.

Influence of Serum Vitamin D Level in the Response of Actinic Keratosis to Photodynamic Therapy with Methylaminolevulinate.

In mouse models of squamous cell carcinoma, pre-treatment with calcitriol prior to photodynamic therapy with aminolevulinic acid (ALA) enhances tumor cell death. We have evaluated the association between vitamin D status and the response of actinic keratoses to photodynamic therapy with methylaminolevulinate. Twenty-five patients with actinic keratoses on the head received one session of photodynamic therapy with methylaminolevulinate. Biopsies were taken at baseline and six weeks after treatment. Immuno-histochemical staining was performed for VDR, P53, Ki67 and -catenin. Basal serum 25(OH)D levels were determined. Cases with a positive histological response to treatment had significantly higher serum 25(OH)D levels (26.96 (SD 7.49) ngr/mL) than those without response (18.60 (SE 7.49) ngr/mL) (p = 0.05). Patients with a complete clinical response displayed lower basal VDR expression (35.71% (SD 19.88)) than partial responders (62.78% (SD 16.735)), (p = 0.002). Our results support a relationship between vitamin D status and the response of actinic keratoses to photodynamic therapy with methylaminolevulinate.

Low-level light-assisted photodynamic therapy using a wearable cap-like device for the treatment of actinic keratosis of the scalp.

BACKGROUND: Daylight photodynamic therapy (dlPDT) is a painless and increasingly cost-effective treatment for actinic keratosis (AK). New protocols avoid incubation, minimizing pain and adverse events. However, it is time-consuming and dependent on specific weather conditions. In patients with AK of the scalp, we evaluated the efficacy of indoor photodynamic therapy (PDT) using a wearable low-level light therapy (LLLT) device, without pre-incubation with a photosensitizing agent. METHODS: In this pilot study, 27 patients with thin and moderately thick AK (Olsen Grades I-II) underwent a single 15-minute session of LLLT using a wearable cap-like device immediately after application of methyl-aminolevulinate (MAL) cream, with no prior preparation of the affected area. Treatment efficacy was quantified by measuring the reduction in AK lesion number and the AK quality of life (AKQoL) score. All AK lesions were mapped at baseline for follow-up 2 months later. Paired pre/post scalp biopsies from 5 patients were analysed using histological and immunohistochemical techniques (p53, p27, cyclin D1, p63, and Ki67 expression). Data were analysed using the Wilcoxon signed-rank test. RESULTS: In all patients we observed a global reduction in the number of AK lesions (71%; p < 0.0001) and AKQoL score (from 5.6 to 4.4; p = 0.034) 2 months after treatment. Histology and immunohistochemistry of skin biopsies from 5 patients also revealed marked improvements after LLLT. No patients reported any pain during treatment. CONCLUSION: PDT using LLLT is a rapid, painless, and efficacious modality for the treatment of AK.

Is photodynamic therapy a relevant therapeutic option in refractory benign familial pemphigus (Hailey-Hailey disease)? A series of eight patients.

INTRODUCTION/BACKGROUND: Treatment of benign familial pemphigus or Hailey-Hailey disease (HHD), a rare inherited condition associated with a significant impairment of quality of life, is often challenging and disappointing with frequent relapses and infectious complications. Topical photodynamic therapy (PDT) may offer new perspectives in this difficult setting. MATERIAL AND METHODS: Eight patients with long-lasting HHD lesions refractory to multiple treatments were treated on at least one involved site with PDT using methyl-amino levulinate with a standardized protocol of three sessions of irradiation separated by 3-week intervals. RESULTS: A complete or partial clearing was achieved in all treated areas, and the result was satisfactorily maintained in all cases after a follow-up period ranging from 3 to 36 months. Results were of higher quality in non-inguinal areas. Tolerance was overall acceptable with local pain during and shortly after irradiation being the main limiting factor. DISCUSSION/CONCLUSION: Our series, although limited in size, emphasizes the interest of PDT in this difficult condition even though results may be incomplete. Treatment-related pain can be adequately managed by prior analgesics, cooling with sprayed water and local tumescent anesthesia. Overall, PDT appears as a relevant option in refractory HHD management with a favorable benefit/risk ratio.

Current evidence and applications of photodynamic therapy in dermatology.

In photodynamic therapy (PDT) a photosensitizer - a molecule that is activated by light - is administered and exposed to a light source. This leads both to destruction of cells targeted by the particular type of photosensitizer, and immunomodulation. Given the ease with which photosensitizers and light can be delivered to the skin, it should come as no surprise that PDT is an increasingly utilized therapeutic in dermatology. PDT is used commonly to treat precancerous cells, sun-damaged skin, and acne. It has reportedly also been used to treat other conditions including inflammatory disorders and cutaneous infections. This review discusses the principles behind how PDT is used in dermatology, as well as evidence for current applications of PDT.

The France-PDT study: a national prospective observational cohort survey on the use of methyl-aminolevulinate photodynamic therapy in France, with up to 6-month follow-up.

BACKGROUND: The efficacy and safety of MAL-PDT have been shown in actinic keratoses (AK), basal cell carcinoma (BCC), and Bowen's disease (BD). OBJECTIVES: To appraise the current use of MAL-PDT in France. METHODS: National prospective cohort survey, including 583 patients treated for the first time with MAL-PDT. Clinical and treatment data were collected at baseline, month 3, and month 6 if applicable. The primary objective was to estimate the rate of misuse of MAL, defined as divergence from the French Summary of Product Characteristics. RESULTS: Of 174 contacted physicians, 66 agreed to participate in the study, and 56 included at least one patient. Among the 456 patients included in the observational cohort, 203 had AK, 130 had BCC, and 63 had BD. Referring to the French SPC of Metvixia®, the MAL-PDT was misused in 48.7% of BCC, 25.6% of AK and 23.4% of BD. The main criteria for misuse in BCC were the performance of two rather than one lighting sessions at baseline cure. The main criteria for misuse in AK were the duration of lighting and the performance of 2 rather than 1 lighting sessions at baseline cure. The main criteria for misuse in BD were the performance of 1 rather than 2 lighting sessions at baseline cure and the duration of illumination. CONCLUSION: Contrasting with the French label, nearly one third of French dermatologists treat BCC with two sessions, as recommended at European level and in Australia. International consensus guidelines are needed to homogenize and rationalize current use of MAL-PDT.

The effect of light fractionation with a 2-h dark interval on the efficacy of topical hexyl-aminolevulinate photodynamic therapy in normal mouse skin.

BACKGROUND: Light fractionation with a 2-h dark interval increases the efficacy of topical aminolevulinic acid (ALA) photodynamic therapy (PDT). Hexyl-aminolevulinate (HAL) is the hexyl ester of ALA. Both HAL and ALA lead to protoporphyrin IX (PpIX) accumulation in endothelial cells and to vascular effects, which are important for light fractionation. We investigated light fractionation for HAL-PDT in a mouse skin model and compared this with ALA. METHODS: Three illumination schemes were studied: (a) 100 J cm(-2) in a single illumination; (b) 50+50 J cm(-2) in a twofold illumination; (c) a small first light fraction until 50% of PpIX was photobleached (ca. 3 J cm(-2)), followed by 97 J cm(-2) 2h later. PpIX fluorescence was measured continuously during illumination. Efficacy was evaluated by daily visual skin damage scoring up to 7 days after PDT. RESULTS: Light fractionation showed a trend towards increased efficacy for HAL-PDT. Both the initial PpIX synthesis and the PpIX resynthesis during the dark interval were higher for ALA, but these were not correlated with efficacy. Single HAL-PDT was more effective than single ALA-PDT. Photobleaching rates of HAL and ALA were similar indicating similar biodistributions at depth. CONCLUSION: Our results provide evidence to support that light fractionation may be beneficial for HAL-PDT. We are cautious because we found only a non-significant increase in response. However, combining our results with literature data suggest that the illumination scheme may be further optimized for HAL-PDT to potentially enhance the effect of light fractionation.