Spanish-Portuguese consensus statement on use of daylight-mediated photodynamic therapy with methyl aminolevulinate in the treatment of actinic keratosis

Home- vs clinic-based daylight photodynamic therapy with 5-aminolevulinic acid nanoemulsion (BF-200 ALA) for actinic keratosis: A randomized, single-blind, prospective study

BACKGROUND

Daylight photodynamic therapy (DL-PDT) has become one of the most effective treatments for the resolution of actinic keratosis (AK) of Olsen grade 1 and 2. Generally, PDT it is carried out in a clinic setting, which involves the patient's and their caregivers commuting to the hospital as well as a significant use of resources to carry it out within the clinic setting.

OBJECTIVES

To determine the efficacy and safety of a home-based treatment of AK with DL-PDT with the BF-200 ALA gel compared to a clinic-based setting.

METHODS

The study was performed as a randomized, single-center, non-inferiority clinical trial with two parallel groups. 9 patients received one clinic-based DL-PDT (group 1) and 11 patients received one session of home-based DL-PDT (group 2). The primary endpoints were the mean AK clearance per patient and the total AK lesion clearance rate 12 weeks after treatment. The secondary endpoints were the number of remaining AKs and new AKs appearing in the treatment field 12 weeks after one PDT session. The pain during and 24 h after PDT as well as the local skin reactions were also assessed.

RESULTS

The overall reduction of AK lesions per patient was similar in both groups with one PDT session. An overall AK clearance per patient of 10 ± 4.33 for group 1 versus 9.73 ± 2.9 for group 2 without statistically significant differences (p = 0.868). Regarding the clearance rate, although it was slightly higher in group 2 (71.58 ± 22.51 vs 82.1 ± 11.13), the analysis did not show statistically significant differences. The mild pain recorded during the treatment course and the mild local skin reactions were similar in both groups. Patient satisfaction was high for both groups without statistically significant differences.

CONCLUSION

Self-performed home-based DL-PDT with BF-200 ALA gel is as effective as the one performed in a clinic-based setting, with a comparable safety profile, high levels of patient satisfaction and with advantages for the patients and their caregivers that can enhance patient´s adherence to the treatment.

Fully home-based methyl aminolevulinate daylight photodynamic therapy for actinic keratosis of the face or scalp: A real life open study

Methyl aminolevulinate daylight photodynamic therapy (MAL DL-PDT) is highly efficacious for the treatment of nonhyperkeratotic actinic keratosis (AK), even when partially performed at home. To evaluate the long-term effectiveness, safety, and patient-reported outcomes of MAL DL-PDT performed completely by the patient in real life conditions. An open prospective study was conducted in Spain among patients diagnosed with at least five AK lesions on the face or the scalp. Patients received instruction and information in infographic format to perform MAL DL-PDT at home. All had been treated with 30% urea daily for 7 days before the day of MAL DL-PDT. Meteorological conditions on the day of the treatment and adverse effects were recorded. Patients underwent follow-up, and a second session of home-based MAL DL-PDT if deemed necessary, 3, 6, and 12 months after the initial treatment session. The study population consisted of 22 patients (19 men and three women, mean [standard deviation, SD] age, 72.05 [6.96] years). A complete response was observed in 47.7% of AK lesions at 3 months (p < 0.001) and 65.9% (n = 199) at 12 months (p < 0.001). Olsen grade II lesions showed the highest rate of response (76.07% at 12 months). The mean (SD) actinic keratosis area and severity index score decreased significantly from 4.99 (2.43) at baseline to 2.33 (1.01) at 12 months (p = 0.0234). Adverse effects were mild and expected. A majority of patients were "satisfied" or "very satisfied" with the treatment instruction provided (90.9%) and the treatment outcome (72.7%). MAL DL-PDT can be applied at home like any other topical treatment for AK. Our results indicate good long-term effectiveness, a high level of patient satisfaction, and no significant side effects.

Combined versus conventional photodynamic therapy with 5-aminolaevulinic acid nanoemulsion (BF-200 ALA) for actinic keratosis: A randomized, single-blind, prospective study

BACKGROUND

Photodynamic therapy (PDT) has become one of the most effective therapies for the treatment of actinic keratosis, allowing the removal of more than one lesion in a single session. However, the pain sustained by the patient during treatment and local skin reactions can limit its use.

OBJECTIVES

To determine the efficacy and safety of combined PDT (daylight PDT followed by conventional PDT) vs conventional PDT 12 weeks after treatment.

METHODS

The study was performed as a randomized, single-center, non-inferiority clinical trial with two parallel groups. A total of 51 patients with grade I and II AKs on the scalp or face were randomized. Twenty-five patients received one session of combined PDT (combPDT), and 26 patients received one session of conventional PDT (cPDT). The primary endpoint was the reduction of AKs, 12 weeks after treatment. The secondary endpoint was the reduction in pain and local skin reaction.

RESULTS

The reduction rate of grade I and II AKs was similar in combPDT and cPDT, showing no statistically significant differences between both groups, 76.67% vs 86.63% [P = .094] and 80.48% vs 83.08% [P = .679], respectively. However, pain was significantly lower in the combPDT group (2.56 vs 5, P < .01), as were local skin reactions.

CONCLUSIONS

CombPDT has proven to be as effective as cPDT for the treatment of grade I and II AKs located on the scalp and face. Furthermore, combPDT has been shown to be considerably more tolerable than cPDT, causing only mild local skin reactions.

Photodynamic therapy regulates fate of cancer stem cells through reactive oxygen species

Photodynamic therapy (PDT) is an effective and promising cancer treatment. PDT directly generates reactive oxygen species (ROS) through photochemical reactions. This oxygen-dependent exogenous ROS has anti-cancer stem cell (CSC) effect. In addition, PDT may also increase ROS production by altering metabolism, endoplasmic reticulum stress, or potential of mitochondrial membrane. It is known that the half-life of ROS in PDT is short, with high reactivity and limited diffusion distance. Therefore, the main targeting position of PDT is often the subcellular localization of photosensitizers, which is helpful for us to explain how PDT affects CSC characteristics, including differentiation, self-renewal, apoptosis, autophagy, and immunogenicity. Broadly speaking, excess ROS will damage the redox system and cause oxidative damage to molecules such as DNA, change mitochondrial permeability, activate unfolded protein response, autophagy, and CSC resting state. Therefore, understanding the molecular mechanism by which ROS affect CSCs is beneficial to improve the efficiency of PDT and prevent tumor recurrence and metastasis. In this article, we review the effects of two types of photochemical reactions on PDT, the metabolic processes, and the biological effects of ROS in different subcellular locations on CSCs.

Daylight photodynamic therapy for prevention of new actinic keratosis and keratinocyte carcinomas in organ transplants. A cryotherapy-controlled randomized clinical trial

BACKGROUND

Organ transplant recipients (OTR) have a higher risk of actinic keratosis (AK) and keratinocyte carcinomas (KC). There are no clinical trials assessing the effectiveness of daylight photodynamic therapy (DPDT) to prevent new AK and KC in OTR.

OBJECTIVES

To determine whether repeated treatments of field cancerization with DPDT are effective in preventing new AK and KC in OTR.

METHODS

A randomized, intra-subject controlled, evaluator-blind, split-face and/or scalp trial, from April 2016 to October 2018. Participants were OTR older than 18 years, 1-year posttransplant, with at least 5 AK on each hemi-face/hemi-scalp. One side received six field treatments with DPDT: two sessions 15 days apart at baseline, two at 3 months and two at 9 months after baseline. Control side received lesion-directed treatment with cryotherapy (double freeze-thaw) at baseline, 3 and 9 months. Total number of lesions (AK and KC) at 21 months, number of new AK and KC at 3, 9, 15 and 21 months and treatment preferences were analysed.

RESULTS

Of 24 men included, 23 were analysed at 3 months; and 21, at 9, 15 and 21 months. Mean (SD) age was 69.8 years (9.2). The total number of lesions at 21 months was 4.7 (4.3) for DPDT and 5.8 (5.0) for control side; P = 0.09. DPDT showed significantly lower means [SD] of new lesions compared to control side at 3 months (4.2 [3.4] vs. 6.8 [4.8]; P < 0.001), 9 months (3.0 [3.3] vs. 4.3 [3.4]; P = 0.04) and 15 months (3.0 [4.6] vs. 4.8 [5.0]; P = 0.02), and non-significant at 21 months (3.7 [3.5] vs. 5.0 [4.5]; P = 0.06). Most participants preferred DPDT.

CONCLUSION

DPDT showed potential effectiveness in preventing new AK and KC in OTR by consecutive treatments of field cancerization. The preference for DPDT could facilitate adherence to the long-term treatment necessary in these patients.

Sequential daylight photodynamic therapy and ingenol mebutate versus 2 sessions of daylight photodynamic therapy for the treatment of actinic keratosis: An observational, prospective, comparative study

BACKGROUND

Field-directed therapy, such as daylight-photodynamic therapy (DL-PDT) or ingenol mebutate (IM), is indicated for multiple actinic keratosis (AK) lesions located on contiguous areas of skin with significant sun damage.

OBJECTIVE

To compare the efficacy of sequential DL-PDT and IM treatment with that of 2 sessions of DL-PDT in AK patients.

MATERIAL AND METHODS

For this observational, multicenter, prospective study we recruited patients for whom DL-PDT was indicated for the treatment of AK lesions (grades I and II) located on the head. After 1 month of follow-up those who did not achieve a satisfactory clinical response received either a second session of DL-PDT or were treated with IM. Epidemiological and clinical data were collected and analyzed.

RESULTS

Forty-three patients were enrolled (39 male, 4 female). The mean (standard deviation, SD) age was 78 (7.84) years, and the mean (SD) number of AK lesions per patient was 9.58 (1.16). After the first session of DL-PDT, 27 patients (62.8%) required further treatment: 13 (48.1%) received a second session of DL-PDT and 14 (51.9%) were treated with IM. After 1 year of follow-up, lesion clearance rates were higher in patients who received 2 sessions of DL-PDT than those treated with sequential DL-PDT plus IM (75.2%vs 54.6%, p = 0.0013). Local skin reactions were more frequent in the DL-PDT plus IM group than the group treated with 2 sessions of DL-PDT (p = 0.0245).

CONCLUSIONS

The combination of DL-PDT plus IM appears to have no synergistic effect in the treatment of field cancerization, and offers no benefits over 2 sessions of DL-PDT monotherapy, although both combinations produced high lesion clearance rates, a good safety profile, excellent cosmetic outcome, and good patient satisfaction.

Daylight Photodynamic Therapy for Actinic Keratoses

Topical photodynamic therapy (PDT) using daylight is effective in the treatment of actinic keratoses (AKs), offering the potential for treatment of large fields such as full face and balding scalp, but with minimal therapy-associated pain. Comparison with conventional PDT indicates similar efficacy for thin and moderate-thickness AKs, but with significantly less discomfort/pain, driving a patient preference for daylight-mediated PDT (DL-PDT) compared with conventional PDT using high-intensity office/hospital-based light sources. Treatment protocol involves the application of a photosensitizing agent without occlusion and subsequent exposure to ambient daylight within 30 min, with patients exposed to daylight for 1.5-2.0 h. Pivotal randomized controlled trials in Europe and Australia have confirmed the efficacy of methyl aminolevulinic acid (MAL) DL-PDT in comparison with conventional MAL-PDT for mild and moderate-thickness lesions on the face and scalp. Initial clearance rates of 70-89% are reported. DL-PDT using a nanoemulsion aminolevulinic acid (ALA) has recently been shown to be at least as effective as MAL DL-PDT in treating mild and moderate-thickness AKs. DL-PDT may offer a better-tolerated method for treating patients with extensive AK disease. There is emerging literature on the potential for field PDT to reduce the number of new AKs developing, potentially preventing/slowing skin cancer development. Conventional PDT remains established as a therapy for Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas (BCCs), and AKs. The evidence for the use of DL-PDT beyond AK is limited, although has been reported in actinic cheilitis, superficial BCC, and acne and cutaneous leishmaniasis. There is emerging interest in combination therapy for AK, using one or more field therapies such as DL-PDT as an option to complement with localized treatment for residual lesions. We review current recommendations and consider the appropriate place for DL-PDT in our treatment armamentarium.

A randomized, intraindividual, non-inferiority, Phase III study comparing daylight photodynamic therapy with BF-200 ALA gel and MAL cream for the treatment of actinic keratosis

Background

The most effective treatment modality for actinic keratosis (AK) is photodynamic therapy (PDT). Major obstacles of PDT are the need of a special illumination device and pain accompanying the illumination. These issues may be overcome by replacing an artificial high‐power light source with natural daylight for more extended illumination at lower light doses.

Objective

To determine whether BF‐200 ALA (a nanoemulsion gel containing 7.8% 5‐aminolaevulinic acid) is non‐inferior to MAL (a cream containing 16% methyl‐aminolaevulinate) in the treatment of mild‐to‐moderate AK with daylight PDT (dPDT). Non‐inferiority of the primary efficacy variable (total lesion clearance rate per patient's side 12 weeks after PDT) is established if the mean response for BF‐200 ALA is no worse than for MAL, within a statistical margin of Δ = −12.5%.

Methods

The study was performed as an intraindividual comparison with 52 patients in seven centres in Germany and Spain. Each patient received one dPDT. Results include clinical endpoints as well as 1‐year follow‐up results.

Results

Twelve weeks after a single dPDT, 79.8% of the AK lesions treated with BF‐200 ALA gel and 76.5% of the lesions treated with MAL cream were completely cleared. The median of differences was 0.0 with a one‐sided 97.5% CI of 0.0, establishing non‐inferiority (P < 0.0001). Results for secondary efficacy parameters were in line with the primary outcome. Recurrence rates 1 year after the treatment were 19.9% for lesions treated with BF‐200 ALA and 31.6% for lesions treated with MAL. Adverse reactions including pain were mostly mild and transient and identical to those previously described for dPDT.

Conclusion

Daylight PDT of AK with BF‐200 ALA is well‐tolerated and non‐inferior to MAL/dPDT. The study demonstrates a trend towards higher efficacies after 3 months and significantly lower recurrence rates after 1 year follow‐up.

Comparison of Blue and White Lamp Light with Sunlight for Daylight-Mediated, 5-ALA Photodynamic Therapy, in vivo

Daylight-mediated photodynamic therapy (d-PDT) as a treatment for actinic keratosis (AK) is an increasingly common technique due to a significant reduction in pain, leading to better patient tolerability. While past studies have looked at different light sources and delivery methods, this study strives to provide equivalent PpIX-weighted light doses with the hypothesis that artificial light sources could be equally as effective as natural sunlight if their PpIX-weighted fluences were equalized. Normal mouse skin was used as the model to compare blue LED light, metal halide white light and natural sunlight, with minimal incubation time between topical ALA application and the onset of light delivery. A total PpIX-weighted fluence of 20 J_eff cm^-2 was delivered over 2 h, and the efficacy of response was quantified using three acute bioassays for PDT damage: PpIX photobleaching, Stat3 crosslinking and quantitative histopathology. These bioassays indicated blue light was slightly inferior to both sunlight and white light, but that the latter two were not significantly different. The results suggest that metal halide white light could be a reasonable alternative to daylight PDT, which should allow a more controlled treatment that is independent of weather and yet should have similar response rates with limited pain during treatment.

Bactericidal Effect of Photodynamic Therapy, Alone or in Combination with Mupirocin or Linezolid, on Staphylococcus aureus

Antibiotic treatments frequently fail due to the development of antibiotic resistance, underscoring the need for new treatment strategies. Antimicrobial photodynamic therapy (aPDT) could constitute an alternative therapy. In bacterial suspensions of Staphylococcus aureus, which is commonly implicated in cutaneous and mucosal infections, we evaluated the in vitro efficacy of aPDT, using the photosensitizing agents rose bengal (RB) or methylene blue (MB), alone or combined with the antibiotics mupirocin (MU) or linezolid (LN). RB or MB, at concentrations ranging from 0.03 to 10 μg/ml, were added to S. aureus ATCC 29213 suspensions containing >10⁸ cells/ml, in the absence or presence of MU or LN (1 or 10 μg/ml). Suspensions were irradiated with a white metal halide (λ 420–700 nm) or light-emitting diode lamp (λ 515 and λ 625 nm), and the number of viable bacteria quantified by counting colony-forming units (CFU) on blood agar. Addition of either antibiotic had no significant effect on the number of CFU/ml. By contrast, RB-aPDT and MB-aPDT effectively inactivated S. aureus, as evidenced by a 6 log₁₀ reduction in bacterial growth. In the presence of MU or LN, the same 6 log₁₀ reduction was observed in response to aPDT, but was achieved using significantly lower concentrations of the photosensitizers RB or MB. In conclusion, the combination of MU or LN and RB/MB-aPDT appears to exert a synergistic bactericidal effect against S. aureus in vitro.

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.

A double-blind randomized controlled trial to assess the efficacy of daylight photodynamic therapy with methyl-aminolevulinate vs. Placebo and daylight in patients with facial photodamage

BACKGROUND

Daylight PDT (dPDT) is easy to use and does not require light equipment. Such therapy has been exhaustively proved to be successful in the treatment of actinic keratosis, but its use in skin photodamage remains unclear.

OBJECTIVE

To evaluate dPDT's efficacy in skin facial photodamage.

PATIENTS AND METHODS

This was a parallel-group double-blind, randomized placebo-controlled trial. Sixty participants with symmetric facial photodamage were allocated to topical methyl aminolevulinate (MAL) and daylight vs. matching placebo and daylight. Primary outcome was global photodamage improvement/failure 1 month after the third session. Secondary outcomes included: pain evaluation; specific photodamage severity scores; sun irradiance quantification and Skindex-29 scores. Adverse events were also investigated.

RESULTS

Primary analysis included all randomized patients. All patients sun-exposed for 120min in 3 sessions. The risk of failure was lower in the MAL-dPDT group than in the placebo plus daylight group (RR: 0.18; 95% CI: 0.08-0.41). Mean solar irradiance (W/m(2)) during the first, second and third sessions was 480.82, 430.07 and 435.84, respectively. Items 5 and 14 of Skindex-29 in the MAL-dPDT group showed statistical significant differences. Two patients in the MAL-dPDT group had serious and non-serious events not directly related to the product.

CONCLUSION

dPDT with MAL was un-painful, effective and safe for the treatment of facial photodamage. Herpes simplex prophylaxis should be considered before sessions.