Background Imiquimod has shown to be efficacious in basal cell carcinoma and actinic keratosis, but with therapeutic burden such as strong skin reactions and long treatment periods. Objectives To compare the safety and efficacy of different application frequencies of the new laser skin microporation device combined with topical 5% imiquimod and the standard use of imiquimod alone for the treatment of actinic keratosis and basal cell carcinomas. Methods In two prospective, randomised, dose finding, pilot studies for basal cell carcinoma and actinic keratosis, we used either imiquimod alone according to the approved dosage (control arm 1) or on microporated skin for 1x/2x/3x/week (arm 1-4), respectively. Strength of imiquimod-induced skin reactions at day 20 (study end) represented the primary endpoint. Secondary study parameters comprised the development and strength of skin erythema including crusting and erosions during the whole study, clearence at day 20 and tolerability as well as safety parameters. Results In both studies (patients/lesions treated and analysed: basal cell carcinoma 16/20 and 13/15; actinic keratosis 18/21 and 13/15) the combined laser and imiquimod therapy led to stronger skin erythema, crusting and erosion levels in the early study phase. Well tolerated without new safety signals, total clearence rates (arms 2-4/control arm 1) were 78%/75% (basal cell carcinoma) and 77%/50% (actinic keratosis), respectively. Conclusions We suggest to call this new treatment approach laser dynamic therapy. Based on our data, the most appropriate laser and imiquimod application frequency might be 2x/week (2-3 shots each at 3 pulses) with a suggested time to heal of 3 weeks. Further studies with larger patient cohorts are needed to substantiate our data. J O U R N A L O F D E R M A T O L O G I C A L R E S E A R C H A N D T H E R A P Y ISSN NO: 2471-2175 RESEARCH DOI : 10.14302/issn.2471-2175.jdrt-14-552 Corresponding Author: Robert Strohal, MD; Professor of Dermatology, Head of Dep. Dept. of Dermatology and Venereology; Federal Academic Teaching Hospital Feldkirch Carinagasse 45-47, 6800 Feldkirch; Austria Telephone: +43/5522/303.1200,-9121; Mobile: +43/664/1142140; Fax: +43/5522/303-7547 Robert.strohal@lkhf.at Running title: Skin microporation and imiquimod in actinic keratosis and basal cell carcinoma

BACKGROUND:Specific immunotherapy via the subcutaneous or oral route is associated with local and, in some cases, systemic side effects and suffers from low patient compliance. Due to its unique immunological features, the skin represents a promising target tissue for effective and painless treatment of type I allergy. The current study was performed to compare the efficacy of transcutaneous immunotherapy via laser-generated micropores to subcutaneous injection. METHODS:BALB/c mice were sensitized by intraperitoneal injection of recombinant grass pollen allergen Phl p 5 together with alum. Subsequently, lung inflammation was induced by repeated intranasal challenge. During the treatment phase, adjuvant-free Phl p 5 was applied in solution to microporated skin or was subcutaneously injected. Lung function and cellular infiltration; Phl p 5-specific serum levels of IgG1, IgG2a, and IgE; and cytokine levels in bronchoalveolar lavage fluids as well as in supernatants of splenocyte cultures were assessed. RESULTS:Both therapeutic approaches reduced airway hyperresponsiveness and leukocyte infiltration into the lungs. Whereas subcutaneous immunotherapy induced a systemic increase in Th2-associated cytokine secretion, transcutaneous application revealed a general downregulation of Th1/Th2/Th17 responses. Successful therapy was associated with induction of IgG2a and an increase in FOXP3+ CD4+ T cells. CONCLUSIONS:Transcutaneous immunotherapy via laser microporation is equally efficient compared with conventional subcutaneous treatment but avoids therapy-associated boosting of systemic Th2 immunity. Immunotherapy via laser-microporated skin combines a painless application route with the high efficacy known from subcutaneous injections and therefore represents a promising alternative to established forms of immunotherapy.

Pantec Biosolutions AG presents a portable fractional ablative laser system based on a miniaturized diode pumped Er:YAG laser. The system can operate at repetition rates up to 500 Hz and has an incorporated beam deflection unit. It is smaller, lighter and cost efficient compared to systems based on lamp pumped Er: YAG lasers and incorporates a skin layer detection to guarantee precise control of the microporation process. The pulse parameters enable a variety of applications in dermatology and in general medicine, as demonstrated by first results on transdermal drug delivery of FSH (follicle stimulating hormone).

A high power, diode-pumped Er:YAG laser platform is presented, which has been integrated into devices for soft as well as hard tissue applications. The highly efficient side pumping by qcw laser diodes allows easy power scalability and miniaturization proven by a portable fractional ablative laser system based on a 2 W laser. The high repetition rate of up to 1 kHz combined with low energy pulses generates high thermal impact and consequently strong skin rejuvenation. Furthermore a laser for hard tissue applications with up to 15 W average output power at repetition rates up to 2 kHz is presented. The good beam quality allows coupling to 200 μm fibers and the variable pulse duration of 1 to 200 μs ensures precise and fast treatments.

The objectives of this study were to investigate a novel laser microporation technology ( P.L.E.A.S.E. Painless Laser Epidermal System) and to determine the effect of pore number and depth on the rate and extent of drug delivery across the skin. In addition, the micropores were visualized by confocal laser scanning microscopy and histological studies were used to determine the effect of laser fluence (energy applied per unit area) on pore depth. Porcine ear skin was used as the membrane for both the pore characterization and drug transport studies. Confocal images in the XY-plane revealed that the pores were typically 150–200 μm in diameter. Histological sections confirmed that fluence could be used to effectively control pore depth — low energy application (4.53 and 13.59 J/cm2) resulted in selective removal of the stratum corneum (20–30 μm), intermediate energies (e.g., 22.65 J/cm2) produced pores that penetrated the viable epidermis (60–100 μm) and higher application energies created pores that reached the dermis (> 150–200 μm). The effects of pore number and pore depth on molecular transport were quantified by comparing lidocaine delivery kinetics across intact and porated skin samples. After 24 h, cumulative skin permeation of lidocaine with 0 (control), 150, 300, 450 and 900 pores was 107 ± 46, 774 ± 110, 1400 ± 344, 1653 ± 437 and 1811 ± 642 µg/cm2, respectively; there was no statistically significant difference between 300, 450 and 900 pore data — probably due to the effect of drug depletion since > 50% of the applied dose was delivered. Importantly, increasing fluence did not produce a statistically significant increase in lidocaine permeation; after 24 h, cumulative lidocaine permeation was 1180 ± 448, 1350 ± 445, 1240 ± 483 and 1653 ± 436 µg/cm2 at fluences of 22.65, 45.3, 90.6 and 135.9 J/cm2, respectively. Thus, shallow pores were equally effective in delivering lidocaine. Increasing lidocaine concentration in the formulation from 10 to 25 mg/ml produced a corresponding increase in permeation (at 24 h, 1650 ± 437 and 4005 ± 1389 µg/cm2, respectively). The validity of the porcine skin model was confirmed as transport across porcine and human skins was shown to be statistically equivalent (at 24 h, 1811 ± 642 and 2663 ± 208 µg/cm2, respectively). The clinical potential of the technology and its capacity to provide significantly faster delivery than conventional passive administration was demonstrated in short duration experiments involving application of a marketed lidocaine cream (LMX4®) to laser-porated skin; after only 5 min of formulation application, lidocaine deposition was measured at 61.3 ± 7.5 µg/cm2. In conclusion, the results demonstrate the ability of P.L.E.A.S.E.® (i) to create well-defined conduits in the skin, (ii) to provide a controlled enhancement of transdermal transport and (iii) to enable improvement in both the rate and extent of drug delivery.

Protection induced by acellular vaccines can be short, requiring novel immunization strategies. Objectives of this study were to evaluate safety and capacity of a recombinant pertussis toxin (PTgen) -coated Viaskin® epicutaneous patch to recall memory responses in healthy adults.This double-blind, placebo-controlled randomized trial (Phase I) assessed the safety and immunogenicity of PTgen administered on days 0 and 14 to healthy adults using Viaskin® patches applied directly or after epidermal laser-based skin preparation. Patch administration was followed by Boostrix®dTpa on day 42. Antibodies were assessed at days 0, 14, 28, 42 and 70.Among 102 volunteers enrolled, 80 received Viaskin-PT (Viaskin-PT 25 μg (n = 25), Viaskin-PT 50 μg (n = 25), laser + Viaskin-PT 25 μg (n = 5), laser + Viaskin-PT 50 μg (n = 25)), Viaskin-placebo (n = 10) or laser + Viaskin-placebo (n = 2). Incidence of adverse events was similar across groups (any local event: 21/25 (84.0%), 24/25 (96.0%), 4/5 (80.0%), 24/25 (96.0%), 8/10 (80.0%), 10/12 (83.0%), respectively). Direct application induced no detectable response. On day 42, PT-IgG geometric mean concentrations were significantly higher following laser + Viaskin-PT 25 μg and 50 μg (139.87 (95% CI 87.30–224.10) and 121.76 (95% CI 95.04–156.00), respectively), than laser + Viaskin-placebo (59.49, 95% CI 39.37–89.90). Seroresponse rates were higher following laser + Viaskin-PT 25 μg (4/5 (80.0%), 95% CI 28.4–99.5) and 50 μg (22/25 (88.0%), 95% CI 68.8–97.5) than laser + Viaskin-placebo (0/12 (0.0%), 95% CI 0.0–26.5).Viaskin-PT applied after laser-based epidermal skin preparation showed encouraging safety and immunogenicity results: anti-PT booster responses were not inferior to those elicited by Boostrix®dTpa. This study is registered at ClinicalTrials.gov (NCT 03035370) and was funded by DBV Technologies.