The role of fractional laser‐assisted drug delivery in enhancing the efficacy of topical bimatoprost solution in the treatment of alopecia areata: An intra‐patient comparative randomized clinical trial

Transepidermal drug delivery is a novel therapeutic technique to boost efficacy of topical drugs.


| INTRODUC TI ON
Alopecia areata is a non-cicatricial alopecia that presents as circular-tooval patches of hair loss.It is an autoimmune-based disease in which inflammatory T cells involve peribulbar of hair follicles in anagen and catagen phase, and results in a rapid shift of hair follicles from anagen phase into telogen phase and leading to miniaturization of hair follicles. 1,2wadays, different treatment modalities have been used for alopecia area, including corticosteroid (topical, intralesional, and oral), minoxidil, contact immunotherapy, and systemic immunosuppressive drugs (i.e., cyclosporine, methotrexate, and tofacitinib). 3,4cently, prostaglandins analogues (i.e., bimatoprost and latanoprost) have been used in the treatment of alopecia areata with promising results.Bimatoprost is a prostamide F 2α analogue that prolongs the anagen phase, and leads to more rapid transfer of hair follicles from the telogen phase to the anagen phase.Moreover, it results in an increased size of the dermal papillae and subsequently hair thickness.Previous studies have demonstrated the efficacy of bimatoprostin treatment of eyelash and eyebrow alopecia. 5,6e thick layer of stratum corneum particularly in the scalp region is an important limitative factor for the absorption of topical drugs.Transepidermal drug delivery (TDD), in which various ablative techniques create microthermal channels, is a novel noninvasive therapeutic technique to boost the efficacy of topical drugs due to the enhancement of the penetration of topical drug into the dermis and target organ.][9][10] In this clinical trial we evaluate the efficacy of the combination of FCO 2 laser and bimatoprost compared to bimatoprost alone in the treatment of alopecia areata.

| Study design
This is a prospective single-blinded intra-patient comparative randomized clinical trial on 20 patients with alopecia areata.Inclusion criteria were the age over 18 years old and SALT score less than 25. 11clusion criteria were taking any drugs that can affect hair growth during the past 3 months, immunosuppression, active infection at the treatment's site, any systemic disease or dermatologic disease with positive Koebner test, pregnancy, lactation, previous history of sensitivity to prostaglandin analogues, history of photosensitivity, history of keloid, or hypertrophic scar.

| Treatment protocol
Informed consent forms were obtained from participants prior to enrollment in the study.Then, demographic features of the patients (sex and age), and clinical characteristics of alopecia areata (duration, site, and SALT score) were recorded at the baseline.In each participant two patches were chosen to randomly receive either topical 0.03% bimatoprost or combined FCO 2 laser and topical 0.03% bimatoprost.
Patients were asked to apply topical 0.03% bimatoprost solution (Excillia, IRAN, INOCLON) twice daily for 3 months.Participants were asked not to wash their scalp after application for at least 12 h.
Patients were instructed to avoid sun exposure during application of the topical drug or to wear a protective hat.
Fractional CO 2 laser (SmartXide2; DEKA Laser, Florence, Italy, 10 600 nm) was performed every 2 weeks for 12 weeks.Patients were asked to apply topical anesthetic cream (Xyla-P, Tehran Chemie Pharmaceutical Co.) under occlusion for 45 min before laser.Then the region was cleaned with normal saline and dried.After sterilization with ethanol 70%, FCO 2 laser was done with the following settings: single pulse; spot size = 15 mm; power = 5w; dwell time = 500 ms; smart stack = 3; spacing = 700 μm; density 8.7%; fluence = 4.68j/cm 2 ; energy = 51.6mj.Then immediately after laser, 0.03% bimatoprost solution was applied with a cotton tip applicator on the alopecic patch.Patients were instructed to continue the application of topical bimatoprost solution twice daily for maximum 12 weeks.

| Assessment of efficacy
Photographs were taken from patches by a digital camera (SX410IS, Canon) in monthly intervals.Then response to treatment was evaluated by measurement of SALT score and physician global assessment (PGA) by two blinded dermatologists based on photographs in monthly intervals.Physician global assessment was estimated as follows: excellent (more than 75%), marked (between 50% and 75%), fair (between 25% and 50%), and poor (less than 25%).Percentage of hair regrowth based on SALT score at the end of study or follow-up period (targeted SALT score) was calculated as follows: [SALT score of baseline-targeted SALT score /SALT score baseline] × 100.Moreover, patients' satisfaction was evaluated based on a 7point scale questionnaire in which scores from −3 (marked worsening), −2 (moderated worsening), −1 (mild worsening), 0 (unchanged), +1 (mild improvement), +2 (moderate improvement), and + 3 (marked improvement) at the end of treatment.

| Side effects
Possible side effects such as dryness, peeling, erythema, pain, infection, blister, ecchymosis, and pruritus were recorded in each session.

| Follow-up sessions
Three months after the end of treatment patients were followed up for evaluation of recurrence rate.

| RE SULTS
Twenty patients with a mean age of 35.6 ± 7.9 years were enrolled in the study and completed the clinical trial (Figure 1).Out of 70% were men and most of them (75%) had alopecia in the last 1-5 months.
About half of patients (55%) showed occipital site of involvement (Table 1).Patients' satisfaction was higher in combination group compared to monotherapy group; however, the difference was not statistically significant (p = 0.27).In monotherapy group, 40% of patients mentioned no change in the alopecic patch after treatment; while 50% and 10% of patients mentioned mild and moderate improvement in alopecic patch after treatment, respectively.In combination therapy group, while 15% of patients mentioned no change in the alopecic patch; mild, moderate and marked improvements were mentioned by 65%, 15%, and 5% of patients, respectively.
Side effects including erythema and pruritus were observed in both treatment groups that were transient and decreased after a few days.
There was no significant difference between two treatment groups regarding side effects (p = 0.26).Transient erythema was observed in 5% and 10% of patients in monotherapy and combination therapy groups, respectively.Pruritus was observed in 75% and 50% of patients in monotherapy and combination therapy groups, respectively.
There was no association between the demographic features of the patients with patients' satisfaction, percentage of hair regrowth, SALT score, and side effects.Moreover, there was no significant difference between two groups regarding the recurrence rate (25% and 30% in combination therapy and monotherapy groups, respectively, p = 0.72). of dermis. 12[14][15][16][17] In the current study, for the first time, we investigate the efficacy of laser-assisted drug delivery in augmentation of efficacy of topical bimatoprost solution in alopecia areata.Results of this study revealed that application of bimatoprost either as monotherapy or following FCO 2 laser leads to significant improvement in alopecic patches; however, laser-assisted drug delivery leads to significantly superior outcome in combination therapy group compared to monotherapy group.

| DISCUSS ION
There are a few studies that evaluate efficacy of topical bimatoprost as monotherapy for the treatment of alopecia areata.
Zaher et al in a prospective study showed significant improvement in patients with patchy type alopecia areata with application twice daily of topical bimatoprost 0.03% solution.Mean percentage of reduction in SALT score was 47.85 ± 29.18% at the end of 3-month treatment.Excellent hair growth was observed in 20% of participants. 6Another randomized clinical trial showed significantly superior outcome and faster response with twice daily application of bimatoprost 0.03% solution compared with once daily  in bimatoprost and triamcinolone groups, respectively. 18i et al in one randomized clinical trial investigated efficacy of combined microneedling (every 2 weeks, up to six sessions) with either topical vitamin D or bimatoprost compared to microneedling alone.Significantly higher reduction in SALT score was achieved with combined microneedling and bimatoprost (51.2%) compared to combined microneedling and topical vitamin D (37.5%) or microneedling alone (20%).At the end of treatment, excellent hair regrowth (more than 75%) was achieved significantly higher in bimatoprost group compared with vitamin D group or monotherapy group (36%, 20%, and 4%, respectively). 19 the current study, significantly higher percentage of reduction in SALT score was demonstrated in combined FCO 2 and bimatoprost Limitations of this clinical trial were small number of participants and short duration of follow-up.Moreover, in order to eliminate possibility of spontaneous improvement, it was better to compare the results with untreated cases as control group.Additionally, we did not evaluate the efficacy of treatment via dermoscopy and pathology.

2. 6 |
Statistical analysis SPSS 21(software IBM) was used for statistical analysis.Quantitative and qualitative data were demonstrated by mean (± standard deviation) and percentage, respectively.Comparison of mean SALT score during the treatment was performed using repeated measures ANOVA test.Comparison between two groups regarding the percentage of reduction of the alopecic patch was done by chi-squared test.Friedman test was utilized for evaluation of the degree of patients' satisfaction and adverse effects between two treatment groups.Furthermore, in order to evaluate treatment efficacy during time two ways ANOVA repeated measure was used.Association of quantitative and qualitative data with percentage of hair growth was done by the Kruskal-Wallis test and the Mann-Whitney test, respectively.

Figure 3 )
Figure3).In addition, combination therapy group showed significantly Nowadays, TDD has been used as an innovative popular technique to enhance the delivery of topical medicines, especially for hydrophobic and high molecular weight lipophilic drugs into target organs.In this technique, different ablative modalities (i.e., FCO 2 laser, erbium lasers, ablative radiofrequency, or microneedling) might be used to create microcolumns into 2-3 mm depth of dermis. 12-17Fractional CO 2 laser can stimulate regrowth of hair follicles via inhibition of inflammatory T cells, transferring hair follicles from the telogen phase into the anagen phase (through Wnt 10 b/β-catenin signaling pathway) and restoring hair follicles from stem cells of papillary dermis and hair bulge.It also can promote hair regrowth via increased local blood circulation, employing thermal effects on papillary dermis and enhancement of topical drug absorption into hair follicles through creating microthermal zones into 2-3 mm-depth

TA B L E 2 F I G U R E 2
Efficacy of treatment in both groups based on SALT score.Efficacy of both treatment groups based on SALT score during treatment course and follow-up session.mometasone furoate 0.1% cream (p = 0.001).Percentages of hair regrowth at the end of 3 months in bimatoprost and mometasone group were 48.95 ± 29.18% and 22.4 ± 20.64%, respectively.In addition relapse was significantly higher in mometasone group compared to bimatoprost group (11.8% and 4%).5 Two studies have evaluated efficacy of bimatoprost following microneedling.Hafiz et al in one clinical trial, compared efficacy of combined microneedling with either topical triamcinolone acetonide (10 mg/mL) or topical bimatoprost solution (0.3 mg/mL) for 12 weeks.Mean percentage of improvement was 27.75 ± 42.39% and 24.03 ± 57.38% in bimatoprost and triamcinolone groups, respectively.Percentage of excellent improvement was 20% and 35%

(
46.43 ± 4.35%) that was nearly similar to the result of combined microneedling and bimatoprost in aforementioned study.Whereas monotherapy with bimatoprost revealed lower reduction in SALT score (21.16 ± 4.06%) that was approximately equal to the monotherapy with microneedling in Ali study.19In this study, although fractional ablative laser led to significantly increased efficacy of topical bimatoprost solution; however percentage of excellent improvement was still relatively low in combination group (15%).Therefore, further studies are required to determine the best parameter's settings in ablative fractional laser for maximum penetration of topical drugs into target organs, along with minimum rate of side effects such as prolonged erythema, post inflammatory pigmentation, and scarring.

TA B L E 3
Efficacy of treatment in both groups based on physician global assessment.F I G U R E 3 (A) Male patient with patchy AA in the scalp before treatment.(B) Fifty percent improvement with topical bimatoprost solution (upper patch) alone and 75% improvement with combination of bimatoprost solution and FCO2 laser after 24 weeks (lower patch).

Table 2 showed
that SALT score was reduced significantly

Percentage of hair growth Topical bimatoprost N (%) FCO 2 laser + topical bimatoprost N (%) p value
Combination of FCO 2 laser and topical bimatoprost solution has superior outcome with faster results compared to topical bimatoprost as monotherapy.Moreover, adding FCO 2 laser to treatment does not