Background: Topical skin-directed therapies are used to induce remissions in early-stage mycosis fungoides (MF). They are rarely curative, and responding patients are subject to frequent relapses, emphasizing the need for alternative therapies.Objective. We sought to evaluate the efficacy and tolerability of topical tazarotene 0.1% gel as adjuvant therapy in the treatment of refractory MF lesions.Methods: A total of 20 adult patients with early patch or plaque MF limited to less than 20% body surface area (BSA) involvement whose lesions were either stable or refractory to therapy for at least 8 weeks enrolled in an open-label pilot study. Tazarotene 0.1% gel was applied to MF lesions once daily for 24 weeks. Continued concomitant use of other medications such as low- to mid-potency topical corticosteroids was permitted for the alleviation of skin irritation. Global improvement, overall disease severity, percent BSA involvement, and pruritus were evaluated every 4 weeks. Up to 6 index lesions were followed up for area, plaque elevation, scaling, and erythema scores. Skin biopsy specimens were to be taken at baseline, week 8, and week 24. Evaluable specimens were stained with hematoxylin and eosin, CD8 antibody, and CD45RO antibody.Results: In all, 20 patients enrolled, 19 received treatment, and 16 completed at least 4 weeks of topical treatment. By intent-to-treat analysis, 11 of 19 patients (58%) achieved at least a moderate (>50%) global improvement in BSA, and 35% of 99 index lesions cleared completely. Significant reductions (mean differences) were also found in the median lesional area score (-37, P = .0013), mean plaque elevation score (-.67, P = .016), mean scaling (-0.70, P = .033), and mean erythema score (-1.03, P = .002). Analysis of overall disease also disclosed statistical differences in percent of change for BSA involvement of 22% (P = .013) and of mean overall disease severity score of 34% (P = .011). Of 19 patients, 16 (84%) experienced mild or moderate local skin irritation manifested by peeling, erythema, burning, and tenderness that was managed successfully with topical steroids or reducing the frequency of treatment. Histopathology and immunohistochemistry results showed reductions in lymphocytic infiltrates and percentage of CD45RO(+) lymphocytes, and increases in the percentage of CD8(+) lymphocytes during the course of therapy.Conclusion: In this small pilot study, tazarotene 0.1% gel was a well-tolerated and effective adjuvant topical for the treatment of refractory MF lesions by clinical and histologic assessments.

Background: Lymphomatoid papulosis (LyP) is a clonal T cell proliferation with large cell histology, a chronic course, and an increased risk of lymphoma. Bexarotene (Targretin®) is an RXR-selective retinoid (rexinoid) approved for the cutaneous manifestations of cutaneous T cell lymphoma. Objective: To determine whether bexarotene is effective in treating LyP. Methods: Ten patients with chronic and symptomatic LyP were prospectively treated with oral (n = 3) or topical gel (n = 7) formulations of bexarotene. Results: A favorable response to bexarotene treatment with decreased numbers or duration of lesions was seen in all with objective responses in 8 patients. Conclusions: Bexarotene may be an effective palliative treatment for LyP, warranting further controlled studies.

Basal cell carcinomas are the most common form of skin cancer. Tazarotene is a retinoic acid receptor selective retinoid that upregulates a tumor suppressor, tazarotene-induced gene 3 (TIG-3), in keratinocytes and psoriasis. Expression of TIG-3 in basal cell carcinomas was studied in an opened-label pilot biomarker study of 22 patients with basal cell carcinomas who applied tazarotene 0.1% gel for up to 12 wk prior to excision. Nineteen paired baseline and treated specimens were compared using immunohistochemistry and in situ hybridization. Compared to overlying normal epidermis, TIG-3 protein and mRNA were decreased in 14 and 18 of 19 basal cell carcinomas (74% and 95%), respectively (p < 0.001). Tazarotene treatment was associated with increased TIG-3 protein and mRNA expression in basal cell carcinomas compared to baseline levels (p < or = 0.001 and p = 0.028, respectively). Sixty percent of basal cell carcinomas treated with tazarotene decreased in size by at least 25%. Ten of 19 lesions improved histologically, including three complete responses. There was a correlation between the increased expression of TIG-3 protein and histologic improvement (p = 0.020), suggesting that suppression of TIG-3 may underlie the development of basal cell carcinomas. This association suggests that reversal of TIG-3 expression may help to explain the mechanism of retinoid action in epidermal differentiation and chemoprevention.

Peripheral T-cell lymphomas (PTCLs) are an uncommon and heterogeneous group of well-differentiated, post-thymic T-cell malignancies that can present in the skin as cutaneous T-cell lymphomas. In general, their prognosis is poor, and specific therapy is not well defined. We report the successful treatment of a patient with relapsed, refractory PTCL who after failing 13 standard single and multiple chemotherapy regimens and experimental agents had a dramatic prolonged response to diftitoxin denileukin (ONTAK ® ). This fusion protein, composed of diphtheria toxin coupled to interleukin-2, is approved for cutaneous T-cell lymphomas, including mycosis fungoides, and should be considered for treatment of the rare subset of peripheral T-cell lymphomas.