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.

We sought to evaluate the efficacy and tolerability of topical tazarotene 0.1% gel as adjuvant therapy in the treatment of refractory MF lesions.

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.

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.

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.