Efficacy, Safety, and Maintenance Use of Topical Bexarotene in Early‐Stage Mycosis Fungoides: A Single‐Center Retrospective Real‐World Study

Topical bexarotene 1% gel is an approved skin-directed treatment for refractory or persistent stage IA-IB cutaneous T-cell lymphoma, but real-world evidence in mycosis fungoides (MF), particularly regarding maintenance use after complete response, remains limited. We retrospectively reviewed 56 patients with histopathologically and immunohistochemically confirmed, previously treated stage IA-IB MF who received topical bexarotene between 2009 and 2022. Clinical response, post-treatment biopsy findings, adverse events, maintenance therapy, and relapse outcomes were analyzed. The cohort included 31 women and 25 men; 42 patients (75.0%) had stage IA and 14 (25.0%) had stage IB disease. Complete response (CR) was achieved in 20 patients (35.7%) and partial response in 15 (26.8%), yielding an overall response rate of 62.5%. Overall response was higher in stage IA than in stage IB disease (73.8% vs. 28.6%; p = 0.003) and in T1a than in T2a disease (77.1% vs. 36.4%; p = 0.044). All biopsied complete responders showed no MF-compatible histology. Adverse events were exclusively local and manageable. Among 18 evaluable complete responders, relapse occurred in 15 (83.3%). Median time to relapse was longer with maintenance topical bexarotene than without maintenance (45 vs. 30 weeks; p = 0.039). Topical bexarotene appears effective and well tolerated in previously treated stage IA-IB MF, with greatest benefit in limited patch-stage disease. Maintenance use after CR may delay relapse, but this exploratory finding requires prospective validation.