Tre-P-01 - Concomitant use of steroids or phototherapy with chlormethine gel among patients with mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL): a real-world evidence study

Abstract

<h3>Background:</h3> Chlormethine gel (also known as mechlorethamine) is a skin-directed therapy approved for the treatment of early-stage mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL). In previously published data, topical steroids and phototherapy were found to be commonly used by patients treated with chlormethine gel. Post-hoc analyses on the PROVe study were carried out to describe the specific treatment sequence and timing of these concomitant therapies and chlormethine gel in a real-world setting among MF-CTCL patients. <h3>Methods:</h3> Data analyzed derives from the observational PROVe study using US-based registry of MF-CTCL patients treated with chlormethine gel and enrolled across 46 centers between March 2015 and October 2018. Patients were followed for up to 2 years after chlormethine gel initiation. Due to the observational nature of the study, patients had visits at irregular intervals. Information on patient demographics, medical history, clinical characteristics, ongoing treatments for MF-CTCL and response were collected. Concomitant use of chlormethine gel with topical steroids or phototherapy were assessed using treatment start and stop dates recorded in the registry, and descriptive statistics were calculated. <h3>Results:</h3> A total of 298 eligible patients were analyzed with a mean ± standard deviation (SD) age of 61±13 years. Approximately 60% were males, 69% had Stage IA/IB and their duration of MF-CTCL was 4.8±6.5 years at chlormethine gel initiation. A total of 186 (85%) reported concomitant use of topical steroids with chlormethine gel during the study period. Of these 186 patients, 138 (74%) patients were already using steroids prior to chlormethine gel initiation, 14 (8%) started chlormethine gel and steroids on same day and the remaining 34 (18%) added steroids later. A total of 81 (27%) reported concomitant use of phototherapy with chlormethine gel during the study period. Of these 81 patients, 67 (83%) patients were already on phototherapy prior to chlormethine gel initiation and the remaining 14 (17%) initiated phototherapy later. <h3>Conclusions:</h3> Among the patients with concomitant therapies, the majority had started steroids or phototherapy and then added chlormethine gel. These observations suggest that in real life settings, combination treatments are standard practice as physicians expect improved outcomes with an acceptable tolerability profile.