Tre-P-02 - Maintenance therapy 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 is a skin-directed therapy approved in US for daily treatment of stage IA/IB mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL). Based on a previous study it has been observed that the alternative treatment schedules and the schedule changes may benefit patients by improving tolerability and response to treatment [1]. This study was carried out to better understand schedule changes before and after achieving partial response (PR) and effect of maintenance therapy i.e., continuing treatment with chlormethine gel after achieving PR, in a real-world setting among MF-CTCL patients. <h3>Methods:</h3> Data is derived from the observational PROVe study using US-based registry of MF-CTCL patients treated with chlormethine gel in combination with other treatments between March 2015 and October 2018. Patients were enrolled across 46 centers and were followed for up to 2 years. Information on patient demographics, clinical characteristics, treatments received for MF-CTCL (including chlormethine gel, topical steroids, phototherapy, radiation therapy, chemotherapy, retinoids and other topical). Responses were collected at enrollment and ongoing visits with no specific visit schedules or clinical assessments due to expected variability in practice patterns. Episodes of treatments with chlormethine gel with start date, stop date and schedule changes were recorded and analyzed. Partial response (PR) was defined as either ≥50% improvement in body surface area (BSA) at least once from gel initiation to the end of study participation or based on the clinical assessment of the physician. For those who achieved PR and following the date of PR, deepening response was defined as achieving either ≥10% additional improvement in BSA (i.e., 60% or more improvement in BSA after achieving 50% improvement at the time of PR) or achieving complete response based on the clinical assessment by physician. Descriptive statistics were reported for schedule changes and maintenance therapy with chlormethine gel. <h3>Results:</h3> Of 298 eligible patients with mean age 61±13 years, 60% were males, and 69% had clinical stage IA/IB. A total of 222 (75%) patients achieved PR following chlormethine gel initiation and during study period. Of these 222, 81% patients did not change their schedule prior to achieving PR and 61% were on a daily schedule immediately prior to PR. Of 203 patients receiving maintenance chlormethine gel post PR, 153 (75%) maintained, 29 (14%) reduced and 24 (12%) increased their dosing schedule in the post-PR period as compared to their schedule prior to PR. Of these 203, 53 (26%) later achieved deepening response. <h3>Conclusions:</h3> 75% of the patients received maintenance therapy with chlormethine gel in combination with other therapies and continued with the same schedule after PR. The study results suggest that continuing maintenance therapy and adjusting chlormethine gel dosing schedule may contribute to deepen treatment responses.