Evaluating Response Trends of Chlormethine/Mechlorethamine Gel in Patients With Stage I-IIA Mycosis Fungoides: Analysis of Individual Patient Data From a Randomized Controlled Phase II Study to Facilitate Optimal Treatment Experiences

INTRODUCTION: Chlormethine (CL) gel was approved for treatment of mycosis fungoides based on the pivotal 201 trial (NCT00168064). Data visualization from individual patients is a powerful tool for discovery of hidden treatment trends. Here, we present a post hoc analysis of individual patient data from the pivotal trial to provide a more granular depiction of treatment and response changes over time, with an emphasis on end of treatment status.

MATERIALS AND METHODS: Individual patient response data were plotted over a 12-month treatment period to visualize patient experiences while using CL gel. Responder status was assigned according to end-of-treatment Composite Assessment of Index Lesion Severity (CAILS) score, and patients were classified as early (≤4 months) or late responders based on timing of response. Baseline and active treatment characteristics were compared between early and late responders, and baseline body surface area (BSA) was compared between responders and patients with stable or progressive disease.

RESULTS: Data from 123 patients with baseline and postbaseline results were included. At the end of treatment, 64.2%/55.3% were responders, 30.9%/34.1% had stable disease, and 4.9%/10.6% had progressive disease by CAILS and mSWAT, respectively. Among patients who responded to treatment, 64.6% and 35.4% were early and late responders, respectively. Response pattern analysis also identified patients with an intermittent response or initial progressive disease. Baseline BSA was not associated with responder status. Late responders had longer treatment duration and higher postbaseline plaque elevation, while early responders had a higher frequency of dermatitis.

CONCLUSIONS: Results presented here can facilitate optimal treatment experiences for patients starting CL gel.