Maintenance and Concomitant Therapy Use with Chlormethine Gel Among Patients with Stage IA/IB Mycosis Fungoides-Type Cutaneous T-Cell Lymphoma (MF-CTCL): A Real-World Evidence Study

Introduction Chlormethine (CL) gel is a skin-directed therapy approved for treatment of stage IA/IB mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL) in the USA. MF-CTCL has a chronic clinical course, requiring long-term maintenance therapy with one or more therapies. This analysis describes real-world patterns of maintenance therapy and use of concomitant therapy with CL gel among patients with stage IA/IB MF-CTCL. Methods In a US-based registry, MF-CTCL patients treated with CL gel were enrolled between 3/2015 and 10/2018 across 46 centers and followed for up to 2 years. Patient demographics, clinical characteristics, CL gel treatment patterns, concomitant treatments, clinical response, and adverse events (AEs) were collected from medical records. Descriptive statistics are reported. Results Of the 206 patients with stage IA/IB MF-CTCL, 58.7% were male, and average age was 60.7 years with 4.6 years since diagnosis. Topical steroids, phototherapy, and topical retinoids were used concomitantly with CL gel in 62.6%, 26.2%, and 6.3% of patients, respectively. Most concomitant therapies (up to 85%) were started before CL gel initiation and, in about half of the cases (up to 57%), were used concurrently for ≥ 12 months. Overall, 158 (76.7%) patients experienced partial response (PR) and 144 continued with maintenance therapy. After achieving PR, most patients (74.3%) kept the same maintenance therapy schedule, most commonly once daily. Of patients who had any skin-related AE (31.6%) or skin-related AEs associated with CL gel (28.2%), nearly half experienced CL gel treatment interruption and ~40% had a dosing reduction. The observed real-world treatment patterns were concordant with National Comprehensive Cancer Network (NCCN) guidelines. Conclusion The study results suggest that continuing CL gel maintenance therapy and combining treatments with CL gel are common practice in the real-world setting, with most maintained on a stable dosing schedule. Careful management of AEs may help patients maintain long-term optimal dosing with less treatment interruptions and dosing reductions.