Effectiveness of narrowband ultraviolet B monotherapy versus combination therapy with systemic agents in patients with early‐stage mycosis fungoides and the association with plaque lesions

Abstract Objective Narrowband ultraviolet B (NB‐UVB) has been recommended as first‐line therapy for early‐stage mycosis fungoides (MF) in international guidelines. NB‐UVB can be used as monotherapy or part of a multimodality treatment regimen. There is limited evidence on the effectiveness and optimal patients of NB‐UVB in combination with systemic therapies in MF. We aimed to assess the effectiveness of the combination versus NB‐UVB monotherapy in early‐stage MF and if plaque lesion status was related to these effects. Methods This observational cohort study included 247 early‐stage MF patients who had received NB‐UVB combined with systemic therapies vs. NB‐UVB monotherapy from 2009 to 2021. The primary outcome was partial or complete response. Overall response rate and median time to response were calculated. Hazard ratios (HRs) were estimated using the Cox model. Results In 139 plaque‐stage patients, the response rate for combination therapy group was higher than that of monotherapy group (79.0% vs. 54.3%, p = 0.006). The adjusted HR for combination therapy compared with NB‐UVB monotherapy was 3.11 (95% CI 1.72–5.63). The combination therapy group also showed shorter time to response (4 vs. 6 months, p = 0.002). In 108 patch‐stage patients, the response rate and time to response in two treatment groups showed no significant difference. There was therefore an observed interaction with patients’ plaque lesion status for the effect size of NB‐UVB combination therapy. No serious adverse events were observed. Conclusions Adding systemic treatments to NB‐UVB did not improve the treatment outcome of patch‐stage patients, but it surpassed NB‐UVB monotherapy for early‐stage patients with plaques.