Off-label Use of Nemolizumab to Address Pruritic Skin Disease: A Case Series in Dermatomyositis Patients.

BACKGROUND

Dermatomyositis (DM) is an inflammatory myopathy frequently accompanied by pruritus, which can be severe, treatment-refractory, and associated with significant impairment in quality of life. Interleukin-31 (IL-31) has emerged as a key mediator of itch and has been implicated in the inflammatory pathways of dermatomyositis, suggesting a potential therapeutic role for IL-31 receptor blockade.

METHODS

We conducted a retrospective case series of 5 patients with dermatomyositis who were treated with nemolizumab for moderate-to-severe pruritus at Mount Sinai Dermatology between June 2025 and November 2025. Clinical response was assessed using patient-reported itch severity measured by numeric rating scale (NRS) scores and the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). Adverse events and short-term outcomes were recorded. Nemolizumab dosed according to approved atopic dermatitis/prurigo nodularis regimens (60 mg SC loading dose followed by 30 mg every 4 wk).

RESULTS

All patients experienced improvement in pruritus following nemolizumab initiation, with a reduction in itch observed in all cases and anecdotal improvement reported as early as 2 days in select patients. Improvements in cutaneous disease activity, as measured by CDASI, were also observed. Nemolizumab was well tolerated, with no serious adverse events.

CONCLUSIONS

In this case series, nemolizumab was associated with rapid improvement in pruritus and cutaneous disease activity in patients with dermatomyositis, including those with longstanding or treatment-refractory disease. These findings support further investigation of IL-31 blockade as a targeted antipruritic strategy and cutaneous disease improvement in dermatomyositis through larger, prospective studies.