PO:25:079 | Anifrolumab in refractory dermatomyositis: a case report

Chiara Calabrese¹, Corrado Campochiaro^1|2, Giacomo De Luca ^1|2, Veronica Batani¹, Marco Matucci-Cerinic^1|2, Lorenzo Dagna ^1|2 | ¹Dipartimento di Reumatologia e Scienze Mediche, ASST Centro Specialistico Ortopedico Traumatologico Gaetano Pini-CTO Milano; ²Università degli Studi di Milano, Dipartimento di Fisiopatologia Medico-Chirurgica e Trapianti, Milano, Italy

Background. Dermatomyositis is a rare autoimmune disease characterized by multisystem involvement. Treatment can be challenging, particularly in refractory cases unresponsive to conventional therapies, for which standardized management protocols are lacking. An increased activation of the type I interferon (IFN-I) pathway has been demonstrated in patients with dermatomyositis, providing a rationale for the use of anifrolumab, a monoclonal antibody targeting the IFN-I receptor, already approved for systemic lupus erythematosus and particularly effective on cutaneous manifestations.

Materials and Methods We report the case of a 57-year-old woman with anti–TIF-1γ–positive dermatomyositis, diagnosed in May 2024, with a history of high-grade serous ovarian carcinoma treated with surgery and chemotherapy (August 2024–February 2025). At rheumatologic evaluation in March 2025, the disease was clinically active with extensive cutaneous involvement, including heliotrope rash, malar rash without sparing of the nasolabial folds, diffuse erythema of the limbs, back, and décolleté, palmar and facial telangiectasias, and distal ulcers on the hands and right ear (Cutaneous Dermatomyositis Disease Area and Severity Index – CDASI: Activity 29, Damage 5). The patient also reported disabling myalgia and progressive gait impairment (Medical Research Council scale – MRC 45/60). Previous treatments (steroids, hydroxychloroquine, mycophenolate mofetil, intravenous immunoglobulins, and anakinra) were ineffective or discontinued due to adverse events, while rituximab was considered inappropriate because of her oncologic history. Therefore, monthly intravenous anifrolumab therapy was initiated.

Results. After two months of anifrolumab treatment, marked clinical improvement was observed in both cutaneous (CDASI Activity 12; Damage 4) (Figure 1A–C, Figure 2A–B) and muscular domains (MRC 50/60), with no adverse events reported, including serious infections. The improvement allowed progressive corticosteroid tapering (from 25 mg to 5 mg of prednisone) without elevation of muscle damage markers or disease flare.

Conclusions. This case suggests that anifrolumab may represent a promising therapeutic option for refractory dermatomyositis. Controlled studies are warranted to confirm its efficacy and safety in this indication.