Macitentan in the Treatment of Digital Ulcers in Patients with Systemic Rheumatic Autoimmune Diseases: A National Multicenter Study of 42 Patients

<b>Objective:</b> To evaluate the real-world safety and efficacy of macitentan (MACI) in patients with systemic autoimmune rheumatic diseases (SARDs) and refractory digital ulcers (DUs). <b>Methods:</b> We conducted a retrospective observational study of 42 patients treated with MACI (10 mg/day) on a compassionate-use basis across Spanish reference hospitals. Given the cohort's heterogeneity, a two-step analysis was performed: a global assessment of all patients, followed by a subgroup analysis restricted to those with systemic sclerosis (SSc) or fulfilling very early SSc (VEDOSS) criteria to explore predictors of response. Efficacy was defined as complete healing, partial response, or a lack of response based on physician assessment. Safety was evaluated through analysis of adverse events. <b>Results:</b> In the global cohort, MACI demonstrated a high rate of complete ulcer healing (82.9%) at the 3-month follow-up, with a significant reduction in median ulcer count (<i>p</i> < 0.001). Subgroup analysis within the SSc/VEDOSS cohort (n = 36) revealed that the presence of gastrointestinal involvement (GI) and a higher baseline DUs were significant predictors of a poorer therapeutic response (<i>p</i> = 0.022 and <i>p</i> = 0.028). The drug was well-tolerated; adverse events were infrequent and rarely led to treatment discontinuation. <b>Conclusions:</b> In this real-world refractory population, MACI was associated with rapid DU healing and a favorable safety profile. GI and higher ulcer burden predicted diminished treatment response in SSc patients. These results support the use of MACI as a valuable therapeutic option for severe digital vasculopathy in SARDs, although further prospective studies are warranted to confirm these observations.