Anifrolumab—A Potential New Systemic Sclerosis Treatment

Background/Objectives: Systemic sclerosis (SSc) is a rare autoimmune disease characterized by chronic inflammation, microvascular injury, and fibrosis of the skin and internal organs. Although there are therapies, there is a need for treatments targeting early pathogenic mechanisms. Type I interferons (IFN-I) are key mediators linking immune dysregulation to vascular and fibrotic damage in SSc. This review summarizes the current evidence supporting IFN-I blockade with anifrolumab as a novel therapeutic strategy. Methods: A narrative review of preclinical, translational, and emerging clinical studies was conducted to evaluate the role of IFN-I signaling in SSc and the therapeutic potential of anifrolumab. Particular focus was placed on the IFN signature, upregulation of interferon-stimulated genes (ISGs), and the association with disease activity and organ involvement. Results: Anifrolumab, a fully human monoclonal antibody targeting the IFN-I receptor subunit 1 (IFNAR1), inhibits the signaling of all IFN-I isoforms, suppressing downstream JAK–STAT activation and ISG expression. Mechanistic data suggest that IFNAR blockade modulates vascular injury, immune activation, and fibrosis. Early findings and ongoing trials indicate potential benefits, particularly in patients with a high IFN signature or rapidly progressive cutaneous and cardiac disease. Conclusions: The current evidence supports IFN-I pathway inhibition as a promising approach in SSc. Ongoing trials will help to determine the clinical efficacy, safety, and optimal patient selection for anifrolumab in this rare but severe disease.