Treatment outcomes of clofazimine-containing regimens in Mycobacterium avium complex pulmonary disease: a retrospective study from two European reference centers

Background Mycobacterium avium complex (MAC) is the major cause of nontuberculous mycobacterial pulmonary disease (NTM-PD) and clofazimine is increasingly used as an adjunctive therapy. We evaluated outcomes and tolerability of clofazimine-containing regimens in MAC-PD across two European centers. Methods Retrospective observational study of MAC-PD treated from 2020 to 2024 in Milan (Italy) and Nijmegen (Netherlands). Diagnosis followed ATS/ERS/ESCMID/IDSA and BTS criteria. Clinical, radiological and microbiological data were collected. Outcomes included treatment completion, mortality and adverse drug events (ADEs). Results A total of 90 cases were included (74% female, median age 68 years). Disease patterns differed by center, with nodular-bronchiectatic forms prevailing in Milan and fibrocavitary disease in Nijmegen. Clofazimine discontinuation due to ADEs occurred in 14%. Overall, 74% completed therapy and mortality was 8%. Conclusion Clofazimine-containing regimens showed acceptable safety and favorable outcomes in diverse European MAC-PD populations, supporting its role as a valuable adjunct in MAC-PD management.