Clofazimine effective alternative to rifampicin for treating Mycobacterium avium lung disease: Study

Retrospective studies have suggested clofazimine as an alternative to rifampicin in MAC-PD treatment. Sanne M.H. Zweijpfenning, Radboudumc Center for Infectious Diseases, HB Nijmegen, The Netherlands, and colleagues sought to determine if a treatment regimen consisting of clofazimine-ethambutol-macrolide non-inferior to the standard treatment regimen (rifampicin-ethambutol-macrolide) in the treatment of M.avium complex pulmonary disease in a single centre non-blinded clinical trial.

The study, published in the CHEST journal, revealed that the clofazimine-ethambutol-macrolide regimen showed similar results to the standard rifampicin-ethambutol-macrolide regimen and should be considered in the MAC-PD treatment. In both the arms, the frequency of adverse events was similar but their nature was different.

Adult patients with MAC-PD were randomly assigned in a ratio of 1:1 to receive clofazimine (n=21) or rifampicin (n=19) as an adjunct to an ethambutol-macrolide backbone. The study's primary outcome was sputum culture conversion following six months of treatment.

The study led to the following findings:

• After six months of treatment, both arms showed similar percentages of sputum culture conversion based on intention-to-treat analysis: 58% for rifampicin; and 62% for clofazimine.
• Study discontinuation, mainly due to adverse events, was equal in both arms (26% versus 33%).
• Based on an on-treatment analysis sputum culture conversion after 6 months of treatment was 79% in both groups.
• In the clofazimine arm, diarrhoea was more prevalent (76% versus 37%), while arthralgia was more frequent in the rifampicin arm (37% versus 5%).
• No difference in the frequency of QTc prolongation was seen between both groups.

"A clofazimine-ethambutol-macrolide regimen is noninferior to the standard rifampicin-ethambutol-macrolide regimen and should be considered in the treatment of M.avium complex pulmonary disease," the researchers wrote.

"Possible drug-drug interactions and individual patient characteristics should be taken into consideration when choosing an antibiotic regimen for MAC-PD," they concluded.

Reference:

Zweijpfenning, S. M., Aarnoutse, R., Boeree, M. J., Magis-Escurra, C., Stemkens, R., Geurts, B., Van Ingen, J., & Hoefsloot, W. (2023). Clofazimine is a safe and effective alternative for rifampicin in Mycobacterium avium complex pulmonary disease treatment – outcomes of a randomized trial. CHEST. https://doi.org/10.1016/j.chest.2023.11.038