Safety and Efficacy of Clofazimine as an Alternative for Rifampicin in Mycobacterium avium Complex Pulmonary Disease Treatment: Outcomes of a Randomized Trial

Abstract

BackgroundRetrospective studies have suggested clofazimine as an alternative for rifampicin in MAC-PD treatment. Research questionIs 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? Study design and MethodsIn this single centre non-blinded clinical trial, we randomly assigned adult patients with MAC-PD in a 1:1 ratio to receive rifampicin or clofazimine as adjuncts to an ethambutol-macrolide backbone. The primary outcome was sputum culture conversion after six months of treatment. ResultsForty patients were assigned to receive either rifampicin (n=19) or clofazimine (n=21) ) next to ethambutol and a macrolide. After 6 months of treatment, both arms showed similar percentages of sputum culture conversion based on intention to treat analysis: 58% (11/19) for rifampicin; 62% (13/21) for clofazimine. Study discontinuation, mainly due to adverse events, was equal in both arms (26% vs 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% vs 37%; p=0.012), while arthralgia was more frequent in the rifampicin arm (37% vs 5%; p=0.011). No difference in the frequency of QTc prolongation was seen between both groups. InterpretationA clofazimine-ethambutol-macrolide regimen showed similar results to the standard rifampicin-ethambutol-macrolide regimen and should be considered in the treatment of MAC-PD. The frequency of adverse events was similar in both arms, but their nature was different. Individual patients characteristics and possible drug-drug interactions should be taken into consideration when choosing an antibiotic regimen for MAC-PD.