Outcomes of Inhaled Amikacin-Containing Multidrug Regimens for Mycobacterium abscessus Pulmonary Disease.

ABSTRACT

BACKGROUND: Mycobacterium abscessus pulmonary disease (M abscessus-PD) is challenging to treat because of its resistance to antibiotics. RESEARCH QUESTION What are the outcomes of treatment-naive patients with M abscessus-PD treated with inhaled amikacin-containing multidrug regimens? STUDY DESIGN AND METHODS: We identified 82 treatment-naive patients with M abscessus-PD from a prospective observational cohort treated with regimens containing inhaled amikacin with or without clofazimine between March 2015 and June 2018 (ClinicalTrials.gov identifier NCT00970801). During the initial phase, all patients received IV amikacin, imipenem (or cefoxitin), and oral azithromycin. Oral clofazimine was added in cases of (1) M abscessus subspecies abscessus (here M abscessus) or (2) M abscessus subspecies massiliense (here M massiliense) with cavitary lesions. During the continuation phase, amikacin was changed from an injectional to inhalational form. RESULTS: Of 82 patients, 46 (56%) had M massiliense-PD and 36 (44%) had M abscessus-PD. Among 59 patients with nodular bronchiectatic disease (72%), 23 of 59 had a concurrent cavitary lesion. The remaining 23 patients (28%) had fibrocavitary disease. Twelve months after treatment initiation, cure was achieved in 53 patients (65%) 42 of 46 patients (91%) with M massiliense-PD and 11 of 36 patients (31%) with M abscessus-PD (P < .001). Symptomatic and radiologic improvements were observed in 72 patients (88%) and 64 patients (78%), respectively, with significantly greater improvement in patients with M massiliense-PD (symptom improvement, 96% vs 78% [P = .047]; improvement on CT scanning, 93% vs 61% [P = .002]). INTERPRETATION: Inhaled amikacin with or without clofazimine in the regimen provides favorable treatment outcomes in M massiliense-PD. However, more effective treatments are needed for M abscessus-PD.