Effectiveness of Amikacin Liposome Inhalation Suspension for Refractory Mycobacterium avium Complex Pulmonary Disease at 6 months post initiation

Abstract Background Amikacin liposome inhalation suspension (ALIS) improved sputum culture conversion rate at 6 months for patients with refractory Mycobacterium avium complex pulmonary disease (MAC-PD) in an international phase 3 trial. Patient characteristics and chest high-resolution CT (HRCT) findings associated with ALIS effectiveness are poorly documented. Objective This study aimed to clarify ALIS effectiveness for refractory MAC-PD at 6 months, elucidating associated patient characteristics and chest CT findings. Methods We reviewed medical records of 12 patients with refractory MAC-PD for whom ALIS treatment was initiated at Toho University Omori Medical Center from November 2021 through September 2022. All patients demonstrated treatment persistence for at least 3 months. They were divided into culture conversion and non-conversion groups using sputum culture conversion status after 6-month ALIS treatment initiation. Clinical and radiological characteristics were compared. Results Altogether, 7 of the 12 patients (58.3%) achieved sputum culture conversion within 6 months. The culture conversion group had shorter pre-ALIS initiation treatment duration [21 months (16–25) vs. 62 months (32–69); p = 0.045]; lower cavitary lesion incidence on HRCT (28.6% vs. 100%; p = 0.028); and fewer clarithromycin (CLA)-resistant strains [0/7 (0%) vs. 3/5 (60%); p = 0.045]. Chest HRCT findings improved in 2 of 7 (28.6%) and 2 of 5 (40%) patients in the culture conversion and non-conversion groups, respectively. Conclusion ALIS facilitated sputum culture conversion within 6 months in 58.3% of patients with refractory MAC-PD. Effectiveness was potentially higher for CLA-susceptible strains and patients with fewer cavitary lesions. Improved CT findings after ALIS did not always correspond to sputum culture conversion.