Inclusion Criteria

• Diagnosis of pulmonary nontuberculous mycobacterial lung disease in accordance with the 2007 ATS/IDSA criteria
• Has evidence of nodular bronchiectasis and/or cavitary disease by chest computed tomography (CT)
• History of chronic infection with either Mycobacterium avium complex or Mycobacterium abscessus or mixed infection with both species
  • Defined as at least 2 documented positive cultures in the prior 2 years, of which at least one was obtained in the 6 months prior to screening
• Positive sputum culture obtained at screening visit with either Mycobacterium avium complex or Mycobacterium abscessus or mixed infection with one dominant species
• Receiving ATS/IDSA guidelines-based treatment regimen defined as adherent to a multi-drug regimen for at least 6 months prior to screening with persistently positive mycobacterial cultures
• Ability to produce at least 3 mL of sputum or be willing to undergo an induction that produces at least 3 mL of sputum for clinical evaluation
• Female of childbearing potential agrees to practice an acceptable method of birth control (e.g., abstinence, hormonal or barrier methods, partner sterilization, or IUD)

Exclusion Criteria

• Forced Expiratory Volume in 1 second (FEV1) <30% of predicted at screening
• Presence of any clinically significant cardiac disease as determined by Investigator
  •  QTc> 450 msec for males or QTc> 470 msec for females
• Hemoptysis of ≥ 60 mL in a 24 hour period within 4 weeks prior to screening
• Active pulmonary malignancy (primary or metastatic) 
• Any malignancy requiring chemotherapy or radiation therapy within one year prior to screening or anticipated during the study period
• Active allergic bronchopulmonary mycosis or any other condition requiring systemic steroids at a dose ≥ equivalent of 10 mg/day of prednisone within 3 months prior to screening or anticipated during the study period
• Pulmonary tuberculosis requiring treatment or treated within 2 years prior to screening
• History of lung transplantation
• Hypersensitivity to aminoglycosides
• Any change study day 1
• Evidence of biliary cirrhosis with portal hypertension
• History of daily, continuous oxygen supplementation
• Smoking tobacco or any substance within 6 months prior to screening or anticipated inability to refrain from smoking throughout the study