Safety, Tolerability, Pharmacokinetics and Efficacy of SPR720 for the Treatment of Patients With Mycobacterium Avium Complex (MAC) Pulmonary Disease

Inclusion Criteria: * Has a diagnosis of NTM-PD due to MAC * Had at least 1 prior positive culture (sputum or bronchoalveolar lavage) positive for MAC in the previous 6 months * Has an induced sputum culture at screening positive for MAC by at least one of the following methods performed by the microbiology laboratory: quantitative culture on solid agar or growth on liquid media (MGIT) * Is either treatment naïve and has not received any prior treatment for MAC, OR if previously treated for MAC, has culture evidence of persistent, recurrent, or relapsed disease and has been off therapy for at least 6 months * In the opinion of the Investigator, is ready to initiate treatment (treatment naïve) or reinitiate treatment (previously treated) within the next 3 months, and for whom a delay, in order to participate in a placebo-controlled clinical trial, is considered reasonable and clinically acceptable * Had clinical signs and symptoms within the 6 weeks before the date of consent that are consistent with NTM-PD with at least two of the following: 1. chronic cough 2. fatigue 3. frequent throat clearing 4. shortness of breath (dyspnea) 5. coughing up of blood (hemoptysis) 6. excessive mucus (sputum) production 7. fever 8. night sweats 9. loss of appetite 10. unintended weight loss 11. wheezing 12. chest pain * Has a measured forced expiratory volume in 1 second (% predicted FEV1) ≥30% on pulmonary function test within 3 months prior to consent * Has a chest radiograph (CXR) or computed tomography (CT) scan within 6 months prior to consent with findings consistent with NTM-PD. If no CXR or CT scan is available, a CXR or CT scan should be performed at screening to confirm eligibility. * Other inclusion criteria per protocol Exclusion Criteria: * Has disseminated or extrapulmonary NTM * Has end-stage NTM-PD or treatment-refractory NTM-PD and is unlikely to respond to protocol-specified SOC treatment * Had isolation on sputum cultures of any species of Mycobacterium other than a species included in MAC within the past 6 months * Had prior isolation of MAC with macrolide resistance * Has received any systemic (oral or IV) or inhaled antibiotic with activity against MAC between consent and randomization * Has a potentially confounding underlying pulmonary disease, including but not limited to cystic fibrosis, active pulmonary malignancy (primary or metastatic), NTM-hypersensitivity disease pneumoconiosis, or another advanced lung disease with a % predicted FEV1\<30% * Other exclusion criteria per protocol