Savara Inc., a society that deals with orphan lung diseases, announced in March the start of a phase 2a clinical trial, OPTIMA, for the evaluation of its main candidate Molgradex, a recombinant inhalation formulation of the stimulating factor of the colony of human macrophage granulocytes (GM-CSF), for the treatment of non-tuberculous mycobacterial pulmonary infection (NTM). Molgradex is currently being studied in a phase 3 global clinical study, IMPALA, for the treatment of autoimmune lung alveolar proteinosis (PAP). The NTM lung infection represents a remarkable therapeutic challenge thanks to the unique ability of these bacteria to circumvent the normal mechanisms of killing of alveolar macrophages. Scientific research in various animal models, including GM-CSF knock-out mice, has shown that GM-CSF plays an important role in the activation process of macrophages to kill mycobacteria, with or without the simultaneous use of antibiotics. Many efforts are concentrated against Mycobacterium abscessus (M. abscessus), being one of the most resistant to antibiotics and some reports of clinical cases demonstrate the role of GM-CSF. OPTIMA is a clinical open, uncontrolled, multicentre, phase 2a study on 30 subjects (≥18 years of age) with persistent NTM lung infection. OPTIMA is aimed at subjects with chronic infection with M. abscessus or Mycobacterium avium complex (MAC), with refractory antibiotic infection or intolerance to standard ones. The study will include a 24-week treatment period and a 12-week follow-up period. The primary endpoint will be the conversion of the sputum culture, defined as at least three consecutive sputum samples without NTM growth.