Inhaled Molgramostim in Pediatric Participants With Autoimmune Pulmonary Alveolar Proteinosis (aPAP).

This is an interventional open-label, single arm, multi-center study in pediatric subjects, age 6 through 18 years, who are diagnosed with autoimmune pulmonary alveolar proteinosis (aPAP).

The diagnosis of aPAP should be confirmed by an anti-GM-CSF antibody test and a history compatible with PAP based on patient symptoms, high resolution computed tomography of the lung, lung biopsy or bronchoalveolar lavage cytology.

The study consists of a 4-week screening period followed by a 48-week open-label treatment period. After completing the 48-week treatment or early withdrawal, subjects will enter a 4-week safety follow up period. The maximum treatment duration is 48-weeks, and the maximum study period will be 56 weeks. During the trial, lung lavage will be allowed as a rescue treatment in case of worsening of aPAP.

Inclusion criteria

• Be ≥6 and <18 years of age, at the time of signing the informed consent and informed assent (if applicable).
• Have a history of pulmonary alveolar proteinosis, based on examination of a lung biopsy, bronchoalveolar lavage cytology, or a high-resolution computed tomogram of the chest.
• Have a positive serum anti-GM-CSF autoantibody test result confirming aPAP.
• Have a hemoglobin (Hb)-adjusted diffusing capacity of the lung for carbon monoxide (DLCO) ≤70% predicted at Screening.

Exclusion criteria

• Have a diagnosis of hereditary (congenital) or secondary PAP, or a metabolic disorder of surfactant production.
• Have undergone treatment with Lung Lavage (WLL) within 1 month of Baseline