Long-term outcomes in five patients with autoimmune pulmonary alveolar proteinosis treated with molgramostim inhalation solution.

Autoimmune pulmonary alveolar proteinosis (aPAP), which accounts for >90% of all cases of PAP, is a rare lung disease mediated by granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies that block GM-CSF signalling, leading to reduced surfactant clearance causing abnormal accumulation of alveolar surfactant and impaired gas exchange [1-3]. The current standard of care for aPAP is whole-lung lavage (WLL), which is invasive, resource intensive, carries procedural risk, does not address the underlying cause of disease and often must be repeated regularly [4]. Hence, there is a therapeutical need to address the underlying pathophysiology of the disease. Studies have explored inhaled GM-CSF augmentation as a primary treatment for aPAP [5-12]. In this real-world case series, we present the beneficial long-term effects of molgramostim inhalation solution, an investigational, recombinant GM-CSF, in five aPAP patients with therapeutic disease challenges.