Can stem cell mist heal lungs damaged by cancer immunotherapy?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Informed consent: Signed written informed consent. * Age and diagnosis: Aged 18-75 years with histologically confirmed malignant tumor. * Treatment history: Received at least one cycle of immune checkpoint inhibitor therapy and developed immune checkpoint inhibitor-related pneumonitis. * Confirmed Grade 3-4 immune checkpoint inhibitor-related pneumonitis (CIP) by clinical evaluation (diagnosis and grading in accordance with the NCCN Guidelines for Management of Immunotherapy-Related Toxicities Version 1.2025), having received standard glucocorticoid therapy for ≥4 weeks, with glucocorticoids either discontinued or tapered to a prednisone-equivalent dose of \<20 mg/day. * Recent HRCT imaging: Persistent residual CIP-related lesions in both lungs, including ground-glass opacity, consolidation, reticular opacity, traction bronchiectasis, and/or honeycombing, involving a large extent of the lung fields; no significant resolution or improvement of these residual lesions on repeated HRCT within the past 4 weeks. * General condition: ECOG PS score 0-1, with stable control of the primary tumor for ≥6 months. * Contraception: Fertile subjects agree to use effective contraception during the study period and for 360 days after the last dose. Exclusion Criteria: * Concomitant medication: Current use of antifibrotic agents such as pirfenidone and nintedanib. * Operational limitation: Inability to cooperate with pulmonary function testing or nebulized inhalation. * History of other pulmonary diseases: Presence of unresolved interstitial lung disease or pulmonary fibrosis induced by targeted therapy, radiotherapy, or other causes. * Severe comorbidities: Including severe cardiac, hepatic, or renal insufficiency, or severe hematological abnormalities. * Specific medical history: Severe neuromuscular disease, history of organ transplantation, active epilepsy, primary or severe acquired/secondary immunodeficiency. * Other factors: Severe allergic constitution, psychiatric disorders, use of other investigational products within 28 days, or any other condition deemed inappropriate by the investigator.