Exploratory Study on the Efficacy and Safety of Nebulized hUC-MSC-Derived Exosomes for Non-Acute CIP

Study Objectives The primary objective of Phase II is to evaluate the percentage of lesion resolution on high-resolution computed tomography (HRCT) as assessed by independent blinded reviewers. Secondary objectives include evaluating effects on pulmonary function, exercise capacity, dyspnea, quality of life, and oxygenation, as well as comprehensively assessing safety and tolerability. Phase I focuses on determining safety, dose-limiting toxicities (DLT), and recommended Phase II dose. Study Population The target population is patients with non-acute CIP aged 18-75 years with histologically confirmed malignancy. Key inclusion criteria include: At least one cycle of immune checkpoint inhibitor (ICI) therapy and development of Grade 3-4 CIP per NCCN Guidelines V1.2025 Standard glucocorticoid treatment for ≥4 weeks, with current dose \<20 mg/day prednisone equivalent or discontinued Persistent residual CIP lesions on HRCT without significant improvement in the past 4 weeks ECOG PS 0-1 and stable primary tumor for ≥6 months Effective contraception during the study and for 360 days after last dosing Key exclusion criteria include: Concomitant use of pirfenidone, nintedanib, or other antifibrotic agents Inability to perform pulmonary function tests or tolerate nebulization Unresolved interstitial lung disease from radiotherapy or targeted therapy Severe cardiac, hepatic, renal, or hematological dysfunction Organ transplantation, severe immunodeficiency, active epilepsy, or severe allergic status Other investigational drug use within 28 days Study Design and Sample Size Phase I: 9-18 subjects, open-label, dose-escalation design to evaluate DLT and safety Phase II: 40 subjects, randomized, double-blind, placebo-controlled design Study Endpoints Phase I Primary Endpoints Incidence of DLT Incidence of adverse events (AE) and serious adverse events (SAE) Phase II Primary Endpoint Percentage of HRCT lesion resolution at Weeks 4, 12, and 24, assessed by independent blinded