PD-L1 Inhibitor Rechallenge After Immunotherapy-Related Pneumonitis in Patients With Lung Cancer

This multicenter observational study will evaluate the safety and effectiveness of immune checkpoint inhibitor rechallenge in adults with lung cancer who developed checkpoint inhibitor pneumonitis. The study will use both retrospective medical records and prospective follow-up data. Participants will not be assigned to any treatment by the study protocol. All treatment decisions will be made by the treating physicians as part of routine clinical care. Participants will be classified into three groups according to their subsequent treatment: rechallenge with a PD-L1 inhibitor, rechallenge with a PD-1 inhibitor, or no immune checkpoint inhibitor rechallenge. The primary outcome is the recurrence of checkpoint inhibitor pneumonitis after rechallenge. Secondary outcomes include immune-related adverse events, progression-free survival, overall survival, objective response rate, and disease control rate at 24 weeks. Approximately 150 participants will be included across multiple study centers in China.

Inclusion Criteria: 1. Age 18 years or older. 2. Histologically confirmed lung cancer. 3. Development of checkpoint inhibitor pneumonitis after treatment with immune checkpoint inhibitor. 4. Eastern Cooperative Oncology Group performance status of 0, 1, or 2. 5. Provision of written informed consent. Exclusion Criteria: 1. Incomplete clinical information required for the study analyses. 2. Considered unsuitable for participation by the investigator.