Background: The use of immune checkpoint inhibitors (ICIs) for advanced cancer is increasing, particularly in combination withchemotherapy. However, previous studies have focused on immune-related adverse events (irAEs) in specific organs, with limited re-search on combination therapy. Objective: We aimed to detect signals of adverse drug reaction (ADR) in both ICIs plus chemotherapy and ICIs alone compared to chemotherapy. Methods: We investigated individual case safety reports (ICSRs) between 2014 and 2022using Korea Institute of Drug Safety and Risk Management Korean Adverse Event Reporting System database (KIDS KAERS DB(2304A0076)). We defined adverse events (AEs) and drugs using MedDRA and the national drug code directory provided by the Min-istry of Food and Drug Safety. To detect signals, we performed disproportionality analysis using indices of reporting odds ratio (ROR) and information component (IC). Results: We identified 206,959 ICSRs in the KIDS KAERS DB, of which 5,154 contained ICIs and 201,805 were for chemotherapy. Compared to chemotherapy, radiation pneumonitis (ROR, 2313.6; IC, 5.4), hyperthyroidism (ROR, 53.4; IC, 4.2), and eczema (ROR,18.3; IC, 3.4) were detected as signals for ICIs. For ICIs with chemotherapy, additional signals including heart failure (ROR 9.65; IC 2.45), proteinuria (ROR 28.67; IC 4.16), and urinary tract infections (ROR 3.46; IC 1.03) were detected. Conclusion The study highlights an essential signal of ADRs associated with ICIs, both alone and in combination therapy, with conditions such as hyperthyroidism, hypothyroidism, and pneumonitis. These AEs should be monitored in clinical settings.

Background: Hypersensitivity pneumonitis (HP) is a condition with an uncertain global incidence, and information on its diagnosis and management is limited. This study aimed to address these knowledge gaps. Methods: This study utilized customized claims data from the Health Insurance Review and Assessment Service (HIRA) in South Korea from January 2010, to December 2021. Patients with HP were identified based on the diagnosis code (International Classification of Diseases, 10th Revision, J67) between 2011 and 2020. Incident HP cases were defined as new HP claims, excluding those with claims in the previous year. The study examined various factors such as age, sex, comorbidities, diagnostic methods, and treatment patterns. Additionally, multivariate logistic regression analysis was performed to identify risk factors associated with treatment initiation. Results: A total of 8,678 HP incident cases were confirmed, with age- and sex-adjusted annual incidence rates ranging from 1.14/100,000 in 2020 to 2.16/100,000 in 2012. The mean age of patients with incident HP was 52 years, with a higher incidence observed among males. Additionally, the most common comorbidity was asthma. Bronchoscopy was performed on 16.9% of patients, and 25.4% of patients did not receive treatment within 1 year of diagnosis. Among those who received treatment, prednisone was the most used systemic steroid, and azathioprine was the most commonly used second-line immunosuppressant.Factors associated with treatment initiation included the female sex, having asthma or gastroesophageal reflux disease (GERD), and undergoing bronchoscopy. Conclusion This study provides valuable insights into the incidence, diagnosis, and treatment patterns of HP in South Korea using nationwide medical claims data.