Immune-Related Adverse Events due to Concomitant Use of Immune Checkpoint Inhibitors and Chinese Herbal Medicines: A Study Based on a Japanese Adverse Event Database.

Abstract

Fatigue is an immune-related adverse event (irAE) associated with immune checkpoint inhibitors (ICIs) used for cancer treatment. Chinese herbal medicines (Ho-zai) are used to treat cancer-related fatigue. However, no interactions between ICIs and Ho-zai have been reported. Herein, we investigated the risk of irAEs associated with the concomitant use of ICIs and Ho-zai. We extracted data of patients who used ICI and Ho-zai from the Japanese Adverse Event Reporting Database. The proportional reporting ratio (PRR) was calculated for patients using ICI, Ho-zai, or both. We focused on cases of interstitial lung disease (ILD) and colitis, which were among the most severe cases of irAEs among these patients. The shrinkage method used by the World Health Organization-Uppsala Monitoring Center was used to detect the interactions. Of the 799,670 patients in the database, 77,219, 2060, and 92 were using ICIs, Ho-zai, and combination treatment, respectively. The ILD and colitis groups included 39,388 and 17,522 patients, respectively. ILD signals were detected for both ICIs and Ho-zai. There were 24 cases of patients treated with concomitant ICIs and Ho-zai who developed ILD. For all combinations of all ICIs and all Ho-zai, Ω025 was negative, which suggested no ILD-related interactions. Colitis signals were detected for ICIs except for atezolizumab, avelumab, and durvalumab. There were eight patients treated with concomitant ICI and Ho-zai who developed colitis. For all combinations of all ICIs and all Ho-zai, Ω025 was negative, which suggested no colitis-related interactions. To our knowledge, this is the first study to investigate interactions between ICIs and Ho-zai. Signals were detected for ILD in both ICI and Ho-zai groups, and colitis in the ICI group. However, the combined use of these treatments did not increase the risk of irAEs.