Adverse Events With Pexidartinib for Patients With Tenosynovial Giant Cell Tumor

According to an analysis of the FDA Adverse Events Reporting System (FAERS) database, the overall safety profile of pexidartinib was generally consistent with the clinical trial findings.

The oral selective colony-stimulating factor 1 receptor (CSF1R) inhibitor pexidartinib was approved by the Food and Drug Administration (FDA) in August of 2019 for the treatment of patients with tenosynovial giant cell tumor (TGCT). However, study authors noted that the clinical trials to define the safety profile of pexidartinib had “limited sample sizes and short follow-up” which could “restrict the detection of rare or delayed adverse events.” According to the prescribing information, the common adverse events with pexidartinib included increased lactate dehydrogenase, increased aspartate aminotransferase, hair color changes, fatigue, increased alanine aminotransferase, decreased neutrophils, increased cholesterol, increased alkaline phosphate, decreased lymphocytes, periorbital edema, decreased hemoglobin, rash, dysgeusia, and decreased phosphate.

This disproportionality analysis used 7,168,342 reports from the FAERS database between the third quarter of 2019 and the second quarter of 2023. After removing duplicate records, there were 668 reports associated with pexidartinib — only those records listing pexidartinib as the “primary suspect” were included. The adverse events identified in the FAERS records closely aligned with those identified in the FDA’s prescribing guidelines. There were also 16 unexpected adverse events, which the study authors noted “expand[ed] upon the existing knowledge derived from pre-marketing clinical trials.” These adverse events not previous documented are: photosensitivity reaction, dysmenorrhea, oligomenorrhea, increased gamma-glutamyltransferase, decreased blood iron, increased blood calcium, prolonged prothrombin time, increased red blood cell distribution width, hepatitis A, seasonal allergies, vanishing bile duct syndrome, cholecystitis, hunger, soft feces, eye color change, and blepharospasm.

Study authors noted that “further prospective clinical trials are warranted to establish a definitive connection between pexidartinib and these newly identified [adverse events].” They also stated, “this study demonstrates the utility of pharmacovigilance databases in complementing clinical trial data for comprehensive drug safety assessment.”

Source:

Lin Y, Zheng X, Lin L, and Chen M. Adverse events of pexidartinib for the treatment of TGCT: A real-world disproportionality analysis using FDA Adverse Event Reporting System database. Front Oncol. Published on August 17, 2025. doi:10.3389/fonc.2025.1594585