Clinical development and management of adverse events associated with FGFR inhibitors

Approved fibroblast growth factor receptor (FGFR) inhibitors include erdafitinib, pemigatinib, and futibatinib. We review the most common toxicities associated with FGFR inhibitors and provide practical advice regarding their management. Hyperphosphatemia can be managed with careful monitoring, dose reduction or interruption, a prophylactic low-phosphate diet, and phosphate-lowering therapy. Ocular adverse events (AEs) are managed by withholding or adjusting the dose of the FGFR inhibitor. Dermatologic AEs include alopecia, which can be managed with minoxidil, and dry skin, which can be treated with moisturizers. Hand-foot syndrome can be prevented by lifestyle changes and managed with moisturizing creams, urea, or salicylic acid. Among gastrointestinal AEs, diarrhea may be managed with loperamide; stomatitis can be managed with baking soda rinses, mucosa-coating agents, and topical anesthetics; and dry mouth may be alleviated with salivary stimulants. Most FGFR inhibitor-associated toxicities are manageable with prophylactic measures and treatments; proactive monitoring is key to ensuring optimal clinical benefits.