Rheumatic and musculoskeletal adverse events with immune checkpoint inhibitors: Data from the United States food and drug administration adverse event reporting system

Background: Despite their efficacy, immune checkpoint inhibitors (ICIs) can cause significant immune-related adverse events (irAEs). Rheumatic and musculoskeletal irAEs can be serious and adversely affect the quality of life. The full spectrum of irAEs is still emerging, and to represent and better understand their scope, we evaluated the United States Food and Drug Administration Adverse Event Reporting System (FAERS) database. Methods: We used AERSMine, an open-access web application to mine FAERS data across 11,919,342 patients from 2011 (first quarter) to 2018 (fourth quarter). Measures of disproportionality were calculated using well-established pharmacovigilance metrics, proportional reporting ratios, and safety signals (information component), in patients receiving ICI. Results: We analyzed 63,979 cancer patients for reports of ICI-associated AEs. Eighty-two percent of these reports were in relation with anti-PD-1 inhibitors. Rates of rheumatic and musculoskeletal AEs were higher in men and in patients >65 years of age. Several statistically significant AEs were identified, most in relation with PD-1 inhibitors. AEs with the highest number of reports included arthralgia (n = 1062), followed by myalgia (n = 532), myositis (n = 438), arthritis (n = 403), and rhabdomyolysis (n = 230). Novel AEs affecting the skeleton included compression fractures, fractures at various skeletal sites (rib, thoracic vertebral, and humerus), osteonecrosis of the jaw, osteitis, and osteomyelitis. Conclusion: A wide spectrum of rheumatic and musculoskeletal AE signals were detected within the FAERS data which may signify the emerging trends of irAEs post approval of ICI. Additional research to explore mechanisms and identify optimal management strategies of these AEs is warranted.