Rheumatic Adverse Events Linked to Immune Checkpoint Inhibitor Therapy for Cancer
The prevalence of rheumatic immune-related adverse events in 524 patients with cancer who received immune checkpoint inhibitors was 6.6%, according to a single-center observational study published in Annals of the Rheumatic Diseases (online November 16, 2017; doi:10.1136/annrheumdis-2017-21225).
“Since immune checkpoint inhibitors (ICIs) are used with increasing frequency, knowledge of rheumatic immune-related adverse events and their management is of major interest,” wrote researchers from the Centre Hospitalier Universitaire in France. “All patients were responsive either to low-to-moderate doses of prednisone or symptomatic therapies and did not require ICI discontinuation.”
All but one of the rheumatic immune-related adverse events involved anti-programmed cell death protein 1(PD-1)/PD-1 ligand 1(PD-L1) antibodies, the study found. The median drug exposure time was 70 days.
Patients who developed musculoskeletal symptoms were referred to the department of rheumatology for consultation. Immune-related adverse events presented in one of two ways, researchers reported: inflammatory arthritis (3.8%) that mimicked rheumatoid arthritis, polymyalgia rheumatica, or psoriatic arthritis, and noninflammatory musculoskeletal conditions (2.8%).
Glucocorticoids were used to treat 19 patients. Two patients also received methotrexate. Nonsteroidal anti-inflammatory drugs, analgesics, and/or physical therapy were used to manage noninflammatory complaints.
With the exception of one patient, ICI treatment continued despite rheumatic immune-related adverse events. Overall, patients who experienced rheumatic side effects had an 85.7% tumor response rate to the checkpoint inhibitor, while patients who did not experience rheumatic side effects had a tumor response rate of just 35.3%.
The difference in tumor response “might be related, in part, to the fact that treatment was continued in all but one patient,” the authors wrote.
“[S]o far,” they added, “the main hypothesis is that the occurrence of immune-related adverse events could be the signal of a well-activated immune reaction leading to an efficient and durable antitumor response.”—Jolynn Tumolo