Myalgia and Arthralgia Immune-related Adverse Events (irAEs) in Patients With Genitourinary Malignancies Treated With Immune Checkpoint Inhibitors.

ABSTRACT

BACKGROUND: Myalgia and arthralgia immune-related adverse events (irAEs) in patients treated with checkpoint inhibitors (CPIs) present a clinical challenge. We describe the clinical characteristics and treatment of myalgia and arthralgia irAEs in CPI-treated patients with genitourinary (GU) malignancies. PATIENTS AND METHODS: Patients with GU malignancies who were treated with CPIs and developed myalgia and arthralgia irAEs that resulted in interruption or discontinuation of CPI therapy were reviewed. Patient-, disease-, and irAE-related data were collected and analyzed. RESULTS: Twenty-one patients were identified. Eighteen (86%) had renal cell carcinoma; 3 (14%) had urothelial carcinoma. The majority (71%) were male; the median age at diagnosis was 56 years (range, 36-78 years). CPI therapy included anti-programmed death-ligand 1 (29%), anti-programmed cell death protein 1 (48%), and combined programmed cell death protein 1/cytotoxic T-lymphocyte-associated protein 4 antibodies (24%). The median time from CPI initiation to myalgia and arthralgia irAE was 5.1 months (range, 0.23-50.5 months). All patients were treated with prednisone with a median initial dose of 40 mg/d (range, 10-90 mg/d) for a median duration of 64 weeks (range, 3-242 weeks). Treatment with methotrexate (14%), infliximab (14%), tocilizumab (10%), gabapentin (10%), and etanercept (5%) was also required in some patients. Six (29%) patients restarted CPI therapy following symptom improvement, 3 (15%) switched to a subsequent therapy, and 12 (55%) patients had an ongoing sustained response to therapy (median, 14.5 months; range, 3-55 months) despite no subsequent anti-cancer therapy. CONCLUSION: Myalgia and arthralgia irAEs in CPI-treated patients with GU malignancies vary in timing of presentation, severity, and treatment. Multidisciplinary teams that include a rheumatologist are critical for optimal management. Durable response to CPIs can be maintained even after therapy discontinuation.