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 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.
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.
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.