A Potential Role for Nivolumab in the Treatment of Fibrous Dysplasia-Related Pain.

Fibrous dysplasia (FD) is a chronic and progressive disorder of bone growth because of decreased osteoblast formation and osteoclast overactivity. Its main symptoms include pain, fracture, and irregular bone growth. Bisphosphonates are the mainstay of therapy for FD with a primary goal of pain relief. A 50-year-old woman presented to ophthalmology in March 2011 with intermittent proptosis, vertical diplopia, and orbital pain. A computed tomography scan of the head revealed a skull base lesion, which was confirmed to be fibrous dysplasia on bone biopsy. Because of significant headache, she was treated with IV pamidronate monthly starting November 2011, which led to pain reduction. Repeated attempts to decrease the frequency of pamidronate were unsuccessful because of breakthrough pain. Oral alendronate and risedronate did not control her symptoms. She remained on risedronate however because of its convenience. In August 2021, she was diagnosed with metastatic melanoma and started nivolumab. Her headache completely resolved for the first time in 10 years. Although nivolumab, a programmed death-1 blocker, has been used in the treatment of bone malignancy, it has not been previously studied in FD. By suppressing RANK ligand-related osteoclastogenesis, nivolumab decreases cancer-associated bone pain. Our case suggests a potential role for nivolumab in treating FD-associated pain.