Belzutifan-induced tumor regression in sporadic hemangioblastoma: a case report and literature review

Sporadic hemangioblastomas (sHBs) are less prevalent than those in von Hippel-Lindau (VHL) disease. Surgical resection and radiation therapy remain the standard treatments, and medical treatment options for sHBs are limited. While belzutifan shows a favorable response in VHL-associated HBs, its efficacy in sHBs is uncertain. We present a case of probable belzutifan-induced tumor reduction in a patient with sHB. We present a case of a 65-year-old man with progressive right-sided hemifacial paresthesia, retro-orbital pain, and periorbital edema, subsequently diagnosed with progressive right trigeminal nerve-associated sHB. The patient did not meet clinical or genetic criteria for VHL disease. Serial magnetic resonance imaging (MRI) demonstrated significant tumor progression over seven years. Treatment included 12.5 Gy of radiation in 2016, subtotal resection in 2021, and re-radiation with 50.6 Gy in 2022. Repeat debulking resection was deemed high-risk due to tumor location, and prior treatment precluded further re-radiation. Following multidisciplinary review and patient preference, medical therapy was pursued, and belzutifan at 120 mg/day was initiated. MRI demonstrated tumor reduction from 3.4 cm to 3.1 cm by month 2. Due to anemia and fatigue, belzutifan was reduced and continued at 80 mg/day with stable hemoglobin above 10.0 and tolerable fatigue. Serial brain MRIs showed a durable tumor reduction, with a −7.00 mm/year median linear growth rate reduction by month 13. To our knowledge, this is the first report of belzutifan treatment for sHB, resulting in tumor reduction. Belzutifan may offer a possible treatment option for residual, progressive, and/or pre-surgical sHBs.