Efficacy of Oral Belzutifan for Retinal Capillary Hemangioblastomas in von Hippel-Lindau Disease.

OBJECTIVE

To evaluate the efficacy of oral belzutifan on retinal capillary hemangioblastomas (RCHs) in patients with von Hippel-Lindau (VHL) disease.

DESIGN

Single-center, retrospective case series.

PARTICIPANTS

Thirty-three patients (42 eyes) with VHL disease and at least one measurable RCH who were treated with oral belzutifan (40-120 mg/day) and examined at the National Eye Institute with at least one follow-up visit.

MAIN OUTCOMES: Change in total active lesion area, juxtalesional exudation, and feeder and draining vessel tortuosity and dilation.

RESULTS

A total of 85 active lesions (42 eyes) were identified at baseline prior to starting belzutifan and were followed for an average of 21.8 ± 14.7 months while on belzutifan. Mean ± standard deviation total active lesion area per eye decreased significantly from 5.8 ± 9.7 mm2 at baseline to 1.2 ± 2.3 mm2 at 1 year (P <0.001) and to 0.5 ± 0.8 mm2 (P <0.001) at 2 years. This change represented an average decrease of 75.0 ± 32.4% at 1 year and 79.5 ± 29.8% at 2 years. No new RCHs were observed during active treatment. However, among patients who discontinued therapy, over 70% of eyes exhibited signs of relapse, including increased lesion area.

CONCLUSIONS

Belzutifan was associated with substantial regression of VHL-associated RCHs and absence of new lesions during on-treatment follow-up. These findings support a role for belzutifan in the management of juxtapapillary tumors and as adjunctive therapy for large or multifocal lesions. Frequent reactivation after treatment cessation suggests that continued administration may be required to maintain disease control.