Propranolol and Von Hippel-Lindau Disease

'Von Hippel-Lindau disease (VHL) is a familial syndrome, autosomal dominant, of predisposition to cancer, associating malignant tumors (renal carcinomas, neuroendocrine tumors of the pancreas), or benign tumors (retinal hemangioblastomas (HB), cerebellar, spinal cord, endolymphatic sac tumors and pheochromocytomas, which is a consequence of a high-penetrance mutations in the VHL tumor-suppression gene. A patient with multiple HB may require multiple interventions, which may leave progressively severe neurological sequelae. Several drug treatments (interferon, tyrosine kinase inhibitors, anti-angiogenic agents) have been proposed and tested as alternatives to surgery or to delay it. None of these studies have demonstrated a favorable benefit-risk balance that would support the use of any of these treatments, which sometimes have major side effects, in routine practice. Propranolol (beta-blocker) is successfully used for the treatment of infantile hemangiomas, the most common vascular tumor of newborns. The mechanism is related to its anti-angiogenetic and pro-apoptotic effects. Recently, in vitro studies demonstrated that propranolol decreased the expression of target genes of the HIF (hypoxia-inducible factor, of which the VHL gene is the main regulator) pathway in hemangioblastoma cells and affected their viability. The efficacy of propranolol (stabilization of all HB and decrease in serum VEGF levels) was demonstrated in a phase III study, but only in retinal HB. The only study that evaluated the effect of propranolol on CNS HB was retrospective and involved a limited number of patients. Nevertheless, it showed a decrease in the growth rate of HB. The investigator therefore propose to perform a randomized controlled trial to study the effect of propranolol on CNS HB growth in patients with VHL disease. Patients will be introduced to the study during a routine follow-up visit or during a telephone call by their neurosurgeon. Eligible patients who have signed the consent form will have a cardiology consultation to rule out a contraindication to the use of propranolol, prior to inclusion/randomization. If a contraindication is detected by the cardiologist, the patient will not be included in the study.

Patients without contraindications will then be included and randomized (1:1) to receive either oral propranolol (120 mg/d, started gradually (with BP and heart rate monitoring at visits) for 24 months or usual follow-up. Randomization will be stratified on the number of initial CNS HB (\<5 or ≥5).

Initial imaging (MRI) workup (brain and spinal cord) will be performed, with mapping and measurements of CNS HB, initially present.

Clinical (every three months) and radiological follow-up every 6 months (MRI) or when new neurological symptoms appear. Tolerance and secondary endpoints will also be assessed during these follow-up visits. Patients will be followed up to 26 months post-randomization.

The primary endpoint will be assessed centrally by two neuroradiologists, blinded to the patient's treatment arm. The other radiological endpoints (edema, growth velocity, de novo HB occurrence) will also be assessed centrally, by the same neuroradiologists, blinded to the treatment arm.

During follow-up, the use of surgery will not be modified by the protocol, and will be left to the discretion of the physician in charge of the patient, according to current recommendations. Statistical analysis:

Randomization will be performed in a 1:1 ratio between the two groups. It will be stratified on the initial number of CNS HB (\<5 or ≥5). Efficacy endpoint analyses will be performed on the intention-to-treat (ITT, all randomized patients) population, in which all patients will be analyzed according to the allocated group.

• To compare the safety (tolerance) between the two treatment arms at 24 months post-randomization [Срок оценки: 24 months]
• To Compare the growth rate of HB between the two treatment arms at 24 months post-randomization [Срок оценки: 24 months]
• Compare the extent of peritumoral edema between the two treatment arms [Срок оценки: 24 months]
• Compare the development of de novo lesions between the two treatment arms every 6 months [Срок оценки: 24 months]
• Compare the angiogenic profile of BHs between the two groups every 6 months [Срок оценки: 24 months]
• Study the evolution of serum VEGF level under treatment at 12 and 24 months [Срок оценки: 24 months]
• Compare the number of patients requiring surgery between the two treatment arms [Срок оценки: 24 months]