Belzutifan special drug use results survey in von Hippel-Lindau (VHL) disease-associated tumors: a post-authorization safety study (PASS) (MK-6482-046)

Study type

• Study topic:
  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Safety study (incl. comparative)
• Data collection methods:
  Combined primary data collection and secondary use of data

Non-interventional study

• Non-interventional study design:
  Cohort
• Non-interventional study design, other:
  Descriptive, longitudinal, multi-center collaborative study

Study drug and medical condition

• Medicinal product name:
  WELIREG
• Study drug International non-proprietary name (INN) or common name:
  BELZUTIFAN
• Anatomical Therapeutic Chemical (ATC) code:
  (L01XX74) belzutifan

  belzutifan
• Medical condition to be studied:
  Von Hippel-Lindau disease

Population studied

• Short description of the study population:
  The study population includes adult Japanese patients (>=15 years of age) with VHL disease associated tumors who received belzutifan for the first time following its approval on 24 June 2025 in Japan, as part of routine clinical practice and in accordance with the local label. Patients are observed from the start of belzutifan administration through the treatment period, with adverse events collected during treatment and for 30 days after treatment discontinuation. The total observation period is up to 24 months or 104 weeks from the first belzutifan administration.
• Age groups:
  • Adolescents (12 to < 18 years)
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Estimated number of subjects:
  69

Study design details

• Study design:
  This is a non-interventional, descriptive, longitudinal, multi-center collaborative study. The study includes subjects in Japan with von Hippel-Lindau (VHL) disease-associated tumors who have received belzutifan in routine clinical practice as indicated by the current local label.
• Main study objective:
  The main objective of this study is to monitor the occurrence of hemorrhages and fractures in Japanese subjects with VHL disease associated tumors receiving belzutifan in routine clinical practice. This study will also describe the overall safety and effectiveness of belzutifan in this population.
• Setting:
  Adult Japanese subjects (>=15 years) with VHL disease associated tumors who received belzutifan for the first time following its approval on 24 June 2025 in routine clinical practice.
• Outcomes:
  The primary outcome for the study will be safety specifically the risk of hemorrhage and fractures during administration of belzutifan in subjects with VHL disease-associated tumors. Safety will be evaluated using investigator-reported adverse events (AEs), including all AEs, adverse drug reactions (ADRs), serious adverse events (SAEs), serious adverse drug reactions (SADRs), and grade 3-5 AEs and ADRs.
• Data analysis plan:
  Study endpoints will be analyzed using descriptive statistical methods. For continuous variables, mean, standard deviation, median, interquartile range, and minimum-maximum will be reported. For categorical variables, including AEs, frequency and percentage distributions will be presented. Cross-tabulations may also be used. Demographic and clinical characteristics will be summarized descriptively for all registered subjects and the safety analysis set, and for the presence or absence of AEs, including select protocol-specified AEs. Continuous and count variables may also be categorized into ranges and described using frequency and percentage distributions. No hypothesis testing or imputation of missing data will be performed. ; ; Subject characteristics and frequency of the outcomes of interest will be described using frequency and percentage (cross-tabulations may also be included) for categorical variables and descriptive statistics (mean, standard deviation, min, max, median, interquartile range) for continuous and count variables. Continuous and count variables may also be categorized into; ranges and described using frequency and percentage distributions. Descriptive summaries will be provided for all registered subjects and, separately, the safety analysis set (if different from all registered subjects).; ; The severity, outcomes, seriousness criteria and action taken with belzutifan of AEs, ADRs, SAEs, SADRs will be summarized descriptively. ;