Efficacy and Safety of BT200 (Rondaptivon Pegol) in Patients With Type 2B Von Willebrand Disease (BT200-VWD2B)

Efficacy and Safety of BT200 (Rondoraptivon Pegol) in Patients With Type 2B Von Willebrand Disease

This randomized clinical trial with a cross-over design is being conducted at the Department of Clinical Pharmacology at the Medical University of Vienna, and a total of 4-6 patients with type 2B von Willebrand disease (VWD) will participate.

The main purpose of this clinical trial is to investigate the efficacy and safety of BT200, a new drug for thrombocytopenic patients with type 2B von Willebrand disease (VWD). Based on previous studies, we expect that this drug will inhibit the breakdown of von Willebrand factor (VWF) in small doses, leading to an increase in von Willebrand factor (VWF), platelet count, and factor VIII. This should also lead to a reduced tendency to bleed.

This study will begin with an observation phase and will then proceed in two periods of approximately 64 days each:

Placebo or BT200 will be administered subcutaneously at a dose of 12 mg on the first day of the study. After that, patients will self-administer the drug at a dose of 6 mg (0.4 mL) or placebo once a week for another 4 weeks starting the following week (a total of 4 times over a period of 4 weeks). During this time, they will be asked to come to our clinic for a follow-up visit.

After a "washout phase" lasting several weeks, during which patients do not receive the study drug/placebo but are asked to record any bleeding events, the second period begins on day 64:

BT200 or placebo is administered again, depending on what the patients received in the first period. Patients therefore receive the study drug for 4 weeks and placebo for 4 weeks; which is administered when is randomized; a follow-up examination also takes place during this period.

At the end of the second period, there is another "washout phase" lasting several weeks. On day 127, the final examination takes place at the clinic, after which patients have the opportunity to participate in an extension study (to be amended).

Study Overview

• Status: Recruiting
• Conditions: Von Willebrand Disease (VWD), Type 2
• Intervention / Treatment: Drug: Placebo; Drug: BT200

• Study Type: Interventional
• Enrollment (Estimated): 6
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Christian Schörgenhofer, Principal Investigator, MD, PHD; Phone Number: 29810 +43 1 40400; Email: christian.schoergenhofer@meduniwien.ac.at
• Study Contact Backup: Name: Bernd Jilma, Subinvestigator, MD; Phone Number: 29810 +43 1 40400; Email: bernd.jilma@meduniwien.ac.at

Study Locations

• Austria
  • Vienna
    • Vienna, Vienna, Austria, 1090
      • Recruiting
      • Medical University of Vienna, Department of Clinical Pharmacology
      • Sub-Investigator: Bernd Jilma, MD
      • Sub-Investigator: Christa Firbas, MD
      • Contact: Bernd Jilma, MD; Phone Number: 29810 +43 1 40400; Email: klin-pharmakologie@meduniwien.ac.at
      • Sub-Investigator: Cihan Ay, MD
      • Sub-Investigator: Miriam Moser, MD
      • Sub-Investigator: Ulla Derhaschnig, MD
      • Sub-Investigator: Georg Gelbenegger, MD, PHD
      • Sub-Investigator: Ingrid Pabinger, MD
      • Sub-Investigator: Daniel Kraemmer, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. ≥18 years old
2. Type 2B VWD with thrombocytopenia and a recent bleeding history (e.g. recurrent haematomas)
3. Able to comprehend and to give informed consent
4. Able to cooperate with the Investigator, to comply with the requirements of the study, and to complete the full sequence of protocol-related procedures

Exclusion Criteria:

1. Clinically significant medical history or ongoing chronic illness that would jeopardise the safety of the patient or compromise the quality of the data derived from his/her participation in this study
2. History of significant drug allergy or anaphylactic reactions
3. Substance abuse, mental illness, or any reason that makes it unlikely in the judgment of the Investigator for the patient to be able to comply fully with study procedures
4. Use of medication during 2 weeks before the start of the study, which in the judgment of the Investigator may adversely affect the patient's welfare or the integrity of the study's results
5. Concurrent treatment with other experimental drugs or participation in another clinical trial with any investigational drug within 30 days or 5 elimination half-lives (whichever is longer) prior to treatment start

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Patients randomized to receive placebo first. They will receive the verum BT200 after an adequate washout period	Drug: Placebo; Placebo for BT200
Experimental: BT200; Patients randomized to receive BT200 (verum) first and placebo in the second phase after an adequate washout period.	Drug: BT200; Aptamer directed against the A1 domain of von Willebrand factor

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary Outcome measure Platelet Counts	Platelet Counts	During the five-week Treatment Phase compared with the five-week Control Phase
Co-Primary Endpoint Clinically evident bleeding	number of clinically evident bleedings	During the five-week Treatment Phase compared with the five-week Control Phase

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
von Willebrand factor antigen	Concentration of von Willebrand factor antigen quantified by Enzyme-linked immunoassay	During the five-week Treatment Phase compared with the five-week Control Phase
von Willebrand factor activity	von Willebrand factor activity quantified by Gp1bM assay	During the five-week Treatment Phase compared with the five-week Control Phase
VWF activity collagen binding	Activity of VWF quantified with a collagen binding assay	During the five-week Treatment Phase compared with the five-week Control Phase
VWF:ristocetin co-factor activity	Activity of VWF quantified with a ristocetin co-factor assay	During the five-week Treatment Phase compared with the five-week Control Phase
Enzyme-linked immunosorbent assay (ELISA) for unbound VWF-A1 domain (REAADS® )	Concentration of unbound VWF-A1 domain quantified by Enzyme-linked immunosorbent assay (ELISA) (REAADS® )	During the five-week Treatment Phase compared with the five-week Control Phase
Platelet function under high shear rates	Platelet Function Analyzer	During the five-week Treatment Phase compared with the five-week Control Phase
BT200 plasma concentrations	plasma concentrations of BT200	During the five-week Treatment Phase compared with the five-week Control Phase
Serious, drug-related AEs	Serious, drug-related AEs	During the five-week Treatment Phase compared with the five-week Control Phase
Premature terminations due to drug-related AEs	Number of participants who premature terminate treatment due to drug-related AEs	During the five-week Treatment Phase compared with the five-week Control Phase
Adverse events indicative of BT200 toxicity	Patterns of serious or non-serious, drug-related AEs, and/or clinically relevant laboratory abnormalities, vital signs, or physical findings suggestive of one or more specific target organs for toxicity of BT200	During the five-week Treatment Phase compared with the five-week Control Phase

Collaborators and Investigators

• Sponsor: Medical University of Vienna

Study record dates

Study Major Dates

• Study Start (Actual): August 14, 2025
• Primary Completion (Estimated): July 31, 2026
• Study Completion (Estimated): July 31, 2026

Study Registration Dates

• First Submitted: September 29, 2025
• First Submitted That Met QC Criteria: November 28, 2025
• First Posted (Estimated): December 9, 2025

Study Record Updates

• Last Update Posted (Estimated): December 9, 2025
• Last Update Submitted That Met QC Criteria: November 28, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: bleeding; placebo; thrombocytopenia; von Willebrand's disease
• Additional Relevant MeSH Terms: Cytopenia; Pathologic Processes; Genetic Diseases, Inborn; Hematologic Diseases; Blood Coagulation Disorders; Hemorrhagic Disorders; Blood Platelet Disorders; Blood Coagulation Disorders, Inherited; Coagulation Protein Disorders; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathological Conditions, Signs and Symptoms; Hemic and Lymphatic Diseases; Thrombocytopenia; Hemorrhage; von Willebrand Diseases
• Other Study ID Numbers: BT200-VWD2B Version 1.1; 2024-518294-34-01 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Upon reasonable request to the PI.
• IPD Sharing Time Frame: After Publication of the trial results, within 3 months of reasonable request to the PI
• IPD Sharing Access Criteria: Fellow Researchers with a reasonable proposal for planned analyses may contact the PI. Anonymized individual data may be shared.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No