A core outcome set for prophylaxis and perioperative treatment of von Willebrand disease: The coreVWD initiative.

Introduction: Treatment options are expanding for von Willebrand disease (VWD). A core outcome set (COS)-a minimum set of agreed-upon outcomes to be used in every clinical trial for a given condition-provides guidance on which outcomes are most important to measure to ensure necessary data is collected for a variety of stakeholders and enable comparison across products and trials.

Aim: coreVWD aimed to develop a COS for trials for prophylaxis and perioperative treatments for VWD.

Methods: A modified Delphi consensus process was used to condense/prioritize a long list of potential outcomes. Over three Delphi rounds, a multi-stakeholder panel (patients, clinicians, pharmaceutical company representatives, HTA organizations, payer, and government organization representatives) rated each outcome from 1 (not important to include in a COS) to 9 (essential to include). Outcomes were eliminated or retained based on pre-determined criteria; a special provision to elevate patient priorities was included. An in-person consensus meeting was held after Delphi round 2.

Results: Thirty-nine panellists participated. The final COS for prophylaxis treatment included 18 outcomes, seven of which are part of a special subset selected for women, girls and people with the potential to menstruate. There were 11 outcomes in the final perioperative branch COS. Six outcomes overlapped both COS.

Conclusions: The coreVWD COS represents a consensus list of outcomes for clinical trials for both factor and non-factor VWD therapies. These outcomes will be useful across the lifecycle of a product, from clinical development through regulatory and market access phases and into patient-provider decision-making.