Hemophilia gene therapy trials demonstrate a “cure” could be achievable, thereby changing disease management. CoreHEM aims to develop multi-stakeholder consensus around a clearly defined, core outcome set (COS) - a minimum set of outcomes that should be measured and reported in all clinical trials of a specific condition - that will demonstrate and allow differentiation of the effectiveness and value of gene therapy relative to the current standard of care. Health technology assessment (HTA) frequently suffers from a lack of relevant, consistently reported outcomes. When uniformly implemented, COS increase the predictability and consistency of appraisals, coverage, and reimbursement decisions by payers and HTA agencies.

A COS was developed using a modified Delphi process, including online surveys and an in-person consensus meeting. A literature review and key informant interviews were used to create an initial list of outcomes for voting. Participants (patients, including representatives from the National Hemophilia Foundation and the World Federation of Hemophilia, healthcare providers, payers, HTA agencies, regulators and industry representatives) condensed and prioritized the list by rating each outcome on a scale of 1 (not important to include) to 9 (essential). Participants could also suggest outcomes for voting. Outcomes were eliminated from consideration if <70 percent rated the outcome from 7–9, unless the patient stakeholder group average score was ≥7.

After two Delphi rounds, there was consensus on three outcomes: frequency of bleeds, factor activity level, and duration of expression. Additional outcomes included after an in-person consensus meeting were chronic pain, mental health status, and utilization of the healthcare system (direct costs). Adverse events of interest were evaluated and separately reported.

Including the coreHEM COS in clinical development programs will ensure that relevant, consistent outcomes are available for decisions by HTA agencies, clinicians, and patients. This should result in faster access to novel, high-value therapies for appropriate patients.