Patients’ Priorities for Gene Therapy: Durability and Bleeding Control
Effectiveness in controlling bleeds and the potential for less frequent use of a treatment are two priorities people with hemophilia place on a potential gene therapy, and both ranked slightly higher than safety, a survey study of patients in the U.S. reports.
The study, “Patient preferences and priorities for haemophilia gene therapy in the US: A discrete choice experiment,” was published in the journal Haemophilia.
Hemophilia is caused by mutations in genes that encode proteins needed for blood clotting. The overall aim of gene therapy for hemophilia is to deliver a healthy version of the mutated gene to a patient, and so restore production of proper clotting proteins.
As hemophilia gene therapies are being developed and moving toward potential regulatory approvals, researchers need to understand patient priorities in choosing among these treatments.
A team led by scientists in the U.S. surveyed a group of hemophilia patients to learn more about such preferences.
The survey was a discrete choice experiment — a survey in which respondents are asked to choose between two or more alternative scenarios, each reflecting the features of a hypothetical therapy. For instance, they might be asked whether they would prefer a very safe therapy of moderate effectiveness, or a highly effective therapy with potentially more severe side effects.
Analyzing choices made allows researchers to zero in on the specific therapy attributes ranked as most important to respondents.
The survey was completed by 183 hemophilia patients: 120 with hemophilia A and 63 with hemophilia B. Nearly half (47%) of respondents reported having severe disease, three-quarters (75%) were white, and all were male. All were adults, with a mean age of 39, and about half (53%) were working full time.
A hypothetical gene therapy’s ability to lower bleeding rates ranked highest in priorities by the largest proportion (31%) of respondents, followed by treatment burden, or its dosing frequency and durability (26%). Other commonly valued attributes of a therapy were its potential safety (17%), and its affects on daily life and physical activity (11%).
“Overall, participants gave the greatest importance to efficacy and administration attributes, where the reduction of annual bleeding rates and the least amount of treatment burden were shown to be clear, meaningful priorities from the patient perspective,” the researchers wrote.
“Uncertainty regarding potential safety issues was a close secondary priority followed by impact on daily life and mental health.”
Several trends were also evident in survey data, the researchers noted. For example, whereas efficacy at preventing bleeds was the most valued attribute among hemophilia A patients, those with hemophilia B were more likely to value treatment frequency of use and durability. Specifically, 32% of hemophilia A patients listed effectiveness in bleed control as their No. 1 priority, as did 29% of hemophilia B patients; treatment durability (burden) was a top consideration for 35% of hemophilia B patients and 23% of those with hemophilia A.
Patients with severe hemophilia, regardless of type, ranked treatment durability as a prime consideration (28%) followed closely by dose frequency (26%).
Uncertainty regarding safety was a top priority for 17% of both these patient groups, and for those with severe hemophilia.
“The inherent uncertainty related to potential safety issues and the impact on daily life were found to be secondary priorities regardless of type or severity of disease,” the team wrote.
“These findings can inform shared decision-making in the clinical setting as well as health technology assessments that value the patient perspective in achieving optimal health outcomes for people with this lifelong condition,” they concluded.