Gene Therapies for Hemophilia Have Positive Real-World Impact, Studies Show

Presentations at ISTH 2021 revealed attributes most important to patients when considering gene therapies and where further research is needed.

People with hemophilia view dose frequency, durability, and effect on annual bleeding rate (ABR) as the most important factors when considering gene therapies and generally have a positive view of their experiences with gene therapies, according to findings presented at the International Society on Thrombosis and Haemostasis (ISTH) 2021 Congress.1,2

These insights into the real-world impact of gene therapies on people with hemophilia were presented in 2 abstracts at ISTH 2021 by Michelle Witkop, DNP, FNP-BC, chair, National Hemophilia Foundation Nursing Work Group,2 and Simon Fletcher, lead research nurse and PhD candidate, Oxford Haemophilia Centre.1 

“Gene therapy for haemophilia has the potential to change the life experience of individuals and their families. Few studies have sought to explore the impact of gene therapy on individuals and their families,” Fletcher and colleagues wrote.1

In that study, Fletcher and colleagues uncovered 5 main themes of how gene therapies impacted the participants (N = 9, mean age, 43.1 years) who participated in semi-structured qualitative interviews along with 1 family member. Among the participants, 8 of whom had hemophilia A and 1 with hemophilia B, some experiences were positive, such as freedom and altruism, but others were negative, such as the adverse events of immunosuppression (which many participants reported being unprepared for), loss of factor expression, and loss of control.

READ MORE: Hemophilia Gene Therapy Registry Launched to Monitor Long-Term Outcomes

Altogether, most participants, of which mean time since gene therapy transfection was 1.89 years (range, 1-5), saw their participation in gene therapies positively but results from the study suggest more work needs to be done. Ongoing interviews hope to add to these data.

"[Gene therapy] freed [participants] from the personal burden of haemophilia and furthered treatment options for the wider haemophilia community... [but] psychosocial support needs to be integrated into gene therapy programmes to help participants and families process their experiences both positive and negative,” Fletcher and colleagues wrote.1 

In another abstract, Witkop and colleagues sought to assess preferences in selecting gene therapies among people with hemophilia in a discrete choice experiment (DCE). They conducted an online study of participants with severe or moderate hemophilia recruited from the National Hemophilia Foundation Community Voices in Research platform and other online patient panels that consisted of 14 choices between hypothetical pairs of treatment scenarios with varying attribute levels. These 6 attributes were developed based on literature review.

Altogether, the DCE had 183 participants with a mean age of 39.3 years (standard deviation [SD], 13.8), 120 with hemophilia A (HA) and 63 with hemophilia B (HB). Using random parameters logit models to estimate relative attribute importance (RAI), the investigators found that dose frequency and durability (RAI: HA, 23%; HB, 35%) and effect on overall ABR (RAI: HA, 32%; HB, 29%) were the most important attributes. These attributes were followed by uncertainty regarding short-term or long-term significant safety issues (RAI both 17%) and together, the 3 attributes made up 70% to 80% of the overall RAI.

Impact on activity of daily life/physical activity, transformative/mental health impact, and post treatment, possibility to undergo minor surgery without need for factor therapy made up the remaining 20-30% of RAI.

“Evidence of patient preferences for novel hemophilia treatment such as gene therapies is limited. Understanding which treatment attributes are important for people with hemophilia A and B will help to inform the value of gene therapy,” Witkop and colleagues wrote.2 

1. Fletcher S, Chaplin S, Holland M, Jenner K, Khair K. Exigency: The real-world impact of gene therapy on the lives of people with haemophilia and their families. An interim report. Presented at: ISTH 2021 Congress; July 17-21, 2021. Abstract PB0660
2. Witkop M, Morgan G, O’Hara J, et al. Preferences of people with hemophilia A and B for treatments including gene therapies in the US: A discrete choice experiment. Presented at: ISTH 2021 Congress; July 17-21, 2021. Abstract PB0658