Gene Therapy for Hemophilia A: A Mixed Methods Study of Patient Preferences and Shared Decision-Making

Gene Therapy in Hemophilia A: Achievements, Challenges, and Perspectives

Strides in advancements of care of persons with hemophilia include development of long-acting factor replacement therapies, novel substitution and hemostatic rebalancing agents, and most recently approved gene therapy. Several decades of preclinical and clinical trials have led to development of adeno-associated viral (AAV) vector-mediated gene transfer for endogenous production of factor VIII (FVIII) in hemophilia A (HA). Only one gene therapy product for HA (valoctocogene roxaparvovec) has been approved by regulatory authorities. Results of valoctocogene roxaparvovec trial show significant improvement in bleeding rates and use of factor replacement therapy; however, sustainability and duration of response show variability with overall decline in FVIII expression over time. Further challenges include untoward adverse effects involving liver toxicity requiring immunosuppression and development of neutralizing antibodies to AAV vector rendering future doses ineffective. Real-life applicability of gene therapy for HA will require appropriate patient screening, infrastructure setup, long-term monitoring including data collection of patient-reported outcomes and innovative payment schemes. This review article highlights the success and development of HA gene therapy trials, challenges including adverse outcomes and variability of response, and perspectives on approach to gene therapy including shared decision-making and need for future strategies to overcome the several unmet needs.

Development of the World Federation of Hemophilia Shared Decision-Making Tool

INTRODUCTION

The use of shared decision-making (SDM) in clinical settings is becoming more prevalent. The evolving and increasingly complex treatment landscape of haemophilia management has augmented the need and desire for SDM between patients and their healthcare team. SDM tools have been used in other chronic conditions and can be an effective form of education for patients and clinicians.

AIM

The World Federation of Hemophilia (WFH) partnered with people with haemophilia (PWH), patient advocacy groups, and healthcare practitioners to form an expert working group to develop an educational tool for PWH and their caregivers. The primary objectives included educating PWH on the available prophylactic treatments and facilitating discussion between PWH and their healthcare team.

METHODS

The tool was proposed and developed by the expert working group, workshopped at conference round tables, and evaluated in two focus groups.

RESULTS

The interactive WFH SDM Tool guides users through the SDM treatment journey and provides an opportunity for reflection on current disease impact and treatment preferences, educational fact sheets and videos, and a comparison between treatment classes. Two forms of the SDM Tool are available: an online platform with a summary page that may be printed and shared and a printable workbook. All evidence in the tool is based on the prescribing information or phase III clinical trial publications. The Tool will be updated twice each year.

CONCLUSION

The WFH SDM Tool is the first available resource that translates published guidance on SDM in haemophilia into a practical, user-friendly tool aimed at facilitating patient-centred treatment decisions.

Shared decision-making related to treatment of haemophilia: A scoping review of influential factors and available support tools

INTRODUCTION

Treatment selection in haemophilia is increasingly challenging given evolving therapeutic options and the need for individualization. Shared decision-making (SDM) approaches have recently gained interest, though a synthesis of available studies is lacking.

AIM

A scoping review was conducted to summarize literature reporting on factors impacting treatment SDM in haemophilia and tools or models available to support such decisions.

METHODS

PubMed, Embase, the Cochrane Library, Web of Science and grey literature were searched for studies published through August 2023. Original studies reporting on facilitators and barriers to haemophilia SDM and SDM tools were included and analyzed for themes, characteristics and gaps.

RESULTS

A total of 625 records were identified and 14 unique studies were selected (factors influencing treatment SDM, n = 7; SDM tools, n = 7). The studies typically included input from persons with haemophilia, caregivers and healthcare practitioners (HCPs). Thematic organization of factors influencing SDM revealed three main categories: knowledge, patient characteristics and HCP-patient interactions. Availability of information was a commonly reported facilitator of SDM, while poor HCP-patient engagement was a commonly reported barrier. Tools varied in focus, with some facilitating general treatment SDM while others supported selection of certain therapy types. The studies underscored additional factors critical for SDM, such as alignment of HCP-patient perceptions, shared language and tailoring of tools to specific subpopulations.

CONCLUSION

Few studies report on treatment SDM factors and tools in haemophilia; available tools vary considerably. It remains unclear whether published tools have been successfully implemented into clinical practice. Additional research is warranted.

The benefits of gene therapy in people with haemophilia

Haemophilia is an inherited bleeding disorder which causes significant morbidity and mortality, especially in the severe form. Prophylaxis with factor replacement has high efficacy in reducing bleeding but is limited by the need for frequent intravenous infusion and fluctuations in haemostasis between doses. Additional prophylaxis therapies are being developed which may overcome some of the current treatment barriers. Gene therapy (GT) is being developed to provide a functional cure such that there is sustained factor expression and minimal to no need for additional haemostatic therapy. There are now two approved gene therapies for haemophilia which may be transformative for many individuals. Benefits of GT should go beyond increasing factor activity and reducing bleeding as persons with haemophilia aim to achieve a 'haemophilia-free mind' and health equity with optimal health and well-being.

Delivery of gene therapy in haemophilia treatment centres in the United States: Practical aspects of preparedness and implementation

INTRODUCTION

Haemophilia treatment centres (HTCs) and healthcare providers (HCPs) will need to adapt to a new treatment paradigm with the emergence of adeno-associated virus (AAV)-based gene therapy for the treatment of haemophilia in adults.

AIM

This review examines the upcoming patient and institutional journeys, along with practical aspects of preparedness for clinical delivery of gene therapy by HTCs.

METHODS

Based on our clinical experience and examination of published literature, we explored the parallel journeys for patients and treatment centres to navigate before, during, and after administration of gene therapy.

RESULTS

The patient journey includes: information gathering; decision making; comprehensive patient assessment; preparation for the infusion itself; short- and long-term monitoring; lifestyle modifications; and the possible need for immunosuppressive treatment. Informed decision-making may require patient education with extensive discussions and an understanding that not all people with haemophilia will choose or be eligible for gene therapy, although eligibility criteria continue to evolve. The institutional journey includes: consideration of biosafety procedures; planning for product procurement, handling, storage, and administration; development of detailed protocols and guidance documents; contingency planning for immunosuppressive and haemostatic management; consideration of clinical capabilities and staff training needs; coordination of efforts by the full multidisciplinary team; and collaboration between referring, dosing, and follow-up treatment centres. Documented protocols and guidance documents are pivotal for this complex therapy to ensure safe handling, optimal delivery, and post-infusion management and follow-up.

CONCLUSION

Successful implementation of this new treatment modality will require communication and collaboration among multiple stakeholders.

Awareness of individual goals, preferences, and priorities of persons with severe congenital haemophilia A for a tailored shared decision-making approach to liver-directed gene therapy. A practical guideline

In clinical medicine, shared decision making (SDM) is a well-recognized strategy to enhance engagement of both patients and clinicians in medical decisions. The success of liver-directed gene therapy (GT) to transform severe congenital haemophilia A (HA) from an incurable to a curable disease has launched a shift beyond current standards of treatment. However, GT acceptance remains low in the community of HA persons. We argue for both persons with haemophilia (PWH) and specialists in HA care including clinicians, as needing SDM-oriented educational programs devoted to GT. Here, we provide an ad hoc outline to implement education to SDM and tailor clinician information on GT to individual PWHs. Based on routine key components of SDM: patient priorities; recommendations based on individual risk reduction; adverse effects; drug-drug interactions; alternatives to GT; and ongoing re-assessment of the objectives as risk factors (and individual priorities) change, this approach is finalized to exploit efficacious communication.

Development of a haemophilia A gene therapy shared decision-making tool for clinicians

INTRODUCTION

As gene therapies are incorporated into clinical practice, shared decision-making (SDM) is recommended for implementation.

AIM

To inform development of a clinician SDM tool for haemophilia A gene therapy.

METHODS

Clinicians at US Hemophilia Treatment Centers completed semi-structured interviews about their experience with SDM and provided feedback on a clinician SDM tool prototype. Interviews were transcribed verbatim for coding and thematic content analysis.

RESULTS

Ten participants enrolled, eight physicians and two haemophilia nurses. All participants care for adults with haemophilia (1-27 years of experience) and 7 have gene therapy trials open at their institution. Confidence in having a clinical discussion about gene therapy included none (N = 1), slight (N = 3), moderate (N = 5) and high (N = 1). All participants reported familiarity with SDM and agreed that the tool would be useful for their clinical practice. Key themes in participant feedback for the tool were (1) language and presentation; (2) content; and (3) implementation. Participants highlighted the importance of providing unbiased information and having companion tools with patient-centric language.

CONCLUSION

These data highlight the need for SDM tools for haemophilia A gene therapy. Key information to include in the tool are safety, efficacy, cost and detailed information on the gene therapy process. Data should be provided in an unbiased format and allow comparison to other treatments. The tool will be evaluated in clinical practice and refined as clinical trial data and real-world experience mature.

Etranacogene dezaparvovec for the treatment of adult patients with severe and moderately severe hemophilia B

INTRODUCTION

Etranacogene dezaparvovec is the first gene therapy approved for treatment of adults with severe and moderately severe hemophilia B.

AREAS COVERED

This review describes the results of the clinical trial program of AMT-060 and etranacogene dezaparvovec, outlining the pharmacokinetic, clinical efficacy and safety data. With the entry of etranacogene dezaparvovec into the market, this review summarizes the treatment landscape in hemophilia B and discusses the current unknowns in the field.

EXPERT OPINION

Gene therapy appears to be a feasible option for adults with severe and moderately severe hemophilia B. Etranacogene dezaparvovec enables most patients to reach stable factor IX (FIX) levels after a single intravenous infusion, eliminating the need for regular prophylaxis; thus, drastically reducing treatment burden and avoiding variable bleeding risk owing to fluctuating FIX activity levels. Efficacy of etranacogene dezaparvovec has been demonstrated even in the presence of preexisting neutralizing antibodies (up to a titer of 1:678), with a relative low risk of transaminitis and its associated potential loss of transgene expression. However, long-term data are required to ascertain the durability of FIX levels achieved and safety. The cost-effectiveness and adoption of innovative payment models for reimbursement are key in choosing gene therapy over existing treatments.