Researchers reported that the hemophilia-specific health-related quality of life questionnaire (Haemo-QOL-A) has been validated for charting quality of life changes in patients with severe hemophilia A undergoing gene therapy, as published in Patient Related Outcome Measures.
Around 80% of hemophilia cases are hemophilia A, which is characterized by recurrent spontaneous bleeding episodes, resulting in joint damage and loss of mobility. Patients with severe hemophilia A experience significant impairment in their quality of life, often struggling in school and in employment.
Standard care for hemophilia A remains prophylactic factor VIII (FVIII) replacement therapy, which is administered intravenously 1 to 4 times a week. This imposes a significant burden of care on patients, sometimes resulting in poor adherence and poorer outcomes.
A novel approach to hemophilia care is gene therapy, which uses a recombinant adeno-associated viral vector to carry the human FVIII gene. Studies on valoctocogene roxaparvovec, an investigational gene therapy, resulted in clinically relevant reductions in the annualized treated bleeding rate.
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To investigate the impact of gene therapy on the quality of life of patients with severe hemophilia A, a validated questionnaire is much needed. The authors of the study set out to investigate the validity and reliability of Haemo-QOL-A. They conducted their study using data from a phase 1/2 open-label dose-escalation study. Participants were male patients with severe hemophilia A aged 18 years and over.
“The phase 1/2 dose-escalation study included participants on FVIII prophylaxis or on-demand therapy who had ≥12 bleeding episodes within 12 months prior to enrollment; participants received an infusion of AAV5-hFVIII-SQ at 6×1012 vg/kg, 2×1013 vg/kg, 4×1013 vg/kg, or 6×1013 vg/kg,” the authors said.
The results revealed that the Haemo-QOL-A demonstrated good construct validity, including convergent validity with the existing EuroQol-5 Dimension questionnaire. A total of 5 of the 6 Haemo-QOL-A domains demonstrated good internal consistency. The validation of this questionnaire is important for clinicians to gauge how gene therapy impacts the quality of life of patients with severe hemophilia A.
Quinn J, Delaney KA, Wong WY, Miesbach W, Bullinger M. Psychometric validation of the Haemo-QOL-A in participants with hemophilia A treated with gene therapy. Patient Relat Outcome Meas. 2022;13:169-180