A Longitudinal Examination of the Quality of Life of Persons with Hemophilia a Switching from Intravenous Recombinant Factor VIII Concentrate to Subcutaneous Non-FVIII Replacement Therapy

Background. In Canada, ‘standard of care’ for persons with hemophilia A (PWH-A) has been regular intravenous infusions of factor VIII (FVIII) concentrates started early in life. Recently, novel non FVIII therapies that do not require intravenous infusion, and are administered infrequently and subcutaneously, have become clinically available. These therapies may impact health-related quality of life (HR-QoL) of PWH-A. This patient-reported outcome can be assessed using the Canadian Hemophilia Outcomes-Kids Life Assessment Tool (CHO-KLATv3.0).

Aim. To compare the long-term HR-QoL of PWH-A pre-/post-switch to emicizumab.

Methods. PWH-A on FVIII prophylaxis, and their caregivers, completed questionnaires at baseline (day of switch to emicizumab), 3-, 6-, and 12-months post-switch. This study was approved by the institutional research ethics board. Informed consent was obtained from participants. PWH-A aged 7-18 years completed the self-report CHO-KLAT, and caregivers of PWH-A aged 0-18 years completed the caregiver-report CHO-KLAT. The CHO-KLAT is scored 0- 100, with 100 representing best HR-QoL. The CHO-KLAT is also scored within 7 domains: activities, autonomy, bleeding, emotional health, hemophilia knowledge, social functioning, and treatment.

Results. PWH-A (N=26; M_age=12.4 years, SD=4.2; 100% male; 97% infusing prophylaxis >twice/week pre-switch) and their caregivers (N=34) completed the questionnaires. Mean CHO KLAT scores increased at 3-months and plateaued by 12-months. Child and caregiver CHO-KLAT scores were significantly correlated at baseline (ρ=.53**, CI=.16-.77) and 12-months (ρ=.92**, CI=.66-.98), indicating similar caregiver versus child-perceived HR-QoL longitudinally. There was a significant improvement in caregiver-reported CHO-KLAT scores from baseline to 3- months, by an average of 8.65 (t₁₈=-3.36, CI=-14.05–3.25). There was a significant improvement in caregiver-reported autonomy from baseline to 12-months (Z=-3.26, p<.001).

Conclusion. PWH-A and their caregivers reported greatest HR-QoL at 3- and 6-months post switch. The HR-QoL findings align with the literature on other chronic conditions, where the greatest changes are observed immediately following a treatment switch, followed by a plateau over time.

Carcao:CSL Behring: Consultancy, Honoraria; Shire/Takeda: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novo Nordisk: Consultancy, Honoraria, Research Funding; Novartis: Research Funding; Bioverativ/Sanofi: Consultancy, Honoraria, Research Funding; Bayer: Consultancy, Honoraria, Research Funding; LFB: Consultancy, Honoraria. Malcolmson:Roche: Research Funding.