Non-Factor Therapy Reduces Burden of Care for Caregivers of Children with Severe Hemophilia a: A Longitudinal Cohort Study Using the Hemophilia Family Impact Tool (H-FIT v1.1)

Background: A child's hemophilia diagnosis has an impact on the caregiver. Caregivers often need to administer routine prophylactic therapy to prevent bleeds. Historically, in patients with severe hemophilia A (PWH-A), this consisted of giving intravenous (IV) clotting factor concentrate (CFC) multiple times per week. With the advent of novel non-factor therapies (e.g., emicizumab), there is an option to deliver prophylaxis subcutaneously (SC) less frequently. The Hemophilia Family Impact Tool (H-FITv1.1) is a caregiver-reported questionnaire that measures the burden of caring for a child with hemophilia. This validated tool can be used to evaluate how the burden of care changes when switching from IV to SC therapy.

Aim: To evaluate the impact of emicizumab, as compared to IV clotting factor, on caregiver burden of care for PWH-A.

Methods: Caregivers of PWH-A (0-18 years) on routine prophylaxis completed the H-FIT at four time points: baseline (day of switch to emicizumab), and at 3, 6, and 12-months post-switch to emicizumab. Institutional research ethics board approval and informed consent from all participants were obtained. The H-FIT is scored from 0 to 100, with 100 representing the lowest family burden.

Results: Caregivers (N=35) of PWH-A (M_age=12.43 years, SD=4.15, 100% male, 97% infusing prophylaxis >twice/week pre-switch) completed the H-FIT. There was a non-statistically significant trend of improved burden of care following a switch to emicizumab (t₁₁=-.81, CI=-14.86-6.86). Age stratification revealed this trend was consistent in children over the age of seven; however, the trend of improvement was not seen in the <7 years of age cohort.

Conclusion: There was a trend of improved burden of caring for PWH-A in caregivers following the child's switch from IV to SC therapy. This trend was not seen in the under 7 cohort, however sample size was limited, and further studies are needed to elucidate age-related differences in care.

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