Adherence to treatment regimen and bleeding rates in a prospective cohort of youth and young adults on low-dose daily prophylaxis for severe hemophilia A

Abstract

BackgroundWhen availability and/or affordability of anti-hemophilic factor concentrates are limited, optimal prophylaxis regimens in severe hemophilia A (HA) remain to be determined. In selected situations, low-dose daily prophylaxis (LDDP) may be an effective and economical option. The goal of our study was to evaluate if subjects on a LDDP regimen could achieve adherence and good clinical outcome.MethodsSeventeen subjects (age between 15.2 and 28.4) on LDDP suffering from severe/moderate HA were followed prospectively for 2 to 3 years as part of a health-related quality of life (HRQoL) study. Bleeding and treatments data were collected using electronic diaries and validated every three months. The SF-36 questionnaire was administered at the beginning of the study and then every 6 months until the end of the study.ResultsThe subjects (mean age 22.0, median 21.9, standard deviation 4.06), were all from a single centre and on LDDP for at least 12 months as part of their routine care before entering the study. Fifteen subjects were prescribed a daily dose of 500 IU factor VIII (FVIII) and 2 subjects received 1000 IU FVIII per day, resulting into a median dose of 7.1 IU/kg/day (ranging from 4 to 13 IU/kg/day) and of 2591 IU/kg/year. Median adherence (the percentage of the prescribed daily dose received) was 84 % (mean 80 %, range 57 % to 94 %) throughout the study. Seventy-six bleeds in the 6 index joints and 51 other types of bleeds were observed throughout the study. The median annualized bleeding rate in joints (ABRjoints) was 0.7 and the median annualized bleeding rate for all bleeds (ABRall) was 1.6. The Physical Component and Mental Component Summary scores of SF-36, and the Hemophilia Joint Health Score were not significantly different over the course of the study (respective medians of 49.8, 52.4 and 16.0 at entry; vs. 52.5, 51.5 and 16.0 upon exit).ConclusionsThis prospective longitudinal study in youth and young adults shows that LDDP may be associated with low ABRs, adequate adherence and HRQoL comparable to previously reported.

Hemophilia prophylaxis adherence and bleeding using a tailored, frequency‐escalated approach: The Canadian Hemophilia Primary Prophylaxis Study

“…17 However, the median adherence level from step 1 of our prophylaxis regimen of almost 93% was higher than has previously been reported. 10,11,[16][17][18][19][20][21][22][23][24][25][26][27][28] The reduced number of infusions, especially in the early years of prophylaxis, and the increased likelihood of infusions in a hospital setting may have contributed to increased adherence.…”

PK‐tailored tertiary prophylaxis in patients with severe hemophilia A at Beijing Children's Hospital

“…One PK characteristic of FVIII is that an increase in infusion frequency is associated with a more stable and higher trough level at the same dose. Daily prophylaxis is therefore associated with improved clinical outcomes, without extra factor consumption …”

A prospective surveillance study of inhibitor development in haemophilia A patients following a population switch to a third‐generation B‐domain‐deleted recombinant factor VIII

“…The implementation of CBDR in 2015, a user‐friendly web‐based tool for patients to report bleeds and infusions, could have introduced a bias in improved reporting of bleeds and perhaps also driven by the feeling of insecurity for PWH having to switch products for non‐health‐related reasons . Still, all the ABRs before and after the switch were comparable or even lower than those reported in the literature for PWH with on‐demand or prophylactic treatments …”