A survey of physicians’ treatment switching practice in people on long-term prophylaxis for hemophilia in five European countries

Figures & data

Figure 1. Profile of treatment switches in PwHA or PwHB in the 12 months prior to the survey. Note. This includes all treatment switches (switches to SHL or EHL treatments); error bars represent standard deviation. Relevant survey question(s): How many of these PwHA or PwHB had their factor replacement product switched in each of the following scenarios? *A total of 30 physicians switched treatment regimens for PwHB, 25 of whom switched patients to regular prophylaxis with rFIXFc. Abbreviations. EHL, extended half-life; PwHA, people with hemophilia A; PwHB, people with hemophilia B; rFIXFc, recombinant FIX Fc fusion protein; SHL, standard half-life.

Figure 2. Collection of health outcomes data: information that physicians (n = 37) always/regularly collected during routine treatment and considered at the time of switching patients to an EHL therapy. Relevant survey question(s): How often do you collect the following health outcome data for your hemophilia patients as part of their routine treatment?/Which specific health outcome measurements do you take into consideration when making a decision to switch a patient’s hemophilia treatment to an EHL factor replacement treatment? [Select all that apply]. Abbreviations. EHL, extended half-life; PK, pharmacokinetic.

Figure 3. Key reasons for switching PwHA or PwHB to rFVIIIFc and rFIXFc, respectively. Relevant survey question(s): What do you consider to be the main reasons behind switching to rFVIIIFc or rFIXFc for this specific patient? [Select all that apply]. *Other reasons included supply issues for PwHA and less vials to take abroad for PwHB. Abbreviations. PwHA, people with hemophilia A; PwHB, people with hemophilia B; rFVIIIFc, recombinant factor VIII Fc fusion protein; rFIXFc, recombinant factor IX Fc fusion protein.

Table 1. Characteristics of PwHA or PwHB switched to rFVIIIFc and rFIXFc, respectively, in the 12 months prior to the survey.

Characteristics, n (%)	PwHA,* n (%)	PwHB,* n (%)
	(N = 113)	(N = 36)
Patient age, years
0–12	9 (8)	3 (8)
13–20	28 (25)	9 (25)
21–40	54 (48)	20 (56)
≥41	22 (19)	4 (11)
Disease severity
Mild (5–40% active clotting factor)	5 (4)	3 (8)
Moderate (1–5% active clotting factor)	49 (43)	17 (47)
Severe (<1% active clotting factor)	59 (52)	16 (44)
Timing of switch to rFVIIIFc or rFIXFc, months previously
3	27 (24)	11 (31)
>3–6	45 (40)	11 (31)
>6–9	25 (22)	10 (28)
>9–12	16 (14)	4 (11)
PK parameters evaluated around time of making switch	74 (65)	20 (56)
Previous inhibitor	20 (18)	8 (22)
Switch discussion initiated by physician (versus patient/caregiver)	100 (88)	34 (94)

*Percentages may not total 100 due to rounding.

Relevant survey question(s): Patient’s current age/Severity of the patient’s disease/Has this patient ever had an inhibitor?/When did you first initiate the patient onto rFVIIIFc or rFIXFc?/Who initiated the discussion to switch this patient onto rFVIIIFc or rFIXFc?/Did you conduct PK parameters around the time of making the switch to rFVIIIFc or rFIXFc?.

Abbreviations. PK, pharmacokinetic; PwHA, people with hemophilia A; PwHB, people with hemophilia B; rFVIIIFc, recombinant factor VIII Fc fusion protein; rFIXFc, recombinant factor IX Fc fusion protein.

Table 2. Physician-estimated ABR in PwHA or PwHB switched to rFVIIIFc and rFIXFc, respectively, and subsequently receiving at least 6 months of therapy.

Physician estimated ABR	PwHA* (n = 33), n (%)		PwHB* (n = 9), n (%)
	Before switch	After switch	Before switch	After switch
0	3 (9)	9 (27)	1 (11)	2 (22)
1	7 (21)	8 (24)	2 (22)	4 (44)
2	3 (9)	3 (9)	0 (0)	0 (0)
≥3	20 (61)	13 (39)	6 (67)	3 (33)

*Percentages may not total 100 due to rounding.

Relevant survey question(s): In the year prior to or in the time since switching to rFVIIIFc or rFIXFc, what is your impression of estimated ABR for this patient? Please exclude any bleeds that occurred during surgery or dental procedures.

Abbreviations. ABR, annualized bleeding rate; PwHA, people with hemophilia A; PwHB, people with hemophilia B; rFVIIIFc, recombinant factor VIII Fc fusion protein; rFIXFc, recombinant factor IX Fc fusion protein.

Figure 4. Physicians’ perception of the impact on PwHA or PwHB switched to rFVIIIFc and rFIXFc, respectively. Relevant survey question(s): Overall, following the switches to rFVIIIFc or rFIXFc described previously, please indicate to what extent you agree or disagree with the following statements on how these patients fared (relative to their previous treatments) – based on my experience with the switch to rFVIIIFc or rFIXFc, I believe that “(…) is improved”. Abbreviations. PwHA, people with hemophilia A; PwHB, people with hemophilia B; rFVIIIFc, recombinant factor VIII Fc fusion protein; rFIXFc, recombinant factor IX Fc fusion protein.

Data availability statement

The datasets generated and/or analyzed during the current study are not publicly available due to their proprietary nature but are available from the corresponding author on reasonable request.