Prophylaxis with a recombinant factor VIII Fc in hemophilia A: long-term follow-up on joint health, efficacy, and safety from phase 3 studies in children and adults

A Hemophilia Joint Health Score-Based Model for the Economic Evaluation of Hemophilia A Prophylaxis Interventions

BACKGROUND AND OBJECTIVE

Hemophilia A is a costly, lifelong illness with multiple prophylaxis options. Previously, these options were assessed using a Peterson score-based model to simulate joint damage over time. This study built a model for the economic evaluation of hemophilia A with less socioeconomic selection bias utilizing the hemophilia joint health score (HJHS).

METHODS

A mechanistically defined HJHS-based state-transition microsimulation model was implemented for the cost-utility analysis conducted over a lifetime horizon from a Canadian provincial Ministry of Health perspective, with a 1.5% discount rate on (costs and outcomes), to compare the following interventions: standard half-life (SHL), extended half-life (EHL), emicizumab, and efanesocotog alfa (EA). The health states are HJHS levels, waiting for surgery, postoperative time, and death. Individuals experience bleeds, joint bleeds (increasing the HJHS), and surgery in each health state. Disutilities include injections and postoperative time. Model validation included face validity, internal validity, comparison analysis, external validity, and predictive validity. Probabilistic analysis, pricing threshold analysis, and one-way scenario analyses were completed.

RESULTS

EA showed lower levels of hospitalizations and surgeries and an improved joint damage experience in the simulation. However, EA was not cost-effective against emicizumab, which continued to be the most cost-effective intervention. Pricing threshold analysis indicated that a price decrease would be required for EA to dominate SHL (50% decrement) and emicizumab (55% decrement).

CONCLUSIONS

This is the first cost-effectiveness model incorporating HJHS to apply sequential joint damage to hemophilia A. While EA offers clinical benefits, our analysis suggests it will not be cost-effective from a Canadian provincial Ministry of Health perspective without a significant price decrease.

Impact of Systematic Joint Examination (Ultrasound, Functional and Physical) on Treatment Management Decisions in Patients With Haemophilia A in France: Final Data From the Prospective, Observational A-MOVE Study

BACKGROUND

Haemophilia management aims to prevent bleeding and preserve joint function. Changes in patients' joint health may influence physicians' decisions to adjust treatment. The Haemophilia Joint Health Score (HJHS) and Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score assess joint health but are not routinely used.

AIM

To evaluate whether systematic joint examination with HJHS and/or HEAD-US had an impact on treatment management decisions in France, using final data from the A-MOVE study.

METHODS

A-MOVE (NCT04133883) was a 12-month prospective, multicentre study, which enrolled persons with haemophilia A (all severities, aged 6-40 years) treated prophylactically or on demand with standard/extended half-life FVIII replacement. At baseline, 6 and 12 months, HJHS/HEAD-US and changes in patients' management were assessed.

RESULTS

Eighty-six patients from 20 sites were included in the final analysis; 68 had HJHS/HEAD-US assessments at 12 months. Over 12 months, 24.4% (n = 21/86) of patients experienced an impact on their haemophilia management due to HJHS/HEAD-US scores; these decisions were impacted by HJHS in about half of the patients (52.4%, n = 11/21) and HEAD-US in almost all patients (95.2%, n = 20/21). Both assessments contributed to a change in management decisions in about half of the patients (47.6%, n = 10/21). Twenty-nine patients (33.7%) had haemophilia management decisions impacted by factors other than HJHS/HEAD-US, including physical examination findings (n = 9) and the occurrence of bleeding episodes (n = 8).

CONCLUSIONS

Final data from the A-MOVE study show that systematic joint assessments, through functional/physical examination (HJHS) and ultrasound (HEAD-US), may impact treatment management decisions in persons with haemophilia A.

Superior Prophylactic Effectiveness of a Recombinant FVIIIFc Over Standard Half-Life FVIII in Hemophilia A: A-SURE Study

OBJECTIVES

The 24-month, prospective, non-interventional, European multicenter A-SURE study evaluated the real-world effectiveness of prophylaxis using an extended half-life recombinant factor VIII (FVIII) Fc fusion protein, efmoroctocog alfa (hereinafter rFVIIIFc), compared with prophylaxis using standard half-life (SHL) FVIII products in patients with hemophilia A.

METHODS

Primary endpoints were annualized bleeding rate (ABR), annualized injection frequency, and annualized factor consumption. A comparative study design unique for an observational hemophilia study was implemented to reduce potential confounding in effectiveness estimates, wherein each patient prescribed rFVIIIFc was matched with one receiving SHL FVIII. Propensity scores were used for adjustment in statistical analyses.

RESULTS

Outcomes for all primary endpoints were significantly better in the rFVIIIFc group (n = 184) compared with the SHL FVIII group (n = 170): mean ABR 1.5 versus 2.3 (difference of -0.8; p = 0.0147); mean annualized injection frequency 114.4 versus 169.2 (difference of -54.8; p < 0.0001); and mean annualized factor consumption 243 024.2 versus 288 718.6 International Units (difference of 45 694.5; p = 0.0003). rFVIIIFc was well tolerated, with no inhibitor development.

CONCLUSIONS

rFVIIIFc has superior prophylactic effectiveness versus SHL FVIII, providing higher bleed protection with fewer injections and lower factor consumption.

Real-world usage and effectiveness of recombinant factor VIII/factor IX Fc in hemophilia A/B: final data from the 24-month, prospective, noninterventional PREVENT study in Germany

Background

Real-world experience with efmoroctocog alfa (a recombinant factor [F]VIII Fc fusion protein [rFVIIIFc]) and eftrenonacog alfa (a recombinant factor IX Fc fusion protein [rFIXFc]) is needed to bridge evidence gaps.

Objectives

To describe rFVIIIFc/rFIXFc usage and effectiveness over a 24-month prospective period.

Methods

PREVENT (NCT03055611), a noninterventional study across 25 German hemophilia treatment centers, enrolled previously treated persons with hemophilia A and B (all ages/severities) on individualized rFVIIIFc/rFIXFc prophylaxis before/at enrollment. Primary endpoints included annualized bleeding rate (ABR), injection frequency (IF), and factor consumption (FC). Additionally, up to 12 months of retrospective FVIII/FIX data were collected. Physician and patient satisfaction, and safety outcomes were also assessed.

Results

Overall, 150 patients received ≥1 rFVIIIFc dose and 47 patients received ≥1 rFIXFc dose, with median prospective follow-up of 20.6 and 21.0 months, respectively. rFVIIIFc/rFIXFc demonstrated low median ABR (0.5/1.7), annualized IF (121.8/52.2 injections/y), and FC (4611.7/2423.9 IU/kg) in line with product labels. Compared with previous FVIII/FIX, there was a 56.0% reduction in ABR for rFVIIIFc (rate ratio, 0.44; 95% CI, 0.31-0.64), with no change for rFIXFc (rate ratio, 0.93; 95% CI, 0.66-1.31); rFVIIIFc/rFIXFc reduced annualized IF (rFVIIIFc, mean difference, -31.7; 95% CI, -40.3 to -23.1; rFIXFc, mean difference, -37.3; 95% CI, -46.9 to -27.8), while FC remained stable (rFVIIIFc, +374.1; 95% CI, +46.8 to +701.3; rFIXFc, +503.9; 95% CI, +95.4 to +912.4). Most physicians and patients were satisfied or highly satisfied with rFVIIIFc/rFIXFc. rFVIIIFc/rFIXFc were well tolerated, with no inhibitor development or treatment-related serious adverse events.

Conclusion

Real-world PREVENT data complement phase 3 trials and show that individualized rFVIIIFc/rFIXFc prophylaxis provided stable bleed protection with low IF and maintained FC. Compared with previous FVIII, ABR was considerably reduced with rFVIIIFc, with stable annualized FC. For rFIXFc, bleed protection was maintained vs previous FIX while reducing annualized IF.

Bleeding control improves after switching to emicizumab: Real-world experience of 177 children in the PedNet registry

INTRODUCTION

Despite the rapid uptake of emicizumab in the paediatric haemophilia A (HA) population, real-world data on the safety and efficacy is limited.

AIM

To report on bleeding and safety in paediatric patients receiving emicizumab prophylaxis.

METHODS

Data were extracted from the multicentre prospective observational PedNet Registry (NCT02979119). Children with haemophilia A, and ≥50 FVIII exposures or inhibitors present receiving emicizumab maintenance therapy were analysed. Data were summarized as medians with interquartile range (IQR, P25-P75). Mean (95% confidence interval (CI)), annualized (joint) bleeding rate (A(J)BR) during emicizumab and ≤2 years before emicizumab prophylaxis were modelled and compared using negative binomial regression.

RESULTS

Total of 177 patients started emicizumab at median 8.6 years (IQR 4.8-13.1), most had no FVIII inhibitors (64%). Follow up before emicizumab was median: 1.68 years (IQR: 1.24-1.90) and during emicizumab: 1.32 years (IQR: .94-2.11). In patients without inhibitors, mean ABR reduced after starting emicizumab from 2.41 (CI 1.98-2.95) to 1.11 (CI .90-1.36, p < .001), while AJBR reduced from.74 (CI .56-.98) to.31 (CI .21-.46, p < .001). Concordantly, in patients with inhibitors, mean ABR reduced from 5.08 (CI 4.08-6.38) to .75 (CI .56-1.01, p < .001), while AJBR reduced from 1.90 (CI 1.42-2.58) to .34 (CI .21-.56, p < .001). Five emicizumab-related adverse events were reported (3% of the cohort), including one patient with antidrug antibodies.

CONCLUSION

This study showed improved bleeding control compared to previous treatment and a favourable safety profile during emicizumab therapy in paediatric haemophilia A patients.