According to a recent study in patients with hemophilia A or B, a switch to extended half-life (EHL) factor concentrates was associated with short-term improvements in health-related quality of life (HRQoL) in comparison with use of standard half-life (SHL) products. The study results were reported in the journal Research and Practice in Thrombosis and Haemostasis.

In Canada, between 2016 and 2018, concentrates of recombinant factors VIII and IX Fc (rFVIIIFc and rFIXFc) were given as EHL products. Use of these involved a switch from SHL- to EHL-based products for many patients. The researchers who performed this analysis had an aim of investigating patient-recorded outcome measures (PROMs) associated with this shift from SHL- to EHL-based factor concentrates.

This prospective cohort analysis evaluated HRQoL in patients ≥6 years of age with hemophilia A or B seen at 8 centers across Canada. Patients either remained on SHL products (33 patients) or switched to EHL products (25 patients). Several PROMs were used to evaluate HRQoL, in both adults and pediatric patients, involving overall HRQoL and multiple domains of HRQoL. Assessments occurred at baseline and at 3 months, 12 months, and 24 months.

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Patients switching to EHL products were switched to both rFVIIIFc (16 patients) and rFIXFc (9 patients). The patients remaining on SHL products received recombinant factor VIII (rFVIII; 27 patients) and recombinant factor IX (rFIX; 6 patients).

Overall HRQoL appeared improved at 3 months with switching to EHL products. Responses on the Hemophilia-Specific Quality of Life questionnaire indicated that at 3 months 29% of patients who switched to the rFIXFc EHL product had a clinically meaningful improvement in this metric, in addition to 12% of patients switched to the rFVIIIFc EHL product.

In multiple domains of HRQoL, such as physical activity and functioning, mental health, and social functioning, 3-month improvements were also demonstrated for varying proportions of patients who were switched to EHL products. However, overall and across domains, improvements with switching generally appeared to diminish by 24 months.

At the end of the study, among patients switching to EHL products, 9 of the 9 (100%) receiving rFIXFc, and 6 of the 7 (86%) receiving rFVIIIFc, expressed a preference for EHL, rather than SHL, products. At this time point, patients remaining on SHL products expressed mixed preferences for remaining on the SHL product or switching to an EHL product.

Overall, the study suggested meaningful improvements in the near term in HRQoL for some patients upon the switch to an EHL rFIXFc or rFVIIIFc. However, the researchers indicated that the results may have reflected a response shift, with improvements early on that became weakened over time.

“On the other hand, the overwhelming majority of switchers voiced a preference for EHL over SHL products at the end-of-study visit, providing compelling evidence that current PROM scores do not reflect patients’ responses to novel therapy in their entirety,” the researchers concluded in their report.

Disclosures: Some authors have declared affiliations with or received grant support from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.


Sun HL, Yang M, Poon MC, et al. The impact of extended half-life factor concentrates on patient reported health outcome measures in persons with hemophilia A and hemophilia B. Res Pract Thromb Haemost. 2021;5(7):e12601. doi:10.1002/rth2.12601