DDAVP trial in discrepant non-severe haemophilia A patients

Prophylaxis use of clotting factor replacement products in people with non-severe haemophilia: A review of the literature

INTRODUCTION

People with non-severe haemophilia appear to be under-treated in many countries, and this may lead to joint damage and worsen quality of life.

AIM

To review literature for clotting factor replacement prophylaxis in people with non-severe haemophilia A and B (HA/HB) in relation to long-term outcomes to support clinical decision-making.

METHODS

A targeted literature search was performed to identify studies published between 2000 and 2021 that included prophylaxis in people with non-severe HA/HB and long-term outcomes, including annualized bleeding rates, joint health and quality of life.

RESULTS

Although eligible articles included 2737 and 2272 people with mild or moderate HA, respectively, only 22% (n = 609) and 29% (n = 668) reported treatment regimens. A total of 549 people with moderate HA were treated with factor replacement prophylaxis and were from high-income countries. On the contrary, nearly all people with mild HA received desmopressin (n = 599). Details of treatment regimens for women with haemophilia and people with HB were sparse. Three studies provided long-term outcomes for people with moderate haemophilia who received prophylaxis with factor concentrate, supporting early prophylaxis in people with a frequent bleeding phenotype regardless of their endogenous clotting factor level to preserve joint health.

CONCLUSION

There remain large knowledge gaps when considering how to provide optimal treatment for people with non-severe haemophilia. Nonetheless, there is a strong rationale that prophylaxis should be considered early in life according to similar strategies as for severe haemophilia for those with a frequent severe bleeding phenotype.

The one-stage assay or chromogenic assay to monitor baseline factor VIII levels and desmopressin effect in non-severe haemophilia A: Superiority or non-inferiority?

Introduction

Diagnosis, treatment monitoring and assessment of desmopressin effect in haemophilia A patients are performed by measurement of factor VIII activity (FVIII). The two assays commonly applied are the one‐stage assay and the chromogenic assay. Especially in non‐severe haemophilia A, discrepancies between these assays are common. It is still unestablished which assay corresponds best with bleeding phenotype and desmopressin effect.

Aim

To correlate FVIII levels measured by the one‐stage assay and by the chromogenic assay with bleeding phenotype and, additionally, to compare FVIII assay discrepancies before and after desmopressin administration.

Method

Factor VIII was measured in 130 non‐severe haemophilia A patients during routine visits to the outpatient clinic and/or during desmopressin testing. FVIII was measured by both the one‐stage assay and the chromogenic assay. Discrepancies between assays were defined as at least a twofold difference of FVIII or an absolute FVIII difference between measurements of ≥0.10 IU/mL. Bleeding phenotype was defined as annual number of treated bleedings (adjusted ABR).

Results

Hundred and thirty non‐severe haemophilia A patients were included. In 31/130 patients, assay results were discrepant. However, FVIII measurements with both assays correlated adequately with adjusted ABR. In addition, in 27/130 patients FVIII measurements at baseline and after desmopressin administration were analysed. In 13/27 patients, all measurements were either equivalent or discrepant when results were compared. In 14/27 patients, this was not the case as both equivalent measurements and discrepant measurements at different time points within one patient were observed.

Conclusion

Neither the one‐stage assay nor the chromogenic assay is superior in predicting bleeding phenotype. In addition, equivalent or discrepant FVIII results measured before desmopressin do not always predict FVIII assay results after desmopressin administration.