Desmopressin response in hemophilia A patients with FVIII:C < 0.10 IU mL(-1.)

Desmopressin in nonsevere hemophilia A: patient perspectives on use and efficacy

Background

Desmopressin increases plasma factor VIII and von Willebrand factor levels in persons with nonsevere hemophilia A. Patients' perspectives on desmopressin are relevant to increase and optimize its suboptimal use. However, patients' views on desmopressin are not reported.

Objectives

To evaluate the perspectives of persons with nonsevere hemophilia A on desmopressin use, barriers for its use, side effects, and their knowledge about desmopressin's efficacy and side effects.

Methods

Persons with nonsevere hemophilia A were included in a cross-sectional, national, multicenter study. Questionnaires were filled out by adult patients and children aged ≥12 years themselves. Caretakers filled out questionnaires for children aged <12 years.

Results

In total, 706 persons with nonsevere hemophilia A were included (544 mild, 162 moderate, [age range, 0-88 years]). Of 508 patients, 234 (50%) patients reported previous desmopressin use. Desmopressin was considered as at least moderately effective in 171 of 187 (90%) patients. Intranasal administration was the modality of choice for 138 of 182 (76%) patients. Flushing was the most reported side effect in 54 of 206 (26%) adults and 7 of 22 (32%) children. The most frequently reported advantage and disadvantage were the convenience of intranasal, out-of-hospital administration by 56% (126/227) and side effects in 18% (41/227), respectively. Patients' self-perceived knowledge was unsatisfactory or unknown in 28% (63/225).

Conclusion

Overall, desmopressin was most often used intranasally and considered effective, with flushing as the most common side effect. The most mentioned advantage was the convenience of intranasal administration and disadvantage was side effects. More information and education on desmopressin could answer unmet needs in patients with current or future desmopressin treatment.

Desmopressin in moderate hemophilia A patients: a treatment worth considering

Desmopressin increases endogenous factor VIII levels in hemophilia A. Large inter-individual variation in the response to desmopressin is observed. Patients with a lower baseline factor VIII activity tend to show a reduced response, therefore, desmopressin is less frequently used in moderate hemophilia A patients (baseline factor VIII activity 1-5 international units/deciliter), even though factor VIII levels may rise substantially in some of them. We aim to describe the response to desmopressin in moderate hemophilia A patients and to identify predictors. We selected data on 169 patients with moderate hemophilia from the multicenter Response to DDAVP In non-severe hemophilia A patients: in Search for dEterminants (RISE) cohort study. Adequate response to desmopressin was defined as a peak factor VIII level ≥ 30, and excellent response as ≥ 50 international units/deciliter after desmopressin administration. We used univariate and multiple linear regression techniques to analyze predictors of the peak factor VIII level. Response was considered adequate in 68 patients (40%), of whom 25 showed excellent response (15%). Intravenous administration, age, pre-desmopressin factor VIII activity and von Willebrand factor antigen, peak von Willebrand factor activity and desmopressin-induced rise in von Willebrand factor antigen were significant predictors of peak factor VIII level and explained 65% of the inter-individual variation. In 40% of moderate hemophilia A patients, desmopressin response was adequate, thus it is important not to with-hold this group of patients from desmopressin responsiveness. Among the six predictors that we identified for desmopressin-induced factor VIII rise, factor VIII activity and desmopressin-induced rise in von Willebrand factor antigen had the strongest effect.

Desmopressin in haemophilia: The need for a standardised clinical response and individualised test regimen

INTRODUCTION

Due to interindividual variation in desmopressin response, non-severe haemophilia A patients require desmopressin testing prior to therapeutic treatment. However, adequate response or frequency of blood sampling is not standardised in international guidelines. Consequently, various definitions and blood sampling protocols are currently applied. Interestingly, sustainability of desmopressin response is not incorporated into these definitions.

AIM

To study desmopressin response rates in a cohort of non-severe haemophilia A patients using currently accepted desmopressin response definitions. This, in order to formulate a standardised, uniform response which includes information on sustainability and to design a standardised blood sampling protocol.

METHODS

Currently used desmopressin responses in non-severe haemophilia A patients were derived from a literature search. Actual desmopressin response rates were individualised in 105 non-severe HA patients from the Erasmus University Medical Centre and classified according to current varying definitions.

RESULTS

Five response definitions were evaluated, three of which included only factor VIII (FVIII):C cut-off levels and two also incorporated FVIII:C-fold increase over baseline.

FVIII

C-fold increase showed no association with desmopressin response sustainability.

FVIII

C 1 hour after infusion (<0.30, ≥0.30-0.49, ≥0.50-0.79 and ≥0.80 IU/mL) was, however, indicative of desmopressin response after 6 hours.

CONCLUSION

We suggest standardised desmopressin response based on clinically relevant FVIII:C levels, e.g. 0.30 and 0.50 IU/mL. In addition, patients with <0.30 IU/mL FVIII:C after 1 hour (non-responder) or ≥0.80 IU/mL (sustained responder) do not require subsequent blood sampling. However, patients with ≥0.30-0.79 IU/mL FVIII:C after 1 hour should undergo blood sampling after 6 hours to additionally determine response sustainability.