Response to desmopressin is strongly dependent on F8 gene mutation type in mild and moderate haemophilia A

Genotype-Dependent Response to Desmopressin in Hemophilia A and Proposal of a Predictive Response Score

BACKGROUND

 Desmopressin (DDAVP) is used in patients with moderate/mild hemophilia A (PWMHs) to increase their factor VIII (FVIII) level and, if possible, normalize it. However, its effectiveness varies between individuals. The GIDEMHA study aims to investigate the influence of F8 gene variants.

MATERIAL AND METHODS

 The study collected the trajectory of FVIII levels from therapeutic intravenous DDAVP tests in four French hemophilia treatment centers. A pharmacological analysis was performed associated with efficacy scores according to F8 variants: absolute and relative responses, as well as new scores: absolute duration (based on duration with FVIII ≥ 0.50 IU.mL-1) and relative duration (based on half-life).

RESULTS

 From enrolled 439 PWMHs, 327 had a hot-spot F8 variant (with ≥5 PWMHs). For these, the median (min-max) basal and peak FVIII were 0.20 (0.02-0.040) and 0.74 (0.14-2.18) IU.mL-1 respectively, with FVIII recovery being 3.80 IU.ml-1 (1.15-14.75). The median FVIII half-life was 3.9 hours (0.7-15.9 hours). FVIII was normalized (≥0.50 IU.mL-1) in 224/327 PWMHs (69%) and the median time with normalized FVIII was 3.9 hours (0.0-54.1 hours). Following the response profiles to DDAVP defined by the four efficacy scores, four groups of F8 variants were isolated, and then compared using survival curves with normalized FVIII (p < 0.0001): "long-lastingly effective" [p.(Glu739Lys), p.(Ser2030Asn), p.(Arg2178His), p.(Gln2208Glu), and T-stretch deletion in intron 13]; "moderately effective" [p.(Ser112Phe), p.(Ala219Thr), p.(Thr2105Ile), p.Phe2146Ser), and p.(Asp2150Asn)]; "moderately ineffective" [p.Ala81Asp), p.(Gln324Pro), p.(Tyr492His), p.(Arg612Cys), p.(Met701Val), p.(Val2035Asn), and p.(Arg2178Cys)]; and "frequently ineffective" [c.-219C > T, p.(Cys2040Tyr), p.(Tyr2169His), p.(Pro2319Leu), and p.(Arg2326Gln)].

CONCLUSION

 In view of our data, we propose indications for DDAVP use in PWMH based on F8 variants for minor and major invasive procedures.

Tachyphylaxis and reproducibility of desmopressin response in perioperative persons with nonsevere hemophilia A: implications for clinical practice

Background

Desmopressin is frequently used perioperatively in persons with nonsevere hemophilia A. However, increase in factor (F)VIII:C after desmopressin use is interindividually highly variable. Tachyphylaxis has only been reported in test setting for persons with hemophilia A, with a remaining response of approximately 70% after a second dose compared with that after a first dose.

Objectives

To study tachyphylaxis of FVIII:C response after multiple administration(s) of desmopressin in perioperative persons with nonsevere hemophilia A.

Methods

We studied FVIII:C levels after desmopressin before (day 0 [D0]) and on days 1 (D1) and 2 (D2) after surgery in 26 patients of the DAVID and Little DAVID studies. We studied tachyphylaxis by comparing the responses at D1 and D2 with that at D0. We also assessed the reproducibility of the D0 response in comparison to an earlier performed desmopressin test.

Results

The median absolute FVIII:C increase was 0.50 IU/mL (0.35-0.74; n = 23) at D0, 0.21 IU/mL (0.14-0.28; n = 17) at D1, and 0.23 IU/mL (0.16-0.30; n = 11) at D2. The median percentage of FVIII increase after the second administration (D1) compared with the first (D0) was 42.9% (29.2%-52.5%; n = 17) and that of the third (D2) compared with the first (D0) was 36.4% (23.7%-46.9%; n = 11). The FVIII:C desmopressin response at D0 was comparable with the desmopressin test response in 74% of the patients.

Conclusion

Tachyphylaxis in the surgical setting was considerably more pronounced than previously reported, with FVIII:C at D1 and D2 of 36% to 43% of the initial response. Our results may have important implications for monitoring repeated desmopressin treatment when used perioperatively.

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.

Desmopressin for bleeding in non‐severe hemophilia A: Suboptimal use in a real‐world setting

Background

Desmopressin is an important treatment option in nonsevere hemophilia A because it has several benefits compared with factor (F) concentrates, including no inhibitor risk and much lower costs. Despite these advantages, data are limited on the real‐world use of desmopressin in the treatment of bleeds.

Objective

To describe the clinical use of desmopressin in relation to other therapeutic modalities in the treatment of bleeding episodes in patients with nonsevere hemophilia A.

Methods

Patients with nonsevere hemophilia A aged 12–55 years were included from the DYNAMO cohort study. Data on the desmopressin test response and treated bleeding events in the period January 2009 to July 2020 were retrospectively collected from medical files. An adequate desmopressin test response was defined based on a peak FVIII level of ≥30 IU/dl.

Results

A total of 248 patients with a median age of 38 years (interquartile range 25–49) were included. An adequate desmopressin test response was documented in 25% and 73% of patients with moderate and mild hemophilia, respectively. In adequate responders, 51% of bleeds were exclusively treated with FVIII concentrates, 24% exclusively with desmopressin, 21% with a combination of both and 4% with other treatments. In 54% of bleeds treated with a single dose of factor concentrates, the expected FVIII level after desmopressin exceeded the level targeted.

Conclusion

Most bleeds in patients with an adequate response to desmopressin are treated with factor concentrates. These findings may indicate a suboptimal use of desmopressin and that barriers to the use of desmopressin should be explored.

Desmopressin treatment combined with clotting factor VIII concentrates in patients with non-severe haemophilia A: protocol for a multicentre single-armed trial, the DAVID study

INTRODUCTION

Haemophilia A is an inherited bleeding disorder characterised by factor VIII (FVIII) deficiency. In patients with non-severe haemophilia A, surgery and bleeding are the main indications for treatment with FVIII concentrate. A recent study reported that standard dosing frequently results in FVIII levels (FVIII:C) below or above FVIII target ranges, leading to respectively a bleeding risk or excessive costs. In addition, FVIII concentrate treatment carries a risk of development of neutralising antibodies. An alternative is desmopressin, which releases endogenous FVIII and von Willebrand factor. In most patients with non-severe haemophilia A, desmopressin alone is not enough to achieve FVIII target levels during surgery or bleeding. We hypothesise that combined pharmacokinetic (PK)-guided administration of desmopressin and FVIII concentrate may improve dosing accuracy and reduces FVIII concentrate consumption.

METHODS AND ANALYSIS

In the DAVID study, 50 patients with non-severe haemophilia A (FVIII:C ≥0.01 IU/mL) with a bleeding episode or undergoing surgery will receive desmopressin and FVIII concentrate combination treatment. The necessary dose of FVIII concentrate to reach FVIII target levels after desmopressin administration will be calculated with a population PK model. The primary endpoint is the proportion of patients reaching FVIII target levels during the first 72 hours after start of the combination treatment. This approach was successfully tested in one pilot patient who received perioperative combination treatment.

ETHICS AND DISSEMINATION

The DAVID study was approved by the medical ethics committee of the Erasmus MC. Results of the study will be communicated trough publication in international scientific journals and presentation at (inter)national conferences.

TRIAL REGISTRATION NUMBER

NTR5383; Pre-results.

Desmopressin in non-severe haemophilia A: Test-response and clinical outcomes in a single Canadian centre review

INTRODUCTION

Desmopressin is an effective haemostatic agent for patients with non-severe haemophilia A; however, response may differ between patients of similar severity. Responsiveness is classified based on various cut-off values for plasma levels of FVIII post-desmopressin administration. Patients may be classified differently depending on the values chosen.

AIM

To classify desmopressin response in non-severe haemophilia A patients with respect to current test-response definitions. Also, to characterize relationships between test response and clinical outcome of desmopressin use.

METHODS

Current desmopressin test-response definitions were obtained from the literature. We adopted peak FVIII level (at 1 hour post-administration) ≥50 IU/dL and <20 IU/dL as complete and no response, respectively, thereby satisfying most reported definitions. Test-responses and clinical outcomes of use between 2007 and 2017 for adult mild/moderate haemophilia A patients were reviewed and correlated.

RESULTS

All patients classified as complete responders (n = 31; peak FVIII ≥50 IU/dL) and the majority of partial responders (n = 11; peak FVIII ≥20 to <50 IU/dL) had good clinical outcomes after desmopressin use for a variety of bleeding episodes and procedures. Two non-responders (peak FVIII <20 IU/dL) given desmopressin for minor bleeding/procedures also had good clinical outcomes. One patient with a partial test-response (peak FVIII 23 IU/dL) required additional factor concentrate to achieve haemostasis.

CONCLUSIONS

Based on our review, we suggest that the determination of desmopressin responsiveness should consider both the change in plasma FVIII levels as well as clinical outcomes associated with prior therapeutic use.

Inhibitor Risk Stratification and Individualized Treatment in Patients With Nonsevere Hemophilia A: A Single-Institution Practice Audit

Inhibitor risk in nonsevere hemophilia A increases with cumulative factor VIII (FVIII) exposure days and high-risk mutations. A standardized approach to minimize inhibitor risk is warranted. Following establishment of a systematic approach to reduce inhibitor risk in nonsevere hemophilia, we evaluated the uptake of these strategies into clinical practice. All adult males with nonsevere hemophilia A followed by British Columbia Adult Hemophilia Program from 2004 to 2016 were included in this retrospective audit. Quality-of-care indicators on inhibitor prevention were examined. Of 108 patients, 18 patients had high-risk FVIII mutations for inhibitor development. Rates of FVIII genotyping and 1-deamino-8-d-arginine-vasopressin (DDAVP) testing in mild patients without contraindications were both over 90%, although DDAVP was used for surgical prophylaxis in only 70% of procedures. Inhibitor testing and clinic visits occurred at a median interval of 22 months. Over 80% of patients with high-risk mutations had documentation and education on their inhibitor risk. Our practice audit demonstrated a high level of recognition and patient education of individual inhibitor risk. Impact of our standardized approach on the incidence of inhibitor development is yet to be determined.

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.

[Mild hemophilia A fortuitously discovered during Henoch-Schönlein purpura]

Henoch-Schönlein purpura is a common form of immunological vasculitis in children. Hemophilia A is a genetic disorder, inherited in a X-linked recessive pattern, and characterized by spontaneous hemorrhage or prolonged bleeding due to factor VIII deficiency. The clinical signs depend on the severity of factor VIII deficiency. We herein report the case of a 4-year-old boy admitted to the emergency room for typical rheumatoid purpura, associated with a lengthening of aPTT, whose exploration had uncovered mild hemophilia A. Laboratory assays should explore lengthening of aPTT: firstly the presence of lupus anticoagulant without bleeding risk, in an inflammatory context; secondly a deficiency of VWF and one of the factors involved in the extrinsic coagulation pathway associated with bleeding risk.

Desmopressin responsiveness at a capped dose of 15 μg in type 1 von Willebrand disease and mild hemophilia A

Desmopressin (DDAVP) is commonly used in the treatment of patients with type 1 von Willebrand disease (VWD) and mild hemophilia A. A patient's responsiveness to DDAVP based on a 0.3  μg/kg dose determines future therapeutic efficacy of the drug. The aim of the study was to determine whether a capped dose of 15 μg subcutaneous DDAVP is able to achieve the same level of DDAVP responsiveness as previously reported. This is a retrospective chart review of patients from 1995 to 2013 in adults and children with type 1 VWD and hemophilia A weighing more than 50 kg. Levels of factor VIII, ristocetin cofactor, and von Willebrand factor antigen were measured before and after 1 h of administration of 15 μg of DDAVP. In patients with type 1 VWD, the complete response rate was 82.5% with a partial response rate of 12.5% and 5% nonresponders. In patients with mild hemophilia A, the complete response rate was 53.8% with a partial response rate of 38.5% and 7.7% nonresponders. These results using a capped 15-μg dose of DDAVP are similar to previously published reports using the 0.3-μg/kg dose.

Molecular and clinical predictors of inhibitor risk and its prevention and treatment in mild hemophilia A

The risk for inhibitor development in mild hemophilia A (factor VIII levels between 5 and 40 U/dL) is larger than previously anticipated, continues throughout life, and is particularly associated with certain mutations in F8. Desmopressin may reduce inhibitor risk by avoiding exposure to FVIII concentrates, but the heterogenous biological response to desmopressin, showing large interindividual variation, may limit its clinical use. However, predictors of desmopressin response have been recently identified, allowing the selection of the best candidates to this treatment.

Mutations in intron 1 and intron 22 inversion negative haemophilia A patients from Western India

Despite increased awareness and diagnostic facilities, 70-80% of the haemophilia A (HA) patients still remain undiagnosed in India. Very little data is available on prevalent mutations in HA from this country. We report fifty mutations in seventy one Indian HA patients, of which twenty were novel. Ten novel missense mutations [p.Leu11Pro (p.Leu-8Pro), p.Tyr155Ser (p.Tyr136Ser), p.Ile405Thr (p.Ile386Thr), p.Gly582Val (p.Gly563Val) p.Thr696Ile (p.Thr677Ile), p.Tyr737Cys (p.Tyr718Cys), p.Pro1999Arg (p.Pro1980Arg), p.Ser2082Thr (p.Ser2063Thr), p.Leu2197Trp (p.Leu2178Trp), p.Asp2317Glu (p.Asp2298Glu)] two nonsense [p.Lys396* (p.Lys377*), p.Ser2205* (p.Ser2186*)], one insertion [p.Glu1268_Asp1269ins (p.Glu1249_Asp1250)] and seven deletions [p.Leu882del (p.Leu863del), p.Met701del (p.Met682del), p.Leu1223del (p.Leu1204del), p.Trp1961_Tyr1962del (p.Trp1942_Tyr1943del) p.Glu1988del (p.Glu1969del), p.His1841del (p.His1822del), p.Ser2205del (p.Ser2186del)] were identified. Double mutations (p.Asp2317Glu; p.Thr696Ile) were observed in a moderate HA case. Mutations [p. Arg612Cys (p.Arg593Cys), p.Arg2326Gln (p.Arg2307Gln)] known to be predisposing to inhibitors to factor VIII (FVIII) were identified in two patients. 4.6% of the cases were found to be cross reacting material positive (CRM+ve). A wide heterogeneity in the nature of mutations was seen in the present study which has been successfully used for carrier detection and antenatal diagnosis in 10 families affected with severe to moderate HA.

The hemophilias and their clinical management

Outcomes for patients with hemophilia have improved dramatically over the past 50 years. With the increased availability of safe clotting factor concentrates, the primary focus in clinical management is now the prevention of long-term complications, most notably the debilitating hemophilic arthropathy that is associated with severe disease. This article reviews evidence-based approaches for managing both children and adults with hemophilia. Definitive evidence of improved clinical results from primary prophylaxis started in young patients with severe hemophilia A and a minimal bleeding history is presented. Furthermore, recent studies showing benefits for initiating prophylaxis in older adolescents and adults with established joint disease are examined. Inhibitors to factor VIII are the most problematic complication of factor replacement therapy. Patient-specific and treatment-related factors that contribute to the risk of inhibitor formation are discussed and controversies and clinical evidence related to approaches for tolerance induction are reviewed.