Regular prophylaxis with activated prothrombin complex concentrates in pediatric hemophilia

BACKGROUND

Regular prophylaxis with activated prothrombin complex concentrates (aPCCs) is effective in adult patients with hemophilia with inhibitors; however, data in children are scarce.

METHODS

This was a single-center retrospective study at Saitama Children's Medical Center. Patients with severe and moderate hemophilia with inhibitors aged <15 years at the start of aPCCs prophylaxis were included. Medical records were retrospectively reviewed.

RESULTS

We treated nine pediatric patients with hemophilia with inhibitors (median age, 1.9 years; age range, 1.3-12.9 years; inhibitor titers before treatment with aPCCs, 5.9-69 BU/mL) using prophylactic aPCCs (doses, 50-100 U/kg; 2-3 times/week). The median prophylactic period was 13 months (range: 5-31 months). The median annualized bleeding rate (ABR) during prophylactic treatment with aPCCs was 2 (range, 0-17). In four patients, ABR was reduced by 19%-100% with prophylactic aPCCs compared to on-demand aPCCs. An adverse effect of treatment was that a patient with hemophilia B developed nephrotic syndrome 34 months after starting regular prophylaxis with aPCCs.

CONCLUSIONS

Regular prophylactic aPCCs reduced the ABR even in younger children with hemophilia A and B. Serious adverse events include nephrotic syndrome, which requires caution.

Radiosynovectomy for the Treatment of Chronic Hemophilic Synovitis: An Old Technique, but Still Very Effective

A radiosynovectomy (RS) should be indicated when recurrent articular bleeds related to chronic hemophilia synovitis (CHS) exist, established by clinical examination, and confirmed by imaging techniques that cannot be constrained with hematological prophylaxis. RS can be performed at any point in life, mainly in adolescents (>13−14 years) and adults. Intraarticular injection (IAI) of a radioactive material in children might be arduous since we need child collaboration which might include general anesthesia. RS is our initial option for management of CHS. For the knee joint we prescribe Yttrium-90, while for the elbow and ankle we prescribe Rhenium-186 (1 to 3 IAIs every 6 months). The procedure is greatly cost efficient when compared to surgical synovectomy. Chemical synovectomy with rifampicin has been reported to be efficacious, inexpensive, simple, and especially practical in developing countries where radioactive materials are not easily available. Rifampicin seems to be more efficacious when it is utilized in small joints (elbows and ankles), than when utilized in bigger ones (knees). When RS and/or chemical synovectomy fail, arthroscopic synovectomy (or open synovectomy in some cases) should be indicated. For us, surgery must be performed after the failure of 3 RSs with 6-month interims. RS is an effective and minimally invasive intervention for treatment of repeated articular bleeds due to CHS. Although it has been published that the risk of cancer does not increase, and that the amount of radioactive material used in RS is insignificant, the issue of chromosomal and/or deoxyribonucleic acid (DNA) changes remains a concern and continued surveillance is critical. As child and adulthood prophylaxis becomes more global, RS might become obsolete in the long-term.

Spanish Consensus Guidelines on prophylaxis with bypassing agents in patients with haemophilia and inhibitors

Prophylaxis with the blood clotting factor, factor VIII (FVIII) is ineffective for individuals with haemophilia A and high-titre inhibitors to FVIII. Prophylaxis with the FVIII bypassing agents activated prothrombin complex concentrates (aPCC; FEIBA® Baxalta) or recombinant activated factor VII (rFVIIa; Novo-Seven®, Novo Nordisk) may be an effective alternative. It was our aim to develop evidence -and expert opinion- based guidelines for prophylactic therapy for patients with high-titre inhibitors to FVIII. A panel of nine Spanish haematologists undertook a systematic review of the literature to develop consensusbased guidance. Particular consideration was given to prophylaxis in patients prior to undergoing immune tolerance induction (ITI) (a process of continued exposure to FVIII that can restore sensitivity for some patients), during the ITI period and for those not undergoing ITI or for whom ITI had failed. These guidelines offer guidance for clinicians in deciding which patients might benefit from prophylaxis with FVIII bypassing agents, the most appropriate agents in various clinical settings related to ITI, doses and dosing regimens and how best to monitor the efficacy of prophylaxis. The paper includes recommendations on when to interrupt or stop prophylaxis and special safety concerns during prophylaxis. These consensus guidelines offer the most comprehensive evaluation of the clinical evidence base to date and should be of considerable benefit to clinicians facing the challenge of managing patients with severe haemophilia A with high-titre FVIII inhibitors.

Combination of hemostatic therapies for treatment of patients with hemophilia A and inhibitors

BACKGROUND

Therapy application and monitoring of patients with hemophilia A (HA) and inhibitors are challenging. In the current study, combined FVIII - bypass therapy was implemented for a cohort of severe HA patients with inhibitors.

METHODS

Plasma of 15 HA patients with inhibitors was spiked ex vivo with FVIII, rFVIIa, FEIBA and their combinations and thrombin generation (TG) was studied. Some patients who experienced hemarthroses or required minor surgeries were treated by a combined concomitant administration of FVIII+FEIBA as IV bolus doses.

RESULTS

TG spiking studies showed individual responses not correlated to inhibitor titer. Combinations of agents augmented TG as compared to any single agent, while combined FVIII+FEIBA yielded the highest TG, supporting it as a potential treatment. Following emergent successful surgery of child treated by concomitant FVIII+FEIBA, a total of 396 episodes in 7/15 patients were treated with concomitant FVIII+FEIBA. Five patients were treated for bleeding episodes only, whereas 2 were children undergoing immune tolerance induction (ITI) with FEIBA prophylaxis. Four minor surgeries were performed on FVIII+FEIBA repeated infusions. Neither thrombosis nor any other adverse events were documented.

CONCLUSION

A combination of FVIII+FEIBA may be effective and safe as an alternative treatment option for some high-responding inhibitor patients.

Estimating the potential cost of a high dose immune tolerance induction (ITI) therapy relative to the cost of a combined therapy of a low dose ITI therapy with bypassing agent prophylaxis

INTRODUCTION

The International Immune Tolerance Study (I-ITI) demonstrated comparable success rates between low (FVIII 50 IU/kg/TIW) and high dose (FVIII 200 IU/kg/day) regimens. While costlier, the high dose ITI regimen achieved shorter time-to-treatment success with fewer bleeding episodes compared to the low dose ITI regimen. Adding bypassing agent prophylaxis (BAP) to a low dose ITI regimen may reduce bleeding while still being less costly than high dose ITI.

AIM AND METHODS

An economic model was developed to compare high dose ITI to low dose ITI with BAP. All model inputs were derived from clinical trials. The I-ITI study indicated a median time to negative inhibitor titre of 4.6 and 9.2 months and average number of bleeds/patient of 4.2 and 9.9 for the high and low dose regimens respectively. Based on the BAP trials, aPCC (85 U/kg/TIW) and rFVIIa (90 μg/kg/day) achieved a 62% and 45% reduction in bleeding frequency respectively. Cost analysis was from a US third party payer perspective and limited to drug costs. One-way, two-way and probabilistic sensitivity analyses were performed.

RESULTS

Costs of low dose ITI with aPCC prophylaxis until negative inhibitor titre is achieved was 24.0% less compared to high dose ITI. Low dose ITI with rFVIIa prophylaxis cost 46.5% more compared to high dose ITI. Model results were robust in the majority of the sensitivity analyses.

CONCLUSION

A low dose ITI regimen with aPCC prophylaxis may be cost saving compared to a high dose ITI regimen with the potential to reduce morbidity by lowering the risk for breakthrough bleeds.

How I use bypassing therapy for prophylaxis in patients with hemophilia A and inhibitors

Inhibitor development poses a significant challenge in the management of hemophilia because once an inhibitor is present, bleeding episodes can no longer be treated with standard clotting factor replacement therapy. Consequently, patients with inhibitors are at increased risk for difficult-to-control bleeding and complications, particularly arthropathy and physical disability. Three clinical trials in patients with inhibitors have demonstrated that prophylaxis with a bypassing agent reduces joint and other types of bleeding and improves health-related quality of life compared with on-demand bypassing therapy. In hemophilia patients without inhibitors, the initiation of prophylaxis with factor (F) VIII or FIX prior to the onset of recurrent hemarthroses can prevent the development of joint disease. Whether this is also true for bypassing agent prophylaxis remains to be determined.

Randomized comparison of prophylaxis and on-demand regimens with FEIBA NF in the treatment of haemophilia A and B with inhibitors

Factor replacement therapy for the treatment of moderate to severe haemophilia A and B can be complicated by the production of inhibitory alloantibodies to factor VIII (FVIII) or factor IX. Treatment with the nanofiltered anti-inhibitor coagulant complex, Factor Eight Inhibitor Bypassing Activity (FEIBA NF), is a key therapeutic option for controlling acute haemorrhages in patients with high-titre inhibitors or low-titre inhibitors refractory to replacement therapy. Given the high risk for morbidity and mortality in haemophilia patients with inhibitors to FVIII or FIX, we conducted this Phase 3 prospective study to evaluate whether prophylaxis with FEIBA NF is a safe and effective treatment option. Over a 1-year period, 17 subjects were treated prophylactically (85 ± 15 U kg⁻¹ every other day) while 19 subjects were treated on demand. The median (IQR) annualized bleeding rate (ABR) during prophylaxis was 7.9 (8.1), compared to 28.7 (32.3) during on-demand treatment, which amounts to a 72.5% reduction and a statistically significant difference in ABRs between arms (P = 0.0003). Three (17.6%) subjects (ITT) on prophylaxis experienced no bleeding episodes, whereas none treated on demand were bleeding episode-free. Total utilization of FEIBA NF for the treatment of bleeding episodes was significantly higher during on-demand therapy than prophylaxis (P = 0.0067). There were no differences in the rates of related adverse events between arms. This study demonstrates that FEIBA prophylaxis significantly reduces all types of bleeding compared with on-demand treatment, and the safety of prophylaxis is comparable to that of on-demand treatment.

Physician preferences for medication attributes for the prophylactic treatment of patients with severe haemophilia A with inhibitors to factor VIII

Prophylaxis may be beneficial for patients with severe haemophilia A who have developed inhibitors to factor VIII. The aim of this study was to determine physicians' preferences for medication attributes in the prophylactic treatment of this patient population. Haematologists from Europe (EU) and the United States (US) participated in a discrete choice exercise to explore their preferences for medication attributes (efficacy, cost, scientific evidence, dosing frequency and administration time) associated with prophylaxis for severe haemophilia A in patients with inhibitors to factor VIII. Physicians' preferences for medication attributes were assessed through completion of 25 trade-off tasks that included a choice between two hypothetical medications each comprised of one randomized level of each medication attribute. Participants also completed a sociodemographic questionnaire. Data were analysed using a random effects logit model. Participants (N = 36: US = 19; EU = 17) were 80.6% men, had a mean of 19.8 years (SD ± 8.1) [range 6-35] of practice experience. The physicians treated an average of 5.7 (± 5.5) patients with severe haemophilia A and inhibitors per month and reported treating 36.2% of these patients prophylactically. The most important medication attributes for prophylactic treatment were efficacy [Relative Importance (RI) = 35.0%] and scientific evidence (RI = 34.1%), whereas treatment cost (12.0%), dosing frequency (10.8%) and administration time (8.2%) were less important. Results were similar across the EU and US. Efficacy and scientific evidence are the primary considerations for physicians' choice of prophylactic medications for use in this patient population.

Modern haemophilia care

Haemophilia care has undergone substantial improvements during the past 40-50 years. Early clotting factor concentrates were not sufficiently refined to enable self-administered treatment at home until the 1970s. Unfortunately, these advances led to transmission of viral diseases including HIV and hepatitis, resulting in an increased burden of morbidity and mortality, especially during the 1980s. Throughout the past two decades, product development, including the advent of recombinant concentrates, has greatly improved the safety and availability of therapy and the focus of care is shifting towards prevention and management of disease sequelae. Long-term substitution therapy (prophylaxis) of the missing clotting factor is the recommended treatment in severe haemophilia, but several research issues remain to be elucidated such as when to start and how to optimise these regimens, and when or whether to stop this expensive treatment. The major side-effect of treatment, development of inhibitors to the infused concentrate, is the main threat to the health of patients and consequently the goal of intense research. Development of new products with improved pharmacokinetics is the next step to improved therapy.

Anti-inhibitor coagulant complex prophylaxis in hemophilia with inhibitors

BACKGROUND

Patients with severe hemophilia A and factor VIII inhibitors are at increased risk for serious bleeding complications and progression to end-stage joint disease. Effective strategies to prevent bleeding in such patients have not yet been established.

METHODS

We enrolled patients with hemophilia A who were older than 2 years of age, had high-titer inhibitors, and used concentrates known as bypassing agents for bleeding in a prospective, randomized, crossover study comparing 6 months of anti-inhibitor coagulant complex (AICC), infused prophylactically at a target dose of 85 U per kilogram of body weight (±15%) on 3 nonconsecutive days per week, with 6 months of on-demand therapy (AICC at a target dose of 85 U per kilogram [±15%] used for bleeding episodes). The two treatment periods were separated by a 3-month washout period, during which patients received on-demand therapy for bleeding. The primary outcome was the number of bleeding episodes during each 6-month treatment period.

RESULTS

Thirty-four patients underwent randomization; 26 patients completed both treatment periods and could be evaluated per protocol for the efficacy analysis. As compared with on-demand therapy, prophylaxis was associated with a 62% reduction in all bleeding episodes (P<0.001), a 61% reduction in hemarthroses (P<0.001), and a 72% reduction in target-joint bleeding (≥3 hemarthroses in a single joint during a 6-month treatment period) (P<0.001). Thirty-three randomly assigned patients received at least one infusion of the study drug and were evaluated for safety. One patient had an allergic reaction to the study drug.

CONCLUSIONS

AICC prophylaxis at the dosage evaluated significantly and safely decreased the frequency of joint and other bleeding events in patients with severe hemophilia A and factor VIII inhibitors. (Funded by Baxter BioScience; Pro-FEIBA ClinicalTrials.gov number, NCT00221195.).

From whole blood to component therapy: the economic, supply/demand need for implementation of component therapy in sub-Saharan Africa

Blood may be transfused as whole blood or as one of its components. Because patients seldom require all of the components of whole blood, it makes sense to transfuse only that portion needed by the patient for a specific condition or disease. This treatment, known as "blood component therapy", allows several patients to benefit from one unit of donated whole blood. Blood components include red blood cells, plasma, platelets, and cryoprecipitate. A considerable literature has accumulated over the past decade indicating that leukocytes present in allogeneic cellular blood components, intended for transfusion, are associated with adverse effects to the recipient. These include the development of febrile transfusion reactions, graft-versus-host disease, alloimmunization to leukocyte antigens, and the immunomodulatory effects that might influence the prognosis of patients with a malignancy. Moreover, it has become evident that such leukocytes may be the vector of infectious agents such as cytomegalovirus (CMV), Human T-Lymphotrophic Virus 1/11 (HTLV-I/II), and Epstein Barr (EBV) as well as other viruses. Effective stewardship of blood ensuring that several patients potentially benefit from components derived from one unit of donated whole blood is important for economic, supply/demand reasons and to protect the national inventory at times of national blood shortage. Blood safety in developing countries can be improved by more appropriate use of blood components rather than whole blood transfusion and the provision of alternatives such as oral and intravenous iron, erythropoietin, saline and colloids. This will facilitate the optimal use of the limited blood supply. Political will and open-mindedness to innovative ways to improve supply, appropriateness, optimal use and safety of blood from all types of donors are essential to promote more evidence-based approaches to blood transfusion practice in sub-Saharan Africa.

When should prophylaxis therapy in inhibitor patients be considered?

Currently, patients with severe haemophilia can expect to lead a relatively normal life including prevention of disabling arthropathy as a result of the development of factor replacement therapy and advances in the understanding of the use of such therapy given prophylactically. Unfortunately, a subset of patients develops neutralizing antibodies termed inhibitors rendering such therapy ineffective. These patients frequently develop recurrent joint bleeding resulting in arthropathy. Until recently, prophylactic therapy was not considered for patients with inhibitors because of the perceived lack of an effective therapeutic agent. However, an accumulation of case reports and a recent prospective study have suggested that prophylaxis with the currently available bypassing agents could be effective and appears to be safe in selected cases. This report will review the current data on prophylaxis with bypassing agents and suggest specific situations in which prophylaxis in inhibitor patients could be considered.

Management of difficult-to-treat inhibitor patients

The workshop looked at seven scenarios based on fictional and real-life cases of difficult-to-treat patients with haemophilia A or haemophilia B and inhibitors with the aim of sharing clinical opinion and experience from around the world. Delegate opinions on the best treatment option for each scenario are described together with actual treatment given in real-life cases and its outcome.