Value contribution of etranacogene dezaparvovec gene therapy in moderately severe and severe haemophilia B through multi-criteria decision analysis

INTRODUCTION

The value of gene therapies for haemophilia needs to be assessed holistically.

AIM

To determine the value of etranacogene dezaparvovec (ED) compared to current extended half-life (EHL) recombinant factors (rFIX), using multi-criteria decision analysis (MCDA).

METHOD

MCDA EVIDEM methodology adapted to orphan drugs was used, with nine quantitative criteria and four contextual criteria. The MCDA framework was rated by 28 multidisciplinary experts. Descriptive statistics were performed for quantitative and qualitative criteria.

RESULTS

Haemophilia B (HB) was considered a severe disease (mean ± SD: 4.3 ± 0.7) with some unmet needs (mean ± SD 3.3 ± 0.9). Experts found ED more effective (mean ± SD 2.0 ± 2.3) and provide better quality of life (QoL) (mean ± SD: 1.8 ± 1.5) than the comparative HB treatments but with safety uncertainties (mean ± SD -1.2 ± 1.8). ED could lead to medical cost and non-medical cost savings over time (mean ± SD: 1.6 ± 2.0 and 2.0 ± 1.5, respectively). The quality of the evidence was high (mean ± SD: 3.9 ± 0.9). ED was considered aligned with the priorities of the National Health System (NHS) and the specific interests of patients. ED's value contribution was 0.45 (+1 = highest value).

CONCLUSIONS

ED brings added value in the treatment of moderately severe and severe HB (sHB) compared to current EHL rFIX, addressing the severity of the disease and increasing efficacy and patients' QoL especially related to the single dose and low bleeding rate. Concerns about long-term safety need to be addressed.

Clinical validation and application of targeted long-range polymerase chain reaction and long-read sequencing-based analysis for hemophilia: experience from a hemophilia treatment center in China

BACKGROUND

Targeted long-read sequencing (LRS) is expected to comprehensively analyze diverse complex variants in hemophilia A (HA) and hemophilia B (HB) caused by the F8 and F9 genes, respectively. However, its clinical applicability still requires extensive validation.

OBJECTIVES

To evaluate the clinical applicability of targeted LRS-based analysis compared with routine polymerase chain reaction (PCR)-based methods.

METHODS

Gene variants of retrieved subjects were retrospectively and prospectively analyzed. Whole-genome sequencing was performed to further analyze undiagnosed cases. Breakpoints of novel genomic rearrangements were mapped and validated using long-distance PCR and long-range PCR combined with sequencing.

RESULTS

In total, 122 subjects were retrieved. In retrospective analysis of the 90 HA cases, HA-LRS assay showed consistent results in 84 cases compared with routine methods and characterized 6 large deletions with their exact breakpoints confirmed by further validation in 6 cases (routine methods only presented failure in amplifying the involved exons). In prospective analysis of the 21 HA subjects, 20 variants of F8 were identified in 20 cases. For the remaining HA patient, no duplication/deletion or single-nucleotide variant (SNV)/insertion and deletion (InDel) was found, but a potential recombination involving exons 14 and 21 of F8 was observed by LRS. Whole-genome sequencing analysis and further verification defined a 30 478 base pairs (bp) tandem repeat involving exons 14 to 21 of F8. Among the 11 HB patients, HB-LRS analysis detected 11 SNVs/InDels in F9, consistent with routine methods.

CONCLUSION

Targeted LRS-based analysis was efficient and comprehensive in identifying SNVs/InDels and genomic rearrangements of hemophilia genes, especially when we first expanded the panel to include F9. However, further investigation for complex gross rearrangement is still essential.

The eTHINK Study: Cognitive and Behavioral Outcomes in Children with Hemophilia

OBJECTIVE

To assess cognitive, behavioral, and adaptive functions in children and young adults with hemophilia treated according to contemporary standards of care.

STUDY DESIGN

Evolving Treatment of Hemophilia's Impact on Neurodevelopment, Intelligence, and Other Cognitive Functions (eTHINK) is a US-based, prospective, cross-sectional, observational study (September 2018 through October 2019). Males (aged 1-21 years) with hemophilia A or B of any severity, with or without inhibitors, were eligible. Participants underwent neurologic examinations and age-appropriate neuropsychological assessments, including standardized tests/ratings scales of early development, cognition, emotional/behavioral adjustment, and adaptive skills.

RESULTS

Five hundred and fifty-one males with hemophilia A (n = 433) or B (n = 101) were enrolled. Performance on cognitive tests was largely comparable with that of age-matched US population norms, although participants in certain age groups (4-5 and 10-21 years) performed worse on measures of attention and processing speed. Furthermore, adolescents and young adults and those with comorbid attention-deficit/hyperactivity disorder (ADHD; n = 64) reported more adaptive and executive function problems in daily life. Incidence of ADHD in adolescents (21%) was higher than expected in the general population.

CONCLUSIONS

In general, males with hemophilia demonstrated age-appropriate intellectual, behavioral, and adaptive development. However, specific patient/age groups showed poorer attention performance and concerns for executive and adaptive development. This study established a normative data set for monitoring neurodevelopment in individuals with hemophilia and highlight the importance of screening and intervention for challenges with cognitive and adaptive skills in this population.

CLINICAL TRIAL REGISTRATION

Evolving Treatment of Hemophilia's Impact on Neurodevelopment, Intelligence, and Other Cognitive Functions (eTHINK); NCT03660774; https://clinicaltrials.gov/ct2/show/NCT03660774.

Factor IX stimulants in preclinical and early phase trials for hemophilia B treatment

INTRODUCTION

Hemophilia B is a X-linked rare inherited bleeding disorder characterized by coagulation factor IX (FIX) deficiency. Therapy for hemophilia B is aimed at replacing the FIX deficiency by means of several plasma-derived or recombinant FIX products. The recent availability of recombinant FIX concentrates with a prolonged FIX half-life represented a great technological advance, permitting more spaced drug infusions and reducing treatment burden among hemophilia B patients.

AREAS COVERED

This review summarizes the main preclinical and phase 1/2 studies investigating the innovative hemostatic products for hemophilia B replacement therapy.

EXPERT OPINION

The significant recent technological advantages in the treatment of hemophilia B has led to the development of innovative FIX products aimed at further extending FIX half-life and using increasingly effective and convenient modes of administration. These novel hemostatic agents, currently in the preclinical or early clinical phase of development, carry the potential of improving patients' health status and quality of life. Continuous research is anyway needed to offer such patients a concrete chance of conducting a normal existence, like to non-affected age-matched individuals.

Real-World Amount of Clotting Factor Concentrates Dispensed and Annual Medical Expenditures for Japanese Patients with Hemophilia B

Introduction

Until extended half-life (EHL) factor IX (FIX) concentrates became available in Japan in 2010, patients with hemophilia B received intravenous FIX replacement therapy with standard half-life (SHL) FIX concentrates.

Purpose

To investigate the amount of factor dispensed and the associated medical expenditures for the treatment of hemophilia B in the real-world clinical setting in Japan.

Methods

This retrospective study comprised patients with hemophilia B (N=197) who had filled prescriptions for FIX concentrates reported in Japan's Medical Data Vision database from 2015 to 2019. Patients were included if they had 2 or more prescriptions for the same FIX concentrates within the first 6 months of the study period and the interval between prescriptions was at least 2 weeks.

Results

Since 2015, there was a decrease in the proportion of patients using SHL FIX concentrates and a corresponding increase in international units of dispensed EHL FIX concentrates. Median annualized dispensed dosages (IU/kg body weight) of EHL FIX concentrates were lower than for SHL concentrates for outpatient use only. Annual total health care expenditures per patient and annual expenditures for prescribed FIX concentrates increased each year during the study period. Following a switch from an SHL to an EHL concentrate, the median amount of prescribed FIX concentrate decreased slightly, although median total health care expenditures and FIX concentrate expenditures increased.

Conclusion

In the real-world setting in Japan, medical expenditures and the proportion of patients prescribed EHL FIX concentrates for the treatment of hemophilia B have increased.

Benefits of rIX-FP prophylaxis in patients with Haemophilia B: real-world evidence from a Spanish reference centre

Standard FIX prophylaxis for PWHB require frequent injections, which has led to the development of extended half-life products like rIX-FP (albutrepenonacog alfa) that has shown good efficacy in clinical studies. This ambispective study aims to report a real-world experience with rIX-FP in a Spanish centre with PWHB who switched from SHL-FIX or began prophylaxis with rIX-FP. Five PWHB were included in this study, Four PTP switched to rIX-FP with prophylaxis every 7 days whilst one PUP started with an every-14-days regimen. 3 PTPs extended their dosing intervals to every 14 days or every 21 days. In all PTPs, median annualized spontaneous and joint bleeding rates were maintained at 0.00 and median (range) of ABR was 0.92 (0.00-2.77) after switch to rIX-FP. Mean trough level with previous product was 3.68% (SD = 2.06), while it was 7.08% (SD = 3) with all rIX-FP dosing intervals. After switching to rIX-FP, all PTP reduced their annual infusion rate between 50 and 84% and their annual FIX consumption by 61% (59-67%). This is the first reported real-world experience with albutrepenonacog alfa in a small cohort in Spain and demonstrates good bleeding control together with a reduction of the infusion rate, factor consumption and higher through factor level than previous treatment.

Nonacog Alfa for Prophylaxis and Treatment of Bleeding Episodes in Previously Treated Patients with Moderately Severe or Severe Hemophilia B in India

Purpose

Hemophilia B is an X-linked congenital bleeding disorder caused by a deficiency of coagulation factor IX (FIX) clotting activity. This study evaluated safety and efficacy of nonacog alfa, a recombinant human blood coagulation FIX replacement product, in males aged 12-65 years with hemophilia B (FIX activity ≤ 2%) with or without inhibitors in India.

Methods

In this multicenter, open-label, post-approval phase 4 study, participants were treated for up to 8 weeks, with up to a 4-week screening period and a subsequent post-treatment 28-day safety observation period. Intravenous nonacog alfa 40 IU/kg (range 13-78 IU/kg) was administered at intervals of 3-4 days, in accordance with the approved local product document.

Results

A total of 25 participants were enrolled and completed the study. No participants developed FIX inhibitors during the study, experienced treatment-related adverse events (AEs) or serious AEs, or developed a thrombotic event and/or hypersensitivity reaction. No participants experienced bleeding events requiring on-demand treatment with nonacog alfa. Seventeen bleeding episodes (16 spontaneous and 1 traumatic) were reported in 10 participants; all occurred post treatment, with the exception of a minor gum-bleeding event, and were managed without treatment. The mean (SD) annualized total factor consumption (TFC) per patient was 224,582 (75,527) IU; the mean (SD) annualized TFC by weight per patient was 3639 (573) IU/kg.

Conclusion

Nonacog alfa was safe and effective for the prevention of hemorrhagic episodes in Indian males with congenital, severe hemophilia B. No participants developed FIX inhibitors, and no new safety signals were reported.

First open-label, single-arm, prospective study of real-world use of FIX replacement therapy in a predominantly pediatric hemophilia B population in China

BACKGROUND

Nonacog alfa (recombinant factor IX [FIX]) is approved in China for the control and prevention of bleeding events in patients with hemophilia B. This was the first study to assess prophylaxis and on-demand therapy with recombinant FIX replacement in a real-world setting in China. This study aimed to evaluate the safety and efficacy of nonacog alfa in Chinese patients with hemophilia B.

METHODS

In this open-label, multicenter study (clinicaltrials.gov identifier NCT02336178), patients received on-demand or prophylactic treatment with intravenous nonacog alfa for approximately 6 months or 50 exposure days, whichever occurred first. The primary safety outcome was medically important events (i.e., development of FIX inhibitors, allergic reactions, and thrombotic events). Key secondary efficacy outcomes included the annualized bleeding rate for on-demand treatment and prophylaxis, response to on-demand treatment, the number of infusions per bleeding event, and the number of breakthrough bleeding events within 48 hours of prophylaxis.

RESULTS

Seventy male patients (mean [standard deviation] age 7.8 [7.2] years) were enrolled (on-demand, n = 37; prophylaxis, n = 57 [24 patients were included in both groups]). Thirty-eight (54%) patients had up to 50 FIX exposure days before the study. The only medically important event was a transient low-titer FIX inhibitor (incidence 1.4%, 95% confidence interval, 0-7.7). The mean annualized bleeding rate was 26.3 for on-demand treatment and 6.5 for prophylaxis. A mean (standard deviation) of 1.5 (1.7) nonacog alfa infusions were given per bleeding episode; 78.8% of episodes resolved with 1 infusion. Response was "excellent" or "good" for 88% of the on-demand infusions. Twenty-three bleeding events (n = 11 patients) occurred within 48 hours of 2032 prophylaxis doses (1.13%).

CONCLUSION

In the real-world setting, nonacog alfa is safe and effective for on-demand treatment and for prophylaxis for patients with hemophilia B in China.

A challenging management of hemophilia B patient with inhibitors undergoing major orthopedic surgeries in a resource-constrained country

In this paper, we report a life-threatening condition and relate our experience in managing a hemophilia B patient who required three surgical procedures, highlighting the difficulties we encountered in our setting and propose some tangible.

Identification of novel glycosylation events on human serum-derived factor IX

Human Factor IX is a highly post-translationally modified protein that is an important clotting factor in the blood coagulation cascade. Functional deficiencies in Factor IX result in the bleeding disorder haemophilia B, which is treated with plasma-derived or recombinant Factor IX concentrates. Here, we investigated the post-translational modifications of human serum-derived Factor IX and report previously undescribed O-linked monosaccharide compositions at serine 141 and a novel site of glycosylation. At serine 141 we observed two monosaccharide compositions, with HexNAc₁Hex₁NeuAc₂ dominant and a low level of HexNAc₁Hex₁NeuAc₁. This O-linked site lies N-terminal to the first cleavage site for the activation peptide, an important region of the protein that is removed to activate Factor IX. The novel site is an N-linked site in the serine protease domain with low occupancy in a non-canonical consensus motif at asparagine 258, observed with a HexNAc₄Hex₅NeuAc₂ monosaccharide composition attached. This is the first reported instance of a site of modification in the serine protease domain. The description of these glycosylation events provides a basis for future functional studies and contributes to structural characterisation of native Factor IX for the production of effective therapeutic biosimilars and biobetters.

'Do not Do' Recommendations in Hemophilia

BACKGROUND

It is important to discard those practices that do not add value. As a result, several initiatives have emerged. All of them try to improve patient safety and the use of health resources.

PURPOSE

To present a compendium of "do not do recommendations" in the context of hemophilia.

METHODS

A review of the literature and current clinical guidelines has been made, based on the best evidence available to date.

RESULTS

The following 13 recommendations stand out: 1) Do not delay the administration of factor after trauma; 2) do not use fresh frozen plasma or cryoprecipitate; 3) do not use desmopressin in case of hematuria; 4) do not change the product in the first 50 prophylaxis exposures; 5) do not interrupt immunotolerance; 6) do not administer aspirin or NSAIDs; 7) do not administer intramuscular injections; 8) do not do routine radiographs of the joint in case of acute hemarthrosis; 9) Do not apply closed casts for fractures; 10) do not discourage the performance of physical activities; 11) do not deny surgery to a patient with an inhibitor; 12) do not perform instrumental deliveries in fetuses with hemophilia; 13) do not use factor IX (FIX) in patients with hemophilia B with inhibitor and a history of anaphylaxis after administration of FIX.

CONCLUSION

The information mentioned previously can be useful in the management of hemophilia, from different levels of care. As far as we know, this is the first initiative of this type regarding hemophilia.

Systematic review and analysis of efficacy of recombinant factor IX products for prophylactic treatment of hemophilia B in comparison with rIX-FP

Aims: Prophylaxis with standard-acting recombinant factor IX (rFIX) in hemophilia B patients requires frequent injections. Extended half-life (EHL) products allow for prolonged dosing intervals, and so reduce this treatment burden. Three technologies are employed to extend the half-life of FIX; glycopegylation, Fc-fusion, and albumin fusion. rIX-FP is a novel albumin fusion protein, which allows for a prolonged dosing interval of up to 14 days. A systematic review and indirect statistical comparison was performed to evaluate the efficacy of both EHL and standard-acting rFIX products compared with rIX-FP in Phase III trials for prophylaxis in adult hemophilia B patients. Materials and methods: A systematic search was conducted in both EMBASE and PubMed to identify Phase III trials of prophylactic rFIX treatment in previously treated hemophilia B patients aged ≥12 years (FIX ≤2%). Annualized bleeding rate (ABR), spontaneous ABR (AsBR), and joint ABR (AjBR) data were extracted from each study. A z-test was performed using the mean of each parameter, and the mean difference in outcome between studies was calculated. Results: Seven articles investigating six rFIX products were identified. Median ABR, AsBR, and AjBR ranged from 0-3.0, 0-1.0, and 0-1.1 (means = 0.8-4.26, 0.13-2.6, and 0.34-2.85), respectively. rIX-FP achieved the lowest median and mean values in all three parameters. Z-tests showed that mean ABR was significantly lower for rIX-FP 7-day prophylaxis compared with the majority of standard-acting and other EHL rFIX products. Limitations: The low number of appropriate trials available for comparison limits the quantity of data available for comparison, and restricts the use of methods of adjustment for variance in study design or patient characteristics. However, these limitations are shared with similar analyses published in this field. Conclusion: This indirect comparison of Phase III trials indicates that rIX-FP efficacy compares favorably vs other rFIX products for prophylaxis in hemophilia B.

Management of Odontogenic Fascial Space Infection in Hemophilia Patients: A Proposed Protocol

Purpose

The purpose of this study was to suggest a protocol for the management of odontogenic space infections in patients with hemophilia which is often incompletely addressed by clinicians because of the fear of excessive bleeding leading to prolonged morbidity.

Methods and Results

Six diagnosed cases of hemophilia (four cases of hemophilia A and two cases of hemophilia B) with odontogenic fascial space infection were included in the study. Apart from routine investigations, assessments were also done to identify inhibitors to factor VIII/IX. Factor VIII/IX was replaced along with infusion of factor eight inhibitor bypass activity (FEIBA) one hour before incision and drainage. All the cases were treated by incision and drainage along with removal of foci under local anesthesia. The postoperative outcome was uneventful in all cases except one in which postoperative bleeding was noted from the extraction site on the third day which was again managed following the designed protocol.

Conclusion

Maintaining good oral hygiene and seeking early dental care are of prime importance in patients with hemophilia to avoid invasive procedures. However, if odontogenic infection develops in these patients, performing timely incision and drainage using our protocol will minimize the complications and give successful outcome.

Health-related quality of life in paediatric haemophilia B patients treated with rIX-FP

INTRODUCTION

Frequent infusions and bleeds can impact on the health-related quality of life (HRQoL) of paediatric haemophilia B patients. rIX-FP (IDELVION^® ) is a fusion protein linking recombinant factor IX with recombinant albumin, and is associated with low bleeding rates with a weekly regimen, which could improve HRQoL.

AIMS

To measure the effect of rIX-FP prophylaxis on the HRQoL of paediatric patients and treatment satisfaction in their caregivers using the Haemo-QoL and Hemo-SAT_P questionnaires, respectively.

METHODS

At baseline and end-of-study (EOS), patients 4-11 years old participating in the PROLONG-9FP program answered the Haemo-QoL questionnaire and gave information on their socio-demographic data and physical activity. Caregivers completed the Hemo-Sat_P . Minimal important differences (MID) (|Cohen's d| > 0.5) between baseline and EOS and the number of responders (patients with meaningful subject-level improvements over time) at EOS were calculated.

RESULTS

Twenty patients (age group I: 4-7 years old [n = 12]; age group II: 8-12 years old [n = 8]) completed the Haemo-QoL questionnaire at baseline. MIDs were found in age group I representing improvement for "physical health" (d = -0.547) domain; 60% of patients were responders for "physical health." In age group II, MIDs were seen in most domains; 71.4% patients were responders in "total score." In caregivers, improvements were seen for most domains of the Hemo-Sat_P with a small effect size. Fewer patients missed school when treated with rIX-FP and 94.1% patients maintained their physical activity level.

CONCLUSION

Prophylaxis with rIX-FP led to substantial improvements in HRQoL in paediatric patients and treatment satisfaction in caregivers.

Practical aspects of extended half-life products for the treatment of haemophilia

Haemophilia A and haemophilia B are congenital X-linked bleeding disorders caused by deficiency of coagulation factor VIII (FVIII) and IX (FIX), respectively. The preferred treatment option for patients with haemophilia is replacement therapy. For patients with severe disease, prophylactic replacement of coagulation factor is the treatment of choice; this has been shown to reduce arthropathy significantly, reduce the frequency of bleeds and improve patients' quality of life. Prophylaxis with standard recombinant factor requires regular intravenous infusion at least two (FIX) to three (FVIII) times a week. Recombinant FVIII and FIX products with an extended half-life are in development, or have been recently licensed. With reported mean half-life extensions of 1.5-1.8 times that of standard products for FVIII and 3-5 times that of standard products for FIX, these products have the potential to address many of the unmet needs of patients currently treated with standard factor concentrates. For example, they may encourage patients to switch from on-demand treatment to prophylaxis and improve the quality of life of patients receiving prophylaxis. Indeed, extended half-life products have the potential to reduce the burden of frequent intravenous injections, reducing the need for central venous lines in children, promote adherence, improve outcomes, potentially allow for more active lifestyles and, depending on the dosing regimen, increase factor trough levels. Members of the Zürich Haemophilia Forum convened for their 19th meeting to discuss the practicalities of incorporating new treatments into the management of people with haemophilia. This review of extended half-life products considers their introduction in haemophilia treatment, including the appropriate dose and schedule of infusions, laboratory monitoring, patient selection, safety considerations, and the economic aspects of care.

Tolerogenic properties of the Fc portion of IgG and its relevance to the treatment and management of hemophilia

Hemophilia, or inherited genetic deficiencies in coagulation factors, results in uncontrolled bleeding requiring replacement therapy with recombinant proteins given preventively or on demand. However, a major problem with these approaches is the potential for development of immune responses to the administered proteins due to the underlying genetic deficiency of the factor(s) throughout life. As such, there is great interest in developing strategies that avoid immunogenicity and induce immune tolerance. Recently, recombinant factor VIII (rFVIII) and rFIX fused to the crystallizable fragment (Fc) domain of immunoglobulin G (IgG) have been developed as therapeutic agents for hemophilia A and B, respectively. Although it is well known that the possession of an Fc domain confers IgG's longer-lasting circulating half-life, it is not generally appreciated that the Fc domain also confers immunoregulatory properties that are associated with the induction of tolerance. Here, we review some of the latest advances in our understanding of the tolerogenic abilities of IgG Fc and the impact of Fc-fusion proteins of rFVIII on the treatment of hemophilia.

Thrombogenicity evaluation in 221 patients with haemophilia B treated with nonacog alfa

Risk for thrombotic events with factor IX replacement therapy in patients with haemophilia B remains a concern for patients, those who treat them, and regulatory agencies, based on experience with early use of prothrombin complex concentrates. The current post hoc analysis assessed the incidence of thrombotic events and changes in prothrombin fragment 1 + 2, thrombin–antithrombin complex, and d-dimer in 221 patients with haemophilia B who received nonacog alfa in clinical studies. Thrombotic event and coagulation marker data were collected from 8 interventional studies utilizing on-demand, prophylactic, and preventive regimens in patients with haemophilia B. Mean age was 25 years (min–max, 0–69), with 51 (23%) patients aged less than 12 years and 15 (7%) aged less than 2 years. None tested positive for inhibitors. Mean time on study was 60.9 ± 32 weeks and mean number of exposure days was 69.3 (min–max, 1–496). Sixty-nine (31%) patients regularly received infusions that were approximately 100 IU/kg as part of a routine prophylaxis regimen, and 29 (13%) patients underwent surgical procedures. No clinical thrombotic events were reported, and no patient experienced clinically significant changes in coagulation markers between baseline and end-of-study testing. These collective data support the low thrombotic risk associated with nonacog alfa in paediatric, adult, and surgical patients with haemophilia B receiving different treatment regimens, including doses of approximately 100 IU/kg. Although careful thrombotic clinical evaluation is important, regular coagulation marker monitoring does not appear to be warranted in patients with haemophilia B.

Diagnosis and care of patients with mild haemophilia: practical recommendations for clinical management

Mild haemophilia is defined by factor levels between 0.05 and 0.40 IU/mL and is characterised by traumatic bleeds. Major issues associated with mild haemophilia are that it may not present for many years after birth, and that awareness, even within families, may be low. Methodological problems exist in diagnosis, such as inconsistencies in results obtained from different assays used to measure factor levels in mild haemophilia. Advances in genetic testing provide insight into diagnosis as well as the likelihood of inhibitor development, which is not uncommon in patients with mild or moderate haemophilia and can increase morbidity. The management of patients with mild haemophilia is a challenge. This review includes suggestions around formulating treatment plans for these patients, encompassing the full spectrum from clinical care of the newly diagnosed neonate to that of the ageing patient with multiple comorbidities. Management strategies consider not only the vast differences in these patients' needs, but also risks of inhibitor development and approaches to optimally engage patients.