Prophylaxis is the new standard of care in patients with haemophilia.

Randomised controlled clinical trial evidence on prophylaxis as optimal care for patients with haemophilia was generated more than a decade ago. However, this knowledge has not translated into clinical practice in South Africa (SA) owing to many barriers to prophylaxis. These include the high treatment burden imposed by prophylaxis (frequent injections two to four times a week), the need for intravenous access to administer replacement clotting factor therapies, and the higher volume of clotting factor required compared with episodic treatment. The recently introduced non-factor therapies in haemophilia care have addressed many of these barriers. For example, emicizumab, which is currently the only globally approved non-factor therapy, can be administered subcutaneously less frequently (weekly, fortnightly or every 4 weeks) and has led to global adoption of prophylaxis as the standard of care in haemophilia by the bleeding disorders community. Haemophilia A is the most prevalent clotting factor deficiency in SA, with >2 000 people diagnosed to date. However, only a few of these patients are currently on prophylaxis. In this 'In Practice' article, we review the rationale for prophylaxis, outline its goals and benefits, and provide evidence-based guidance on which haemophilia patients should be prioritised for emicizumab prophylaxis. This consensus guidance facilitates the adoption of prophylaxis as a national policy and the new standard of care in haemophilia in SA.

Home therapy for inherited bleeding disorders in South Africa: Results of a modified Delphi consensus process.

BACKGROUND: Optimal care of patients with inherited bleeding disorders requires that bleeding episodes are treated early, or still better prevented, through extension of patient care beyond hospital-based treatment to home-based therapy. In South Africa (SA), adoption of home therapy is variable, in part owing to lack of consensus among healthcare providers on what constitutes home therapy, which patients should be candidates for it, how it should be monitored, and what the barriers to home therapy are. OBJECTIVES: To conduct a modified Delphi process in order to establish consensus on home therapy among haemophilia healthcare providers in SA. METHODS: Treaters experienced in haemophilia care were invited to participate in a consensus-seeking process conducted in three rounds. In round 1, provisional statements around home therapy were formulated as questions and collated in a structured list. In rounds 2 and 3, evolving versions of the questionnaire were administered to participants. Consensus was defined as ≥70% agreement among the participants. RESULTS: The panel composition included an equal number of physicians and non-physicians. The participation rate was 100% through all three consensus rounds. The group reached consensus for 92% of the statements. Consensus of 100% was reached on starting home therapy in paediatric patients, requiring all patients on home therapy to sign informed consent and indemnity, and providing round-the-clock support for patients on home therapy. CONCLUSIONS: The home therapy consensus statements in this report have the potential to translate to policy on home therapy and to guide the initiation, practice and evaluation of home therapy programmes in SA.

Gene and cell therapy in South Africa: Current status and future prospects.

South Africa has a high disease burden resulting from communicable and non-communicable diseases. Current therapeutic interventions rarely result in a cure and the associated lifelong treatment places a considerable strain on an overburdened health sector. Gene and cell therapies present novel alternatives to disease management, offering the promise of a single treatment and a lifelong cure. Although challenges remain, investment in the field has started to bear fruit, with a number of gene and cell therapeutics reaching the market in the past decade. To take full advantage of these developments, it is important that a proactive approach to nurturing appropriate human and material resources is adopted in the country.

Patient blood management: A solution for South Africa.

For more than 70 years the default therapy for anaemia and blood loss was mostly transfusion. Accumulating evidence demonstrates a significant dose-dependent relationship between transfusion and adverse outcomes. This and other transfusion-related challenges led the way to a new paradigm. Patient blood management (PBM) is the application of evidence-based practices to optimise patient outcomes by managing and preserving the patient's own blood. 'Real-world' studies have shown that PBM improves patient outcomes and saves money. The prevalence of anaemia in adult South Africans is 31% in females and 17% in males. Improving the management of anaemia will firstly improve public health, secondly relieve the pressure on the blood supply, and thirdly improve the productivity of the nation's workforce. While high-income countries are increasingly implementing PBM, many middle- and low-income countries are still trying to upscale their transfusion services. The implementation of PBM will improve South Africa's health status while saving costs.

Gene and cell therapy in South Africa: current status and future prospects

South Africa has a high disease burden resulting from communicable and non-communicable diseases. Current therapeutic interventions rarely result in a cure and the associated lifelong treatment places a considerable strain on an overburdened health sector. Gene and cell therapies present novel alternatives to disease management, offering the promise of a single treatment and a lifelong cure. Although challenges remain, investment in the field has started to bear fruit, with a number of gene and cell therapeutics reaching the market in the past decade. To take full advantage of these developments, it is important that a proactive approach to nurturing appropriate human and material resources is adopted in the country

Home therapy for inherited bleeding disorders in south Africa: results of a modified delphi consensus process

Background. Optimal care of patients with inherited bleeding disorders requires that bleeding episodes are treated early, or still better prevented, through extension of patient care beyond hospital-based treatment to home-based therapy. In South Africa (SA), adoption of home therapy is variable, in part owing to lack of consensus among healthcare providers on what constitutes home therapy, which patients should be candidates for it, how it should be monitored, and what the barriers to home therapy are.Objectives. To conduct a modified Delphi process in order to establish consensus on home therapy among haemophilia healthcare providers in SA.Methods. Treaters experienced in haemophilia care were invited to participate in a consensus-seeking process conducted in three rounds. In round 1, provisional statements around home therapy were formulated as questions and collated in a structured list. In rounds 2 and 3, evolving versions of the questionnaire were administered to participants. Consensus was defined as ≥70% agreement among the participants.Results. The panel composition included an equal number of physicians and non-physicians. The participation rate was 100% through all three consensus rounds. The group reached consensus for 92% of the statements. Consensus of 100% was reached on starting home therapy in paediatric patients, requiring all patients on home therapy to sign informed consent and indemnity, and providing round-the-clock support for patients on home therapy.Conclusions. The home therapy consensus statements in this report have the potential to translate to policy on home therapy and to guide the initiation, practice and evaluation of home therapy programmes in SA

Emerging therapies for haemophilia - Global perspective.

The therapeutic options for people with haemophilia (PWH) have rapidly evolved in the last 5 years. Moving on from conventional plasma-derived and recombinant clotting factor concentrates (CFC), there now are extended half-life CFCs (~1.8× for FVIII and ~4.5× for FIX) to as well as several novel haemostasis agents administered subcutaneously (weekly to monthly) such as bispecific antibody which brings together FIXa with FX like FVIII, a liver-targeted siRNA against antithrombin which can reduce its levels enough to allow significant haemostasis and an antibody against tissue factor pathway inhibitor which then also enhances haemostasis. Successful gene therapy for both haemophilia A and haemophilia B has been demonstrated by gene transfer using adeno-associated virus vectors. Sustained clinically significant elevation (>5%) to normal factor levels has been demonstrated. Some of these products have already obtained market authorization whilst others are at various stages of development. The choices of products for the treatment of haemophilia have never been better. Whilst the immediate superiority of all these products providing better haemostasis and convenience than conventional CFCs, their exact position in the clinical algorithm will need to be defined based on the long-term safety and efficacy data. However, most of these products are likely to remain out of reach of >70% of PWH in the world. The biggest challenge will be to find and establish mechanisms for wider access to these transformational haemostasis products for all PWH around the world.

Pharmacokinetic modelling and validation of the half-life extension needed to reduce the burden of infusions compared with standard factor VIII.

INTRODUCTION: Currently, no universally accepted definition of extended half-life (EHL) recombinant FVIII (rFVIII) exists. Identifying the minimum half-life extension ratio required for a reduction in dosing frequency compared with standard rFVIII could enable a more practical approach to decisions around prophylaxis with EHL rFVIII. AIM: To identify the half-life extension ratio required to decrease rFVIII dosing frequency by at least 1 day while maintaining the proportion of patients with plasma rFVIII levels above 1 IU/dL and without increasing the total weekly dose. METHODS: A previously published population pharmacokinetic model for standard rFVIII was used to estimate the percentage of patients with factor VIII (FVIII) levels always >1 IU/dL using various benchmark regimens. Using modelling, dosing frequency was reduced while rFVIII half-life was extended until the percentage of patients with FVIII >1 IU/dL equalled that of the benchmark regimen. RESULTS: Benchmark 3×/wk dosing totalling 100 IU/kg/wk of rFVIII resulted in 56.6% of patients with FVIII levels always >1 IU/dL. With 2×/wk dosing, totalling 80 or 90 IU/kg/wk, half-life extensions required to maintain 56.6% of patients at FVIII levels >1 IU/dL were 1.30 and 1.26, respectively. A half-life extension ratio of 1.33 was required to change dosing from every 48 hours to every 72 hours (both at 105 IU/kg/wk) while maintaining 92.8% of patients with FVIII >1 IU/dL. CONCLUSION: Based on this investigation, EHL rFVIII products should have a minimum half-life extension ratio of 1.3 to provide a reduction in dosing frequency from 3× to 2×/wk compared with standard rFVIII products while maintaining the same minimum FVIII trough level.

Defining extended half-life rFVIII-A critical review of the evidence.

INTRODUCTION: Recent haemophilia treatment advances include new recombinant FVIII (rFVIII) products with improved pharmacokinetic (PK) properties that aim to reduce the burden of prophylaxis. These treatments are commonly referred to as extended half-life rFVIII products (EHL rFVIII). There is no uniform definition of what constitutes an EHL rFVIII. Such a definition would help physicians, patients and funders understand the properties of standard and EHL rFVIIIs and thus provide clarity when selecting an EHL in clinical settings. AIM: To critically assess the published evidence on new and emerging rFVIII products in order to propose a definition to classify EHL rFVIIIs. METHODS: We systematically searched PubMed, EMBASE and regulatory authorities (FDA/EMA/Health Canada) websites for publications and regulatory submissions describing prospective crossover PK studies evaluating rFVIIIs that demonstrate improved PK parameters in adults and adolescents with severe haemophilia A. RESULTS: Following critical analyses of the published data, we developed a holistic approach to defining rFVIIIs as EHLs, which requires all of the following: (i) using technology designed to extend rFVIII half-life; (ii) lacking bioequivalence with a standard rFVIII comparator-above the FDA/EMA cut-off of 125% for the 90% confidence intervals for area under the curve ratio; and (iii) having an extended half-life ratio measured in a PK comparator crossover study. CONCLUSION: In this systematic review, a pragmatic definition of EHL rFVIII has been proposed that should provide better clarity in clinical discussions surrounding the appropriate use of rFVIII products. At present, only products using PEGylation or Fc fusion half-life extension technology meet the proposed criteria for definition of EHL rFVIII.

Improved joint health in subjects with severe haemophilia A treated prophylactically with recombinant factor VIII Fc fusion protein.

INTRODUCTION: Joint arthropathy is the long-term consequence of joint bleeding in people with severe haemophilia. AIM: This study assessed change in joint health over time in subjects receiving recombinant factor VIII Fc fusion protein (rFVIIIFc) prophylaxis. METHODS: ALONG is the phase 3 pivotal study in which the benefit of rFVIIIFc as a prophylactic treatment for bleeding control was shown in previously treated severe haemophilia patients ≥12 years of age (arm 1: 25-65 IU/kg every 3-5 days, arm 2: 65 IU/kg weekly and arm 3: episodic). After completing ALONG, subjects had the option to enrol into the extension study (ASPIRE). This interim, post hoc analysis assessed changes in joint health over ~2.8 years in these patients. RESULTS: Forty-seven subjects had modified Haemophilia Joint Health Score (mHJHS) data at A-LONG baseline, ASPIRE baseline and ASPIRE Year 1 and Year 2. Compared with A-LONG baseline (23.4), mean improvement at ASPIRE Year 2 was -4.1 (95% confidence interval [CI], -6.5, -1.8; P = .001). Regardless of prestudy treatment regimen, subjects showed continuous improvement in mHJHS from A-LONG baseline through ASPIRE Year 2 (prestudy prophylaxis: -2.4, P = .09; prestudy episodic treatment: -7.2, P = .003). Benefits were seen in subjects with target joints (-5.6, P = .005) as well as those with severe arthropathy (-8.8, P = .02). The mHJHS components with the greatest improvement at ASPIRE Year 2 were swelling (-1.4, P = .008), range of motion (-1.1, P = .03) and strength (-0.8, P = .04). CONCLUSIONS: Prophylaxis with rFVIIIFc may improve joint health over time regardless of prestudy prophylaxis or episodic treatment regimens.

Deep-vein thrombosis in the era of high HIV and tuberculosis prevalence: A prospective review of its diagnosis and treatment in a quaternary centre.

BACKGROUND: Venous thromboembolic disease (VTE) is a leading cause of morbidity and mortality worldwide. HIV and tuberculosis (TB) infections have an aetiological association with VTE. Implementation of national HIV and TB programmes in South Africa (SA) has changed the burden of these two conditions, with resultant effects on VTE prevalence. Furthermore, with the increased use of direct oral anticoagulants (DOACs), baseline thrombosis data are needed to evaluate the effect of these new agents. OBJECTIVES: To determine real-life baseline VTE characteristics in a pre-DOAC era, and to document the association of HIV and TB infections with VTE. METHODS: This was a single-centre prospective cohort study performed in a quaternary care centre at Charlotte Maxeke Johannesburg Academic Hospital, SA. Key inclusion criteria included signed informed consent by adults (≥18 years) with a new episode of thrombosis. Procedures included physical examination, thrombosis risk factor assessment, duplex Doppler examination, thrombophilia screening, inpatient treatment and outpatient follow-up. RESULTS: Ninety-nine participants with confirmed thrombosis met the inclusion criteria. Participants were predominantly black (79.8%) and female (64.6%), with a median age of 46 (interquartile range (IQR) 38 - 57) years. The prevalences of HIV and TB were 53.0% and 21.2%, respectively. The most common risk factors for thrombosis were TB (17.2%) and malignancies (14.1%). Thrombophilia screening had a low diagnostic yield. The median time to target international normalised ratio during hospitalisation was 5.5 (IQR 4.0 - 7.0) days and the median duration of hospitalisation was 9 (IQR 7 - 11) days. The overall mortality rate in the cohort at 3 months post hospitalisation was 12.1%. CONCLUSIONS: This prospective study provides real-life data on thrombosis diagnosis and management at a quaternary public healthcare facility, providing a valuable baseline against which the effect of new DOAC anticoagulants can be assessed. Further research is required to clarify the aetiological association between thrombosis and HIV and TB.

Treatment of bleeding episodes with recombinant factor VIII Fc fusion protein in A-LONG study subjects with severe haemophilia A.

INTRODUCTION: The Phase 3 A-LONG study demonstrated the safety and efficacy of rFVIIIFc for the control and prevention of bleeding episodes in severe haemophilia A. AIM: To describe the treatment of bleeding episodes with rFVIIIFc in the A-LONG study. METHODS: A-LONG subjects (<1 IU dL-1 endogenous FVIII) were treated with individualized prophylaxis (Arm 1), weekly prophylaxis (Arm 2) or episodic treatment (Arm 3). Information recorded for each bleeding episode included type, location and dose to treat the episode. RESULTS: During A-LONG, 757 bleeding episodes occurred during the efficacy period; the majority [456 (60%)] occurred in Arm 3 (episodic treatment). Of 93 subjects in the prophylaxis arms who entered the study with target joints, 43 (60%) in Arm 1 and 11 (52%) in Arm 2 did not experience a target joint bleed. Overall, 98% of bleeding episodes (and 98% of bleeds involving a target joint) resolved with one or two infusions; the median dose per infusion to treat a bleed was 27 IU kg-1 (27 IU kg-1 for target joints). Using population pharmacokinetic simulations, FVIII activity levels were predicted to be below the upper limit of normal (150 IU dL-1 ) in most patients in the event that rFVIIIFc is used to treat a bleeding episode in close proximity to a prophylactic dose. CONCLUSIONS: These findings demonstrate the efficacy of rFVIIIFc for the treatment of acute bleeding episodes in subjects with severe haemophilia A, regardless of treatment regimen.

Low-factor consumption for major surgery in haemophilia B with long-acting recombinant glycoPEGylated factor IX.

INTRODUCTION: Surgery in patients with haemophilia B carries a high risk of excessive bleeding and requires adequate haemostatic control until wound healing. Nonacog beta pegol, a long-acting recombinant glycoPEGylated factor IX (FIX), was used in the perioperative management of patients undergoing major surgery. AIM: To evaluate the efficacy and safety of nonacog beta pegol in patients with haemophilia B who undergo major surgery. METHODS: This was an open-label, multicentre, non-controlled surgery trial aimed at assessing peri- and postoperative efficacy and safety of nonacog beta pegol in 13 previously treated patients with haemophilia B. All patients received a preoperative nonacog beta pegol bolus injection of 80 IU kg-1 . Postoperatively, the patients received fixed nonacog beta pegol doses of 40 IU kg-1 , repeated at the investigator's discretion. Safety assessments included monitoring of immunogenicity and adverse events. RESULTS: Intraoperative haemostatic effect was rated 'excellent' or 'good' in all 13 cases. Apart from the preoperative injection, none of the patients needed additional doses of nonacog beta pegol on the day of surgery. The median number of postoperative doses of nonacog beta pegol was 2.0 from days 1 to 6 and 1.5 from days 7 to 13. No unexpected intra- or postoperative complications were observed including deaths or thromboembolic events. No patients developed inhibitors. CONCLUSIONS: These results indicated that nonacog beta pegol was safe and effective in the perioperative setting, allowing major surgical interventions in patients with haemophilia B with minimal peri- and postoperative concentrate consumption and infrequent injections as reported with standard FIX products.

Recombinant B-domain-deleted porcine sequence factor VIII (r-pFVIII) for the treatment of bleeding in patients with congenital haemophilia A and inhibitors.

INTRODUCTION: Development of inhibitors to human FVIII (hFVIII) significantly complicates the control of bleeding events in patients with haemophilia A. AIM: This prospective, multicentre, open-label, non-comparative, Phase II study evaluated the haemostatic activity of a recombinant B-domain-deleted porcine FVIII (r-pFVIII), in the treatment of non-life/non-limb-threatening bleeding in individuals with haemophilia A and FVIII inhibitors. METHODS: Acute bleeding episodes in patients with pFVIII inhibitor titres <0.8 BU mL-1 were treated with 50 U kg-1 body weight r-pFVIII. Those with pFVIII inhibitor titres of >0.8 BU mL-1 received an initial calculated r-pFVIII loading dose followed by 50 U kg-1 treatment dose. Treatment continued at 6-hourly intervals until bleeding was determined, controlled or till a maximum of eight doses was reached. RESULTS: All 25 bleeding episodes in nine patients (mean age: 23.7 years; range: 14-34 years) were controlled successfully with eight or fewer injections of r-pFVIII. The median time from bleeding onset to the administration of r-pFVIII was 5.7 h (range: 1.5-20.0 h). Twenty of the bleeding episodes (80%) were controlled with one treatment dose of r-pFVIII (with or without a loading dose, median dose: 200.8 U kg-1 ; range: 50-576 U kg-1 ) regardless of pFVIII level. r-pFVIII was well tolerated and no treatment-emergent serious adverse events were considered by the investigator to be related to r-pFVIII administration. CONCLUSION: The results suggest that FVIII replacement therapy with r-pFVIII could be a viable alternative to bypassing agents for the treatment of bleeding episodes in individuals with haemophilia A and FVIII inhibitors.

Deep-vein thrombosis in the era of high HIV and tuberculosis prevalence: A prospective review of its diagnosis and treatment in a quaternary centre

Background. Venous thromboembolic disease (VTE) is a leading cause of morbidity and mortality worldwide. HIV and tuberculosis (TB) infections have an aetiological association with VTE. Implementation of national HIV and TB programmes in South Africa (SA) has changed the burden of these two conditions, with resultant effects on VTE prevalence. Furthermore, with the increased use of direct oral anticoagulants (DOACs), baseline thrombosis data are needed to evaluate the effect of these new agents.Objectives. To determine real-life baseline VTE characteristics in a pre-DOAC era, and to document the association of HIV and TB infections with VTE.Methods. This was a single-centre prospective cohort study performed in a quaternary care centre at Charlotte Maxeke Johannesburg Academic Hospital, SA. Key inclusion criteria included signed informed consent by adults (≥18 years) with a new episode of thrombosis. Procedures included physical examination, thrombosis risk factor assessment, duplex Doppler examination, thrombophilia screening, inpatient treatment and outpatient follow-up.Results. Ninety-nine participants with confirmed thrombosis met the inclusion criteria. Participants were predominantly black (79.8%) and female (64.6%), with a median age of 46 (interquartile range (IQR) 38 - 57) years. The prevalences of HIV and TB were 53.0% and 21.2%, respectively. The most common risk factors for thrombosis were TB (17.2%) and malignancies (14.1%). Thrombophilia screening had a low diagnostic yield. The median time to target international normalised ratio during hospitalisation was 5.5 (IQR 4.0 - 7.0) days and the median duration of hospitalisation was 9 (IQR 7 - 11) days. The overall mortality rate in the cohort at 3 months post hospitalisation was 12.1%.Conclusions. This prospective study provides real-life data on thrombosis diagnosis and management at a quaternary public healthcare facility, providing a valuable baseline against which the effect of new DOAC anticoagulants can be assessed. Further research is required to clarify the aetiological association between thrombosis and HIV and TB

Evaluation of the utility of the ISTH-BAT in haemophilia carriers: a multinational study.

INTRODUCTION: There has been increasing recognition in recent years that female carriers of haemophilia manifest abnormal bleeding; however, data on the use of bleeding assessment tools in this population are lacking. AIM: Our objective was to validate the ISTH-BAT in haemophilia carriers to describe bleeding symptoms and allow for comparisons with factor levels and other patient groups. METHODS: This was a prospective, observational, cross-sectional study performed by members of Global Emerging HEmostasis Panel (GEHEP). Unselected consecutive haemophilia carriers were recruited and a CRF and the ISTH-BAT were completed by study personnel. RESULTS: A total of 168 haemophilia carriers were enrolled: 155 haemophilia A and 13 haemophilia B. The mean age was 40 years (range: 20-82). Carriers had higher mean bleeding scores (BS) compared with age-matched controls (n = 46; 5.7 vs. 1.43; P < 0.0001) and Type 3 VWD OC (n = 32; 3.0; P = 0.009), but lower BS compared with women with Type 1 VWD (n = 83; 8.7; P < 0.0001). Fifteen carriers reported haemarthrosis, and of those six had normal FVIII/FIX levels. There was a significant but weak negative correlation between BS and factor level (Spearman's r2  = -0.36, P < 0.001). CONCLUSION: Our results show that haemophilia carriers experience abnormal bleeding, including haemarthrosis. Overall, BS in women with Type 1 VWD > haemophilia carriers > Type 3 VWD OC > controls. Understanding the performance of the ISTH-BAT in this population is a critical step in future research aimed at investigating the underlying pathophysiology of abnormal bleeding, with the ultimate goal of optimizing treatment.

TRUST trial: BAY 86-6150 use in haemophilia with inhibitors and assessment for immunogenicity.

INTRODUCTION: The most serious and challenging complication of haemophilia treatment is development of inhibitors to replacement factors VIII or IX. Innovative therapies currently being explored for patients with haemophilia and inhibitors include BAY 86-6150, a modified recombinant activated factor VII (FVIIa). Immunogenicity remains a substantial barrier in this endeavour. AIM: To present safety and efficacy results of the BAY 86-6150 study in patients with inhibitors and report detailed analysis of epitope mapping in a patient who developed anti-BAY 86-6150 antibodies. METHODS: Patients aged 12-62 years with moderate or severe haemophilia A or B were eligible for the phase 3 TRUST trial if they had a history of high-titre inhibitors. Four escalating doses of BAY 86-6150 (6.5, 20, 50, 90 µg kg-1 ) were planned with ≥10 patients per dose level. Bleeding episodes were treated with BAY 86-6150. Development of anti-BAY 86-6150 antibodies was considered a serious adverse event. RESULTS: TRUST was discontinued after one patient in the 6.5-µg kg-1 cohort developed anti-BAY 86-6150 neutralizing antibodies following three exposures. The anti-BAY 86-6150 antibodies cross-reacted with and neutralized wild-type FVIIa (WT-FVIIa). Post hoc epitope mapping using peripheral blood mononuclear cells from the responding patient found that none of the 14 peptides unique to BAY 86-6150 were recognized by the patient's T cells, but strong responses were detected against 2 WT-FVIIa peptides. CONCLUSION: In the single patient with haemophilia A who developed anti-BAY 86-6150 antibodies, results of T-cell epitope mapping indicated BAY 86-6150 was no more immunogenic than WT-FVIIa.