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.

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

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

Extended half-life clotting factor concentrates: results from published clinical trials.

Extended half-life clotting factor concentrates have been recently introduced into the armamentarium of treatments for patients with haemophilia A and B. In general, the data from published studies have demonstrated these products to be safe with no inhibitors reported in previously treated patients and efficacious with the advantage of a longer half-life allowing for less frequent intravenous infusions of factor. This enhanced convenience has led to some patients not previously on prophylaxis to begin prophylaxis while for others, especially children, has led to the ability to provide prophylaxis with reduced use of central venous catheters. The extended half-life factor IX products are now allowing patients to dose every 1-2 weeks while maintaining higher trough levels while the extended half-life factor VIII products have reduced the frequency of administration for patients on prophylaxis to as infrequent as once per week for some patients and to twice per week for all patients including younger children. It is important to note that data from previously untreated patients have not been published yet and the incidence for inhibitors in this patient population is as of yet unknown. The era of extended half-life clotting factor products has begun and the challenge for the haemophilia community will be how to best integrate these products into haemophilia clinical practice.

Changes in the amino acid sequence of the recombinant human factor VIIa analog, vatreptacog alfa, are associated with clinical immunogenicity.

BACKGROUND: Vatreptacog alfa, a recombinant human factor VIIa (rFVIIa) analog developed to improve the treatment of bleeds in hemophilia patients with inhibitors, differs from native FVIIa by three amino acid substitutions. In a randomized, double-blind, crossover, confirmatory phase III trial (adept(™) 2), 8/72 (11%) hemophilia A or B patients with inhibitors treated for acute bleeds developed anti-drug antibodies (ADAs) to vatreptacog alfa. OBJECTIVES: To characterize the formation of anti-vatreptacog alfa ADAs in hemophilia patients with inhibitors. METHODS/PATIENTS: This was a post hoc analysis of adept(™) 2. Immunoglobulin isotype determination, specificity analysis of rFVIIa cross-reactive antibodies, epitope mapping of rFVIIa single mutant analogs and pharmacokinetic (PK) profiling were performed to characterize the ADAs. RESULTS: Immunoglobulin isotyping indicated that the ADAs were of the immunoglobulin G subtype. In epitope mapping, none of the rFVIIa single mutant analogs (V158D, E296V or M298Q) contained the complete antibody epitope, confirming that the antibodies were specific for vatreptacog alfa. In two patients, for whom PK profiling was performed both before and after the development of ADAs, vatreptacog alfa showed a prolonged elimination phase following ADA development. During the follow-up evaluation, the rFVIIa cross-reactivity disappeared after the last vatreptacog alfa exposure, despite continued exposure to rFVIIa as part of standard care. CONCLUSIONS: Results from the vatreptacog alfa phase III trial demonstrate that the specific changes made, albeit relatively small, to the FVIIa molecule alter its clinical immunogenicity.

Genetic factors influencing inhibitor development in a cohort of South African haemophilia A patients.

A critical complication of factor VIII (FVIII) replacement therapy in Haemophilia A (HA) treatment is inhibitor development. Known genetic factors predisposing to inhibitor development include FVIII (F8) gene mutations, ethnicity, a family history of inhibitors and FVIII haplotype mismatch. The aim of this study was to characterize and correlate these genetic factors in a cohort of South African HA patients. This was a retrospective study that included 229 patients and involved the analysis of patient files, HA molecular and clinical databases and molecular analysis of the F8 gene haplotype. Of the 229 patients, 51% were of black ethnicity, 49% were white, 5% had mild HA, 4% were moderate and 91% were severe, 36% were int22 positive and 13% were inhibitor positive. Of the inhibitor positive patients, 72% were black patients. Inhibitors were reported in 27% of black int22 positive patients, 13% of black int22 negative patients, 9% of white int22 positive patients and 7% of white int22 negative. The H1 haplotype was more common in whites (75%) and H2 was more common in blacks (74%). H3 and H5 were only found in black patients and had a higher frequency of inhibitor development than H1 and H2. In this small HA cohort, black patients had a significantly higher frequency of inhibitor development and the results were indicative of an association between inhibitor development, ethnicity and haplotype.

Recombinant factor VIIa analog in the management of hemophilia with inhibitors: results from a multicenter, randomized, controlled trial of vatreptacog alfa.

BACKGROUND: Vatreptacog alfa, a recombinant factor VIIa (rFVIIa) analog with three amino acid substitutions and 99% identity to native FVIIa, was developed to improve the treatment of hemophilic patients with inhibitors. OBJECTIVES: To confirm the safety and assess the efficacy of vatreptacog alfa in treating bleeding episodes in hemophilic patients with inhibitors. PATIENTS AND METHODS: In this international, multicenter, randomized, double-blind, active-controlled, crossover, confirmatory phase III trial (adept(™) 2) in patients with hemophilia A or B and inhibitors, bleeds were randomized 3 : 2 to treatment with vatreptacog alfa (one to three doses at 80 µg kg(-1) ) or rFVIIa (one to three doses at 90 µg kg(-1) ). Treatment failures after three doses of trial product (TP) were managed according to the local standard of care. RESULTS: In the 72 patients enrolled, 567 bleeds were treated with TP. Both vatreptacog alfa and rFVIIa gave 93% effective bleeding control at 12 h. Vatreptacog alfa was superior to rFVIIa in secondary efficacy outcomes, including the number of doses used to treat a bleed and sustained bleeding control 24-48 h after the first dose. Eight patients (11%) developed antibodies against vatreptacog alfa, including four with cross-reactivity against rFVIIa and one with an in vitro neutralizing effect to vatreptacog alfa. CONCLUSIONS: This large randomized controlled trial confirmed the well-established efficacy and safety profile of rFVIIa, and showed that vatreptacog alfa had similar or better efficacy than rFVIIa. However, because of the development of anti-drug antibodies, a positive benefit-risk profile is unlikely to be achieved with vatreptacog alfa.

Assessment of outcomes.

Effective healthcare delivery necessitates evaluation of the effect of interventions in the form of outcome assessment. Treatment effect includes measurement of how the patient feels, functions and survives following healthcare interventions. In haemophilia, which is a rare bleeding disorder, outcome assessment was characterized by a lack of validated outcome measurement tools and the challenges of hemophilia study design to collect outcome data. The aim of this communication is to share current thinking and, through practical examples, provide a state of the art practice in the assessment of hemophilia outcomes from a healthcare provider, patient/family and funder perspective. This discussion is timely and particularly relevant to the care of people with hemophilia on the eve of a number of novel hemophilia treatment products which are about to be licensed for use, specifically the long-acting factor VIII and factor IX concentrates. The first section by Dr Blanchet gives an overview of the tools currently available for assessment of structure/function, patient activities and patient participation in hemophilia healthcare delivery, pointing out the challenge of developing new tools and appropriate validation of currently available tools. The second section by Mr Brian O'Mahony emphasizes the essential collaboration and partnership between healthcare providers and people with hemophilia in collating the outcome data. In the third and final section, Mr Leigh McJames, gives a funder's perspective of the desirable outcomes of hemophilia care.

Guidelines for the management of hemophilia.

Hemophilia is a rare disorder that is complex to diagnose and to manage. These evidence-based guidelines offer practical recommendations on the diagnosis and general management of hemophilia, as well as the management of complications including musculoskeletal issues, inhibitors, and transfusion-transmitted infections. By compiling these guidelines, the World Federation of Hemophilia aims to assist healthcare providers seeking to initiate and/or maintain hemophilia care programs, encourage practice harmonization around the world and, where recommendations lack adequate evidence, stimulate appropriate studies.

Phase I, randomized, double-blind, placebo-controlled, single-dose escalation study of the recombinant factor VIIa variant BAY 86-6150 in hemophilia.

BACKGROUND: BAY 86-6150 is a new human recombinant factor VIIa variant developed for high procoagulant activity and longer action in people with hemophilia with inhibitors. OBJECTIVES: To investigate the safety, tolerability, pharmacodynamics, pharmacokinetics and immunogenicity of BAY 86-6150 in non-bleeding hemophilia subjects. METHODS: The study included non-bleeding men (18-65 years of age) with moderate or severe hemophilia A or B with or without inhibitors. Sixteen subjects were randomized 3 : 1 to four cohorts of escalating doses of BAY 86-6150 (6.5, 20, 50 or 90 µg kg(-1) [n = 3 per cohort]) or placebo (n = 1 per cohort); an independent data-monitoring committee reviewed previous cohort data before the next dose escalation. Blood sampling was performed predose and postdose; subjects were monitored for 50 days postdose. RESULTS: At the tested doses, BAY 86-6150 was not associated with clinically significant adverse events or dose-limiting toxicities. BAY 86-6150 pharmacokinetics exhibited a linear dose response, with a half-life of 5-7 h. Subjects demonstrated consistent, dose-dependent thrombin generation ex vivo in platelet-poor plasma (PPP) (mean peak effect, 26-237 nm thrombin from 6.5 to 90 µg kg(-1)). Peak thrombin levels over time paralleled BAY 86-6150, with thrombin kinetics appearing to be slightly shorter; thus, circulating BAY 86-6150 retained activity. There were corresponding decreases in activated partial thromboplastin and prothrombin times. No subject developed de novo anti-BAY 86-6150 neutralizing antibodies during the 50-day follow-up. CONCLUSIONS: In this first-in-human, multicenter, randomized, double-blind, placebo-controlled, single-dose escalation study, BAY 86-6150 was tolerated at the highest dose (90 µg kg(-1)), with no safety concerns. Safety and efficacy will be further evaluated in phase II/III studies.