The need for speed in the management of haemophilia patients with inhibitors

Bleeding in patients with hemophilia who have inhibitors: Modeling US medical system utilization and cost avoidance between recombinant factor VIIa products with different clinical dosing requirements

BACKGROUND: A mainstay of treatment in patients with hemophilia with inhibitors (PWIs) is the use of a recombinant factor VIIa (rFVIIa) bypassing agent. A new rFVIIa product may allow reduced rFVIIa utilization for on-demand treatment of bleeding episodes (BEs). OBJECTIVE: A decision analytic health economic model was developed to compare the utilization and consequent need for bleed-related clinical encounters of 2 rFVIIa products, with the International Nomenclature Name of eptacog alfa (EA) and eptacog beta (EB). METHODS: This study uses recent, peer-reviewed, and published data from clinical trials with similar endpoints for 1 million insured male lives in the United States. rFVIIa product utilization was modeled in hemophilia (A and B) PWI for on-demand treatment of BEs with rFVIIa treatment. Estimated annual BE rates were modeled to include prophylaxis and on-demand management. The clinical encounter avoidance estimates are based on refractory bleeding through 24 hours. RESULTS: In a cohort of 1 million insured, 5-6 patients with hemophilia A or B with inhibitors annually receive on-demand treatment for a total of 59 mild/moderate BEs. The model suggests that EB requires less unit utilization per BE (13,125 μg and 17,850 μg for the 75μg/kg and 225μg/kg dose regimens, respectively) than EA 90 μg/kg dosing (20,178μg), with wholesale acquisition costs expanding the difference. Further, both EB initial dose regimens would permit decreased total nonmedication health plan spending for the acute treatment of BEs by reducing the need for clinical encounters arising from BEs that fail to respond within 24 hours. CONCLUSIONS: With reduced infusion requirements, the model consistently shows that EB could generate lower insured-cohort drug utilization, as well as reduce costly clinical encounters by keeping mild and moderate BEs amenable to home bypassing agent management. DISCLOSURES: The article was funded by HEMA Biologic, LLC. The authors approved all content and results in this article without being subject to sponsor censorship. Mr Jensen, Mr Cyr, and Ms Hathway are employees of PRECISIONheor, which provides consulting services to the pharmaceutical industry, including HEMA Biologics, LLC. Dr Batt is an advisor to PRECISIONheor. Dr Alexander is a former employee of HEMA Biologics, LLC, and provides consulting services to the pharmaceutical industry.

The evolution of factor VIIa in the treatment of bleeding in haemophilia with inhibitors

The use of activated factor VII (FVIIa) for the treatment of bleeding events in haemophilia patients with inhibitors was first reported over 30 years ago. Since then clinical trials, registries, case series, real‐world experience and an understanding of its mechanism of action have transformed what was originally a scientific curiosity into one of the major treatments for inhibitor patients, with innovative therapeutic regimens, dose optimization and individualized care now widely practiced. Given current understanding and use, it might be easy to forget the years of clinical research that led up to this point; in this review, we lay out changes based on broad eras of rFVIIa use. These eras cover the original uncertainty associated with dosing, efficacy and safety; the transformation of care ushered in with its widespread use; and the optimization and individualization of patient care and the importance of specialized support provided by haemophilia treatment centres. Today with the introduction of novel prophylactic agents such as emicizumab, we once again find ourselves dealing with the uncertainties of how best to utilize rFVIIa and newer investigational variants such as marzeptacog alfa and eptacog beta; we hope that the experiences of the past three decades will serve as a guide for this new era of care.

Safety analysis of rFVIIa with emicizumab dosing in congenital hemophilia A with inhibitors: Experience from the HAVEN clinical program

BACKGROUND

Recombinant activated factor VII (rFVIIa; eptacog alfa activated, NovoSeven® , Novo Nordisk A/S) is a bypassing agent used in congenital hemophilia A patients with inhibitors. Emicizumab (Hemlibra® ; F Hoffmann-La Roche Ltd) is a recombinant, humanized, bispecific monoclonal antibody used for routine prophylaxis in patients with congenital hemophilia A with inhibitors. Concomitant use of the hemostatic agents rFVIIa and emicizumab carries a theoretical increased risk of thrombotic complications. Roche and Novo Nordisk collaboratively analyzed all available data on the use of rFVIIa in patients receiving emicizumab prophylaxis in the Study to Evaluate the Efficacy, Safety, and Pharmacokinetics of Prophylactic Emicizumab Versus no Prophylaxis in Hemophilia A Participants With Inhibitors (HAVEN) clinical development program.

OBJECTIVE

Obtain further insights into the concomitant clinical use and safety of rFVIIa and emicizumab.

METHODS

The initial individual rFVIIa dose, dosing intervals and cumulative dosing were evaluated in the HAVEN 1, HAVEN 2, and HAVEN 4 trials. All adverse events reported in each of the three trials in patients treated with rFVIIa, including available narratives, were assessed.

RESULTS

The vast majority of bleeds occurred in HAVEN 1. When rFVIIa was used to treat a bleeding episode, a 100 ± 20 μg/kg dose was used to initiate treatment in the majority of cases. The dosing interval, as well as cumulative dosing were consistent with prescribing information and current practice. No serious adverse events, no thrombotic microangiopathy cases, or thromboembolic events were assessed to be associated with rFVIIa when used in conjunction with emicizumab prophylaxis in the HAVEN trials.

CONCLUSION

rFVIIa use in the context of emicizumab prophylaxis does not change the rFVIIa safety profile as described in the product information.

Real-World Early Treatment with Room Temperature-Stable Recombinant Factor VIIa in Hemophilia A/B and Inhibitors: SMART-7™ Post Hoc Analyses

Treating hemophilia A or B patients with inhibitors is particularly challenging, as they do not respond to replacement therapy with factor VIII or factor IX concentrates. A room temperature–stable formulation of recombinant activated factor VII (rFVIIa; NovoSeven ^® ), which provides improved convenience and treatment access to patients compared with the earlier formulation of rFVIIa, was shown to be safe and effective in a post-authorization, multinational, observational study (Study Monitoring Antibodies against Room Temperature–stable factor 7 [SMART-7™]). In post hoc, subgroup analyses of SMART-7™ data, the hemostatic response following rFVIIa monotherapy in patients with hemophilia A or B with inhibitors by time to first treatment and in different age cohorts was assessed. A total of 482/618 bleeding episodes treated with rFVIIa monotherapy and with (1) valid efficacy assessment, (2) no missing time for bleed start, (3) no missing time for any dose administration, and (4) valid time to first treatment were included in the analyses. Data on the type and location of bleeding episodes treated with rFVIIa monotherapy were also collected. The majority of bleeding episodes treated with rFVIIa monotherapy were treated within 1 hour after bleeding onset (318/482 [66%]) and, among them, 96.5% (307/318) were effectively treated (i.e., bleeding stopped). Hemostatic efficacy remained high for bleeding episodes treated >1 to ≤4 hours after the onset, with 94/101 (93.1%) treated effectively. Cause and location of bleeding varied across the different age groups assessed. Real-world evidence from post hoc, subgroup analyses of SMART-7™ data confirmed that patients were able to treat themselves quickly and that early treatment with rFVIIa was associated with high efficacy.

Use of the UKHCDO Database for a postmarketing surveillance study of different doses of recombinant factor VIIa in haemophilia

INTRODUCTION

Recombinant factor VIIa (rFVIIa) is recommended in Europe at standard (3 × 90 μg kg^-1 ) or high (1 × 270 μg kg^-1 ) doses. When granting the license for the high dose, the European Medicines Agency (EMA) requested postmarketing surveillance for thrombosis. This was conducted by the United Kingdom National Haemophilia Database (NHD) on behalf of Novo Nordisk and the EMA.

AIM

To assess the use and safety of rFVIIa utilizing prospective data collected by the NHD (1 January 2008 to 30 June 2011).

RESULTS

Data were obtained from 67 haemophilia A/B patients with inhibitors treated for 1057 bleeds and 31 acquired haemophilia patients treated for 70 bleeds. Initial rFVIIa dose was categorized post hoc as low (<90 μg kg^-1 ), intermediate (≥90-<180 μg kg^-1 ) or high (≥180-<270 or ≥270 μg kg^-1 ). For haemophilia A/B, high and lower initial rFVIIa dose was used for 38.4% and 51.4% of episodes, respectively, while for acquired haemophilia, the values were 11.4% and 77.1% respectively. Median initial doses were higher for haemophilia A/B (146.3 μg kg^-1 ) than acquired haemophilia (90.5 μg kg^-1 ). A single administration of rFVIIa was the most frequently used regimen for haemophilia A/B, in contrast with standard recommendations and previous reports. For acquired haemophilia, most episodes were treated with multiple doses. No adverse drug reactions or thromboembolic events were reported for any rFVIIa dose.

CONCLUSION

The novel use of a national database for postmarketing surveillance has demonstrated acceptable safety for all recommended doses of rFVIIa.

Rationale for individualizing haemophilia care

Owing to the heterogeneity in the clinical phenotype of haemophilia A and B, it is now recognized that disease severity (based on factor VIII/IX activity) may no longer be the most appropriate guide for treatment and that a 'one-size-fits-all' approach is unlikely to achieve optimal therapy. Based on the present literature and consensus views of a group of experts in the field, this article highlights key gaps in the understanding of the diverse relationships between bleeding phenotype and factors such as joint health, genetic susceptibility, laboratory parameters, quality of life and management of pain. Early prophylaxis is a potential 'gold standard' therapy and issues surrounding inhibitor development, variations in its clinical use and long-term outcomes are discussed. Comprehensive treatment should be individualized for all patients (including those with mild or moderate haemophilia and carriers). Wherever possible all patients should be given prophylaxis. However, adult patients with a milder haemophilia phenotype may be candidates for ceasing prophylaxis and switching to on-demand treatment. Regardless, all treatment (on-demand and prophylaxis) should be tailored towards both the patient's personal needs and their clinical profile. In addition, as the associations between risk factors (psychosocial, condition-related and treatment-related) and clinical features are unique to each patient, an individualized approach is required to enable patients to alter their behaviour in response to them. The practical methodologies needed to reach this goal of individualized haemophilia care, and the health economic implications of this strategy, are ongoing topics for discussion.

The potential correlation between patient-reported symptoms and the use of additional haemostatic medication for joint bleeding in haemophilia patients with inhibitors: a post hoc exploratory analysis of recombinant activated factor VII data from the ADEPT2 trial

: Haemophilia treatment guidelines advocate early home-based treatment of acute bleeds. In the ADEPT2 trial, data were collected on the home treatment of bleeds with recombinant activated factor VII (rFVIIa) in haemophilia patients with inhibitors and self-reported bleeding-related symptoms. A total of 93% of all bleeds, and 91.5% of joint bleeds, were treated successfully with one to three doses of 90 μg/kg rFVIIa. However, some patients self-administered additional haemostatic medication (AHM) up to 48 h after the first rFVIIa treatment. The aim of this trial was to investigate the relationship between patient-reported symptoms, time to treatment initiation, and the use of AHM. A post hoc analysis was conducted on 177 joint bleeds and the patient-reported categorical symptoms of pain, swelling, mobility, tingling, and warmth, and the pain visual analogue scale (VAS) score. Analyses were descriptive and used logistic regression modelling. Complete symptom data were available for 141, 136, and 129 joint bleeds at 0 or 1, 3, and 6 h, respectively. Pain and pain VAS assessments were the best predictors of AHM use. Patients who self-administered AHM had higher mean pain VAS scores at each time point; both pain and pain VAS scores declined over time. Time to treatment initiation was an independent predictor for AHM use. Higher initial pain scores and longer time to treatment were the best predictors for administration of AHM. The observation that some patients chose to self-infuse in the face of declining levels of pain warrants further study to better understand the reasons behind patient decision-making.

Rapid rFVIIa enhanced on-demand dosing in haemophilia inhibitor patients

Recombinant factor VII activated (rFVIIa) is a bypassing agent widely used in haemophilia A and B patients with antibodies against coagulation factors VIII or IX. When used according to the correct doses, rFVIIa may control bleeding, subclinical bleeding and rebleeding, avoiding the effect of neutralising inhibitors. Because of the fast action of the rFVIIa, haemostasis occurs promptly and enables a fast bleeding control with on-demand treatment in home or in surgical setting. Rapidity is also a distinguishing feature in preparation and injection of rFVIIa to cope the restraining times of busy patients and parents. The effective haemostatic activity of rFVIIa enables a sustained bleeding control, which is implemented with every other day (eod) administration and suited for enhanced on-demand therapy and short-term repeated infusions use of rFVIIa to prevent microhaemorrhages or rebleeding. Comprehensive appreciation of these pharmacological and pharmacodynamic' characteristics will likely be a further stimulus to the wider enhanced on-demand use of rFVIIa.

Joint disease, the hallmark of haemophilia: what issues and challenges remain despite the development of effective therapies?

Although effective therapies for haemophilia have been available for decades, the prevention and treatment of joint disease remain major clinical concerns for all haemophilia patients. Early identification of joint disease is vital to initiate or modify treatment, and prevent arthropathy. However, there remains a need for more sensitive and accurate methods, which may also detect improvement in patient outcome with new therapies or different prophylaxis regimens. These topics were explored at the Ninth Zürich Haemophilia Forum. A summary of our shared views on the limitations of current assessment methods, and the potential advantages of more recently developed tools, is provided. Ultrasonography enables more frequent routine monitoring and the early detection of joint disease. In addition, serological markers may provide suitable biomarkers of early arthropathy. To prevent arthropathy, in our opinion, prophylaxis is key to prevent joint bleeds and subsequent initiation of the 'vicious circle of joint disease'. However, issues remain, including when prophylaxis should be started, stopped, and if it is efficacious for inhibitor patients. Once joint bleeding has occurred, enhanced on-demand treatment should be considered. For more advanced stages of joint disease, the issues regarding the treatment options available are explored. Radiosynovectomy should be performed to treat chronic synovitis, and may prevent the need for elective orthopaedic surgery (EOS). Ultimately, however, EOS can be considered once all other treatment options have been explored. While, bypassing agents have facilitated the use of EOS in inhibitor patients, a multidisciplinary approach and careful surveillance is required for good patient outcome.

Barriers and perceived limitations to early treatment of hemophilia

Early treatment of bleeds in hemophilia patients, both with and without inhibitors, has been shown to be of immense benefit in the overall clinical outcome. Despite the advantages of treating the bleeding episodes early, significant barriers and limitations remain. The aim of this review is to highlight the various barriers and perceived limitations to early therapy of bleeding episodes, especially in patients who have developed inhibitors to factor VIII. The peer-reviewed literature was searched for articles on hemophilia patients, with and without inhibitors, and early treatment, to identify the barriers to early treatment and potential impact on patient outcomes. The most important barrier is the educational barrier, which involves lack of awareness among patients regarding the signs of a bleed, as well as importance of early therapy. It is also common for parents or caregivers of school-age children to exhibit inconvenience and scheduling barriers. Distance to the treatment center can also play a role here. Some patients experience financial barriers related to cost of clotting factor products, insurance coverage, or insurance caps and out-of-pocket costs. Rarely, there can also be problems related to venous access or home infusion. Lastly, multiple psychosocial barriers can prevent adherence to treatment regimens. Identification and addressing these individual barriers will result in improved compliance rates, prevent joint damage, be more cost-effective, and lead to better overall health of these patients.

Real-world outcomes with recombinant factor VIIa treatment of acute bleeds in haemophilia patients with inhibitors: results from the international ONE registry

The ONE Registry (OR) was an international prospective observational study of on-demand recombinant factor VIIa (rFVIIa) treatment for mild to moderate bleeds in haemophilia A/B patients with inhibitors. To describe real-world use of single and multi dose rFVIIa and to compare outcomes, including effectiveness, safety, quality of life and treatment satisfaction associated with treatment. Baseline data included demographics, treatment, medical and bleed history and patient/caregiver-reported outcomes regarding bleeds. rFVIIa was prescribed according to routine practice; regimens varied and initial dose was categorized as low (LD, ≤ 120 μg kg(-1) ), intermediate (ID, >120 and <250 μg kg(-1) ) or high (HD, ≥ 250 μg kg(-1) ). OR included 102 patients and 85 (83%) reported 494 bleeds overall. Mean age was 23 years (SD 16.4), with 52% ≥ 18 years. Majority of bleeds (n = 350, 71%) involved ≥ 1 joints; 46% involved a target joint. Median initial dose was 90 μg kg(-1) in LD (range 87-120, n = 156), 174 μg kg(-1) in ID, (range 121-249, n = 127) and 270 μg kg(-1) in HD, (range 250-375, n = 211). For spontaneous bleeds, effective haemostasis rate at 9 h was 63% LD, 60% ID and 56% HD. Rates of combined partially effective/effective haemostasis was 85% LD, 96% ID and 86% HD. Median number of doses in HD was one (range 1-7), compared with two in LD (range 1-17) and ID (range 1-23). No thromboembolic events were reported in 1145 doses given. These observational data in real life are consistent with previous studies which have shown similar overall effectiveness of rFVIIa and similar effectiveness and safety across different patterns of standard initial dosing.

Health-related quality of life in haemophilia patients with inhibitors and their caregivers

Data on the health-related quality of life (HRQoL) of congenital haemophilia patients with inhibitors (CHwI) and their caregivers are limited. To understand the association between patient demo-graphics/clinical characteristics with HRQoL among CHwI patients and caregivers, a survey was developed to assess HRQoL with haemophilia-specific QoL questionnaires (HAEMO-QoL/HAEM-A-QoL). In the cross-sectional study, paper-pencil questionnaires were mailed to 261 US CHwI patients/caregivers in July 2010. Descriptive analyses were performed to characterize HRQoL by age and to identify drivers of impairment, from both patient/caregiver perspectives. HRQoL scores were transformed on a scale of 0-100, with higher scores indicating higher impairment in HRQoL. Ninety-seven respondents completed the HRQoL assessment. HRQoL impairment was higher in adult patients. In children ages 8-16 years, mean HAEMO-QoL total score was 33.8 (SD = 15.5), and 35.0 (SD = 16.1) in children ages 4-7 years; for adult patients the mean HAEM-A-QoL total score was 42.2 (SD = 14.8). Adults reported highest impairment in the 'sports/leisure' subscale (Mean = 62.5, SD = 18.7), whereas patients 8-16 years reported highest impairment in the 'physical health' subscale (Mean = 50.8, SD = 30.5).Caregivers of patients ages 4-7 years reported greatest impairment within the 'family' subscale (Mean = 55.6, SD = 19.4). Caregivers were ''considerably/very much'' bothered by their child's inhibitors and reported higher QoL impairment for their child than parents who were not bothered. Within ChwI patients, HRQoL impairments increased with age and existed across a range of physical/psychosocial domains. In addition, caregiver burden also affected the perceived HRQoL of paediatric CHwI patients. Additional research is considered necessary to further understand the support caregivers need while caring for children with CHwI.

Management of muscle haematomas in patients with severe haemophilia in an evidence-poor world

Treatment studies in haemophilia focus on joint bleeds; however, some 10-25% of bleeds occur in muscles. This review addresses management of muscle haematoma in severe haemophilia, defines gaps in the published evidence, and presents a combined clinician and physiotherapist perspective of treatment modalities. The following grade 2C recommendations were synthesized: (i) Sport and activity should be based on individual factor levels, bleeding history and physical characteristics, (ii) Musculoskeletal review aids the management of children and adults, (iii) 'Time to full recovery' should be realistic and based on known timelines from the healthy population, (iv) Diagnosis should be carried out by both a clinician and physiotherapist, (v) Severe muscle bleeds should be treated similarly to surgical patients: a 50% trough for 10-14 days followed by high-level prophylaxis, (vi) Protection, rest, ice, compression and elevation should be implemented in the acute stage, and (vii) Physiotherapy and rehabilitation should be divided into: control of haemorrhage (phase 1); restoration of Range of Movement (ROM) and strength (phase 2); functional rehabilitation and return to normal living (phase 3). Recommendations specifically for inhibitor patients include: (i) Minor to moderate bleeds should be managed by home-treatment within 1 h of bleed onset using either one injection of rFVIIa 270 μg kg(-1), or two to three injections of rFVIIa 90 μg kg(-1) (2-3 h intervals), or FEIBA 50-100 U kg(-1) (repeated at 12-hourly intervals, if necessary) and (ii) Severe muscle bleeds should be supervised by the treatment centre and include bypassing agents until clinical improvement is observed.