Patient/caregiver-reported recombinant factor VIIa (rFVIIa) dosing: home treatment of acute bleeds in the Dosing Observational Study in Hemophilia (DOSE)

Efficacy and safety evaluation of eptacog beta (coagulation factor VIIa [recombinant]-jncw) for the treatment of hemophilia A and B with inhibitors

INTRODUCTION

Bypassing agents (BPAs) are used to treat acute bleeding episodes, manage bleeding during perioperative care, and prophylactically minimize bleed occurrence in persons with hemophilia A or B with inhibitors (PwHABI). However, the effectiveness of BPAs that have been prescribed for the last several decades can be variable, motivating the development of a new recombinant activated factor VII, eptacog beta.

AREAS COVERED

This review covers key eptacog beta findings from phase 1b and phase 3 (PERSEPT) clinical trials, which formed the basis for its regulatory approval to treat PwHABI ages 12 and older. Descriptions of eptacog beta structure and glycosylation profile, mechanism of action, preclinical study results, and cost analyses are also presented.

EXPERT OPINION

PwHABI have had only two options for bleed treatment for the past several decades. With its distinct glycosylation profile, eptacog beta offers a novel therapy aiming to improve upon BPAs currently in use, providing an option with more than one dosing regimen and a rapid response that allows most bleeds to be treated with just one dose. This has become particularly important given the use of subcutaneous medications (e.g., emicizumab) for prophylaxis of bleeding. Clinicians should consider eptacog beta as a BPA for all PwHABI.

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.

Eptacog beta efficacy and safety in the treatment and control of bleeding in paediatric subjects (<12 years) with haemophilia A or B with inhibitors

Introduction

Eptacog beta is a new recombinant activated human factor VII bypassing agent approved in the United States for the treatment and control of bleeding in patients with haemophilia A or B with inhibitors 12 years of age or older.

Aim

To prospectively assess in a phase 3 clinical trial (PERSEPT 2) eptacog beta efficacy and safety for treatment of bleeding in children <12 years of age with haemophilia A or B with inhibitors.

Methods

Using a randomised crossover design, subjects received initial doses of 75 or 225 μg/kg eptacog beta followed by 75 μg/kg dosing at predefined intervals (as determined by clinical response) to treat bleeding episodes (BEs). Treatment success criteria included a haemostasis evaluation of ‘excellent’ or ‘good’ without use of additional eptacog beta, alternative haemostatic agent or blood product, and no increase in pain following the first ‘excellent’ or ‘good’ assessment.

Results

Treatment success proportions in 25 subjects (1–11 years) who experienced 546 mild or moderate BEs were 65% in the 75 μg/kg initial dose regimen (IDR) and 60% in the 225 μg/kg IDR 12 h following initial eptacog beta infusion. By 24 h, the treatment success proportions were 97% for the 75 μg/kg IDR and 98% for the 225 μg/kg IDR. No thrombotic events, allergic reactions, neutralising antibodies or treatment‐related adverse events were reported.

Conclusion

Both 75 and 225 μg/kg eptacog beta IDRs provided safe and effective treatment and control of bleeding in children <12 years of age.

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 and dose-dependency of eptacog beta (activated) in a dose escalation study of non-bleeding congenital haemophilia A or B patients, with or without inhibitors

INTRODUCTION

Varying initial doses of activated eptacog beta (recombinant human FVIIa, rhFVIIa) may provide therapeutic options when treating bleeding in patients with congenital haemophilia who have developed inhibitory antibodies to factor VIII (FVIII) or factor IX (FIX). This study evaluated escalated doses of a new rhFVIIa product as a prelude to selecting the doses for clinical efficacy evaluation in haemophilia patients.

AIM

To assess the safety, pharmacokinetics, and laboratory pharmacodynamics of 3 doses of rhFVIIa in non-bleeding patients with congenital haemophilia A or B with or without inhibitors.

METHODS

Adult male patients (18-75 years old) with congenital haemophilia A or B (with or without inhibitors) received infusions of rhFVIIa at doses of 25, 75 or 225 μg/kg body weight. Ten patients were treated at each dose level, and each patient received 2 different dose levels. Descriptive methods were used to analyse the data.

RESULTS

Administration of rhFVIIa at all doses was well tolerated. Pharmacokinetic analyses showed that peak FVIIa plasma levels (C_max ) were approximately proportional to dose and correlated well with peak thrombin generation. Total AUC_0-inf also was approximately dose proportional. Clot formation and duration correlated with FVIIa activity. Repeat doses did not produce an immunological response.

CONCLUSION

In the first dose-escalation study of rhFVIIa to support product registration, eptacog beta at doses of 25, 75, and 225 μg/kg was pharmacodynamically active and well tolerated in non-bleeding patients with congenital haemophilia A or B.

Safety and efficacy of recombinant activated coagulation factor VII in congenital hemophilia with inhibitors in the home treatment setting: A review of clinical studies and registries

Self-administration of factor and bypassing agents by persons with hemophilia in the home setting is recommended to facilitate earlier intervention after bleeding episodes. The objective of this review was to summarize recombinant activated coagulation factor VII (rFVIIa) safety and efficacy data from clinical trials and patient registries documenting use in the home treatment setting in people with congenital hemophilia with inhibitors (CHwI). A total of 16 studies and registries were identified for inclusion; 14 evaluated on-demand treatment of acute bleeding episodes (865 patients, 9024 bleeding episodes) and 2 evaluated use for secondary prophylaxis (108 patients, 42,861 prophylaxis days). In the on-demand studies, efficacy was consistently high (81%-96%), and thrombotic events were uncommon (n = 3). In the secondary prophylaxis studies, rFVIIa was associated with a 45% to 59% reduction in bleeding episodes and no thrombotic events. These data support the clinical practice of administering rFVIIa in patients in the home treatment setting after initiation under a physician's care.

A Budget Impact Model of Hemophilia Bypassing Agent Prophylaxis Relative to Recombinant Factor VIIa On-Demand

BACKGROUND

Hemophilia patients use factor-clotting concentrates (factor VIII for hemophilia A and factor IX for hemophilia B) for improved blood clotting. These products are used to prevent or stop bleeding episodes. However, some hemophilia patients develop inhibitors (i.e., the patient's immune system develops antibodies against these factor concentrates). Hence, these patients do not respond well to the factor concentrates. A majority of hemophilia patients with inhibitors are managed on-demand with the following bypassing agents: recombinant factor VIIa (rFVIIa) and activated prothrombin complex concentrate (aPCC). The recently published U.S. registries Dosing Observational Study in Hemophilia (DOSE) and Hemostasis and Thrombosis Research Society (HTRS) reported higher rFVIIa on-demand use for bleed management than previously described.

OBJECTIVE

To estimate aPCC and rFVIIa prophylaxis costs relative to rFVIIa on-demand treatment cost based on rFVIIa doses reported in U.S. registries.

METHODS

A literature-based cost model was developed assuming a base case on-demand annual bleed rate (ABR) of 28.7 per inhibitor patient, which was taken from a randomized phase 3 clinical trial. The doses for rFVIIa on-demand were taken from the median dose per bleed reported by the DOSE and HTRS registries. Model inputs for aPCC and rFVIIa prophylaxis (i.e., dosing and efficacy) were derived from respective randomized clinical trials. Cost analysis was from the U.S. payer perspective, and only direct drug costs were considered. The drug cost was based on the Medicare Part B 2014 average sale price (ASP). Two-way sensitivity and threshold analyses were performed by simultaneously varying on-demand ABR, prophylaxis efficacy, and unit drug cost. In addition to studying relative costs associated with on-demand and prophylaxis treatments, relative cost per bleeding episode avoided were also calculated for aPCC and rFVIIa prophylaxis treatments. The prophylaxis efficacy reported in the trials were used to determine the number of bleeding episodes avoided.

RESULTS

Based on the median on-demand dose of 695 mcg per kg per bleed, reported by the DOSE registry, the annual rFVIIa on-demand cost was $34,009 per kg of body weight. The annual rFVIIa on-demand cost was $22,020 per kg of body weight when the median dose of 450 mcg per kg per bleed reported by the HTRS registry was considered. The annual cost rose to $38,461 per kg of body weight when the rFVIIa on-demand dose of 786 mcg per kg per bleed among patients infusing an initial dose ≥ 250 mcg per kg was considered. The aPCC (85 units per kg per every other day) and rFVIIa (90 mcg per kg per every day) annual prophylaxis costs were $26,536 and $60,700, respectively. Also, aPCC and rFVIIa prophyaxis treatments were estimated to prevent a total of 20.8 and 12.9 annual bleeding episodes, respectively. When compared with the on-demand dose of 695 mcg per kg per bleed (DOSE registry), the annual aPCC and rFVIIa prophylaxis costs were 21.9% lower and 78.4% higher, respectively. Additionally, aPCC prophylaxis saved $360 per kg for each bleeding episode avoided. rFVIIa prophylaxis cost $2,066 per kg for each bleeding episode avoided. Compared with the on-demand dose of 450 mcg per kg per bleed (HTRS registry), aPCC and rFVIIa prophylaxis costs were 20.5% and 174.9% higher, respectively. In this case, aPCC and rFVIIa prophylaxis treatment costs were $217 per kg and $2,995 per kg, respectively, for each bleeding episode avoided. aPCC and rFVIIa prophylaxis costs were 31.0% lower and 57.8% higher, respectively, when compared with the rFVIIa on-demand dose of 786 mcg per kg per bleed, among patients infusing an initial dose ≥ 250 mcg per kg (HTRS registry). In this case, aPCC prophylaxis saved $573 per kg for each bleeding episode avoided, while rFVIIa prophylaxis costs $1,724 per kg for each bleeding episode avoided. Results of the 2-way sensitivity analyses were robust in the majority of the scenarios considered.

CONCLUSIONS

aPCC prophylaxis may be cost saving for managing hemophilia patients with inhibitors who bleed frequently and infuse significant quantities of rFVIIa on-demand.

Beyond stopping the bleed: short-term episodic prophylaxis with recombinant activated factor FVII in haemophilia patients with inhibitors

Preventing haemarthroses and arthropathy is a major challenge in patients with haemophilia and inhibitors, as treatment options are limited. One potential strategy is short-term episodic prophylaxis, which extends bypassing agent therapy beyond the resolution of bleeding to include the post-bleed inflammatory phase. At the 13^th Zürich Haemophilia Forum, an expert panel reviewed the rationale behind this strategy, explored its current use with recombinant activated factor VII (rFVIIa) and considered treatment monitoring and optimisation. Two protocols are currently used for short-term episodic prophylaxis, both of which stipulate on-demand rFVIIa until resolution of bleeding, followed by daily dosing for ≥3 days to prevent re-bleeds. Short-term episodic prophylaxis should be individualised to optimise outcomes, perhaps through early treatment initiation or by combining rFVIIa with other treatments (e.g. factor VIII, tranexamic acid). Encouraging treatment compliance can also improve outcomes. Additionally, there is a need to develop objective clinical outcome measures, biomarkers and imaging protocols that can monitor treatment outcomes and joint disease in patients with inhibitors. A proactive approach incorporating a systematic package of care is needed. Currently, short-term episodic prophylaxis with rFVIIa may be an alternative treatment option to on-demand treatment for patients with inhibitors.

A Comparison of Efficacy Between Recombinant Activated Factor VII (Aryoseven) and Novoseven in Patients With Hereditary FVIII Deficiency With Inhibitor

Introduction:

This study compared the efficacy of Aryoseven with Novoseven to control bleeding episodes in patients with hemophilia A with inhibitors.

Methods:

Sixty-six patients were randomized into 2 groups, with 4 consecutive block randomization. These groups received Aryoseven and Novoseven dosages of 90 to 120 μg/kg intravenously every 2 hours.

Results:

Median (interquartile range) level of factor VIII (FVIII) inhibitor in groups A and B was 15.0 and 19.0 Bethesda Unit (BU) preadministration. Bleeding onset in group A was 1246 ± 1104 minutes and in group B was 2301 ± 1693 minutes ( P = .311). The Kavakli global response scores and treatment success rate was comparable in both the groups. The side effects in groups A (9.7%) and B (2.9%) were comparable.

Conclusion:

Biosimilar recombinant activated FVII is found to be as effective as Novoseven in the treatment of acute joint bleeding in patients with hemophilia with inhibitors. Its usage will decrease the gaps in hemophilia.

Mixing and administration times of bypassing agents: observations from the Dosing Observational Study in Hemophilia (DOSE)

DOSE (Dosing Observational Study in Hemophilia) was a prospective, observational diary study designed to evaluate the use of bypassing agents in patients prescribed recombinant activated factor VII (rFVIIa) as first-line treatment in the home setting. Patients with congenital hemophilia with inhibitors and caregivers participated, and as part of the study, the time spent preparing and administering product was recorded for bypassing agent (BPA) infusions. The aim of this manuscript is to present the results of the analysis of the time spent preparing and administering a single dose of either rFVIIa or plasma-derived activated prothrombin complex concentrate (pd-aPCC). Diaries were completed for 18 adult patients and 19 caregivers of 21 children with 176 BPA-treated bleeding episodes and 1,350 BPA infusions (1,270 rFVIIa, 80 pd-aPCC). The median preparation and administration times were 5.0 minutes and 5.0 minutes for rFVIIa and 29.0 minutes and 24.5 minutes for pd-aPCC, respectively. Preparation and administration times were significantly shorter with rFVIIa than pd-aPCC (P<0.0001). The significantly shorter combined preparation and administration time of rFVIIa, taking into consideration the faster-than-recommended aPCC infusion rates, suggests that rFVIIa permits a rapid and safe initiation of treatment once a bleeding episode is identified and a decision is made to treat at home.

Dosing, efficacy, and safety of recombinant factor VIIa (rFVIIa) in pediatric versus adult patients: the experience of the Hemostasis and Thrombosis Research Society (HTRS) Registry (2004-2008)

BACKGROUND

The longitudinal registry of the Hemostasis and Thrombosis Research Society (HTRS) provided data on treatment of bleeding episodes for pediatric and adult patients with congenital hemophilia complicated by inhibitors to factor VIII or IX.

PROCEDURE

Data from 2,041 recombinant factor VIIa (rFVIIa)-treated episodes were recorded in the HTRS Registry between January 2004 and November 2008 and included in this retrospective analysis. The authors compared dosing, efficacy, and safety in 1,712 episodes in 284 children (age ≤18 years) and 329 episodes in 145 adults (>18 years).

RESULTS

Patients were predominantly non-Hispanic white (52% of children, 68% of adults) with hemophilia A (91%). The majority of bleeds were spontaneous (55% pediatric, 69% adult) and occurred in the joint (55% pediatric, 65% adult). rFVIIa was used first line in most episodes (90% pediatric, 93% adult); 27% of episodes in both age groups were treated with a single dose. Children and adults received comparable median number of doses (three) and duration of therapy (1 day); adults had lower median [range] initial doses (90 [46-400] µg/kg vs. 120 [37-400] µg/kg) and median [range] total doses (270 [46-21,392] µg/kg vs. 480 [50-43,200] µg/kg) than children. Effectiveness was comparable between the groups. No thromboembolic complications were reported.

CONCLUSIONS

Dosing of rFVIIa was somewhat higher in pediatric than adult patients in the HTRS registry population, with similar effectiveness. Safety assessment, demonstrating lack of thromboembolic events associated with treatment of bleeding episodes, was similar between the children and adults in this retrospective registry.

New developments in the treatment of pediatric hemophilia and bleeding disorders

PURPOSE OF REVIEW

Disorders of hemostasis such as hemophilia, von Willebrand disease (VWD), and other clotting protein deficiencies lead to significant morbidity in the pediatric population. Because of the limitations of current treatment options, novel therapies are being developed, many of which are reviewed here.

RECENT FINDINGS

Several new observations about the nature of clotting protein physiology have been made recently, creating novel perspectives on the treatment options. This review will mostly focus on the current therapy as well as new progress in hemophilia care (particularly strategies to prolong half-life of clotting factor replacements, the management of inhibitors, gene therapy, and novel therapeutic approaches), and briefly mention some progress in VWD and fibrinogen deficiency therapies.

SUMMARY

New therapeutic developments have the potential to dramatically decrease morbidity and improve the quality of life of children with bleeding disorders.

Effect of acute bleeding on daily quality of life assessments in patients with congenital hemophilia with inhibitors and their families: observations from the dosing observational study in hemophilia

INTRODUCTION

Quality-of-life (QOL) assessments in frequently bleeding patients with congenital hemophilia with inhibitors and their families are confounded by preexisting arthropathy and family circumstances. Periodic QOL assessments typically made on nonbleed days may not provide complete reflections of the burden on patients/families.

AIM

To evaluate the impact of bleeding episodes on patients/caregivers/families and the association between monthly QOL scores and patients' average diary experiences.

METHODS

Frequently bleeding inhibitor patients (≥four bleeds in 3 months), or their caregivers, provided daily assessment of EuroQol five-dimensional questionnaire and EuroQol five-dimensional questionnaire visual analogue scale, pain (11-point Likert scale), and family anxiety/stress/activity change over 3 to 6 months. QOL scores were stratified by bleed/nonbleed days.

RESULTS

Patient QOL assessments were recorded by 37 of the 39 enrolled patients/caregivers (3771 of 3777 eligible dairy days, 472 bleed/3299 nonbleed days). Median (range) diary duration was 91 (66-180) days, with 8.2% (0%-72.2%) bleed days. Mean health scores were significantly worse on bleed days than on nonbleed days (P < 0.0001 for all): EuroQol five-dimensional questionnaire index, 0.66 versus 0.82; visual analogue scale health, 69.7 versus 77.4; and pain score, 4.1 versus 1.8. Bleed days also had higher (P < 0.001) proportions of days with abnormalities in family anxiety/stress (42% vs. 30%) and family activity changes (34% vs. 21%).

CONCLUSIONS

Assessing the impact of hemophilia with inhibitors on patient/family QOL typically includes periodic (likely nonbleed day) evaluations reflecting baseline abnormalities. Daily assessment, however, indicated that frequent acute bleeds impair QOL beyond patient's nonbleed day baseline. New approaches are required to assess the cumulative impact of frequent acute bleeds on patients and their families.

Capturing daily assessments and home treatment of congenital hemophilia with inhibitors: design, disposition, and implications of the Dosing Observational Study in Hemophilia (DOSE)

OBJECTIVE

The daily recordings of treatment by patients with congenital hemophilia with inhibitors and their caregivers were assessed as part of the Dosing Observational Study in Hemophilia (DOSE) to understand the patterns of bypassing agent use and health-related quality of life.

METHODS

Frequently bleeding patients prescribed recombinant activated factor VII as first-line therapy were eligible. Participants recorded daily paper diaries for at least 90 days and until at least four bleeding episodes had occurred. Web-based entry was optional. Assessment included bleeding status, work or school day status, bleeding episode, treatment, impact on planned activities, and health-related quality of life.

RESULTS

Diaries were completed by 18 adults and 19 caregivers (21 children). A total of 4063 diary days and 194 bleeding episodes over 491 bleed days were recorded. A small proportion of diary days were bleed days (8.2%) or treatment days (8.2%). Half the bleed days were not planned work or school days for patients (53%) or caregivers (48%). An exact agreement was observed between electronic and paper records for 93% of the reviewed health-related quality of life measurements.

CONCLUSION

Daily diary completion by patients and caregivers is feasible and provides insight into the impact of congenital hemophilia with inhibitors on daily activities and overall quality of life. Positive participation and completion rates were supported by frequent patient contact made by independent patient support liaison personnel.