Optimizing outcomes for patients with severe haemophilia A

Understanding treatment burden in hemophilia: development and validation of the Hemophilia Treatment Experience Measure (Hemo-TEM)

BACKGROUND

To capture the broad range of treatment burden issues experienced by adolescent and adult people with hemophilia (PWH), the Hemophilia Treatment Experience Measure (Hemo-TEM) was developed. We describe the development of this new hemophilia-specific patient-reported outcome (PRO) measure including concept elicitation, cognitive debriefing, and psychometric validation.

RESULTS

Concept elicitation interviews were conducted with 5 clinical experts and 30 adult PWH in the United States (US). The qualitative analysis of these interviews and a review of the literature informed the PRO measure development. The project team reviewed concept endorsement rates and generated a 27-item preliminary version of the Hemo-TEM. Cognitive debriefing interviews were conducted to ensure participant understanding and item relevance in samples of (adolescent (n = 20) and adult (n = 14)) PWH in the US. The refined, validation-ready version of the Hemo-TEM included 30 items. Lastly, data from 3 clinical trials comprised the 4 analysis sets used for the psychometric validation with a sample size of N = 88. Item reduction dropped 4 items resulting in a final 26-item measure. Factor analysis generated 5 domains in the Hemo-TEM [injection difficulties (3 items), physical impact (6 items), treatment bother (7 items), interference with daily life (4 items), and emotional impact (6 items)] and a total score. All scores were reliable [internally consistent (0.84-0.88)]. For convergent validity, with the exception of one domain, all hypothesized associations were met. Preliminary sensitivity to change effect sizes were between - 0.30 and - 0.70. Meaningful change thresholds ranged from 6 points (physical impact and emotional impact) to 10 points (treatment bother) with 8 points for the Hemo-TEM total score.

CONCLUSIONS

Findings from the concept elicitation, cognitive debriefing, and psychometric validation phases provide evidence that the Hemo-TEM is a well-designed, valid, and reliable measure of the burden of hemophilia treatment, including treatment impact on adolescent and adult PWH.

Targeting of antithrombin in hemophilia A or B with investigational siRNA therapeutic fitusiran-Results of the phase 1 inhibitor cohort

BACKGROUND

Fitusiran, an investigational small interfering RNA therapy, reduces antithrombin production to rebalance hemostasis in people with hemophilia A or B, with or without inhibitors.

OBJECTIVES

To evaluate the safety and efficacy of fitusiran treatment for people with moderate/severe hemophilia A or B with inhibitors.

PATIENTS/METHODS

In this open-label phase 1, part D study, 17 males with hemophilia A or B with inhibitors received three once-monthly subcutaneous injections of fitusiran 50 mg (n = 6) or 80 mg (n = 11); followed for up to 112 days. Endpoints included safety (primary), pharmacokinetics/pharmacodynamics (secondary), annualized bleeding rate, and patient-reported outcomes (exploratory).

RESULTS

The most common adverse event was injection site erythema (n = 8). No thrombotic events were reported. At nadir, mean (standard error of the mean [SEM]) antithrombin activity decreased from baseline by 82.0% (2.2) and 87.4% (0.7) in the 50 mg and 80 mg groups, respectively. Antithrombin reduction was associated with increased thrombin generation. 11/17 (64.7%) participants had no bleeds during the observation period (mean [standard deviation] 69.4 [16.3] days). Mean (SEM) changes from baseline in Haemophilia Quality of Life Questionnaire for Adults total (-9.2 [2.9]) and physical health (-12.3 [3.9]) domain scores suggested clinically meaningful improvement.

CONCLUSIONS

Monthly fitusiran was generally well tolerated, lowered antithrombin levels from baseline, and resulted in improved thrombin generation. These preliminary results suggest that monthly fitusiran treatment may reduce bleeding episodes and improve quality of life in participants with hemophilia A or B with inhibitors.

Correlation between Hemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score and Hemophilia Joint Health Score (HJHS) in patients with hemophilic arthropathy

BACKGROUND

Hemophilic arthropathy, a condition manifested as joint destruction due to spontaneous joint bleeding, is one complication of hemophiliac patients. Early detection and intervention may improve the outcome, in which ultrasonography can be an ideal modality with the introduction of HEAD-US (Hemophilia Early Arthropathy Detection with Ultrasound) protocol. Studies have shown US benefit in hemophiliac patients, including its potential as an alternative for the Hemophiliac Joint Health Score (HJHS) system. However, many of the studies were conducted in countries with better management of hemophilia using prophylaxis treatment. It is unclear whether HEAD-US has a correlation with HJHS in countries using episodic treatment only, like in Indonesia.

PURPOSE

This study aimed to explore the correlation between HEAD-US and HJHS in hemophiliac patients with joint problems in Indonesia.

MATERIALS AND METHODS

A cross-sectional correlation study between HEAD-US and HJHS was performed with primary data collected from 120 hemophilic patients. US examination was performed on elbow, knee and ankle joints using the HEAD-US scoring method by a musculoskeletal radiologist. HJHS examination was conducted by a trained physiotherapist and a medical rehabilitation specialist. All examiner is member of multidisciplinary Hemophiliac Management Team in Cipto Mangunkusumo General Hospital in Jakarta, Indonesia.

RESULTS

The mean age of the participant was 9.3 (5-14) years old. The median score of HEAD-US was 8 (1-28) with most of the joint abnormalities found on the ankles. The median score of HJHS was 3 (0-35), with most joint abnormalities found on the knees. There was a moderate correlation between HEAD-US and HJHS score (p < 0.05, r = 0.65).

CONCLUSION

HEAD-US shows a moderate correlation to HJHS in hemophiliac patients who received episodic treatment. HEAD-US can provide additional value in the anatomical evaluation of the joint and could be complementary to HJHS in assessing the joint status in hemophilic patient.

Changes in Muscle Activity Patterns and Joint Kinematics During Gait in Hemophilic Arthropathy

Hemophilic arthropathy is the result of repetitive intra-articular bleeding and synovial inflammation. In people with hemophilic arthropathy (PWHA), very little is known about the neural control of individual muscles during movement. The aim of the present study was to assess if the neural control of individual muscles and coordination between antagonistic muscle pairs and joint kinematics during gait are affected in PWHA. Thirteen control subjects (CG) walked overground at their preferred and slow velocity (1 m/s), and 14 PWHA walked overground at the preferred velocity (1 m/s). Joint kinematics and temporal gait parameters were assessed using four inertial sensors. Surface electromyography (EMG) was collected from gluteus maximus (GMAX), gluteus medius (GMED), vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL), tibialis anterior (TA), semitendinosus (ST), and biceps femoris (BF). Waveforms were compared using the time-series analysis through statistical parametric mapping. In PWHA compared to CG, EMG amplitude during the stance phase was higher for LG (for both velocities of the CG), BF (slow velocity only), and ST (preferred velocity only) (p < 0.05). Co-contraction during the stance phase was higher for MG-TA, LG-TA, VL-BF, VM-ST, LG-VL, and MG-VM (both velocities) (p < 0.05). MG and LG were excited earlier (preferred velocity only) (p < 0.05). A later offset during the stance phase was found for VL, BF, and ST (both velocities), and BF and GMAX (preferred velocity only) (p < 0.05). In addition, the range of motion in knee and ankle joints was lower in PWHA (both velocities) and hip joint (preferred velocity only) (p < 0.05). In conclusion, the neural control of individual muscles and coordination between antagonistic muscles during gait in PWHA differs substantially from control subjects.

Emicizumab prophylaxis among infants and toddlers with severe hemophilia A and inhibitors-a single-center cohort

BACKGROUND

Emicizumab is a bispecific antibody that bridges factor IXa and factor X to restore hemostasis in patients with hemophilia A (HA). Its efficacy and safety have been proven in multicenter trials. However, real world data regarding its use in very young children are currently lacking. Ancillary test results for monitoring emicizumab's hemostatic effect and their clinical correlations are scarce.

METHODS

Children with HA and inhibitors treated by emicizumab were prospectively followed at our center. Laboratory follow-up included rotational thromboelastometry (ROTEM) and thrombin generation (TG), prior to and during treatment.

RESULTS

Eleven children whose median age was 26 months were treated by emicizumab and followed for a median of 36 weeks. During follow-up, none experienced hemarthrosis or any other spontaneous bleeds. For 7/11 patients, emicizumab prophylaxis was sufficient to maintain hemostasis without additional supplemental therapy. Only 4/11 patients were occasionally treated with recombinant activated FVII for trauma. Two minor surgeries were safely performed without supplemental therapy while another procedure was complicated by major bleeding. TG parameters improved for all patients, correlating with their clinical status. Interestingly, the lowest TG values were obtained for patients experiencing bleeding episodes, while ROTEM parameters in all patients were close to the normal range.

CONCLUSIONS

This study confirms the safety and efficacy of emicizumab in reducing bleeds in young children with HA with inhibitors, including infants. However, surgeries warrant caution as emicizumab prophylaxis may not be sufficient for some procedures. TG may more accurately reflect the hemostasis state than ROTEM in pediatric patients treated with emicizumab.

Assessment of haemophilic arthropathy through balance analysis: a promising tool

The purpose of this study was to develop a tool able to distinguish between subjects who have haemophilic arthropathy in lower limbs and those who do not by analyzing the centre of pressure displacement. The second objective was to assess the possible different responses of haemophiliacs and healthy subjects by creating a classifier that could distinguish between both groups. Fifty-four haemophilic patients (28 with and 26 without arthropathy) and 23 healthy subjects took part voluntarily in the study. A force plate was used to measure postural stability. A total of 276 centre of pressure displacement parameters were calculated under different conditions: unipedal/bipedal balance with eyes open/closed. These parameters were used to design a Quadratic Discriminant Analysis classifier. The arthropathy versus non-arthropathy classifier had an overall accuracy of 97.5% when only 10 features were used in its design. Similarly, the haemophiliac versus non-haemophiliac classifier had an overall accuracy of 97.2% when only 7 features were used. In conclusion, an objective haemophilic arthropathy in lower limbs evaluation system was developed by analyzing centre of pressure displacement signals. The haemophiliac vs. non-haemophiliac classifier designed was also able to corroborate the existing differences in postural control between haemophilic patients (with and without arthropathy) and healthy subjects.

Durable engraftment of genetically modified FVIII-secreting autologous bone marrow stromal cells in the intramedullary microenvironment

Genetically modified FVIII‐expressing autologous bone marrow‐derived mesenchymal stromal cells (BMSCs) could cure haemophilia A. However, culture‐expanded BMSCs engraft poorly in extramedullary sites. Here, we compared the intramedullary cavity, skeletal muscle, subcutaneous tissue and systemic circulation as tissue microenvironments that could support durable engraftment of FVIII‐secreting BMSC in vivo. A zinc finger nuclease integrated human FVIII transgene into PPP1R12C (intron 1) of culture‐expanded primary canine BMSCs. FVIII‐secretory capacity of implanted BMSCs in each dog was expressed as an individualized therapy index (number of viable BMSCs implanted × FVIII activity secreted/million BMSCs/24 hours). Plasma samples before and after implantation were assayed for transgenic FVIII protein using an anti‐human FVIII antibody having negligible cross‐reactivity with canine FVIII. Plasma transgenic FVIII persisted for at least 48 weeks after implantation in the intramedullary cavity. Transgenic FVIII protein levels were low after intramuscular implantation and undetectable after both intravenous infusion and subcutaneous implantation. All plasma samples were negative for anti‐human FVIII antibodies. Plasma concentrations and durability of transgenic FVIII secretion showed no correlation with the therapy index. Thus, the implantation site microenvironment is crucial. The intramedullary microenvironment, but not extramedullary tissues, supported durable engraftment of genetically modified autologous FVIII‐secreting BMSCs.

Economic Burden of Illness among Persons with Hemophilia B from HUGS Vb: Examining the Association of Severity and Treatment Regimens with Costs and Annual Bleed Rates

OBJECTIVES

To determine US societal burden of illness, including direct and indirect costs and annual bleed rate (ABR), for persons with hemophilia B (HB), a rare and debilitating genetic disorder, and to examine associations of hemophilia severity and treatment regimens with costs and ABR.

METHODS

From 2009 to 2014, the Hemophilia Utilization Group Studies Part Vb collected prospective data from 10 US hemophilia treatment centers. Participants with HB completed initial surveys on sociodemographic characteristics, clinical characteristics, and treatment patterns. During the 2-year follow-up, participants reported bleeding episodes, work absenteeism, and caregiver time quarterly. These data were used to calculate ABR and indirect costs. Direct costs were calculated using 1-year clinical chart records and 2-year dispensing records.

RESULTS

Of the 148 participants, 112 with complete medical records and one or more follow-up survey were included. Total mean annual per-person costs were $85,852 (median $20,160) for mild/moderate HB, $198,733 (median $147,891) for severe HB, and $140,240 (median $63,617) for all participants without inhibitors (P < 0.0001). Mean ABR for participants with severe HB on prophylaxis (5.5 ± 7.9 bleeds/y) was almost half that of those treated episodically. Clotting factor and indirect costs accounted for 85% and 9% of total costs, respectively. Compared with episodic treatment, prophylaxis use was associated with 2.5-fold higher clotting factor costs (P < 0.01), low but significantly more missed parental workdays (P < 0.0001) and clinician (P < 0.001) or nursing visits (P < 0.0001), less part-time employment and unemployment, and lower hospitalizations costs (P = 0.17) and ABR (P < 0.0001).

CONCLUSIONS

HB is associated with high economic burden, primarily because of clotting factor costs. Nevertheless, prophylaxis treatment leads to clinical benefits and may reduce other nonfactor costs.

Combination of hemostatic therapies for treatment of patients with hemophilia A and inhibitors

BACKGROUND

Therapy application and monitoring of patients with hemophilia A (HA) and inhibitors are challenging. In the current study, combined FVIII - bypass therapy was implemented for a cohort of severe HA patients with inhibitors.

METHODS

Plasma of 15 HA patients with inhibitors was spiked ex vivo with FVIII, rFVIIa, FEIBA and their combinations and thrombin generation (TG) was studied. Some patients who experienced hemarthroses or required minor surgeries were treated by a combined concomitant administration of FVIII+FEIBA as IV bolus doses.

RESULTS

TG spiking studies showed individual responses not correlated to inhibitor titer. Combinations of agents augmented TG as compared to any single agent, while combined FVIII+FEIBA yielded the highest TG, supporting it as a potential treatment. Following emergent successful surgery of child treated by concomitant FVIII+FEIBA, a total of 396 episodes in 7/15 patients were treated with concomitant FVIII+FEIBA. Five patients were treated for bleeding episodes only, whereas 2 were children undergoing immune tolerance induction (ITI) with FEIBA prophylaxis. Four minor surgeries were performed on FVIII+FEIBA repeated infusions. Neither thrombosis nor any other adverse events were documented.

CONCLUSION

A combination of FVIII+FEIBA may be effective and safe as an alternative treatment option for some high-responding inhibitor patients.

Home treatment of haemarthrosis with recombinant activated factor VII in patients with haemophilia A or B and inhibitors: experience from developing countries

Supplemental Digital Content is available in the text

Home therapy for uncomplicated mild/moderate bleeding can decrease healthcare burden, promote self-esteem, reduce complications, and provide near-normal quality of life. To evaluate recombinant activated factor VII (rFVIIa) as home therapy for joint bleeds in Algeria, Morocco, Oman, Saudi Arabia, and United Arab Emirates. Twenty-seven patients aged more than 2 years with congenital haemophilia and inhibitors were monitored for up to 8 months after a first haemarthrosis episode treated with rFVIIa. Assessments were made by patients/caregivers with a standardized diary. The main measures included home-managed bleeds, haemostasis, and pain relief within 9 h after first injection. Additional analyses included convenience, time to pain resolution, and doses given within 48 h. Of 132 bleeds, 84 (63.6%) were managed at home. Of these, successful haemostasis (partial or complete) was achieved at 9 h in 87.8%, with pain relief for 84.0%. For all treatment settings, successful haemostasis at 9 h was achieved for 86.3% of bleeds, with pain relief achieved for 74.8% of bleeds. Higher initial dosing was associated with fewer injections. Median time to complete haemostasis was 48 h (spontaneous bleeds) and 24 h (traumatic bleeds). Median time to complete pain relief was 24 h for both bleed types. Satisfaction with treatment was high. No safety concerns were reported. Results from this observational study agree with previous data on the safety and efficacy of home treatment with rFVIIa and will help to increase awareness and aggregate experience, fostering confidence in home management of haemophilia patients with inhibitors in developing countries.

Considerations in individualizing prophylaxis in patients with haemophilia A

Prophylaxis is considered optimal care for children and adults with severe haemophilia A because of its proven ability to reduce joint and other bleeding episodes. However, a 'one size fits all' approach to prophylaxis is not ideal, potentially leading to over-treatment in some individuals and under-treatment in others. Moreover, a generic plan fails to take into account a patient's lifestyle and personal preferences. This article reviews the factors contributing to bleeding risk and joint damage and uses case studies to illustrate how these contributors can be weighed to individualize the prophylactic regimen, thereby increasing the likelihood of therapeutic success.

Management of joint bleeding in hemophilia

Hemarthrosis, the hallmark of severe hemophilia, is the major cause of serious bleeding events, disability and reduced quality of life in patients with factor VIII or factor IX deficiency. Joint bleeding is one of the greatest challenges confronting individuals treating hemophilia, and its economic impact is enormous. This article reviews the current management of hemophilic joint bleeding and discusses the potential impact of novel therapies.

Opinions on radiosynovectomy for chronic haemophilic synovitis: point/counterpoint

Joint bleeding is the hallmark of severe haemophilia and the major cause of disability in patients with this coagulopathy. Repeated bleeding into the same joint can lead to chronic synovitis and progressive arthropathy. Radiosynovectomy is one option for the treatment of chronic haemophilic synovitis, but concerns about the risks of exposure to ionizing radiation have divided clinicians as to the safety and appropriate use of the procedure. This article presents two differing viewpoints, one from a pair of orthopaedic surgeons who collectively have performed more than 300 radiosynovectomies in patients with haemophilia. They maintain that radiosynovectomy is a simple, effective, safe and low-cost technique children and adults with chronic haemophilic synovitis. The other perspective is from an experienced haemophilia treater who directs a major US haemophilia treatment centre. She believes that unresolved questions about the safety of radiation exposure in children argue against the use of radiosynovectomy in paediatric patients with haemophilia.

Role of exercise and physical activity on haemophilic arthropathy, fall prevention and osteoporosis

In older men with haemophilia, arthropathy resulting from a lifetime of intra-articular bleeding contributes to the loss of independence and increased morbidity that occurs with age. A regular exercise programme that incorporates aerobics, strength training and balance and flexibility activities is a key component of successful ageing, helping to improve functional mobility and reduce the risk of falls, osteoporosis and osteoporotic fractures. Because of the special challenges associated with haemophilia, which include both the underlying coagulopathy and, in many cases, extensive joint damage, patients beginning an exercise regimen should be referred to appropriately trained physiotherapists (preferably someone associated with a haemophilia treatment centre) for evaluation, education and instruction and follow-up. Various assistive devices may make exercise easier to perform and more comfortable.

Challenges and controversies in haemophilia care in adulthood

Overall life expectancy and quality of life among persons with haemophilia have increased in recent years, primarily because of the advances in factor replacement therapy and better treatment of infectious diseases. Older haemophilic patients now face aging co-morbidities that are common in the general male population, such as cardiovascular or metabolic diseases, prostate hypertrophy and hepatic, prostate and other cancers. The prevalence of cardiovascular disease and incidence of vascular events among older haemophilic patients can be expected to increase and haemophilic patients may become prone to some cardiovascular risk factors, warranting preventative measures. The treatment of long-term complications of hepatitis C virus infection such as liver cirrhosis and hepatic cancer can be expected to be required in a large portion of the older haemophilia population for some years to come. Appropriate antiviral treatment and close monitoring for possible disease advancement will constitute an important part of routine medical care, and special considerations may be appropriate in conjunction with invasive procedures, chemo- or radiotherapy. At the moment, hard data on which to base the management of these conditions are largely lacking, but can be expected to increase dramatically in the coming decades. In the meantime, the ageing population of haemophilia patients should be offered the same comprehensive health care offered to the general population, which may require a restructuring of health care delivery.

Recombinant factor VIII in the management of hemophilia A: current use and future promise

Hemophilia A is a rare inherited bleeding disorder due to mutation of the gene that encodes the coagulation protein factor VIII. Historically, prior to the availability of treatment with factor VIII preparations, most boys died from uncontrolled bleeding, either spontaneous bleeding or after injury, before reaching 20 years of age. One of the most impressive triumphs of modern medicine is that with current recombinant factor VIII replacement therapy, a boy born in the 21st century with severe hemophilia A can anticipate a normal life expectancy with essentially no permanent complications from bleeding. For severe hemophilia A, current optimal treatment should have two goals: first, to provide sufficient factor VIII to prevent spontaneous bleeding, and second, to provide sufficient factor VIII to have normal coagulation function after any trauma. However, the replacement therapy requires tremendous resources for effective use, and remains extraordinarily expensive. Thus there are opportunities for further advances in therapy for hemophilia A. Two major concerns continue to trouble current optimal treatment approaches: some patients will develop neutralizing antibodies during the first 50 infusions of therapeutic factor VIII, and second, to administer therapeutic factor VIII every other day in young boys often requires placement of a central venous access device, and such use carries the life-threatening risks of infection and thrombosis. Because of the effectiveness of current therapy, any new developments in treatment will require significant concerns for safety, both immediate and in the long term. A number of research groups seek to prolong the biological efficacy of infused recombinant factor VIII. Currently, one such promising development is in the advanced stages of clinical trial. The goals will be to improve further the quality of life of an individual with severe hemophilia A, and to reduce the burden of current treatment strategies on families and medical resources. Hopefully, the hemophilia community will continue to participate actively in the clinical trials needed to address these new challenges.