Prophylactic therapy for hemophilia in a developing country, Turkey

Clotting factor concentrates for preventing bleeding and bleeding-related complications in previously treated individuals with haemophilia A or B

BACKGROUND

The hallmark of severe hemophilia (A or B) is recurrent bleeding into joints and soft tissues with progressive joint damage, despite on-demand treatment. Prophylaxis has long been used, but not universally adopted, because of medical, psychosocial, and cost controversies.

OBJECTIVES

To determine the effectiveness of clotting factor concentrate prophylaxis in managing previously-treated individuals with hemophilia A or B.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. In addition, we searched MEDLINE and Embase and online trial registries. Most recent search of Group's Coagulopathies Trials Register: 24 February 2021.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs evaluating people with hemophilia A or hemophilia B, who were previously treated with clotting factor concentrates to manage their hemophilia.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed trials for eligibility, assessed risk of bias and extracted data. The authors used the GRADE criteria to assess the certainty of the evidence.

MAIN RESULTS

Ten trials (including 608 participants) were eligible for inclusion. Eight of the trials (477 participants) had arms comparing two or more prophylactic regimens to one another and four of the trials (n = 258) compared prophylaxis to on-demand treatment (two trials had multiple arms and were included in both comparisons). Comparison of two or more prophylactic regimens For trials comparing one prophylaxis regimen to another, given the heterogeneity of the data, none of the data were pooled for this comparison. Considering the individual trials, three trials reported the primary outcome of joint bleeding, and none showed a dfference between dosing regimens (low-certainty evidence). For the secondary outcome of total bleeding events, prophylaxis with a twice-weekly regimen of FIX likely results in reduced total bleeds compared to a once-a-week regimen of the same dose, mean difference (MD) 11.2 (5.81 to 16.59) (one trial, 10 participants, low-certainty evidence). Transient low-titer anti-FVIII inhibitors were reported in one of the trials. Blood-transmitted infections were not identified. Other adverse events reported include hypersensitivity, oedema, and weight gain. These were, however, rare and unrelated to study drugs (very low-certainty evidence). Comparison of prophylactic and on-demand regimens Four of the trials (258 participants) had arms that compared prophylaxis to on-demand treatment. Prophylaxis may result in a large decrease in the number of joint bleeds compared to on-demand treatment, MD -30.34 (95% CI -46.95 to -13.73) (two trials, 164 participants, low-certainty evidence). One of these trials (84 participants) also reported the long-term effects of prophylaxis versus on-demand therapy showing improved joint function, quality of life, and pain; but no differences between groups in joint structure when assessed by magnetic resonance imaging (MRI). In one trial (84 participants) validated measures for joint health and pain assessment showed that prophylaxis likely improves joint health compared to an on-demand regimen with an estimated change difference of 0.94 points (95% CI 0.23 to 1.65) and improves total pain scores, MD -17.20 (95% CI -27.48 to -6.92 (moderate-certainty evidence). Two trials (131 participants) reported that prophylaxis likely results in a slight increase in adverse events, risk ratio 1.71 (1.24 to 2.37) (moderate-certainty evidence). No inhibitor development and blood-transmitted infections were identified. Overall, the certainty of the body of evidence was judged to be low because of different types of bias that could have altered the effect.   AUTHORS' CONCLUSIONS: There is evidence from RCTs that prophylaxis, as compared to on-demand treatment, may reduce bleeding frequency in previously-treated people with hemophilia. Prophylaxis may also improve joint function, pain and quality of life, even though this does not translate into a detectable improvement of articular damage when assessed by MRI.  When comparing two different prophylaxis regimens, no significant differences in terms of protection from bleeding were found. Dose optimization could, however, result in improved efficacy. Given the heterogeneity of the data, pooled estimates were not obtained for most comparisons.  Well-designed RCTs and prospective observational controlled studies with standardised definitions and measurements are needed to establish the optimal and most cost-effective treatment regimens.

On-demand treatment in persons with severe haemophilia

There are two main modes of replacement therapy for haemophilia patients: either to stop bleeding (on-demand) or regular infusions of clotting factor to prevent bleeds (prophylaxis). Fifty yr of clinical experience have provided evidence of the superiority of prophylaxis by showing a reduction in bleeds and development of arthropathy. Prophylaxis has been described extensively in terms of efficacy and health-economic aspects; however, on-demand treatment has received less attention. The aim of this study was to critically review the published literature on PubMed and discuss potential gaps of knowledge in on-demand treatment in persons with severe haemophilia without inhibitors by focusing on two key aspects: how on-demand treatment is provided and what outcome measures have been reported. We identified 134 papers of which 112 were excluded. Of the remaining 22 papers, 16 were comparative studies between prophylaxis and on-demand treatment and six were descriptions of on-demand treatment. The results showed limited reporting on data related to the key aspects of treatment on-demand. Early studies looked at degrees of joint bleeds and different treatment regimens in finding the optimal dose. However, from the late 1980s, there was almost no research into on-demand therapy except efficacy and safety studies of new rFVIII products and studies to prove superiority of prophylaxis over treatment on-demand. The success of on-demand therapy may depend on several factors, for example time to initial dose after a bleed and duration of treatment. Data on these key factors are limited and highlight the necessity of research to optimise replacement therapy.

Clotting factor concentrates given to prevent bleeding and bleeding-related complications in people with hemophilia A or B

BACKGROUND

The hallmark of severe hemophilia is recurrent bleeding into joints and soft tissues with progressive joint damage, notwithstanding on-demand treatment. Prophylaxis has long been used but not universally adopted because of medical, psychosocial, and cost controversies.

OBJECTIVES

To determine the effectiveness of clotting factor concentrate prophylaxis in the management of people with hemophilia A or B.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register. In addition, we searched major electronic databases (MEDLINE, EMBASE, CENTRAL), handsearched relevant journals and abstract books and reference lists of relevant articles.Last search of Group's Coagulopathies Trials Register: 07 April 2011.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials evaluating people with severe hemophilia A or hemophilia B receiving prophylactic clotting factor concentrates.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed studies for eligibility, assessed risk of bias and extracted data.

MAIN RESULTS

Six studies (including 142 participants) were eligible for inclusion. Two compared three-times-a-week prophylactic administration with on-demand treatment in children with hemophilia. Pooled results from these two studies showed a rate ratio of 0.30 (95% confidence interval; 0.12 to 0.76) for all bleedings and 0.22 (95% confidence interval 0.08 to 0.63) for joint bleedings favouring prophylaxis. Results on the number of patients with preserved joints after three to seven years of follow-up were not pooled due to significant heterogeneity. Three of the remaining four studies evaluated hemophilia A; one showed a statistically significant decrease in frequency of joint bleeds with prophylaxis compared to placebo, with a rate difference of -10.73 (95% confidence interval -16.55 to -4.91) bleeds per year. Two studies compared two prophylaxis regimens, failing to demonstrate an advantage of one regimen over the other in terms of bleeding frequency. The fourth study evaluated hemophilia B and showed fewer joint bleeds with weekly (15 IU/kg) versus bi-weekly (7.5 IU/kg) prophylaxis, rate difference -3.30 (95% confidence interval -5.50 to -1.10) bleeds per year. Non-significant increases in both inhibitor and infectious complications were observed in patients on prophylaxis, which occurred more often when using long-term venous access.

AUTHORS' CONCLUSIONS

There is strong evidence from randomised controlled trials and observational trials that prophylaxis preserves joint function in children with hemophilia as compared to on-demand treatment. There is insufficient evidence from randomised controlled trials to confirm the observational evidence that prophylaxis decreases bleeding and related complications in patients with existing joint damage. Well-designed randomised controlled trials and prospective observational controlled studies are needed to establish the best prophylactic regimen and to assess the effectiveness of prophylactic clotting factor concentrates in adult patients.

Hemophilia-Specific Quality of Life Index (Haemo-QoL and Haem-A-QoL questionnaires) of children and adults: result of a single center from Turkey

The aim of this study is to describe the health status, health care received, and their impact on the quality of life in patients with hemophilia. Patients with severe factor VIII or IX deficiency without inhibitors or other chronic disease were enrolled. Turkish version of the Hemophilia-Specific Quality of Life Index (Haemo-QoL) questionnaire was administered to the pediatric patients aged 4 to 16 years and Haem-A-QoL to the adult patients. Joints were evaluated according to the World Federation of Hemophilia (WFH) orthopedic joint scores.Thirty-nine children/adolescents and 31 adult patients were enrolled. Mean Haemo-QoL scores were 39.6 +/- 15.0 for the children and mean Haem-A-QoL 47.4 +/- 14.1 for the adult patients, respectively. Internal consistency reliability was generally sufficient. Total Cronbach's alpha coefficient was >.70 (range .77-.96) in all the age groups. Mean total WFH orthopedic joint scores were 1.83 +/- 2.7, 4.9 +/- 4.96, and 6.94 +/- 6.15 in 4-7, 8-12, and 13-16-year-old groups, respectively. They were more impaired in the adult patients (16.23 +/-14.12). These results show that the Turkish version of the Haemo-QoL and Haem-A-QoL are reliable instruments to measure the quality of life in the pediatric and adult patients with severe hemophilia. When compared to the Haemo-QoL scores of an international multicenter West European study of children, quality of life in the Turkish patients were more impaired in the subscales of physical health, feeling, view, school and sport, and treatment as well as more impaired WFH joint scores. The authors recommend primary factor prophylaxis and encouraging the patients to learn home treatment to improve joint scores and quality of life.

Tailored prophylaxis in severe hemophilia A: interim results from the first 5 years of the Canadian Hemophilia Primary Prophylaxis Study

BACKGROUND

Prophylactic treatment for severe hemophilia A is likely to be more effective than treatment when bleeding occurs, however, prophylaxis is costly. We studied an inception cohort of 25 boys using a tailored prophylaxis approach to see if clotting factor use could be reduced with acceptable outcomes.

METHODS

Ten Canadian centers enrolled subjects in this 5-year study. Children were followed every 3 months at a comprehensive care hemophilia clinic. They were initially treated with once-weekly clotting factor; the frequency was escalated in a stepwise fashion if unacceptable bleeding occurred. Bleeding frequency, target joint development, physiotherapy and radiographic outcomes, as well as resource utilization, were determined prospectively.

RESULTS

The median follow-up time was 4.1 years (total 96.9 person-years). The median time to escalate to twice-weekly therapy was 3.42 years (lower 95% confidence limit 2.05 years). Nine subjects developed target joints at a rate of 0.09 per person-year. There was an average of 1.2 joint bleeds per person-year. The cohort consumed on average 3656 IU kg(-1)year(-1) of factor (F) VIII. Ten subjects required central venous catheters (three while on study); no complications of these devices were seen. One subject developed a transient FVIII inhibitor. End-of-study joint examination scores--both clinically and radiographically--were normal or near-normal.

CONCLUSIONS

Most boys with severe hemophilia A will probably have little bleeding and good joint function with tailored prophylaxis, while infusing less FVIII than usually required for traditional prophylaxis.

Long-term evaluation of radioisotope synovectomy with Yttrium 90 for chronic synovitis in Turkish haemophiliacs: Izmir experience

Since 2001 we have performed 105 radioisotope synovectomy (RS) in 65 children and young adults, age ranging from 3 to 25 years with a average of 15 years in Ege University Hospital, Izmir, Turkey. One fourth of cases were below 10 years of age. All patients had severe haemophilia A and B. Ten patients (17 joints) had high responder inhibitor. We prefer to use Yttrium 90 for all joints (5 mCi for knees; 2 mCi for others). The knees were injected in 56 cases, elbows in 24 cases, ankles in 23 cases and shoulders in two cases. Steroid injections were not preferred as the principle drug of choice. Mean follow-up period after procedure was 2 years (range: 6 months to 3.5 years). All inhibitor patients had satisfactory results. The best results were obtained in elbows than knees and ankles. Excellent rates (no bleeding) were observed in grade-II synovitis 84% for knees, 93% for elbows and 50% for ankles. Because of the excellent and good response (bleeding reduction to 75%), rates were 100% for knees and elbows and 92% for ankles. In six cases, repeated injections were given at 6-month interval and all of them had good results. The grading of synovitis seems to be an important parameter than the age of the patient. Even in patients below 10 years of age, outcomes are not satisfactory in all joints with grade-III vs. grade-II synovitis (12% vs. 73%). No serious complications were observed during and after procedure except two cases. A mild and transient inflammatory reaction was observed in the ankle. There was a minimal radioisotope leakage to superficial skin in the elbow. RS seems to be a safe and effective treatment for chronic synovitis causing recurrent joint bleedings.

The Hemophilia Utilization Group Study (HUGS): determinants of costs of care in persons with haemophilia A

OBJECTIVE

The main objective of this study was to examine factors associated with utilization and costs for persons with haemophilia.

STUDY DESIGN

Utilization data and patient characteristics were collected through medical record review of 336 patients receiving treatment for at least 90% of their haemophilia care at one of five comprehensive haemophilia treatment centres in California.

PRINCIPAL FINDINGS

The range of factor VIII deficiency in our sample was similar to the distribution among haemophilic patients in the Western United States; 215 (64%) had severe FVIII deficiency. The mean age in our sample was 21.4 (SD = 16.2) years old and 114 (34%) were HIV-positive. In the multivariate model predicting the total cost of health care during 1995 (adjusted R2 = 0.40), total annual costs were significantly (P < 0.05) associated with being HIV-seropositive, infusing FVIII concentrate through a port vs. i.v. infusion, the number of comorbidities, moderate arthropathy (compared with no arthropathy), mild arthropathy, history of inhibitor to FVIII, and current prophylactic FVIII concentrate infusion.

CONCLUSION

As expected, total health-care costs were correlated with comorbid medical conditions, such as HIV and sequelae of haemophilia such as arthropathy. Health policy should consider risk adjustment for the presence of complications such as arthropathy and HIV infection in the financing of haemophilia treatment to promote more equitable delivery of these services.

Prophylaxis in factor IX deficiency product and patient variation

To determine the dosing needed to maintain a prophylactic level of factor IX (FIX) >/=2%, 15 non-inhibitor severe (</=1% FIX) deficient subjects participated in a double-blind, two-period crossover study to assess the pharmacokinetics of two FIX concentrates, Mononine (pd-FIX), an ultra-high-purity plasma-derived concentrate, and BeneFix (r-FIX), a recombinant product. The median recovery in the pd-FIX group was 1.67 IU dL(-1) per IU kg-1+/-1.07 vs. 0.86 IU dL(-1) per IU kg(-1)+/-0.32 in the r-FIX group (P = 0.0002). The median half-life for pd-FIX was 12.9 +/-1.7 h compared with 13.7 +/- 2.9 h for r-FIX (P = 0.016). Fitted dose activity curves were computer-simulated to depict multiple-dose activity curves for each patient with each product that would maintain prophylactic levels of >/=2%. Based on pharmacokinetic analysis the median amount of concentrate needed to maintain a prophylactic level >/=2% for 30 days when administered every third day is 677 IU kg(-1) pd-FIX (range 388-6005 IU kg(-1) pd-FIX) compared with 1168 IU kg(-1) r-FIX (range 268-13085 IU kg(-1) r-FIX). The median cost for 30 days of prophylaxis of an average 25-kg 8-year-old child at the current University of Iowa Price (0.87 US dollars Mononine/0.86 US dollars BeneFix as of December 2002) if given every third day would be 19,972 US dollars and 34,456 US dollars for r-FIX. However, because of wide inter-patient variability in recovery and half-life, pharmacokinetic evaluation of each patient is necessary to determine the appropriate dosing schedule and product best suited for prophylaxis.

Inhibitor development and substitution therapy in a developing country: Turkey

Prevalence of inhibitor in developing countries, such as Turkey, where fresh frozen plasma (FFP) is still in use due to high cost of concentrates, is unknown. To determine the frequency of inhibitors in Turkish haemophiliacs exposed to blood products, 53 haemophilia A patients (age range 1-20; median: 11 years) and 12 haemophilia B patients (age range 3-20; median: 10 years), were evaluated; 31 haemophilia A patients (23 severe) received plasma-derived concentrates and 22 patients (10 severe) only FFP. No haemophilia B patients developed inhibitor, compared with seven of 53 (13%) haemophilia A patients, all with a severe defect (7/33; 21%) and treated with concentrates (7/23; 30%), whereas severe patients treated with FFP showed a lower risk to develop inhibitors (0/10, P = 0.07). Inhibitors were detected after 8-125 exposure days (median: 52). Intermediate-purity concentrates and pasteurization seemed to be linked with a higher risk of inhibitor compared to high-purity concentrates and solvent-detergent inactivation for seven patients with inhibitor. In four of seven inhibitor patients low-dose concentrate was administered at 25 IU kg-1 twice weekly and inhibitor disappeared in 1-4 months. This regimen might be recommended for immune tolerance in developing countries for its lower cost.