Evaluation of CDC's Hemophilia Surveillance Program - Universal Data Collection (1998-2011) and Community Counts (2011-2019), United States

Race and ethnicity and the success of immune tolerance induction among people with severe haemophilia A in the United States

INTRODUCTION

Immune tolerance induction (ITI) is the only treatment to eradicate inhibitors in people with severe haemophilia A with inhibitors. Since the risk of inhibitor development is greater among Black and Hispanic persons, it has been hypothesized that race and ethnicity may influence ITI success. Limited studies have evaluated this hypothesis.

AIM

To examine the success of ITI according to race and ethnicity.

METHODS

Participants who entered the Community Counts (CC) Registry between 2013 and 2017, were aged ≥3 years at study entry, and received ITI were included (n = 559). The proportion of participants with successful ITI was examined with adjusted prevalence ratios (aPRs) and corresponding 95% confidence intervals (95% CIs).

RESULTS

Among 559 participants, 56.9%, 19.1%, 18.1% and 4.3% were Non-Hispanic (NH) White, NH Black, Hispanic and Asian, respectively, and 1.7% were coded as other or missing. Approximately 80% of Hispanic, NH Black and NH White participants had good/very good prognosis, defined as having a pre-ITI peak inhibitor of < 200 Bethesda Units per millilitre. Nearly 60% of participants (59.7%) achieved successful ITI, 20.7% and 19.5% experienced partially successful or failed ITI, respectively. Successful ITI was non-significantly lower in NH Black (54.2%; aPR = 0.95, 95% CI 0.62-1.44) and Hispanic (55.4%; aPR = 0.89, 95% CI 0.71-1.13) relative to NH White participants (62.6%).

CONCLUSION

In this study, 60% of participants in the CC Registry had successful ITI, consistent with previous studies. The proportion with successful ITI was generally comparable across racial and ethnic groups with similar prognosis. These findings do not support the hypothesis that ITI response varies according to race or ethnicity.

Defining the impact of immune tolerance induction on clinically relevant outcomes in a US cohort of severe hemophilia A

ABSTRACT

Although the near-term benefit of immune tolerance induction (ITI) for the treatment of people with severe hemophilia A with inhibitor is apparent, the magnitude of the longer-term impact of ITI on clinical outcomes remains undefined. We examined the association between receiving ITI and the success of ITI on clinical outcomes including (1) clinical events, (2) health care use, (3) quality of life/function, (4) socioeconomic status, and (5) death, using the Community Counts (CC) registry of US Hemophilia Treatment Centers between 2013 and 2017. Multivariate logistic regression, negative binomial, and Poisson models were used. Included in this study were 3659 people with severe hemophilia A with median age of 21 years when entering the CC registry. Among 576 participants with inhibitors, 485 had received ITI (84%). ITI was successful in 299 (61.7%) and partially successful or failed in 95 (19.5%) or 91 (18.7%), respectively. Those that received ITI had fewer treated bleeds, less chronic pain, better function, and higher educational attainment than those not receiving ITI. Successful vs partially successful and failed ITI was associated with fewer treated bleeds, less health care use, less chronic pain, better function, and fewer missed days of school or work. Mortality was not associated with ITI, regardless of its success. Those with successful ITI had similar rates of treated bleeds, chronic pain, and health care use as those with no inhibitors. Undergoing ITI, particularly if successful, improved clinical outcomes but not mortality. These findings support decision making regarding initiation of ITI and inform future clinical trials.

Race, ethnicity, and immune tolerance induction in hemophilia A in the United States

Background

In racially diverse communities, treatment of chronic diseases can vary across racial and ethnic groups.

Objectives

To examine healthcare disparities in hemophilia care in the United States by evaluating receipt of immune tolerance induction (ITI) among different racial and ethnic groups.

Methods

In this cross-sectional study, people with severe hemophilia A with an inhibitor who entered the Center for Disease Control and Prevention Community Counts registry between 2013 and 2017, were aged ≥5 years at study entry, and had a history of an inhibitor (n = 614) were included. The proportion of participants receiving ITI was examined according to race and ethnicity in bivariable analysis and multivariable analysis adjusting for demographic and clinical covariates. Unadjusted and adjusted prevalence ratios and corresponding 95% CIs were computed.

Results

Among 614 participants included in the study, 56.4% were non-Hispanic (NH) White, 19.7% were NH Black, 18.4% were Hispanic, and 4.9% were Asian. ITI was received by 85.2% of participants. On bivariable analysis, ITI treatment did not vary by race or ethnicity. On multivariable analysis, NH Black and Hispanic participants were significantly less likely to receive ITI compared to NH White participants (adjusted prevalence ratio, 0.91 [95% CI, 0.84-0.99] and 0.84 [95% CI, 0.75-0.93], respectively).

Conclusion

Although the role of ITI may evolve with growing use of emicizumab and the introduction of new hemophilia treatment products, understanding characteristics that influence care, particularly race and ethnicity, where physician bias and patient mistrust can occur, will remain relevant and applicable to other complex therapies, including gene therapy.

Results of genetic analysis of 11 341 participants enrolled in the My Life, Our Future hemophilia genotyping initiative in the United States

BACKGROUND

Hemophilia A (HA) and hemophilia B (HB) are rare inherited bleeding disorders. Although causative genetic variants are clinically relevant, in 2012 only 20% of US patients had been genotyped.

OBJECTIVES

My Life, Our Future (MLOF) was a multisector cross-sectional US initiative to improve our understanding of hemophilia through widespread genotyping.

METHODS

Subjects and potential genetic carriers were enrolled at US hemophilia treatment centers (HTCs). Bloodworks performed genotyping and returned results to providers. Clinical data were abstracted from the American Thrombosis and Hemostasis Network dataset. Community education was provided by the National Hemophilia Foundation.

RESULTS

From 2013 to 2017, 107 HTCs enrolled 11 341 subjects (68.8% male, 31.2% female) for testing for HA (n = 8976), HB (n = 2358), HA/HB (n = 3), and hemophilia not otherwise specified (n = 4). Variants were detected in most male patients (98.2%% HA, 98.1% HB). 1914 unique variants were found (1482 F8, 431 F9); 744 were novel (610 F8, 134 F9). Inhibitor data were available for 6986 subjects (5583 HA; 1403 HB). In severe HA, genotypes with the highest inhibitor rates were large deletions (77/80), complex intron 22 inversions (9/17), and no variant found (7/14). In severe HB, the highest rates were large deletions (24/42). Inhibitors were reported in 27.3% of Black versus 16.2% of White patients.

CONCLUSIONS

The findings of MLOF are reported, the largest hemophilia genotyping project performed to date. The results support the need for comprehensive genetic approaches in hemophilia. This effort has contributed significantly towards better understanding variation in the F8 and F9 genes in hemophilia and risks of inhibitor formation.

Advances in Hemophilia A Management

Hemophilia A is an inherited insufficiency of Factor VIII (FVIII), one of the critical clotting factors. The gold standard for the management of moderate-to-severe hemophilia A is prophylaxis using regular replacement therapy with clotting factor concentrates. Compared with conventional treatment, extended half-life products reduce the burden of frequent factor replacement injections. Of note, up to 30% of patients with hemophilia A receiving prophylactic factor infusions develop "inhibitors," neutralizing anti-FVIII autoantibodies. Therapeutic options for patients with hemophilia A and inhibitors include the immune tolerance induction (ie, eradication of inhibitors) and the management of acute bleeds with bypassing agents and/or emicizumab. Emicizumab is a biphasic monoclonal antibody mimicking activated FVIII, approved for patients with hemophilia A with/without inhibitors. Gene therapy is an emerging therapy for hemophilia A, essentially curing patients with hemophilia A or transforming them to a milder phenotype by establishing continuous endogenous expression of FVIII after one-time treatment.

Bleeding Disorders in Women and Girls: State of the Science and CDC Collaborative Programs

Women and girls with bleeding disorders experience abnormal and excessive bleeding that can negatively impact their overall health and quality of life. In this report, we provide an overview of the biology, types, clinical care, and state of the science related to bleeding disorders in girls and women and describe Centers for Disease Control and Prevention (CDC) activities related to (1) surveillance of bleeding disorders in women; (2) scientific review, research, and collaboration to inform health care gaps in identifying and caring for women with bleeding disorders; and (3) development of health promotion and education programs to bring awareness about bleeding disorders to both women and girls in the population at large and various health care providers who care for women. Findings generated from surveillance and research activities inform the development of new public health programs aimed at improving diagnostic and health care services and empowering women with bleeding disorders with the knowledge they need to navigate a complex health care system with the need for specialty care services. Additional work is needed to improve provider awareness and understanding of the unique needs of women and girls with bleeding disorders to achieve appropriate care and treatment and ensure optimal outcomes and quality of life.

Integrated Hemophilia Patient Care via a National Network of Care Centers in the United States: A Model for Rare Coagulation Disorders

Rare, chronic diseases such as hemophilia and other congenital coagulation disorders require coordinated delivery of services for optimal outcomes. Hemophilia Treatment Centers (HTCs) are specialized, multidisciplinary health-care centers providing team-based care to meet the physical, psychosocial, and emotional needs of people with hemophilia (PWH) and may serve as a model for other rare coagulation disorders. Health-care purchasers, as well as the general medical community, may not appreciate the breadth and quality of services provided by HTCs. They exemplify the acculturalization and actualization of integrated care by providing comprehensive diagnostic and treatment services that reduce morbidity, mortality, avoidable emergency room visits, hospitalizations, and overall costs, while promoting a longer lifespan and improved patient functioning and outcomes. This is accomplished by a team-based approach relying upon a shared decision-making model to effectively prevent complications and manage symptoms in PWH, who are dependent on high-cost treatments. This article provides a concise yet comprehensive description of the core components of an HTC and the regional and national networks in the United States, which together achieve their incomparable value for all stakeholders.