The availability of new drugs for hemophilia treatment

PHAREO study: Perceived and observed accessibility to therapeutic drugs used for treating patients with inherited bleeding disorders

WHAT IS KNOWN AND OBJECTIVE

The dispensing of clotting factor concentrates in hospital pharmacies imposes accessibility constraints on patients and their caregivers, thereby increasing the disease burden. Very few studies have addressed these issues so far in terms of individual perceptions and actual difficulties. The PHAREO study aims to report patient's perception of treatment accessibility and evaluate spatial accessibility.

METHODS

The PHAREO study is an observational survey based on a questionnaire specifically designed for the study purpose in collaboration with patients' representatives in the second demographic and economic French region.

RESULTS AND DISCUSSION

We collected 293 responses (participation rate of 64.1%) which show that 89.8% of respondents were either very or rather satisfied with regard to access to treatment. However, respondents reported difficulties in accessing the hospital pharmacy. The data also showed that 79.2% of respondents tended to over-estimate travel time which was reported above their acceptable threshold for 39.2% of them. The main determinants of dissatisfaction were parental burden (OR 2.5 [1.3; 4.8], p = 0.008) and waiting time at the hospital pharmacy (OR 1.5 [1.1;2.0], p = 0.016, per 10 min increase).

WHAT IS NEW AND CONCLUSION

The PHAREO study provides subjective and objective data regarding satisfaction levels of persons with haemophilia and other coagulation deficiencies, with a high representativeness rate for patients on prophylaxis (87.5%). Both respondents and hospital pharmacists pled for an evolution of the current dispensing circuit to improve access to treatment and reduce the burden for patients. Currently, the community pharmacists are apart from the dispensing circuit. The authors propose improvements in the pathway of care for patients and their caregivers by including the community pharmacists alongside the hospital pharmacists in a centralized coordination scheme.

Factor-mimetic and rebalancing therapies in hemophilia A and B: the end of factor concentrates?

Hemophilia A (HA) and B are inherited bleeding disorders caused by a deficiency of factor VIII or factor IX, respectively. The current standard of care is the administration of recombinant or purified factor. However, this treatment strategy still results in a high economic and personal burden to patients, which is further exacerbated by the development of inhibitors—alloantibodies to factor. The treatment landscape is changing, with nonfactor therapeutics playing an increasing role in what we consider to be the standard of care. Emicizumab, a bispecific antibody that mimics the function of factor VIIIa, is the first such nonfactor therapy to gain US Food and Drug Administration approval and is rapidly changing the paradigm for HA treatment. Other therapies on the horizon seek to target anticoagulant proteins in the coagulation cascade, thus “rebalancing” a hemorrhagic tendency by introducing a thrombotic tendency. This intricate hemostatic balancing act promises great things for patients in need of more treatment options, but are these other therapies going to replace factor therapy? In light of the many challenges facing these therapies, should they be viewed as a replacement of our current standard of care? This review discusses the background, rationale, and potential of nonfactor therapies as well as the anticipated pitfalls and limitations. This is done in the context of a review of our current understanding of the many aspects of the coagulation system.

Hemophilia A Gene Therapy: Current and Next-Generation Approaches

INTRODUCTION

: Hemophilia comprises a group of X-linked hemorrhagic disorders that result from a deficiency of coagulation factors. The disorder affects mainly males and leads to chronic pain, joint deformity, reduced mobility, and increased mortality. Current therapies require frequent administration of replacement clotting factors, but the emergence of alloantibodies (inhibitors) diminishes their efficacy. New therapies are being developed to produce the deficient clotting factors and prevent the emergence of inhibitors.

AREAS COVERED

: This article provides an update on the characteristics and disease pathophysiology of hemophilia A, as well as current treatments, with a special focus on ongoing clinical trials related to gene replacement therapies.

EXPERT OPINION

: Gene replacement therapies provide safe, durable, and stable transgene expression while avoiding the challenges of clotting factor replacement therapies in patients with hemophilia. Improving the specificity of the viral construct and decreasing the therapeutic dose are critical toward minimizing cellular stress, induction of the unfolded protein response, and the resulting loss of protein production in liver cells. Next-generation gene therapies incorporating chimeric DNA sequences in the transgene can increase clotting factor synthesis and secretion, and advance the efficacy, safety, and durability of gene replacement therapy for hemophilia A as well as other blood clotting disorders.