Savings without changing: How to use the MyPKfit® device to improve treatment strategies in a cohort of patients with haemophilia A

"Getting the Dose Right"-Revisiting the Topic With Focus on Biologic Agents

Nearly two decades after the Peck and Cross article '"Getting the dose right: facts, a blueprint, and encouragements" was published, a review of dose recommendations for biologics shows that the success in getting the dose right appears to have improved given the relatively low incidence of drug withdrawals and dosing/label changes. However, the clinical experience with monoclonal antibodies (MAbs) following approval has been less than perfect. In inflammatory diseases, the disease burden changes with time and high treatment failure rates have been reported. In addition, the use of concomitant steroids and immunosuppressant drugs with MAbs is common. These concomitant agents have their own safety issues and many immunosuppressant agents are not well-tolerated although they have been shown to reduce the incidence of anti-drug antibodies (ADA). This same complexity is seen in MAbs used in oncology as well, although with these agents the doses appear to be higher than needed, which results in high treatment costs and incidence of adverse events. Given the complexity of MAb pharmacokinetics, which makes providing a detailed description of dose options difficult, product labeling should include the options for alternative dose strategies and potentially include the use of therapeutic drug monitoring with dose individualization which have been shown to improve clinical response and reduce the incidence of ADA. So, while the recommended dosing for biologics seems improved over the issues noted 17 years ago, we still have some work to do.

Blood-Induced Arthropathy: A Major Disabling Complication of Haemophilia

Haemophilic arthropathy (HA) is one of the most serious complications of haemophilia. It starts with joint bleeding, leading to synovitis which, in turn, can cause damage to the cartilage and subchondral bone, eventually inducing degenerative joint disease. Despite significant improvements in haemophilia treatment over the past two decades and recent guidelines from ISTH and WFH recommending FVIII trough levels of at least 3 IU/dL during prophylaxis, patients with haemophilia still develop joint disease. The pathophysiology of HA is complex, involving both inflammatory and degenerative components. Early diagnosis is key for proper management. Imaging can detect joint subclinical changes and influence prophylaxis. Magnetic resonance imagining (MRI) and ultrasound are the most frequently used methods in comprehensive haemophilia care centres. Biomarkers of joint health have been proposed to determine osteochondral joint deterioration, but none of these biomarkers has been validated or used in clinical practice. Early prophylaxis is key in all severe haemophilia patients to prevent arthropathy. Treatment is essentially based on prophylaxis intensification and chronic joint pain management. However, there remain significant gaps in the knowledge of the mechanisms responsible for HA and prognosis-influencing factors. Better understanding in this area could produce more effective interventions likely to ultimately prevent or attenuate the development of HA.

Pharmacokinetic-guided versus standard prophylaxis in hemophilia: a systematic review and meta-analysis

BACKGROUND

With population pharmacokinetic (PK) modeling more readily available and PK-guided prophylaxis endorsed by current hemophilia guidelines, we conducted a systematic review to summarize current evidence in the literature.

OBJECTIVES

To assess the efficacy of PK-guided compared with non-PK-guided prophylaxis.

METHODS

We did not restrict inclusion to specific study design labels and included all studies consisting of at least one distinct cohort arm receiving PK-guided prophylaxis. We searched the following databases from inception to date of search: MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and the EU Clinical Trial Register. Following title, abstract, and full-text screening conducted independently by 2 review authors, we summarized studies qualitatively and synthesized included randomized clinical trials (RCTs) quantitatively by fitting random-effects models.

RESULTS

Search of databases on February 3, 2023, yielded 25 studies fitting our inclusion criteria. Of those, only 2 RCTs and 17 nonrandomized studies included a standard prophylaxis comparator group. Furthermore, risk of bias in the latter was substantial, primarily due to before-after study designs and retrospective comparator groups. Thus, nonrandomized studies were only presented qualitatively. A random-effects meta-analysis of the 2 identified RCT remained inconclusive with regards to bleeding outcomes (ratio of means, 1.15; 95% CI, 0.85-1.56) and factor consumption (ratio of means, 0.82; 95% CI, 0.58-1.18).

CONCLUSION

Evidence in the literature suggesting a clinical benefit of PK-guided over standard fixed-dose prophylaxis was weak and mainly found in nonrandomized studies limited by lack of concurrent controls, heterogeneity in outcome reporting, small sample sizes, and high risk of bias.

Effects of PK-guided prophylaxis on clinical outcomes and FVIII consumption for patients with moderate to severe Haemophilia A

INTRODUCTION

In recent years, there has been increased focus on individualizing treatment for persons with hemophilia including pharmacokinetic-guided (PK) dosing.

AIMS

In this retrospective study clinical outcomes before and after PK-guided prophylaxis were examined.

MATERIALS AND METHODS

Eight Haemophilia Treatment Centres from the United States participated in the study and included 132 patients classified into two cohorts: those undergoing a PK-assessment for product switch (switchers) or to optimize treatment (non-switchers). Subset analyses for the two most common products and patients with dosing per prescription label were included for annual bleeding rates (ABR), mean weekly consumption outcomes, and annualized cost of prophylaxis.

RESULTS

The most common products before and after index date were octocog alfa, rurioctocog alfa pegol, and efmoroctocog alfa. Seventy-four (56%) patients were identified as switchers and 58 (44%) patients were classified as non-switchers. The majority of patients (78.0%) experienced either a decrease in ABR post-index or maintained 0 ABR during pre- and post-index time periods, with similar proportions identified in both switchers (77.0%) and non-switchers (79.3%) populations. Non-switchers were identified as having no significant change in cost of therapy, while switchers experienced increased cost of therapy driven by higher price of extended half-life products. Within subset analyses, patients receiving rurioctocog alfa pegol and efmoroctocog alfa had mean ABR under 1 after index date.

CONCLUSION

PK-guided prophylaxis has the potential to improve clinical outcomes without increase in cost of therapy for patients maintaining product and can aid in maintaining effective protection against bleeds in those switching product.

The road to implementation of pharmacokinetic-guided dosing of factor replacement therapy in hemophilia and allied bleeding disorders. Identifying knowledge gaps by mapping barriers and facilitators

Clinical guidelines and expert groups recommend the use of pharmacokinetic (PK)-guided dosing of factor replacement therapy for the treatment of bleeding disorders, especially for patients with hemophilia. Although PK-guided dosing is increasingly applied, it is generally not considered standard clinical practice. The aim of this scoping review is to map barriers and facilitators for the implementation of PK-guided dosing in clinical practice and to identify knowledge gaps. A literature search was performed and 110 articles were included that describe PK-guided dosing in patients with bleeding disorders, mostly hemophilia A. We defined two overarching themes, efficacy and feasibility, and discuss five topics within each theme. For each topic, barriers, facilitators and knowledge gaps were described. Although consensus was found with regard to some topics, contradicting reports were found for others, especially with respect to the efficacy of PK-guided dosing. These contradictions highlight the need for future research to elucidate current ambiguities.

Cost-Effectiveness Analysis of Pharmacokinetic-Guided Prophylaxis Versus Standard Prophylaxis in Adults with Severe Hemophilia A in China

Introduction

Multiple studies have demonstrated the effectiveness of pharmacokinetic (PK)-guided individualized prophylaxis with human coagulation factor VIII (FVIII) compared with standard prophylaxis, but no studies have evaluated the economics of PK-guided prophylaxis in China. Hence, we conducted this study to assess the cost-effectiveness of PK-guided prophylaxis with recombinant FVIII (rFVIII) versus standard prophylaxis in Chinese adult patients with severe hemophilia A.

Methods

A discrete event simulation model was developed to simulate 10,000 patients with hemophilia A who received rFVIII treatment over a 1-year time horizon. The standard prophylaxis rFVIII dose was 30 IU/kg by intravenous injection. The PK-guided prophylaxis dosage was adjusted for each patient to maintain FVIII trough level at 1–5 IU/dL. Dosing interval for both approaches was kept fixed at 48 h. The health outcomes included annual joint bleed rate (AJBR) and quality-adjusted life years (QALYs). The model considered the costs of drug. Incremental cost-effectiveness ratio (ICER) was estimated and scenario analysis was performed.

Results

A total of 94.3% of patients receiving PK-guided individualized prophylaxis achieved the goal of maintaining the trough concentration at 1–5 IU/dL compared with 62.7% on standard prophylaxis. AJBR and QALYs gained in PK-guided and standard prophylaxis were 1.527 vs 1.601, and 0.8384 vs 0.8383, respectively. Costs of drug prophylaxis and costs of treatment for bleeding events in PK-guided prophylaxis (148,641.47 USD; 4546.43 USD) were lower than those in standard prophylaxis (159,620.93 USD; 4753.39 USD). An average saving of USD 11,186.47 was obtained by the PK-guided approach. The prophylaxis treatment scenarios were the most influential factors.

Conclusion

PK-guided individualized prophylaxis appeared to be a dominant treatment compared with standard prophylaxis, with slightly higher QALYs but lower total costs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02220-3.

Pharmacokinetic-guided prophylaxis improved clinical outcomes in paediatric patients with severe haemophilia A

BACKGROUND

The traditional weight-based dosing regimen can lead to under- or overdosage due to the interindividual variability of pharmacokinetic (PK) parameters. PK-guided prophylaxis can be an optimized therapy choice.

AIM

This study aimed to investigate the clinical outcomes of PK-guided prophylaxis in 46 boys with severe haemophilia A.

METHODS

Forty-six boys with severe haemophilia A were enrolled in Beijing Children's Hospital. The PK tests were performed using a five-point assay. PK parameters were calculated using WinNonlin software. The dosing regimen and bleeding rates recorded during the observation period. The adjustment was based on PK evaluation, bleeding details, doctor's advice and patients' choice.

RESULTS

The half-life time, in vivo recovery and clearance of Kovaltry were 14.34 ± 2.68 h, 1.78 ± 0.29 kg/dl and 3.38 ± 0.94 ml/kg/h, respectively. In 18 patients without any change in the dosing regimen, the trough level was 4.0 ± 2.41 IU/dl and the bleeding rates were similar after PK tests. For patients with a higher trough level after adjustment, higher dose and frequency were observed, as well as a higher trough level. Also, reduced annual bleeding rate (ABR), annual joint bleeding rate and annual spontaneous bleeding rate (ASBR) were found. In five patients with a reduced trough level, lower infusion frequency and weekly coagulation factor VIII (FVIII) consumption were observed, with no statistically significant difference in ABR and ASBR.

CONCLUSION

PK-guided prophylaxis can help haemophiliac patients improve quality of life by decreasing bleeds with appropriate FVIII consumption and reducing infusion frequency without increments in bleeds, thus optimizing haemophilia treatment.