Inhibitor in Congenital Factor VII Deficiency; a Rare but Serious Therapeutic Challenge-A Systematic Literature Review
Journal of clinical medicine. 2021;10(2)
BACKGROUND Congenital factor (F) VII deficiency is a rare coagulation factor deficiency with an estimated incidence of 1 per 500,000 individuals. Patients with severe FVII deficiency present a broad range of clinical presentations. Alloimmunization against exogenous FVII, as the main challenge of replacement therapy, is an extremely rare phenomenon that is accompanied by a high rate of life-threatening bleeding, that renders replacement therapy less effective. Due to the importance of the issue, we performed a systematic literature review in order to assess incidence, molecular basis, clinical presentations, and therapeutic challenge and management of inhibitor in congenital FVII deficiency. Strategy of search: This systematic review was performed in accordance with PRISMA guidelines. We performed an English-language literature review in the PubMed, EMBASE, Scopus, and Google Scholar databases, using the following keywords: "factor VII inhibitor", "factor VII inhibitors", "FVII inhibitors", "congenital FVII deficiency", "recombinant factor VII", "anti rFVIIa", "replacement therapy", and "alloantibody". RESULTS Out of 380 patients in the 13 studies, 27 had inhibitor against FVII; 18 were male, 7 were female, while the sex of 2 was not stated. The majority (92%) developed a high-titer inhibitor (Bethesda Unit > 5). All patients had severe FVII deficiency (FVII:C < 10%), and the majority received recombinant FVII prior to inhibitor development (N: 24, 89%). Among ten patients with a detected mutation, three subjects had a common non-sense (30%), and two had a deletion (20%). CONCLUSIONS Inhibitor development is a relatively rare phenomenon seen only in severe FVII deficiency, where it is associated with severe and life-threatening presentations, treatment challenge, and economic burden on the patients and their families.
Recombinant FVIIa in elective non-orthopaedic surgery of adults with haemophilia and inhibitors: A systematic literature review
Haemophilia : the official journal of the World Federation of Hemophilia. 2021
AIM: To assess available evidence on the use of rFVIIa in non-orthopaedic surgery including dental surgery in adult patients with congenital haemophilia with inhibitors (PWHI). METHODS A systematic literature search was performed according to a prespecified search string; prespecified criteria were used to select applicable studies including PWHI ≥18 years of age who underwent any non-orthopaedic surgery using rFVIIa. RESULTS Thirty-three publications met the eligibility criteria, of which 26 publications - including 46 procedures in 44 patients - were selected for the qualitative analysis. Most publications were case reports or case series (21/26). Primary authors assessed rFVIIa as effective in maintaining haemostasis during and after most major surgeries (22/32). rFVIIa dose was mainly on label, with higher doses used in 4 cases, and a lower dose in 1 case. Duration of treatment was mostly 5-10 days (range: 3 days to 1 month post-operatively). Adverse events related to rFVIIa were rare. CONCLUSIONS Assessing non-orthopaedic surgery in this patient population is hampered by a paucity of published data; nevertheless, the current evidence indicates that rFVIIa is effective in achieving haemostasis in haemophilia patients with inhibitors undergoing elective non-orthopaedic or dental surgery. rFVIIa was generally well tolerated in these patients, with thrombotic events occurring rarely. These data, generated to help clinicians manage congenital haemophilia with inhibitors, highlight the need for more systematic reporting of rFVIIa and all other therapeutic agents in non-orthopaedic surgery and dental surgery in patients with congenital haemophilia and inhibitors.
Indirect Treatment Comparison of Damoctocog Alfa Pegol versus Turoctocog Alfa Pegol as Prophylactic Treatment in Patients with Hemophilia A
Journal of blood medicine. 2021;12:935-943
PURPOSE To assess the efficacy and FVIII consumption of BAY 94-9027 versus N8-GP in prophylaxis in adolescent and adult patients with severe hemophilia A (HA). PATIENTS AND METHODS A systematic literature review was conducted to identify studies on the efficacy of BAY-94-9027 and N8-GP for prophylaxis in patients with HA aged ≥12 years without a history of inhibitors. Eight studies met systematic literature review inclusion criteria, but only data from PROTECT VIII on BAY 94-9027 and PATHFINDER 2 on N8-GP could be used for an indirect comparison. Matching-adjusted indirect comparison (MAIC) and simulated treatment comparison were performed. RESULTS No significant differences (unadjusted and adjusted) were observed in the mean annualized bleeding rate (ABR) for any bleed and proportion of patients with zero bleeds when comparing BAY 94-9027 to N8-GP. The adjusted treatment difference [incidence rate ratio (IRR)] in terms of ABR was 1.11 (95% CI, 0.85-1.44). The odds ratio (OR) of any bleed, measuring the relative effect of BAY 94-9027 versus N8-GP on the proportion of patients with zero bleeds, was 1.03 (95% CI, 0.60-1.77). FVIII consumption was significantly lower in BAY 94-9027 [mean adjusted difference=-1292.57 IU/kg/year (95% CI, ‒2152.44 to ‒432.70)]; a 26.7% reduction in consumption of BAY-94-9027. The results of the sensitivity analyses were similar to the main analysis for mean ABRs, percentages of patients with zero bleeds, and significant reduction in rFVIII consumption. For patients on BAY 94-9027 every-5-days and every-7-days, no differences versus every-4-days N8-GP were observed for the mean ABR for any bleed [IRR=0.90 (95% CI, 0.68‒1.20)] and proportion of patients with zero bleeds [OR=1.06 (95% CI, 0.56‒2.02)]. CONCLUSION BAY 94-9027 prophylaxis demonstrated 26.7% lower annual consumption when compared to N8-GP with similar efficacy in terms of ABR and percentage of patients with zero bleeds.
Use of recombinant activated factor VII for the treatment of perioperative bleeding in noncardiac surgery patients without hemophilia: A systematic review and meta-analysis of randomized controlled trials
Journal of critical care. 2020;62:164-171
PURPOSE To evaluate the efficacy and safety of perioperative use of recombinant activated factor VII (rFVIIa) in noncardiac patients. MATERIALS AND METHODS We searched electronic databases for randomized controlled trials (RCTs) that involved the use of rFVIIa through December 13, 2019 in noncardiac patients without hemophilia. Two investigators extracted the related data and assessed the quality of the included trials. RESULTS Eleven RCTs examining 993 perioperative patients were ultimately included. The use of rFVIIa did not decrease all-cause mortality (RR:0.90; 95% CI:0.50,1.64; I(2) = 0.0%; P = 0.738), shorten the length of ICU (SMD:-0.15; 95% CI:-0.47,0.17; I(2) = 0.0%; P = 0.346) or hospital (SMD:0.42; 95% CI:-0.05,0.89; I(2) = 0.0%; P = 0.078) stay, or increase incidence of the thromboembolic events (RR:1.30; 95% CI:0.70,2.41; I(2) = 0.0%; P = 0.403) among perioperative patients. However, individual RCT analyses showed that the use of rFVIIa could reduce the volume of blood loss (including prostatic cancer, severe acute pancreatitis (SAP), and spinal disease) and the transfusion of RBCs (including prostatic cancer, SAP, and spinal disease) and FFP (SAP) in a subset of perioperative patients. Publication bias was not present. CONCLUSIONS For perioperative hemorrhagic patients, rFVIIa-based hemostatic therapy showed no effect on mortality, ICU or hospital LOS, or the rate of thromboembolic events, although it appears to decrease blood loss and reduce the need for blood product transfusion in a subset of patients.
Epidemiological Challenges in Rare Bleeding Disorders: FVIII Inhibitor Incidence in Haemophilia A Patients-A Known Issue of Unknown Origin
International journal of environmental research and public health. 2020;18(1)
There is a broad range of factor products approved in Germany for haemophilia A treatment. Since the introduction of recombinant coagulation factor VIII (FVIII) products in the 1990s, there has been substantial debate whether there is a difference in inhibitor incidence between single FVIII products or product classes. Neither haemophilia registries nor clinical studies, including a randomised controlled clinical trial, provided a consistent and definite answer. The reasons were mainly related to methodological challenges in conducting controlled studies in a rare disease. In this analysis, the most relevant epidemiological challenges and main problems were examined, including study bias, potential overlap of individual studies and advanced development of therapy and methods in the course of time. Meta-analyses on two levels showed that therapies using recombinant products resulted in different event rates when compared to plasma-derived products. These results are accompanied by substantial study heterogeneity evidenced by Cochran's Q tests. Only three studies have been identified that meet the standards of current clinical guidance. To finally resolve this ongoing and disputable safety issue of replacement therapy, collaboration among registry owners, academia and regulators must be fostered.
A systematic review evaluating the efficacy and factor consumption of long-acting recombinant factor VIII products for the prophylactic treatment of hemophilia A
Journal of medical economics. 2020;:1
Aims: Long-acting (LA) recombinant FVIII (rFVIII) products with extended dosing intervals have been developed for the treatment of hemophilia A; however, no direct head-to-head trial has been conducted to compare the efficacy of these products.Materials and methods: A systematic literature search was conducted to identify published Phase III clinical trials of prophylactic LA rFVIII treatment in previously treated patients aged ≥12 years, with moderate-to-severe hemophilia A (endogenous FVIII levels ≤2%). Studies that did not meet these criteria, or did not report the included outcomes, were excluded. Bleeding rates and consumption were extracted and summarized; only data for the dosing frequencies indicated in the US product labels (which are similar to those indicated in the European Medicines Agency labels) were included.Results: Five articles met the inclusion criteria; these studies only included patients with severe hemophilia A. Treatment length, reported outcomes and dose (range: 20-65 IU/kg) varied between studies. Median annualized bleeding rate (ABR) (IQR) reported in the relevant studies was 1.14 (0.00, 4.30), rVIII-SingleChain 2 or 3 times weekly; 1.6 (0.0, 4.7), rFVIIIFc 2 times weekly followed by every 3-5 days; 1.9 (0.0, 5.8), BAX855 2 times weekly; 1.18 (0.00, 4.25), N8-GP every 4 days; 1.9 (0.0, 5.2) and 4.1 (2.0, 10.6), BAY 94-9027 2 times weekly for the cohort who experienced >1 or <1 bleed in the study run-in phase, respectively. Median spontaneous ABR was 0.0 across studies reporting relevant data. Reported consumption was comparable among all LA products.Limitations: The primary limitation of this systematic review was the variation in study design and not all studies reported all desired outcomes, which limited the quantity of data available.Conclusions: This systematic review identified pivotal trial data for LA rFVIII products. Real-world evidence are needed to understand how these products perform in clinical practice.
Management of direct factor Xa inhibitor-related major bleeding with prothrombin complex concentrate: a meta-analysis
Blood advances. 2019;3(2):158-167
A targeted antidote for reversal of direct factor Xa (FXa) inhibitors is now available for clinical use in the United States, but it is costly and has limited availability. In a systematic review, we evaluated the safety and effectiveness of 4-factor prothrombin complex concentrate (4F-PCC) as an alternative for managing direct FXa inhibitor-related major bleeding. A systematic literature search was conducted using Medline, Embase, and the Cochrane Register of Controlled Trials up to September 2018. No comparative studies were found. Ten case series with 340 patients who received PCC for direct FXa inhibitor-related major bleeding were included. The pooled proportion of patients with effective management of major bleeding was 0.69 (95% confidence interval [CI], 0.61-0.76) in 2 studies using the International Society on Thrombosis and Haemostasis (ISTH) criteria and 0.77 (95% CI, 0.63-0.92) in 8 studies that did not use the ISTH criteria; all-cause mortality was 0.16 (95% CI, 0.07-0.26), and thromboembolism rate was 0.04 (95% CI, 0.01-0.08). On the basis of evidence with very low certainty from single-arm case series, it is difficult to determine whether 4F-PCC in addition to cessation of direct oral FXa inhibitor is more effective than cessation of direct oral FXa inhibitor alone in patients with direct FXa inhibitor-related major bleeding.
Systematic review and analysis of efficacy of recombinant factor IX products for prophylactic treatment of hemophilia B in comparison with rIX-FP
Journal of medical economics. 2019;:1
AIMS: Prophylaxis with standard-acting recombinant factor IX (rFIX) in hemophilia B patients requires frequent injections. Extended half-life (EHL) products allow for prolonged dosing intervals and so reduce this treatment burden. Three technologies are employed to extend the half-life of FIX; glycopegylation, Fc-fusion, and albumin fusion. rIX-FP is a novel albumin fusion protein, which allows for a prolonged dosing interval of up to 14 days. A systematic review and indirect statistical comparison was performed to evaluate the efficacy of both EHL and standard-acting rFIX products compared with rIX-FP in Phase III trials for prophylaxis in adult hemophilia B patients. MATERIALS AND METHODS A systematic search was conducted in both EMBASE and PubMed to identify Phase III trials of prophylactic rFIX treatment in previously treated, hemophilia B patients aged ≥12 years (FIX: ≤2%). Annualized bleeding rate (ABR), spontaneous ABR (AsBR), and joint ABR (AjBR) data were extracted from each study. A z-test was performed using the mean of each parameter, and the mean difference in outcome between studies was calculated. RESULTS Seven articles investigating six rFIX products were identified. Median ABR, AsBR and AjBR ranged from 0-3.0, 0-1.0, and 0-1.1 (means 0.8-4.26, 0.13-2.6, and 0.34-2.85), respectively. rIX-FP achieved lowest median and mean values in all three parameters. Z-tests showed that mean ABR was significantly lower for rIX-FP 7-day prophylaxis compared with the majority of standard-acting and other EHL rFIX products. LIMITATIONS The low number of appropriate trials available for comparison limits the quantity of data available for comparison and restricts the use of methods of adjustment for variance in study design or patient characteristics. However, these limitations are shared with similar analyses published in this field. CONCLUSION This indirect comparison of Phase III trials indicates that rIX-FP efficacy compares favorably versus other rFIX products for prophylaxis in hemophilia B.
Continuous infusion of recombinant activated factor VII: a review of data in congenital hemophilia with inhibitors and congenital factor VII deficiency
Journal of blood medicine. 2018;9:227-239
Introduction: Continuous infusion (CI) of clotting factors as a replacement therapy for perioperative hemostatic protection has been performed for many years, including with factors VIII and IX and recombinant activated factor VII (rFVIIa). This approach provides steady factor levels without requiring frequent administration of bolus doses. Aim: To review safety, efficacy, and dosing data regarding CI of rFVIIa for hemostatic management of patients with congenital hemophilia with inhibitors (CHwI) or congenital factor VII deficiency (C7D). Materials and methods: A literature review identified instances of CI of rFVIIa in patients with CHwI or C7D undergoing surgery or experiencing bleeding episodes. Data regarding safety, efficacy, and dosing were extracted. Results: The safety and efficacy of 50 mcg/kg/h CI of rFVIIa following a 90 mcg/kg bolus injection, vs a standard bolus injection regimen, was reported for 24 patients with CHwI undergoing elective surgery in an open-label, randomized, Phase III trial. Efficacy was similar between CI and bolus injection groups at all postoperative time points assessed. Additionally, a postmarketing surveillance study reported effective (80%) and partially effective (20%) CI of rFVIIa in a Japanese cohort of ten patients with CHwI who underwent 15 surgical procedures. Finally, the safety and dosing of rFVIIa CI in 193 and 26 patients with CHwI and C7D, respectively, were reported in 11 prospective studies, 10 retrospective studies, and 30 case reports. No unexpected safety findings were reported. Conclusion: rFVIIa CI has been performed safely and effectively in patients with CHwI and C7D undergoing surgery and during bleeding episodes in patients with CHwI.
Methodologies for data collection in congenital haemophilia with inhibitors (CHwI): critical assessment of the literature and lessons learned from recombinant factor VIIa
Haemophilia : the Official Journal of the World Federation of Hemophilia. 2018;24((4):):536-547
AIMS: To systematically review the effectiveness of on-demand treatment with recombinant coagulation factor VIIa (rFVIIa) in congenital haemophilia with inhibitors and, if feasible, perform a meta-analysis of the data. MATERIALS AND METHODS Publications from Embase((R)) , MEDLINE((R)) , MEDLINE((R)) In-Process and the Cochrane Central Register of Controlled Trials were searched. Selected publications were reviewed for inclusion by two independent expert reviewers. Discrepancies were reconciled by a third independent reviewer. Data from selected studies were extracted using a predefined grid to ensure uniform and comparable results were captured. RESULTS A systematic search (cut-off date of 2 May 2016) identified 20 studies (13 observational; seven randomized controlled trials). All studies were of sufficient quality to include in this analysis and comprised 1221 participants, with 5981 bleeds in 746 individuals treated with rFVIIa. Haemostatic overall effectiveness of the individual studies identified ranged from 68% to 100% at ≤12 hours, 86% to 96% at 13-24 hours and 76% to 99% at 24-48 hours with rFVIIa <100 mug/kg, with similar rates reported for the ≥250 mug/kg dose. However, heterogeneity between the studies precluded pooling of results. CONCLUSIONS Data from the individual studies confirmed that rFVIIa is an effective therapy for the on-demand treatment of bleeds in congenital haemophilia with inhibitors. However, the high levels of heterogeneity between studies precluded pooling of results for a valid, reliable or precise summary measure. There remains a need to implement standardized clinical definitions and measurements for the effectiveness and safety of haemophilia therapies in future clinical trials.