Efficacy, safety, and immunogenicity of rurioctocog alfa pegol for prophylactic treatment in previously treated patients with severe hemophilia A: a systematic review and meta-analysis of clinical trials

Background: Patients with severe hemophilia often present with painful joint and soft tissue bleeding which may restrict them from their daily activities. The current standard of care still relies on a regular prophylactic factor VIII (FVIII), which has a high daily treatment burden. Recently, rurioctocog alfa pegol, a third-generation recombinant FVIII with a modification in its polyethylene glycol (PEG) component, has been developed. Several trials have studied this synthetic drug as bleeding prophylaxis in severe hemophilia A. This study aims to evaluate the efficacy, safety, and immunogenicity of rurioctocog alfa pegol for previously treated patients with severe hemophilia A. Methods: This study was conducted in conformity with the PRISMA guidelines. Data were retrieved from PubMed, Scopus, Cochrane Library, Wiley Online Library, and CINAHL (via EBSCOhost). Study qualities were assessed using the Methodological Index for Non-Randomized Studies (MINORS) and Modified Jadad scales. Results: Four studies involving 517 previously treated severe hemophilia A patients were included in this study. The pooled mean of total annualized bleeding rate (ABR) and hemostatic efficacy was 2.59 (95% CI = 2.04–3.14) and 92% (95% CI = 85%–97%), respectively. Only 30 (2.3%) non-serious and one (1.4%) serious adverse events were considered related to rurioctocog alfa pegol treatment. At the end of the studies, no development of FVIII inhibitory antibodies was observed. None of the developed binding antibodies to FVIII, PEG-FVIII, or PEG was correlated to the treatment efficacy and safety. Conclusions: Despite the limited availability of direct comparison studies, our analyses indicate that rurioctocog alfa pegol could serve as a safe and effective alternative for bleeding prophylaxis in previously treated hemophilia A patients. Moreover, it appears to have low immunogenicity, which further increases the safety profile of the drug in such clinical conditions.

EFFICACY AND SAFETY OF MOROCTOCOG ALFA IN AN OPEN, MULTICENTER, PROSPECTIVE, CLINICAL STUDY IN CHILDREN 2 TO 6 YEARS OF AGE WITH SEVERE HEMOPHILIA A

The purpose of the study was to assess the efficacy, safety and pharmacokinetics of the moroctocog alfa (Octofactor) in children aged 2-6 with haemophilia A. Materials and methods of research : six patients between 2 and 6 years of age (average age 4.3±0.8 years) were included in the open multicenter prospective clinical trial. The efficacy of the drug was assessed against the background of the introduction of 30±10 IU/kg every 2–3 days, the safety was assessed by the frequency and causality of adverse reactions. Results: 7 post-traumatic bleeding was registered. The average prophylactic dose of the drug is 37.84±7.13 IU/kg. The dose of the drug for stopping bleeding was 1000 IU. 2 adverse events have been reported that are not related to moroсtocog alfa. Conclusion: the obtained data indicate the efficacy and safety of moroсtocog alfa in the study group of patients.

Efficacy of Individualized Preventive Treatment of Patients with Severe Hemophilia A Guided by Multiple Clinical Parameters and Pharmacokinetics

Objective: To investigate the effect of multiple clinical parameters (age, weight, blood types, and bleeding types) on FⅧ pharmacokinetic parameters (PK parameters) in adult patients with severe hemophilia A (SHA), draw up individualized preventive treatment plans, and observe clinical efficacy and economic benefit. Methods: Forty SHA patients treated in our hospital from January 2018 to May 2019 were enrolled, with their age, weight, blood types, bleeding types, and PK parameters measured to analyze the effects of clinical parameters on PK parameters. Individualized preventive treatment was developed, and patients were followed up for 1 year. The annual bleeding times (ABR), annual joint bleeding times (AJBR), and annual FⅧ dosage were observed and compared before and after treatment. Results: Weight, blood types and bleeding types could affect the PK parameters of FVIII. A prevention plan was formulated under the guidance of FVIII half-life. After 1 year of follow-up, ABR decreased by 88.9%, AJBR decreased by 90%, and annual FⅧ dosage increased by 47%. The dosage of FⅧ in 8 patients after was less than that before prevention, and the average half-life time of these 8 patients was 13.32 h. Conclusions: 1. Weight, blood types, and bleeding types of adult SHA patients could affect FVIII half-life. As body mass index increased, FVIII half-life were significantly prolonged. The FVIII half-life of patients with type O blood were significantly shorter than those with other blood types, and the FVIII half-life of knee joint bleeding were conspicuously shorter than those of elbow joint bleeding. 2. Individualized preventive treatment could markedly reduce bleeding times. For patients with a long half-life period, the total annual FⅧ dosage could be reduced to achieve bleeding prevention and economic benefit.

Efficacy of rFVIIIFc for First-Time Immune Tolerance Induction (ITI) Therapy: Final Results from the Global, Prospective VerITI-8 Study

Introduction: Inhibitor development is a major complication of factor VIII (FVIII) replacement therapy, affecting approximately 30% of people with severe hemophilia A (Peyvandi et al Lancet 2016). Inhibitor eradication is the standard of care to restore responsiveness to FVIII; however, ITI regimens often require frequent high-dose factor injections over a long period (DiMichele et al Haemophilia 2007; Carcao et al Haemophilia 2021). Median (interquartile range [IQR]) time (months) to negative titer in the International ITI Study with high-dose FVIII was 4.6 (2.8-13.8) (n=31); negative titer to normal recovery was 6.9 (3.5-12.0) (n=23); and normal recovery to tolerance was 10.6 (6.3-20.5) (n=22) (Hay and DiMichele Blood 2012). Recombinant factor VIII Fc fusion protein (rFVIIIFc) is an extended half-life (EHL) FVIII that showed potential benefits for ITI in retrospective clinical data and case reports (Malec et al Haemophilia 2016; Groomes et al Pediatr Blood Cancer 2016; Carcao et al Haemophilia 2021). VerITI-8 (NCT03093480) is the first prospective study of rFVIIIFc in first-time ITI and follows on from the reITIrate (NCT03103542) study of rFVIIIFc for rescue ITI (Königs et al Res Pract Thromb Haemost, ISTH 2021). Aim: Describe outcomes in the verITI-8 study of first-time ITI with rFVIIIFc over 48 weeks in subjects with severe hemophilia A and high-titer inhibitors. Methods: VerITI-8 is a prospective, single-arm, open-label, multicenter study exploring efficacy of rFVIIIFc for first-time ITI in people with severe hemophilia A with high-titer inhibitors. Initial screening was followed by an ITI period in which all subjects received rFVIIIFc 200 IU/kg/day until tolerization or 48 weeks had elapsed (Figure). This was followed by tapered dose reduction to standard prophylaxis and follow-up. Key inclusion criteria included males with severe hemophilia A, high-titer inhibitors (historical peak ≥5 Bethesda units [BU]/mL), and prior treatment with any plasma-derived or recombinant standard half-life or EHL FVIII. Key exclusion criteria included coagulation disorder(s) other than hemophilia A and previous ITI. The primary endpoint was time to tolerization (successful ITI) with rFVIIIFc defined by inhibitor titer <0.6 BU/mL, incremental recovery (IR) ≥66% of expected IR (IR ≥1.32 IU/dL per IU/kg) (both at 2 consecutive visits), and t ½ ≥7 hours (h) within 48 weeks. Secondary endpoints included number of subjects achieving ITI success, annualized bleed rates (ABR), and adverse events (AEs). Results: Sixteen subjects were enrolled and received ≥1 rFVIIIFc dose. Median (range) age at baseline was 2.1 (0.8-16.0) years, and historical peak inhibitor titer was 22.4 (6.2-256.0) BU/mL (Table). Twelve (75%), 11 (69%), and 10 (63%) subjects, respectively, achieved a negative inhibitor titer, an IR >66%, and a t½ ≥7 h (ie, tolerance) within 48 weeks. Median (IQR) times in weeks to achieve these markers of success were 7.4 (2.2-17.8), 6.8 (5.4-22.4), and 11.7 (9.8-26.2) (ie, 2.7 [2.3-6.0] months to tolerance), respectively. One subject achieved partial success (negative inhibitor titer and IR ≥66%), and 5 subjects failed ITI, of which 2 had high inhibitors throughout, 2 experienced an increase in inhibitor levels, and 1 recorded a negative inhibitor titer at 282 days. Most bleeds occurred in the ITI period when median (IQR) ABRs (n=13) were 3.8 (0-10.1) overall, 0 (0-2.6) for spontaneous, 1 (0-4) for traumatic, and 0 (0-3.1) for joint. During tapering, median (IQR) ABRs (n=10) were overall, 0 (0-2.4); spontaneous, 0 (0-0); traumatic, 0 (0-1.3); and joint, 0 (0-0). All 16 subjects experienced ≥1 treatment-emergent AE (TEAE), the most frequent of which was pyrexia in 7 subjects (44%). One subject reported ≥1 related TEAE (injection site pain). Nine subjects (56%) experienced ≥1 treatment-emergent serious AE (TESAE). TESAEs occurring in ≥2 subjects included vascular device infection, contusion, and hemarthrosis. No treatment-related TESAEs, discontinuations due to AEs, or deaths were reported. Conclusions: rFVIIIFc is the first EHL FVIII with prospective data for first-time ITI in patients with severe hemophilia A with historical high-titer inhibitors. Evaluated within a 48-week timeframe, rFVIIIFc offered rapid time to tolerization (median 11.7 weeks; 2.7 months) with durable responses in almost two-thirds of subjects and was well tolerated. Optimizing ITI to eradicate inhibitors remains a priority. Figure 1 Figure 1. Disclosures Malec: CSL Behring: Consultancy; Genentech: Consultancy; HEMA Biologics: Consultancy; Pfizer: Consultancy; Sanofi: Consultancy, Research Funding; Takeda: Consultancy; Bioverativ: Consultancy, Research Funding, Speakers Bureau; Shire: Consultancy; Bayer: Consultancy. Van Damme: Pfizer: Consultancy; Shire: Consultancy; Bayer: Consultancy. Chan: Bioverativ: Consultancy. Jain: Sanofi: Ended employment in the past 24 months; Takeda: Current Employment, Current holder of stock options in a privately-held company. Sensinger: Sanofi: Current Employment, Current holder of stock options in a privately-held company. Dumont: Sanofi: Current Employment, Current holder of stock options in a privately-held company. Lethagen: Sobi: Current Employment, Current holder of stock options in a privately-held company. Carcao: Bayer, Bioverativ/Sanofi, CSL Behring, Novo Nordisk, Octapharma, Pfizer, Roche, and Shire/Takeda: Research Funding; Bayer, Bioverativ/Sanofi, CSL Behring, Grifols, LFB, Novo Nordisk, Pfizer, Roche, and Shire/Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Peyvandi: Roche: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Sobi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Ablynx, Grifols, Kedrion, Novo Nordisk, Roche, Shire, and Sobi: Other: Personal Fees. OffLabel Disclosure: adheres to routine clinical practice

Nonneutralizing FVIII-specific antibody signatures in patients with Hemophilia A and in healthy donors

Previous studies identified nonneutralizing FVIII-specific antibodies in the circulation of severe and non-severe hemophilia A patients without FVIII inhibitors and also in some healthy individuals. To gain a better understanding of the nature of these nonneutralizing antibody responses, we analyzed and compared anti-FVIII antibody signatures in three study cohorts - previously treated severe as well as non-severe hemophilia A patients without FVIII inhibitors, and healthy donors. FVIII-binding IgM, IgG1-4 and IgA antibodies were differentiated, FVIII-specificity was assessed and associated apparent affinity constants were determined. Our results indicate that the nonneutralizing FVIII-specific antibody response in all study cohorts is dominated by IgG1 and IgA. Prevalences, titers and affinities of these nonneutralizing antibodies were higher in the hemophilia A cohorts than in healthy donors. Stratification for the anti-HCV antibody status demonstrated the presence of FVIII-specific IgA with elevated titers in severe hemophilia A patients with an active or past HCV infection when compared to HCV antibody positive non-severe patients or HCV antibody negative patients and healthy donors. Increased titers and affinities of FVIII-specific IgG1 antibodies were observed in a considerable number of hemophilia A patients as opposed to healthy subjects independently of the patients' anti-HCV antibody status. Overall, our findings support the hypothesis that the generation of nonneutralizing anti-FVIII antibodies in healthy individuals and in non-inhibitor hemophilia A patients might be based on similar immune mechanisms. However, differences in prevalences, titers and affinities of these antibodies indicate distinct differences in the antibody evolution between healthy individuals and patients.

Impact of pharmacokinetics to reduce bleeding in a cohort of patients with severe hemophilia A in a personalized comprehensive management program

Introduction: In recent decades, hemophilia A treatment has been focused on body weight, without taking pharmacokinetic parameters into account. Previous research has shown that the individual pharmacokinetic response is more effective in predicting the required dose of clotting factor. We want to evaluate the impact on reducing the frequency of bleeding in patients treated with recombinant factor VIII, based on a personalized comprehensive management program. Objective: Our aim was to compare the results of a standard comprehensive treatment program (stage I) vs. a personalized pharmacokinetic - based treatment program (stage II) in a cohort of 60 patients with severe hemophilia without inhibitors. Results:The median age was 15.5 years (3 - 68). The ABR was 1.03 (62 episodes) in the first stage and 0.58 (35 episodes) in the second one, (p = 0.004). By type of bleeding, the impact of the intervention differs significantly in spontaneous bleeding (p = 0.007) and a 73% reduction in the first stage. There were no significant differences in traumatic bleeding. Conclusions: The use of pharmacokinetics for personalized dosing of patients with severe hemophilia A, significantly reduces ABR and spontaneous bleeding, improving the patient's quality of life and costs for the health system.

Efficacy, safety, and immunogenicity of rurioctocog alfa pegol for prophylactic treatment in previously treated patients with severe hemophilia A: a systematic review and meta-analysis of clinical trials

Background: Patients with severe hemophilia often present with painful joint and soft tissue bleeding which may restrict them from their daily activities. The current standard of care still relies on a regular prophylactic factor VIII (FVIII), which has a high daily treatment burden. Recently, rurioctocog alfa pegol, a third-generation recombinant FVIII with a modification in its polyethylene glycol (PEG) component, has been developed. Several trials have studied this synthetic drug as bleeding prophylaxis in severe hemophilia A. This study aims to evaluate the efficacy, safety, and immunogenicity of rurioctocog alfa pegol for previously treated patients with severe hemophilia A. Methods: This study was conducted in conformity with the PRISMA guidelines. Data were retrieved from PubMed, Scopus, Cochrane Library, Wiley Online Library, and CINAHL (via EBSCOhost). Study qualities were assessed using the Methodological Index for Non-Randomized Studies (MINORS) and Modified Jadad scales. Results: Four studies involving 517 previously treated severe hemophilia A patients were included in this study. The pooled mean of total annualized bleeding rate (ABR) and hemostatic efficacy was 2.59 (95% CI = 2.04–3.14) and 92% (95% CI = 85%–97%), respectively. Only 30 (2.3%) non-serious and one (1.4%) serious adverse events were considered related to rurioctocog alfa pegol treatment. At the end of the studies, no development of FVIII inhibitory antibodies was observed. None of the developed binding antibodies to FVIII, PEG-FVIII, or PEG was correlated to the treatment efficacy and safety. Conclusions: Despite the limited availability of direct comparison studies, our analyses indicate that rurioctocog alfa pegol could serve as a safe and effective alternative for bleeding prophylaxis in previously treated hemophilia A patients. Moreover, it appears to have low immunogenicity, which further increases the safety profile of the drug in such clinical conditions.

Rurioctocog Alfa Pegol Use in Immune Tolerance Induction: Interim Results from an Open-Label Multicenter Clinical Trial in Previously Untreated Patients with Severe Hemophilia a

Background The development of inhibitors to exogenous factor VIII (FVIII) is a serious treatment complication in patients with hemophilia A. Immune tolerance induction (ITI) is the only proven method for the eradication of FVIII inhibitors. This prospective, multicenter, open-label, phase 3 study (NCT02615691) is being conducted to determine the safety, immunogenicity, and efficacy of the extended half-life (EHL) recombinant FVIII rurioctocog alfa pegol (Adynovate ®; Baxalta US Inc., a Takeda company, Lexington, MA, USA) in previously untreated patients (PUPs) with severe hemophilia A. The data presented here aims to evaluate the efficacy and safety of ITI therapy with rurioctocog alfa pegol in patients who developed FVIII inhibitors. Methods Eligible patients were ˂6 years of age with severe hemophilia A (FVIII <1%) and <3 exposure days (ED) to rurioctocog alfa pegol, octocog alfa, or plasma transfusion at any time prior to screening. Patients with detectable FVIII inhibitory antibodies at screening or a history of FVIII inhibitors prior to screening (≥0.6 Bethesda units [BU]) were excluded from the study. Patients received intravenous rurioctocog alfa pegol as prophylaxis (25-50 IU/kg, up to 80 IU/kg ≥1 × weekly) and/or on-demand therapy (10-50 IU/kg, up to 80 IU/kg depending on bleed severity). Patients who developed a high-titer FVIII inhibitor (>5.0 BU) or low-titer FVIII inhibitor (≥0.6 BU to ≤ 5.0 BU) plus poorly controlled bleeding despite increased FVIII doses and/or bypassing agents, were eligible for ITI therapy. Dosing for ITI therapy ranged between 50 IU/kg 3 × weekly (low dose) and 100-200 IU/kg daily (high dose) at investigator discretion. This protocol-specified interim analysis was conducted after 50 patients had completed ≥50 EDs without developing confirmed inhibitors to rurioctocog alfa pegol or had developed a confirmed FVIII inhibitor at any time. The data cut-off was 30 August 2019. The primary endpoint of this study was the success rate of ITI with rurioctocog alfa pegol. Success was defined as an inhibitor titer persistently <0.6 BU, FVIII incremental recovery (IR) ≥66% of baseline following 84- to 96-hour wash-out, and FVIII half-life ≥6 hours (dependent on protocol version). Secondary endpoints included the rates of partial success and failure of ITI, and annualized bleeding rate (ABR) during ITI. The number and percentage of patients reporting adverse events (AEs) and serious AEs (SAEs) were recorded for patients treated with ITI. Informed consent and ethics approval were obtained. Results As of the data cut-off, 59 (73.8%) of 80 enrolled patients had received ≥1 dose of rurioctocog alfa pegol; 18 patients did not meet the eligibility criteria (screen failures) and 4 discontinued prior to treatment. 10 patients developed an inhibitor to rurioctocog alfa pegol (high titer: n=5; low titer: n=5), of these, 6 patients were enrolled to receive ITI and only 5 of these (83.3%) actually received ≥1 dose of rurioctocog alfa pegol for the treatment of FVIII inhibitors (low dose: n=3; high dose: n=2). Of these 5 patients, 1 completed high-dose ITI therapy and this was successful (based on negative inhibitor titer and IR ≥66% of baseline). The remaining 4 patients were continuing in the study at the time of the data cut-off. Of the 5 patients who received ≥1 dose of ITI, 4 (80.0%) had a total of 17 AEs, 3 (60.0%) experienced 8 SAEs, and 1 experienced a treatment-related SAE of FVIII inhibition. It is important to note that the onset date of FVIII inhibitor development in this patient occurred prior to initiation of ITI. One patient experienced 2 catheter-related AEs, both of which resolved, and no patients experienced thrombotic AEs, study procedure-related AEs, or AEs leading to discontinuation of treatment. Discussion This is the first prospective study of the EHL recombinant FVIII rurioctocog alfa pegol for the treatment of PUPs with severe hemophilia A. These preliminary results demonstrate that rurioctocog alfa pegol has a safety profile consistent with previous studies. In addition, these interim data suggest that using a high-dose regimen for ITI therapy is potentially efficacious in PUPs who have developed FVIII inhibitors, although only 1 patient had completed ITI at the time of this interim analysis. Disclosures Sidonio: Pfizer: Consultancy; Octapharma: Consultancy, Research Funding; Catalyst: Consultancy; Novo Nordisk: Consultancy; Bayer: Consultancy; Guardian Therapeutics: Consultancy; Genentech: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Biomarin: Consultancy. Thompson: Global Blood Therapeutics: Current equity holder in publicly-traded company; CRISPR Therapeutics: Research Funding; Vertex: Research Funding; Editas: Research Funding; Graphite Bio: Research Funding; Novartis: Research Funding; Agios: Consultancy; Beam: Consultancy; Celgene/BMS: Consultancy, Research Funding; Biomarin: Research Funding; Baxalta: Research Funding; bluebird bio, Inc.: Consultancy, Research Funding. Peyvandi: Bioverativ: Honoraria; Sanofi: Consultancy, Honoraria; Sobi: Consultancy, Honoraria; Spark: Honoraria; Takeda: Honoraria; Roche: Honoraria; Grifols: Honoraria. Yeoh: Grifols: Honoraria; Roche: Honoraria; Pfizer: Honoraria; Takeda: Honoraria. Lam: Takeda: Consultancy, Honoraria; Roche: Honoraria; Bayer: Honoraria; Pfizer: Consultancy, Honoraria. Maggiore: IQVIA: Current Employment. Engl: Takeda: Current equity holder in publicly-traded company; Baxalta Innovations GmbH, a Takeda company: Current Employment. Allen: Takeda: Current equity holder in publicly-traded company; Takeda Development Center Americas, Inc.: Current Employment. Tangada: Takeda Development Center Americas, Inc: Current Employment; Takeda: Current equity holder in publicly-traded company.