Efficacy, PK and Safety Results of Clinical Study Of Recombinant Fusion Protein Linking Coagulation Factor IX With Albumin (rIX-FP) In Previously Treated Patients With Hemophilia B

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1109-1109 ◽  
Author(s):  
Aaron Lubetsky ◽  
Toshko Lissitchkov ◽  
Elena Santagostino ◽  
Gantcho Jotov ◽  
Tami Barazani-Brutman ◽  
...  

Abstract Background The standard of care for patients with severe hemophilia B is replacement treatment with Factor IX (FIX) 2-3 times a week. A fusion protein genetically linking recombinant human coagulation FIX with recombinant human albumin (rIX-FP) was developed with the aim to extend the half-life of FIX. In the completed Phase I pharmacokinetic study, the mean half-life of rIX-FP was found to be over 5 times longer than the subjects’ previous FIX. Thus, rIX-FP has potential to prevent bleedings for longer periods, allowing reduction in the frequency of injections compared to standard FIX and to reduce the number of injections required to treat a single bleed. Aims This was a Phase I/II open-label, multicenter study of rIX-FP in previously treated patients 12-65 years of age with severe hemophilia B (FIX ≤ 2%). The study evaluated the safety and efficacy of rIX-FP, including prevention of bleeding episodes during weekly prophylaxis of rIX-FP. Methods After completion of a 14-day rIX-FP pharmacokinetic assessment, 13 subjects in the prophylaxis arm received weekly prophylaxis of rIX-FP for approximately 11 months, and 4 subjects in the on-demand arm received rIX-FP upon occurrence of bleeding events. The treatment doses were initially selected based upon the pharmacokinetic profile of rIX-FP and subject’s bleeding phenotype, and doses could be adjusted at the Investigator’s discretion. Results Seventeen subjects were enrolled from hemophilia treatment centers in Israel and Bulgaria; the mean age was 26 years (range 13 to 46 years). Following a single injection of 25 IU/kg rIX-FP (n=13), the mean FIX activity level was 3.75% and 2.67% above baseline at Day 7 and Day 14, respectively, and the mean half-life of rIX-FP was 95 hours (comparable to the previously reported Phase I data). Over the 11 month treatment period, rIX-FP demonstrated a good safety profile with a total of over 700 EDs. The treatment was well tolerated and no FIX inhibitor formation was observed. There was no AE considered to be related to treatment with rIX-FP. No subject was withdrawn from the study due to safety concerns or lack of hemostatic efficacy. All 13 prophylaxis subjects were successfully maintained on a weekly routine regimen of rIX-FP for the entire duration of the study, with annualized spontaneous bleeding rates of 1.255 and 1.134 (mean and median respectively). Furthermore, three prophylaxis subjects who received only on-demand treatment prior to study entry had greater than 80% reduction in the annualized bleeding rate compared to their annualized bleeding rate prior to study entry. All bleeding events were treated successfully with ≤ 2 injections of rIX-FP, with approximately 90% of bleeds treated with a single injection of rIX-FP. The mean weekly consumption of rIX-FP was reduced markedly compared to the subjects’ weekly consumption of the previous FIX product. Conclusion This Phase I/II study demonstrated the clinical efficacy of rIX-FP for once weekly routine prophylaxis to prevent spontaneous bleeding episodes and for the treatment of bleeding episodes. In addition, rIX-FP showed an excellent safety and an improved PK profile over currently marketed factor IX products. Disclosures: Lubetsky: CSL Behring: Investigator for CSL clinical trial of rIX-FP Other. Lissitchkov:CSL Behring: Investigator for CSL Behring clinical trial of rIX-FP Other. Santagostino:CSL Behring: Honoraria, Investigator for CSL Behring clinical trial of rIX-FP Other, Research Funding, Speakers Bureau. Jotov:CSL Behring: sub-investigator for CSL Begring trial of rIX-FP Other. Barazani-Brutman:CSL Behring: study coordinator for CSL Behring rIX-FP trials Other. Voigt:CSL Behring: Employment. Moises:CSL Behring: Employment. Jacobs:CSL Behring: Employment. Martinowitz:CSL Behring: Honoraria, Investigator for CSL rIX-FP trials Other, Speakers Bureau.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1121-1121 ◽  
Author(s):  
Uriel Martinowitz ◽  
Aaron Lubetsky ◽  
Elena Santagostino ◽  
Gantcho Jotov ◽  
Jacob Luboshitz ◽  
...  

Abstract Abstract 1121 Factor IX (FIX) replacement therapy is the standard of care for patients with haemophilia B. FIX products currently available have a relatively short half-life, requiring 2–3 times a week intravenous prophylactic treatment to achieve a significant bleeding reduction. A recombinant FIX albumin fusion protein (rIX-FP) was generated by genetic fusion of human recombinant albumin to rFIX to extend the half life of FIX. A Phase I/II open-label, multicenter, clinical study of rIX-FP has been completed in previously treated patients with severe hemophilia B (FIX ≤ 2%) as part of the PROLONG - 9FP clinical developmental program. The objectives of the study were to evaluate the prevention of bleeding episodes during once weekly prophylaxis and to assess the hemostatic efficacy of rIX-FP for the treatment of bleeding, in addition to safety and pharmacokinetic (PK) assessments. The study consisted of a 10 to 14 day PK evaluation period, and a 3 to 12 month safety and efficacy evaluation period, during which subjects received either on-demand or prophylaxis treatment. Subjects receiving weekly prophylactic treatment were initially treated with a dose based upon the subject's PK profile, bleeding phenotype, and physical activity level. The dose could be adjusted based on clinical outcome, while maintaining a 7 day treatment interval. Subjects receiving on-demand treatment were treated with a dose based upon the subject's PK profile and WFH recommendations for treatment of bleeding episodes. Seventeen study subjects from hemophilia treatment centers in Israel and Bulgaria participated in the study, 13 of whom received weekly prophylaxis treatment and 4 of whom received on-demand treatment. Following a single infusion of 25 IU/kg rIX-FP (n=13), the PK parameters (t1/2 = 94 hrs, AUC0-inf= 3414 hr*IU/dL) were comparable to those previously reported from the Phase I study (Blood prepublished Aug 2, 2012). In addition, rIX-FP maintained a baseline-corrected mean trough level of 3.8% and 2.7% at Day 7 and Day 14, respectively, after 25 IU/kg rIX-FP administration. There were no AEs considered as possibly related to rIX-FP. There were no allergic reactions, inhibitors to FIX or antibodies to rIX-FP reported. All 10 prophylaxis subjects who were previously receiving routine prophylaxis with FIX were maintained successfully on weekly treatment with rIX-FP for the entire study. Furthermore, three prophylaxis subjects who were previously treated on-demand were maintained successfully on weekly prophylaxis treatment with rIX-FP with at least 85% reduction in the annualized spontaneous and total bleeding rate compared to the annualized bleeding rate prior to study entry. All of the bleeding events were treated successfully, including approximately 90% of the events with a single infusion of rIX-FP. The mean weekly product consumption of rIX-FP (IUs) was reduced compared to the consumption of the previous FIX product (IUs). No subject was withdrawn from the study due to safety concerns or lack of hemostatic efficacy. This Phase I/II study has demonstrated the clinical efficacy of rIX-FP for once weekly routine prophylaxis to prevent spontaneous bleeding episodes and treatment of bleeding episodes, in addition to the excellent safety characteristics and improved PK profile. A detailed analysis of the efficacy of weekly routine prophylaxis and treatment of bleeding episodes, improved PK and safety properties of rIX-FP will be presented. Disclosures: Martinowitz: CSL Behring: Honoraria, Investigator for CSL clinical study of rIX-FP Other. Lubetsky:CSL Behring: Investigator for CSL clinical trial of rIX-FP Other. Santagostino:CSL Behring: Honoraria, Investigator for CSL Behring clinical trial of rIX-FP Other, Research Funding, Speakers Bureau. Jotov:CSL Behring: sub-investigator for CSL clinical trial of rIX-FP Other. Barazani-Brutman:CSL Behring: study coordinator for CSL Behring clinical trial of rIX-FP Other. Voigt:CSL Behring: Employment. Moises:CSL Behring: Employment. Jacobs:CSL Behring: Employment. Lissitchkov:CSL Behring: Investigator for CSL Behgring clinical trial of rIX-FP Other.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 548-548 ◽  
Author(s):  
Elena Santagostino ◽  
Christine Voigt ◽  
Denise Wolko ◽  
Grace Cole ◽  
Yanyan Li ◽  
...  

Abstract A fusion protein genetically linking recombinant human coagulation FIX with recombinant human albumin (rIX-FP) has been developed with an improved PK profile, thus improving hemophilia B treatment by allowing less frequent dosing. Two Phase 3 studies (CSL654-3001 and CSL654-3002) were completed. CSL654-3001 study evaluated safety and efficacy of rIX-FP for prophylaxis treatment (PT) of every 7-, 10- and 14-day and on-demand (ODT) of bleeding episodes in 63 previously treated patients (PTP), 12-61 years of age with hemophilia B (FIX ≤ 2%). Subjects in the on-demand arm received only ODT for 6 months and then switched to every 7-day PT. Subjects in the prophylaxis arm received every 7-day PT, and eligible subjects switched to every 10- or 14-day PT for approximately 12-18 months. Annualized spontaneous bleeding rates (AsBR) were compared between ODT and PT periods (in on-demand arm), and between 7-day PT and 10- or 14-day PT (in prophylaxis arm). CSL654-3002 study evaluated safety and efficacy of rIX-FP for weekly prophylaxis regimen in 27 previously treated patients younger than 12 years with hemophilia B (FIX ≤ 2%) for approximately 12 months. Annualized spontaneous bleeding rates (AsBR) were calculated. The median annualized spontaneous bleeding rate were all 0.00 for all treatment interval (7-day, 10-day or 14-day) and in both studies age groups (1-11 years and 12-65 years) during the two completed phase 3 studies. Seventy-six subjects from both studies continued their prophylaxis regimen in the on-going extension study. In addition, subjects (including children), switched to longer treatment intervals of 10-day, 3 times per month or 14-day or lowered their weekly prophylaxis dose. Nine subjects switched to 21-day treatment interval with 100 IU/kg rIX-FP. As of 28 July 2015, at least 50 subjects (PTP) had achieved 100 EDs without developing an inhibitor to FIX or antibodies to rIX-FP. The long term safety and efficacy of rIX-FP will be presented. This presentation includes the new information regarding the change to longer than 7-day treatment regimens in the extension study, among those subjects (1-61 years of age) that previously participated in the lead in studies. Conclusion: The Prolong - 9FP clinical programdemonstrated the clinical efficacy of rIX-FP for routine prophylaxis every 7-, 10- and 14-day treatment intervals. Routine prophylaxis once every 21 days may be effective in preventing bleeding episodes in a selected patient population. In addition, rIX-FP demonstrated favorable long-term safety and tolerability. Disclosures Santagostino: Novo Nordisk: Speakers Bureau; Bayer: Speakers Bureau; CSL Behring: Speakers Bureau; Baxter/Baxalta: Speakers Bureau; Pfizer: Research Funding, Speakers Bureau; Biogen/Sobi: Speakers Bureau; Biotest: Speakers Bureau; Kedrion: Speakers Bureau; Octapharma: Speakers Bureau; Roche: Speakers Bureau. Voigt:CSL Behring: Employment. Wolko:CSL Behring: Employment. Cole:CSL Behring: Employment. Li:CSL Behring: Employment. Jacobs:CSL Behring: Employment.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2407-2407 ◽  
Author(s):  
Lynn M Malec ◽  
Stacy E. Croteau ◽  
Michael Callaghan ◽  
Davide Matino ◽  
Kenneth Dale Friedman ◽  
...  

Background: Factor IX (FIX) has distinct pharmacokinetic properties compared to factor VIII including significant distribution to the extravascular space. Extravascular distribution and binding to type IV collagen is important in hemostasis but not readily measureable in clinical practice for patients with hemophilia B receiving factor products. We previously reported data regarding use of EHL-FIX products in a cohort of patients who demonstrated issues with spontaneous bleeding and poorly controlled bleeding events; we now report data from an expanded cohort including performance of all EHL-FIX products available in US and Canada. Aims: To characterize the use and performance of EHL-FIX in clinical practice at six hemophilia treatment centers (HTCs). Methods: An electronic survey regarding center specific use of EHL-FIX amongst patients with severe hemophilia B (HB) was sent in summer 2019, including 4 previously surveyed centers and 2 additional centers. Providers were asked if patients utilizing EHL-FIX for prophylaxis had experienced 1) spontaneous/minimally traumatic bleeding events at factor levels >10% or 2) poorly controlled bleeding events requiring more frequent/higher doses of EHL-FIX than anticipated in addition to patterns of EHL-FIX product switching. Results: Surveyed HTCs cared for 90 patients with HB including 67 (74%) who utilized EHL-FIX, including 26 (39%) recombinant factor IX (FIX) albumin fusion protein (rFIX-FP), 37 (55%) recombinant factor IX Fc fusion protein (rFIXFc), and 4 (6%) received glycopegylated recombinant FIX (rFIX-GP). All patients had severe hemophilia B with the exception of one smaller center also contributing data regarding moderate HB patients on prophylaxis. All centers reported having patients with unexpected spontaneous/minimally traumatic bleeding and poorly controlled bleeding which did not seem to be dependent on age (median age 14.5 years, range 1.4-44). This occurred in 18 patients on prophylaxis, including 16 of 26 (62%) patients using rFIX-FP, and 2 of 4 (50%) of patients using rFIX-GP. Conclusions: Although plasma FIX activity levels have driven prophylaxis and bleed management decisions, clinical experience suggests novel properties of EHL-FIX may impact hemostasis. Although achieving seemingly adequate FIX plasma troughs (>10%), limited clinical experience suggests patients with SHB may have a differential response to EHL-FIX, noted in our cohort with FIX-FP and rFIX-GP. Successful bleed prevention or control in SHB may be predicted by the distribution of FIX in circulation and extravascular space, and the presence of FIX in tissues at time of injury. These data demonstrate the importance of real-world monitoring of efficacy of new FIX products and suggest the need for more robust mechanisms to understand the hemostatic performance of products. Disclosures Malec: Bayer: Honoraria; Spark: Honoraria; CSL: Honoraria; Sanofi: Consultancy, Honoraria, Speakers Bureau; Takeda: Honoraria. Croteau:Novo Nordisk: Consultancy, Honoraria, Research Funding; Shire: Consultancy, Honoraria; Bayer: Consultancy, Honoraria; Bayer: Consultancy, Honoraria; Octapharma: Honoraria; Octapharma: Honoraria; Genentech: Consultancy, Honoraria; Pfizer: Research Funding; Spark Therapeutics: Research Funding; Novo Nordisk: Consultancy, Honoraria, Research Funding; Spark Therapeutics: Research Funding; Pfizer: Research Funding; Genentech: Consultancy, Honoraria; CSL Behring: Consultancy, Honoraria; CSL Behring: Consultancy, Honoraria; Shire: Consultancy, Honoraria. Callaghan:Biomarin, Bioverativ, Grifols, Kedrion, Pfizer, Roche/Genentech, Shire, and Spark Therapeutics: Consultancy; Alnylum: Equity Ownership; Bayer: Consultancy, Speakers Bureau; Takeda: Consultancy, Research Funding; Sanofi: Consultancy; Global Blood Therapeutics: Consultancy; Novonordisk: Consultancy, Speakers Bureau; Octapharma: Consultancy; Pfizer: Research Funding; Roche: Research Funding; Shire/Takeda: Speakers Bureau; Roche/Genentech: Speakers Bureau. Matino:Bayer: Honoraria, Research Funding; Sobi: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Roche: Research Funding; Bioviiix: Honoraria; Sanofi: Honoraria. Friedman:CSL: Consultancy; Bayer: Consultancy; Genentech: Consultancy; Instrumentation Laboratory: Consultancy; Siemens: Consultancy. Sidonio:Grifols: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genetech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda-Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bioverativ: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Uniqure: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Biomarin: Membership on an entity's Board of Directors or advisory committees; Kedrion: Research Funding.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3955-3955
Author(s):  
Vicente R. Cortina ◽  
T. Lissichkov ◽  
K. Zavilska ◽  
M. Matysiak ◽  
L. Gercheva ◽  
...  

Abstract Objectives The objective of the present study was two fold: first, to determine the pharmacokinetic (PK) profile of the plasma-derived FIX concentrate AlphaNine® in patients with congenital severe haemophilia B (FIX:C 2%). To do this, two PK studies were carried out one six months after the first. The second objective was a comparison of the Alphanine® PK profile with the recombinant Factor IX, BeneFIX®. Patients and methods The first study was a prospective, five-center, open-label, comparative, PK study carried out in 25 severe hemophilia B patients who received 2 single doses of 65–75 IU/kg of AlphaNine® within 6 months (t=0 and t=6). The following parameters were assessed: in vivo recovery, half-life, AUC, mean residence time and clearance. As an extension of the study, a single dose of 65–75 IU/kg of BeneFIX® was administered in 9 out of 25 patients, after a wash-out period of 7–15 days. Results Table 1 summarizes the results obtained when comparing AlphaNine® within a period of time of 6 months (PK1 vs PK2) in 25 patients. Table 2 shows the results obtained when comparing the in vivo recovery of AlphaNine ® vs BeneFIX ® in the 9 patients studied. Conclusions These results confirm that AlphaNine® PK has similar profile as other plasma derived FIX products presently available to treat Hemophilia B patients. In addition, our results show that the recombinant FIX studied, BeneFIX® has a reduced in vivo recovery when is compared to AlphaNine®. Table 1 Parameter AlphaNine® (PK1) t=0 m AlphaNine® (PK2) t=6 m Results are expressed as Mean (SD) In vivo recovery (IU/dl:IU/kg) 1.0 (0.2) 1.2 (0.4) Half-life (h) 34.5 (6.2) 33.7 (5.4) Clearance (ml/min) 0.07 (0.01) 0.07 (0.01) AUC0-inf (IUxh/dl) 1602 (312) 1644 (360) MRT0-inf (h) 35.8 (5.4) 34.6 (5.2) Table 2 Parameter AlphaNine® (PK2) BeneFIX® Results are expressed as Mean (SD); * p<0.05 for the comparison of the in vivo recovery for the BeneFIX® group with the AlphaNine® PK2 In vivo recovery (IU/dl:IU/kg) 1.3 (0.5) 0.8 (0.2)*


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 19-19
Author(s):  
Vance MacDonald ◽  
Xin Ying Lee ◽  
Alexandre Caillaud ◽  
Maria Luckevich ◽  
Anthony Bentley

Introduction: Congenital hemophilia B is a rare blood disorder, caused by mutations in the F9 gene that lead to dysfunctional, reduced, or no clotting factor IX (FIX), resulting in prolonged bleeding episodes and in severe cases, spontaneous bleeding episodes. Maintaining sufficient FIX activity in the bloodstream through routine prophylactic administration of FIX, is the standard of care for prevention of bleeds in hemophilia B patients in Canada. Breakthrough bleeding (BTB) episodes are treated acutely with additional doses of FIX. In Canada, real-world data for patients with hemophilia B, including clinical outcomes and consumption rates of FIX, are recorded in the Canadian Bleeding Disorders Registry (CBDR). FIX products for patients with hemophilia B are subject to national competitive procurement processes administered by the Canadian Blood Service (CBS) and Héma-Québec. Nonacog beta pegol (N9-GP), an extended half-life (EHL) recombinant FIX concentrate, was recently awarded a CBS contract and subsequently made available across Canada (except Québec) from April 1, 2018 to adult patients. For those patients already on another EHL FIX treatment, a forced switch to N9-GP occurred. The objective of the present study was to estimate the impact on treatment costs of switching from a prior FIX to N9-GP, based on real-world annualized bleed rates (ABRs) and FIX consumption volumes (pre- and post-N9-GP switch) for patients on prophylaxis with their previous treatment and N9-GP, as recorded in the CBDR as of 30 September 2019. Methods: Real-world data from the CBDR for FIX consumption and ABR were used to inform a cost consequence model, developed in Microsoft Excel. Only patients for whom data existed in the CBDR for 6-months pre-switch to N9-GP and who had received ≥3 months of N9-GP treatment were included. Since April 2018, N9-GP replaced eftrenonacog alfa as the EHL product available to adult patients covered by CBS, while nonacog alfa continued to be the recombinant standard half-life (SHL) product available. Based on this, it was assumed that the EHL to N9-GP switches were from eftrenonacog alfa and the SHL switches are from nonacog alfa. For comparison of N9-GP with nonacog alfa and eftrenonacog alfa, treatment of adult males (assumed body weight of 70 kg) with severe hemophilia B was modeled over a 1-year time horizon. Since the competitive procurement process used in Canada results in confidential per-unit FIX prices, a price from a similar market was used for assessment of the cost impact. The German market was selected because all recombinant FIX products available in Canada are reimbursed in Germany. Converting the German per-IU prices, as published in the Lauer-Taxe®, using the Bank of Canada average exchange rate for the previous year, resulted in a price of CAD $2.54, $1.50 and $2.18 per IU for N9-GP, nonacog alfa, and eftrenonacog alfa, respectively. Real-world annualized mean FIX consumption volumes for prophylaxis, per BTB and real-world mean total ABRs for each product were then multiplied by the price per IU for each FIX product to derive estimates of real-world annual treatment costs associated with the use of nonacog alfa and eftrenonacog alfa (pre-switch), and N9-GP (post-switch). Results: Real-world annual prophylaxis consumption volumes, as reported in the CBDR, were reduced following treatment switch to N9-GP (Table 1). The switch to N9-GP was associated with improved ABRs, from 7.38 to 2.56 and 4.76 to 2.68 for patients on prior treatment with nonacog alfa and eftrenonacog alfa, respectively. Comparative treatment costs (for prophylaxis and BTB) based on real-world data were reduced from $643,400 to $412,700 when switching from nonacog alfa to N9-GP and from $486,938 to $358,822 when switching from eftrenonacog alfa to N9-GP. Treatment with N9-GP was therefore associated with a 35.8% and 26.3% reduction in costs following a switch from nonacog alfa, and eftrenonacog alfa, respectively. Conclusion: Real-world FIX consumption and bleeding outcomes data demonstrate that N9-GP is cost-saving compared with nonacog alfa and eftrenonacog alfa (assuming per-IU prices based on German costs converted to Canadian dollars) while also achieving a reduction in ABR, regardless of whether patients previously received an SHL or EHL FIX product. N9-GP can therefore be considered a dominant treatment option compared with nonacog alfa and eftrenonacog alfa for the treatment of hemophilia B. Disclosures MacDonald: Novo Nordisk Canada Inc: Current Employment. Lee:Novo Nordisk A/S: Current Employment. Caillaud:Novo Nordisk Canada Inc: Current Employment. Luckevich:Novo Nordisk Canada Inc.: Current Employment. Bentley:Mtech Access: Consultancy, Other: Consultant for Novo Nordisk.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1411-1411
Author(s):  
John Roberts ◽  
Cecilia Fosser ◽  
Michael Tortorici ◽  
Alex Veldman ◽  
Iris C. Jacobs ◽  
...  

Abstract Factor IX (FIX) replacement is an effective therapy for hemophilia B patients. The current clinical rationale for maintaining higher trough levels of FIX is to transition patients from a severe hemophilia phenotype (eg. FIX <1% of normal) to a moderate (FIX of 1-5%) or mild disease state (FIX >5%), thereby reducing the total number of bleeding events. Although there is a tentative linkage between trough FIX levels and bleeding tendency which guides hemophilia B management, a thorough quantitative analysis was undertaken for rIX-FP (Idelvion) to robustly define the FIX exposure versus clinical outcome relationship. Pooled adult hemophilia B data from the rIX-FP Phase III development program was utilized for the analysis. A Cox proportional hazards model was employed to relate time-to-bleed event data and various individual measures of exposure (FIX activity) and dosing regimen, while testing the influence of covariates (e.g. baseline FIX). FIX activity levels were simulated using a validated rIX-FP population pharmacokinetic (PK) model. The analysis included all recorded bleeding episodes in subjects receiving either prophylaxis and/or on-demand regimens. Dose amounts and intervals included 50 IU/kg (every 1 week) and 75 IU/kg (every 2 weeks, or every 10 days). A total of 478 bleeding episodes (267 spontaneous bleeds, 190 traumatic bleeds, 21 other bleeds) from 57 adult patients were included in the primary analysis. The highest proportion of bleeds occurred during the on-demand portion of the clinical studies. Patients maintaining cumulative FIX activity trough levels above 5% and 10% were predicted to have significant reductions in bleeding risk of 83% and 81%, respectively, per 1 year above these levels, compared to patients not maintaining these FIX activity trough levels. Cumulatively, maintaining FIX levels above 2% was not statistically significant for risk reduction. Furthermore, a time-direct evaluation relating daily FIX trough activity to daily bleeding risk found that >2%, >5% and >10% FIX activity thresholds were significant predictors of bleeding events with 69% (95% CI, 53 to 80) 77% (95% CI, 67 to 84) and 78% (95% CI, 69 to 85) risk reductions, respectively. Although >2% was significant, the wider confidence intervals suggest a more reliable risk reduction at the >5% and >10% levels. This in-depth exposure-response analysis of rIX-FP determined a strong relationship between FIX activity levels and hemophilia B bleeding risk reduction. Trough FIX activity above 5% (either cumulatively or on any given day) was identified as a statistically significant and overall sufficient pharmacological threshold for reduction of bleeding risk in adult hemophilia B patients receiving rIX-FP. Trough FIX activity > 10% was also a predictor of significant risk reduction, and the magnitude of risk reduction was similar to that of achieving levels > 5%. These results are aligned with existing World Hemophilia Foundation (WFH) hemophilia severity definitions where patients with a range of observed FIX activity 5-40% are categorized as a single mild hemophilia phenotype. Post-approval clinical exposure versus response relationships may also be affected by an individual's level of physical activity which was not assessed in the current analysis. Overall, this analysis demonstrates the quantitative clinical rationale for optimization of adult rIX-FP dose regimens through targeting and maintaining FIX activity trough levels above 5% to 10%. Disclosures Roberts: CSL Behring: Employment. Fosser:CSL Behring: Consultancy; Cytel: Employment. Tortorici:CSL Behring: Employment. Veldman:CSL Behring: Employment. Jacobs:CSL Behring: Employment. Sidhu:CSL Behring: Employment.


Blood ◽  
2011 ◽  
Vol 118 (10) ◽  
pp. 2695-2701 ◽  
Author(s):  
Claude Negrier ◽  
Karin Knobe ◽  
Andreas Tiede ◽  
Paul Giangrande ◽  
Judi Møss

Abstract Replacement therapy with factor IX (FIX) concentrates is the recommended treatment for patients with hemophilia B, an X-linked bleeding disorder occurring in 1:25 000 male births. N9-GP is a recombinant FIX molecule with a prolonged half-life which is obtained by site-directed glycoPEGylation where a 40-kDa polyethylene glycol molecule is attached to the activation peptide of FIX. This first human dose trial in patients with hemophilia B investigated the safety and pharmacokinetic properties of a single IV dose of N9-GP. Sixteen previously treated patients received one dose of their previous FIX product followed by one dose of N9-GP at the same dose level (25, 50, or 100 U/kg). None of the patients developed inhibitors. One patient developed transient hypersensitivity symptoms during administration of N9-GP and was excluded from pharmacokinetic analyses. In the remaining 15 patients, N9-GP was well-tolerated. The half-life was 93 hours, which was 5 times higher than the patient's previous product. The incremental recovery of N9-GP was 94% and 20% higher compared with recombinant and plasma-derived products, respectively. These results indicate that N9-GP has the potential to reduce dosing frequency while providing effective treatment of bleeding episodes with a single dose. The trial was registered at www.clinicaltrials.gov as NCT00956345.


Blood ◽  
2010 ◽  
Vol 115 (10) ◽  
pp. 2057-2064 ◽  
Author(s):  
Robert T. Peters ◽  
Susan C. Low ◽  
George D. Kamphaus ◽  
Jennifer A. Dumont ◽  
John V. Amari ◽  
...  

Abstract Treatment of hemophilia B requires frequent infusions of factor IX (FIX) to prophylax against bleeding episodes. Hemophilia B management would benefit from a FIX protein with an extended half-life. A recombinant fusion protein (rFIXFc) containing a single FIX molecule attached to the Fc region of immunoglobulin G was administered intravenously and found to have an extended half-life, compared with recombinant FIX (rFIX) in normal mice, rats, monkeys, and FIX-deficient mice and dogs. Recombinant FIXFc protein concentration was determined in all species, and rFIXFc activity was measured in FIX-deficient animals. The half-life of rFIXFc was approximately 3- to 4-fold longer than that of rFIX in all species. In contrast, in mice in which the neonatal Fc receptor (FcRn) was deleted, the half-life of rFIXFc was similar to rFIX, confirming the increased circulatory time was due to protection of the rFIXFc via the Fc/FcRn interaction. Whole blood clotting time in FIX-deficient mice was corrected through 144 hours for rFIXFc, compared with 72 hours for rFIX; similar results were observed in FIX-deficient dogs. Taken together, these studies show the enhanced pharmacodynamic and pharmacokinetic properties of the rFIXFc fusion protein and provide the basis for evaluating rFIXFc in patients with hemophilia B.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1491-1491 ◽  
Author(s):  
Elena Santagostino ◽  
Iris C. Jacobs ◽  
Christine Voigt ◽  
Annettee Feussner ◽  
Tharin Limsakun

Abstract A recombinant fusion protein linking recombinant coagulation factor IX (FIX) with recombinant human albumin (rIX-FP) has been developed to extend the plasma half-life of FIX, thus improving hemophilia B treatment by allowing less frequent dosing than required with standard plasma-derived (pd) and recombinant (r) FIX products. The PROLONG-9FP clinical program aims to evaluate the use of rIX-FP for prophylaxis and on-demand treatment of bleeding in patients with severe hemophilia B. In a completed Phase I pharmacokinetic (PK) study in subjects aged 15 to 58 years (y), the mean half-life of rIX-FP was 92 hours, 5 times longer than the half-life of the FIX products previously used by the subjects. The mean trough FIX activity after injection of rIX-FP was 7.4% (day 7) at a dose of 25 IU/kg, and 13.4% (day 7) and 5.5% (day 14) at a dose of 50 IU/kg (Santagostino E, et al. Blood 2012; 120:2405-11). A Phase II study demonstrated the efficacy of weekly prophylaxis with rIX-FP, with excellent safety and an improved PK profile. Following completion of these studies, 2 Phase III, open-label, multicenter studies have been conducted in previously treated patients (PTPs) with severe hemophilia B, aged 12 to 65 years (NCT01496274) and < 12 years (NCT01662531). Both studies, which were designed to evaluate the long term safety and efficacy of rIX-FP for both prophylaxis and on-demand treatment of bleeding episodes, consisted of an initial PK evaluation period followed by a treatment period during which subjects were administered rIX-FP as prophylaxis and on-demand treatment. Subjects from 42 hemophilia treatment centers in 12 countries participated; to date, the PROLONG-9FP clinical program encompasses over 100 hemophilia B subjects for the PK evaluation. Here, we report on the PK results from these 2 studies. During the 14-day PK evaluation periods, blood samples for PK analysis were taken before dosing, and then at 30 minutes, 3, 24, 48, 72, 120, 168, 240 and 336 hours after injection of 50 IU/kg rIX-FP. A subgroup of subjects also completed a PK evaluation of their previously used Factor IX products (pdFIX and rFIX), with sampling before dosing, and then at 30 minutes, 3, 6, 12, 24 and 48 hours after 50 IU/kg FIX injection. Plasma FIX activity (FIX:C) was measured by a one-stage clotting assay (CSL Behring central laboratory). The mean plasma FIX half-life after injection of 50 IU/kg rIX-FP was 105, 92 and 84 hours in the respective age groups of 12 to 61 years (n = 46), 6 to 11 years (n = 15) and 1 to 5 years (n = 12); the baseline corrected mean incremental recovery (IR) was 1.3, 1.1 and 1.0 IU/dL per IU/kg, the mean area under the curve (AUC) was 7,360, 4,949 and 4,358 IU*hr/dL, and the clearance was 0.7, 1.1 and 1.3 mL/h/kg in the respective age groups. The time to 5% FIX:C after injection of 50 IU/kg rIX-FP administration was Day 10 for children and Day 14 for adults; at Day 14, the mean trough FIX activity in children was 3%. Compared with the FIX products previously used by the subjects, rIX-FP had a 30 to 40% higher incremental recovery, > 5-times longer half-life, larger AUC and lower clearance. In conclusion, compared with standard FIX products, rIX-FP demonstrated an improved PK profile with a prolonged half-life in all age groups (1 to 61 years). At 14 days after injection of rIX-FP, the mean trough FIX activity is 3% in children and above 5% in adults, supporting a treatment interval of 14 days for routine prophylaxis. Treatment intervals of 7-, 10- and 14 days for routine prophylaxis were tested in the pivotal Phase III studies; every 21 day regimen will be tested in selected age groups during the Phase IIIb extension study. Detailed PK results will be presented during the meeting. Disclosures Santagostino: CSL: Honoraria, Speakers Bureau. Jacobs:CSL Behring: Employment. Voigt:Csl Behring: Employment. Feussner:CSL Behring: Employment. Limsakun:CSL Behring: Employment.


Blood ◽  
2011 ◽  
Vol 118 (8) ◽  
pp. 2333-2341 ◽  
Author(s):  
Henrik Østergaard ◽  
Jais R. Bjelke ◽  
Lene Hansen ◽  
Lars Christian Petersen ◽  
Anette A. Pedersen ◽  
...  

Abstract Current management of hemophilia B entails multiple weekly infusions of factor IX (FIX) to prevent bleeding episodes. In an attempt to make a longer acting recombinant FIX (rFIX), we have explored a new releasable protraction concept using the native N-glycans in the activation peptide as sites for attachment of polyethylene glycol (PEG). Release of the activation peptide by physiologic activators converted glycoPEGylated rFIX (N9-GP) to native rFIXa and proceeded with normal kinetics for FXIa, while the Km for activation by FVIIa–tissue factor (TF) was increased by 2-fold. Consistent with minimal perturbation of rFIX by the attached PEG, N9-GP retained 73%-100% specific activity in plasma and whole-blood–based assays and showed efficacy comparable with rFIX in stopping acute bleeds in hemophilia B mice. In animal models N9-GP exhibited up to 2-fold increased in vivo recovery and a markedly prolonged half-life in mini-pig (76 hours) and hemophilia B dog (113 hours) compared with rFIX (16 hours). The extended circulation time of N9-GP was reflected in prolonged correction of coagulation parameters in hemophilia B dog and duration of effect in hemophilia B mice. Collectively, these results suggest that N9-GP has the potential to offer efficacious prophylactic and acute treatment of hemophilia B patients at a reduced dosing frequency.


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