Prophylaxis Study of Recombinant Factor VIII Manufactured Protein-Free (rAHF-PFM) in Patients With Hemophilia A

Study Overview
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Brief Summary
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The primary purpose of this randomized, two-arm parallel clinical study in 66 previously treated patients with severe or moderately severe hemophilia A is to compare the rate of bleeding episodes for standard prophylaxis (20-40 IU/kg every 48 ± 6 hours; actual dose determined by the investigator) with that of alternate prophylaxis (20-80 IU/kg every 72 + 6 hours; actual dose determined by Baxter utilizing an algorithm and the patient's pharmacokinetic data). The rates of bleeding episodes for the on-demand regimen and the prophylaxis regimens will also be compared for the cross-over portion of the study. Enrolled patients will be treated originally on demand for a period of 6 months and then they will be randomized into one of the prophylaxis arms. Prophylactic treatment will last for a period of 12 months +/- 2 weeks.

Official Title
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Advate Antihemophilic Factor (Recombinant), Plasma/Albumin Free Method (ADVATE rAHF-PFM): A Phase 4 Study Comparing Two Prophylactic Regimens in Subjects With Severe or Moderately Severe Hemophilia A

Conditions
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Hemophilia A

Intervention / Treatment
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* Drug: Antihemophilic factor, recombinant, manufactured protein-free
* Drug: Antihemophilic factor, recombinant, manufactured protein-free


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The subject has severe or moderately severe hemophilia A as defined by a baseline factor VIII level <= 2% of normal, as tested at screening The subject has a documented history of at least 150 exposure days to factor VIII concentrates (either plasma-derived or recombinant) The subject is within 7 to 65 years of age The subject has a Karnofsky performance score > (greater than) 60 The subject is human immunodeficiency virus negative (HIV-) or is HIV+ with a CD4 count >= 400 cells/mm³ (CD4 count determined at screening, if necessary) The subject has been on a documented on-demand treatment regimen for at least 12 months immediately prior to enrollment The subject has a documented history (e.g. in medical charts or dispensing information, or signed investigator statement) of at least 8 joint hemorrhages in the 12 months immediately prior to enrollment The subject resides within the coverage area of the mobile compliance device; coverage area will be determined at screening The subject or the subject's legally authorized representative has provided written informed consent Exclusion Criteria: The subject has a known hypersensitivity to factor VIII concentrates or mouse or hamster proteins The subject has a history of factor VIII inhibitors with a titer >= 0.6 BU (by Bethesda or Nijmegen assay) at any time prior to screening The subject has a detectable factor VIII inhibitor at screening, with a titer >= 0.4 BU (by Nijmegen Assay) in the central laboratory The subject has severe chronic liver disease as evidenced by, but not limited to, any of the following: International Normalized Ratio (INR) > 1.4, hypoalbuminemia, portal vein hypertension including presence of otherwise unexplained splenomegaly and history of esophageal varices. The subject has been diagnosed with an inherited or acquired hemostatic defect other than hemophilia A (e.g., qualitative platelet defect or von Willebrand's Disease) The subject has been treated during the last sixty (60) days prior to or is being treated at screening/enrollment with an immunomodulating drug. The subject has participated in another investigational study within thirty (30) days of enrollment The subject has previously participated in a clinical study with rAHF-PFM The subject's clinical condition may require a major surgery (defined as moderate to critical risk and perioperative blood loss ≥ 500 mL) during the period of the subject's participation in the study The subject is female of childbearing potential with a positive pregnancy test

Ages Eligible for Study
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Minimum Age: 7 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1<br>Standard prophylaxis | Drug: Antihemophilic factor, recombinant, manufactured protein-free<br>* Standard prophylaxis: 20-40 IU/kg every 48+/-6 hours, actual dose determined by investigator<br>|
| Experimental: 2<br>PK-driven prophylaxis | Drug: Antihemophilic factor, recombinant, manufactured protein-free<br>* PK-driven prophylaxis: 20-80 IU/kg every 72+/-6 hours, actual dose determined by Baxter using an algorithm and the patient´s pharmacokinetic data<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Transformed Annualized Bleed Rate Estimates From Each of the 1-year Prophylaxis Regimens | Participants were Randomized to Receive 1 of the 2 Following Prophylaxis Regimens (Study Part 2): 1. Standard prophylaxis (20-40 IU/kg (every 48 ±6 hour), exact regimen determined by investigator) 2. PK-driven prophylaxis (20-80 IU/kg (every 72 ±6 hour), exact regimen determined by sponsor) Annualized bleed rates were transformed using the square root of the number of bleeding episodes observed (X = bleeds/year), X' = √(X + 0.5). This transformation was performed to stabilize the variance and align the sample distribution with the assumption of normality inherent in using the t-test. | 12 months ±2 weeks | 
| Median Annualized Bleed Rate Estimates From Each of the 1 Year Prophylaxis Regimens | Participants were Randomized to Receive 1 of the 2 Following Prophylaxis Regimens (Part 2 of the study): 1. Standard prophylaxis- infusions every 48 ±6 hours, dosed at 20 to 40 IU/kg. 2. PK-driven prophylaxis- infusions every 72 ±6 hours dosed at 20 to 80 IU/kg. | 12 months ±2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Difference of Transformed Annualized Bleeding Rate Between On-Demand and Standard Prophylaxis Treatment Regimens | Annualized bleed rates were transformed using the square root of the number of bleeding episodes observed (X bleeds/year), X' = √(X + 0.5). This transformation was performed to stabilize the variance and align the sample distribution with the assumption of normality inherent in using the paired t-test. Mean Difference of Transformed Annualized Bleeding Rate (TABR) = (On-Demand Treatment TABR) - (Standard Prophylaxis Treatment TABR). Participants from the On-Demand portion of the study were subsequently randomized to either Standard Prophylaxis or PK-Driven Prophylaxis, (i.e the same participants were analyzed across the two measurement time periods). | On-demand 6 months (± 2 weeks); followed by Prophylaxis 12 months (± 2 weeks) | 
| Mean Difference of Transformed Annualized Bleeding Rate Between On-Demand and PK-Driven Prophylaxis Treatment Regimens | Annualized bleed rates were transformed using the square root of the number of bleeding episodes observed (X bleeds/year), X' = √(X + 0.5). This transformation was performed to stabilize the variance and align the sample distribution with the assumption of normality inherent in using the paired t-test. Mean Difference of Transformed Annualized Bleeding Rate (TABR) = (On-Demand Treatment TABR) - (PK-Driven Prophylaxis Treatment TABR) Participants from the On-Demand portion of the study were subsequently randomized to either Standard Prophylaxis or PK-Driven Prophylaxis, (i.e the same participants were analyzed across the two measurement time periods). | On-demand 6 months (± 2 weeks); followed by Prophylaxis 12 months (± 2 weeks) | 
| Mean Difference of Transformed Annualized Bleeding Rate Between On-Demand and Any Prophylaxis Treatment Regimens | Annualized bleed rates were transformed using the square root of the number of bleeding episodes observed (X bleeds/year), X' = √(X + 0.5). This transformation was performed to stabilize the variance and align the sample distribution with the assumption of normality inherent in using the paired t-test. Mean Difference of Transformed Annualized Bleeding Rate (TABR) = (On-Demand Treatment TABR) - (Any Prophylaxis Treatment TABR). Any Prophylaxis = Standard or PK-Driven Prophylaxis Participants from the On-Demand portion of the study were subsequently randomized to either Standard Prophylaxis or PK-Driven Prophylaxis, (i.e the same participants were analyzed across the two measurement time periods). | On-demand 6 months (± 2 weeks); Prophylaxis 12 months (± 2 weeks) | 
| Total Weight-Adjusted Dose of rAHF-PFM Used Per Year for Each Prophylaxis Arm | Participants were Randomized to Receive 1 of the 2 Following Prophylaxis Regimens (Part 2 of the study): 1. Standard prophylaxis- infusions every 48 ±6 hours, dosed at 20 to 40 IU/kg. 2. PK-driven prophylaxis- infusions every 72 ±6 hours dosed at 20 to 80 IU/kg. | 12 months ±2 weeks | 
| Bleeding Episodes Treated With 1 to ≥4 Infusions | The number of bleeding episodes treated with 1, 2, 3, or ≥4 infusions of rAHF-PFM to achieve adequate hemostasis | Throughout the study period (4 years and 5 months) | 
| Assessment of Hemostasis for Treatment of Bleeding Episodes | Number of rAHF-PFM-treated bleeding episodes with an assessment of hemostasis (4-point ordinal scale): Excellent: Full pain relief & bleeding cessation within  8 hrs of 1 infusion. Additional infusions may have been given to maintain hemostasis; Good: Definite pain relief and/or improvement in bleeding within  8 hrs after infusion. Possibly requires >1 infusion for complete resolution; Fair: Probable or slight relief of pain & slight improvement in bleeding within  8 hrs after infusion. Requires >1 infusion for complete resolution; None: No improvement or condition worsens | On-demand 6 months (± 2 weeks); Prophylaxis 12 months (± 2 weeks) | 
| Total Area Under the Curve (AUC) | Total AUC estimated by AUC 0-48h plus an area extrapolated from the log-linear regression model | Pharmacokinetic evaluations: 30 minutes pre-infusion up to 48 hours post-infusion | 
| Area Under the Curve | Area under the factor VIII (FVIII) plasma concentration versus time curve (AUC) from 0 to 48 hours estimated using the linear trapezoidal method | Pharmacokinetic evaluations: 30 minutes pre-infusion up to 48 hours post-infusion | 
| Maximum Plasma Concentration (C-max) | Maximal Factor VIII Concentration After Infusion | Within 1 hour post-infusion | 
| Adjusted Incremental Recovery (IR) | Change in factor VIII concentration from pre- to post-infusion at initial and termination study visits. Adjusted IR defined as: [Cmax (IU/dL) - pre-infusion FVIII (IU/dL)]/dose (IU/kg) | 30 minutes pre-infusion to 48 hours post-infusion | 
| Terminal Half-life | Computed from the regression slope in the terminal phase of the model. Terminal half life is the time it takes for the plasma concentration or the amount of drug in the body to be reduced by 50%. | Pharmacokinetic evaluations: 30 minutes pre-infusion up to 48 hours post-infusion | 
| Weight-Adjusted Clearance | Computed as the weight-adjusted dose divided by total AUC | Pharmacokinetic evaluations: 30 minutes pre-infusion up to 48 hours post-infusion | 
| Mean Residence Time | Computed as total Area Under the Moment Curve (AUMC) divided by the total AUC | Pharmacokinetic evaluations: 30 minutes pre-infusion up to 48 hours post-infusion | 
| Volume of Distribution at Steady State | Computed as weight-adjusted clearance * mean residence time | Pharmacokinetic evaluations: 30 minutes pre-infusion up to 48 hours post-infusion | 
| Factor VIII Inhibitor Development | Number of treated participants who developed factor VIII inhibitors | Throughout study period (4 years and 5 months) | 
| Number of Participants With AEs Related to Investigational Product (IP) | Number of treated participants with AEs judged to be possibly or probably related to treatment with IP | Throughout study period (4 years and 5 months) | 
| Number of Participants Who Reported ≥1 AE Regardless of Relatedness to Investigational Product (IP) | Number of treated participants with 1 or more AE regardless of relatedness to IP | Throughout study period (4 years and 5 months) | 
| Number of Participants Who Reported ≥1 AE Regardless of Relatedness to IP by Treatment Regimen |  | Throughout the study period (4 years and 5 months) | 
| Number of Participants With SAEs by Preferred MedDRA Term and Treatment Regimen |  | Throughout the study period (4 years and 5 months) | 
| AEs With Onset ≤1 Hour Following the End of an Infusion, Regardless of Relatedness |  | Throughout study period (4 years and 5 months) | 
| Number of Participants With Severe SAEs and Severe Non-SAEs by Preferred MedDRA Term and Treatment Regimen | This outcome is focused only on SEVERE SAEs and SEVERE non-SAEs | Throughout the study period (4 years and 5 months) | 
| Baseline Health-related Quality of Life (HRQoL) Scores: PF, RP, BP, GH, VT, SF, RE, MH, PCS, and MCS | Physical Functioning (PF); Role Limitation Due to Physical Health (RP); Bodily Pain (BP); General Health (GH); Vitality (VT); Social Functioning (SF); Role Limitation Due to Emotional Problems (RE); Mental Health (MH), Physical Component Score (PCS); Mental Component Score (MCS). Baseline SF-36v1 Scores, where data available. Scores range 0-100, higher scores represent better health. There is no total overall score; scoring is done for subscores and summary scores. The raw data from the SF-36 items were transformed to norm based scores for each of the 8 HRQoL/SF-36 health domain scores. | Baseline | 
| Health-related Quality of Life (HRQoL) Scores: PF, RP, BP, GH, VT, SF, RE, MH, PCS, and MCS at the End of Treatment Regimens | Physical Functioning (PF); Role Limitation Due to Physical Health (RP); Bodily Pain (BP); General Health (GH); Vitality (VT); Social Functioning (SF); Role Limitation Due to Emotional Problems (RE); Mental Health (MH), Physical Component Score (PCS); Mental Component Score (MCS). Baseline SF-36v1 Scores, where data available. Scores range 0-100, higher scores represent better health. There is no total overall score; scoring is done for subscores and summary scores. The raw data from the SF-36 items were transformed to norm based scores for each of the 8 HRQoL/SF-36 health domain scores. | End of on-demand treatment period (6 months) and at study termination (approximately 18 months) | 
| HRQoL Scores Change From On-Demand Treatment Regimen Period Through Prophylaxis Period | Differences in health domain scores = (End of on-demand treatment) - (End of prophylaxis regimen). A negative value for the median difference equates to a larger domain score for the prophylaxis regimen Physical Functioning (PF); Role Limitation Due to Physical Health (RP); Bodily Pain (BP); General Health (GH); Vitality (VT); Social Functioning (SF); Role Limitation Due to Emotional Problems (RE); Mental Health (MH), Physical Component Score (PCS); Mental Component Score (MCS). Scores range 0-100, higher scores represent better health. There is no total overall score; scoring is done for subscores and summary scores. The raw data from the SF-36 items were transformed to norm based scores for each of the 8 HRQoL/SF-36 health domain scores. | End of on-demand treatment period (6 months) and at study termination (approximately 18 months) | 
| Bodily Pain HRQoL Scores Change From On-Demand Period Through Prophylaxis Period | Change = (End of on-demand treatment) - (End of prophylaxis regimen). A negative value for the median difference equates to a larger domain score for the prophylaxis regimen. Scores range 0-100, higher scores represent better health. There is no total overall score; scoring is done for subscores and summary scores. The raw data from the SF-36 items were transformed to norm based scores. | End of on-demand treatment period (6 months) and at study termination (approximately 18 months) | 
| Physical Component Scores (PCS) HRQoL Scores Change From On-Demand Period Through Prophylaxis Period | Change = (End of on-demand treatment) - (End of prophylaxis regimen) A negative value for the median difference equates to a larger domain score for the prophylaxis regimen. Scores range 0-100, higher scores represent better health. There is no total overall score; scoring is done for subscores and summary scores. The raw data from the SF-36 items were transformed to norm based scores. | End of on-demand treatment period (6 months) and at study termination (approximately 18 months) |