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An Open-label Extension Study of an Investigational Drug, Fitusiran, in Patients With Moderate or Severe Hemophilia A or B

Phase 1
Completed
Conditions
Hemophilia A
Hemophilia B
Interventions
Registration Number
NCT02554773
Lead Sponsor
Genzyme, a Sanofi Company
Brief Summary

Primary Objective:

To evaluate the long-term safety and tolerability of fitusiran in male patients with moderate or severe hemophilia A or B

Secondary Objectives:

* To investigate the long-term efficacy of fitusiran

* To characterize the safety and efficacy of concomitantly administered Factor VIII (FVIII), Factor IX (FIX) or bypassing agents (BPA) and fitusiran for treatment of bleeding episodes

* To assess changes in health-related quality of life (QOL) over time

* To characterize antithrombin (AT) reduction and thrombin generation (TG) increase

* To characterize the pharmacokinetics (PK) of fitusiran

Detailed Description

It is anticipated that patients in this study will receive treatment with open label fitusiran for approximately 7 years or until fitusiran becomes commercially available, whichever occurs first.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
34
Inclusion Criteria
  • Completed and tolerated study drug dosing in study TDR14767 (ALN-AT3SC-001)
  • Male aged ≥18 years
  • Moderate or severe, clinically stable hemophilia A or B as evidenced by a laboratory FVIII or FIX level ≤5% at screening. Patients with a FVIII or FIX level >5% at screening will be eligible on provision of a historic laboratory report indicating a trough level ≤5%
  • Willing and able to comply with the study requirements and provide written informed consent
Exclusion Criteria
  • Clinically significant liver disease
  • Patients known to be human immunodeficiency virus seropositive and have a CD4 count <200 cells/μL
  • History of venous thromboembolism
  • Current serious mental illness that, in the judgment of the Investigator, may compromise patient safety, ability to participate in all study assessments, or study integrity
  • Clinically relevant history or presence of cardiovascular, respiratory, gastrointestinal, renal, neurological, inflammatory, or other diseases that, in the judgment of the Investigator, precludes study participation

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
FitusiranFitusiran (SAR439774)Patients will be administered subcutaneous (SC) fitusiran once monthly or every 2 months according to the dose selection rules defined in protocol.
Primary Outcome Measures
NameTimeMethod
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious Adverse Events (SAEs)From first dose of study drug (Day 1) up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

An adverse event (AE) is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An SAE is any untoward medical occurrence that results: death or life-threatening or inpatient hospitalization or prolongation of existing hospitalization or persistent or significant disability or congenital anomaly or medically important event. All AEs collected in LTE14762 were considered TEAE because all participants received dose in the parent study. AEs of special interest (AESI) are alanine aminotransferase (ALT) or aspartate aminotransferase (AST) elevations \>3× upper limit of normal (ULN) or suspected or confirmed thromboembolic events or severe or serious injection site reactions or systemic injection associated reactions or cholecystitis or cholelithiasis.

Number of Participants With Potentially Clinically Significant Abnormality: Physical ExaminationFrom first dose of study drug (Day 1) up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Physical examination included, at a minimum, an assessment of the participant's general appearance; skin; head, eyes, ears, nose, and throat; examinations of lymph nodes, abdomen, extremities/joints, neurological and mental status; heart and respiratory auscultation; peripheral arterial pulse; and pupil, knee, achilles, and plantar reflexes.

Number of Participants With Potentially Clinically Significant Abnormality (PCSA): HematologyFrom first dose of study drug (Day 1) up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Blood samples were collected to determine the hematology laboratory significant abnormalities. Here, DFB = decrease from baseline, NB = non-black, and B = black.

Number of Participants With Potentially Clinically Significant Abnormality: Clinical ChemistryFrom first dose of study drug (Day 1) up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Blood samples were collected to determine the clinical chemistry laboratory abnormalities. Here, mmol/L = millimoles per liter, LLN = lower limit of normal, mg/L = milligram per liter, umol/L = micromoles per liter, mL/min = milliliter per minute, m\^2 = meter square, CB = conjugated bilirubin, and DB = direct bilirubin.

Number of Participants With Potentially Clinically Significant Abnormality: UrinalysisFrom first dose of study drug (Day 1) up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Urine samples collected to determine the significant abnormalities in urine.

Number of Participants With Potentially Clinically Significant Abnormality: Vital SignsFrom first dose of study drug (Day 1) up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Participants vital signs were examined to determine the abnormalities. Vital signs included weight, supine systolic blood pressure (SSBP) and supine diastolic blood pressure (SDBP). Here, mmHg = millimeter of mercury, and IFB = increase from baseline.

Number of Participants With Potentially Clinically Significant Abnormality: Electrocardiogram (ECG)From first dose of study drug (Day 1) up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Standard 12-lead ECGs were recorded after at least 15 minutes in the supine position using an electrocardiographic device. The following were assessed: heart rate, rhythm, interval between the peaks of successive QRS complexes (RR), interval from the beginning of the P wave until the beginning of the QRS complex (PR), interval from start of the Q wave to the end of the S wave (QRS), interval between the start of the Q wave and the end of the T wave (QT), QT interval corrected for heart rate (QTc) automatic correction evaluation, QRS axis, left ventricular hypertrophy criteria, right ventricular hypertrophy criteria, repolarization charges, and overall cardiac impression for each participant. Here, msec = milliseconds.

Secondary Outcome Measures
NameTimeMethod
Area Under the Concentration Versus Time Curve From Time 0 to the Real Time (AUClast) of FitusiranPre-dose and 0.5, 2, 4, 8 and 24 hours post-dose on Day 1, and Months 12 and 24

AUClast was defined as area under the concentration versus time curve from time 0 to the last measurable concentration. The non-compartmental PK analysis was performed.

Apparent Total Body Clearance (CL/F) of FitusiranPre-dose and 0.5, 2, 4, 8 and 24 hours post-dose on Day 1 and Month 12

CL/F was defined as apparent clearance of study drug from the body. The non-compartmental PK analysis was performed.

Terminal Half-Life (t1/2z) of FitusiranPre-dose and 0.5, 2, 4, 8 and 24 hours post-dose on Day 1 and Month 12

t1/2z associated with the terminal slope (λz) determined according to the following equation: t1/2z = 0.693/λz; where, λz is the slope of the regression line of the terminal phase of the plasma concentration versus time curve, in semi-logarithmic scale. The non-compartmental PK analysis was performed.

Apparent Volume of Distribution at the Steady State After Single Extravascular Dose (Vss/F) of FitusiranPre-dose and 0.5, 2, 4, 8 and 24 hours post-dose on Day 1 and Month 12

Vss/F was defined as apparent volume of distribution of study drug at steady state concentration. The non-compartmental PK analysis was performed.

Annualized Bleeding Rate (ABR) During the Efficacy PeriodFrom Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

The ABR was annualized for each participant using the following formula: ABR = total number of bleeding events/total number of days in the respective period x 365.25. The efficacy period was defined as treatment Day 29 to earlier of end of study date before the dose pause or the last fitusiran administration date before the dose pause + 28 days, whichever comes first for original dose regimen (SAS 1) and the dose re-start Day 169 to the end of study visit for AT-based dose regimen (SAS 2).

Thrombin Generation at the End of Treatment RegimenFrom Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

The TG data was analyzed by CoagScope and assay performed using calibrated automated thrombogram method. The baseline under the original dose and regimen was the last non-missing assessment before the first significant dose.

Maximum Observed Concentration (Cmax) of FitusiranPre-dose and 0.5, 2, 4, 8 and 24 hours post-dose on Day 1, and Months 12 and 24

Cmax was defined as maximum plasma concentration observed. The non-compartmental Pharmacokinetic (PK) analysis was performed.

Time to Reach the Maximum Concentration (Tmax) of FitusiranPre-dose and 0.5, 2, 4, 8 and 24 hours post-dose on Day 1, and Months 12 and 24

tmax was defined as time to reach Cmax. The non-compartmental PK analysis was performed.

Area Under the Concentration Versus Time Curve Extrapolated to Infinity (AUCinf) of FitusiranPre-dose and 0.5, 2, 4, 8 and 24 hours post-dose on Day 1 and Month 12

AUCinf was defined as area under the concentration versus time curve extrapolated to infinity. The non-compartmental PK analysis was performed.

Annualized Spontaneous Bleeding Rate During the Efficacy PeriodFrom Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

A spontaneous bleeding episode was defined as a bleeding event that occurred for no apparent or known reason, particularly into the joints, muscles, and soft tissues. The efficacy period was defined as treatment Day 29 to earlier of end of study date before the dose pause or the last fitusiran administration date before the dose pause + 28 days, whichever comes first for original dose regimen (SAS 1) and the dose re-start Day 169 to the end of study visit for AT-based dose regimen (SAS 2).

Annualized Joint Bleeding Rate During the Efficacy PeriodFrom Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

A joint bleeding episode was defined as an event that is characterized by an unusual sensation in the joint ("aura") in combination with 1) increasing swelling or warmth over the skin over the joint; 2) increasing pain; or 3) progressive loss of range of motion or difficulty in using the limb as compared with baseline. The efficacy period was defined as treatment Day 29 to earlier of end of study date before the dose pause or the last fitusiran administration date before the dose pause + 28 days, whichever comes first for original dose regimen (SAS 1) and the dose re-start Day 169 to the end of study visit for AT-based dose regimen (SAS 2).

Time Intervals Between Bleeding EventsFrom Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Bleed-free duration was defined as the time interval between 2 protocol-defined treated bleeding events, excluding events that occurred during the intercurrent periods.

Annualized Weight-Adjusted Consumption of Coagulation Factor VIII (FVIII) and Coagulation Factor IX (FIX)From Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Number of coagulation factor injections per bleed was determined. IU= international units, and kg= kilogram.

Annualized Weight-Adjusted Consumption of Bypassing Agent (BPA) of Recombinant Factor VIIa (rFVIIa)From Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

Number of BPA injections per bleed was determined.

Annualized Weight-Adjusted Consumption of Bypassing Agent (BPA) of Activated Prothrombin Complex Concentrate (aPCC)From Day 29 up to end of the study, maximum of up to 76 months

Number of BPA injections per bleed was determined.

Change From Baseline in EuroQoL 5-Dimension 5-level Questionnaire (EQ-5D-5L) Index and Visual Analog Scale (VAS) Scores at Month 24Baseline and Month 24

The EQ-5D-5L is a standardized and disease-generic instrument for use as a measure of quality of life (QoL) outcome. The EQ-5D-5L consists of 2 parts: EQ-5D descriptive system and EQ VAS. The EQ-5D descriptive system included questions for each of following 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems, slight problems, moderate problems, severe problems and extreme problems. The VAS recorded participant's self-rated health on a vertical 20-centimeter. VAS scale ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). The EQ-5D-5L questionnaire scores range from 0-100, where 0= worst self-perceived health and 100= best self-perceived health. Positive change from baseline indicates an improvement in QoL. Baseline refers to the last non-missing value on or before the first significant treatment in TDR14767(ALN-AT3SC-001) or LTE14762 study.

Change From Baseline in Hemophilia Quality of Life Questionnaire (Haem-A-QoL) Total Score and Physical Health Scores at Month 24Baseline and Month 24

The Haem-A-QoL questionnaire is psychometrically tested QoL assessment instrument for participants with hemophilia and includes 46 items contributing to 10 QoL domains (physical health, feelings, view of yourself, sports and leisure, work and school, dealing with hemophilia, treatment, future, family planning, partnership and sexuality). Scoring for each item is based on a 5-point Likert scale (1= never, 2= rarely, 3= sometimes, 4= often, and 5= all the time), and the physical health and total transformed scores range from 0 to 100. Higher scores indicated greater impairment. Baseline refers to the last non-missing value on or before the first significant treatment in TDR14767(ALN-AT3SC-001) or LTE14762 study.

Antithrombin Activity Level at the End of Treatment RegimenFrom Day 29 up to end of the study (SAS 1: up to 76 months and SAS 2: up to 40 months)

The AT activity level was analyzed up to end of treatment regimen. The baseline under the original dose and regimen was the last non-missing assessment before the first significant dose.

Recovery of Fraction of the Dose Excreted in Urine (fe) in 0-24 Hours After Fitusiran AdministrationPostdose, 0 to 6 hours, 6 to 12 hours, 12 to 24 hours at Month 24

fe was defined as the amount of fitusiran excreted in urine in 0-24 hour. The non-compartmental PK analysis was performed.

Trial Locations

Locations (1)

Clinical Trial Site

🇬🇧

Truro, United Kingdom

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