Pharmacokinetics, Safety and Efficacy Study of Recombinant Antithrombin Versus Placebo in Preterm Preeclampsia

Phase 3

Completed

Conditions: Preeclampsia

Interventions: Other: Normal Saline 0.9%
Biological: Recombinant human antithrombin (ATryn)

Registration Number: NCT02059135

Lead Sponsor: rEVO Biologics

Brief Summary: The purpose of the study is to assess the efficacy, safety and pharmacokinetics (PK) of recombinant human antithrombin (ATryn) in addition to expectant management for the treatment of preterm preeclampsia (PPE). Efficacy will be assessed by comparing the difference in extension of gestational age from the time of randomization into the study until delivery between ATryn and placebo treated subjects. In addition, the effect of ATryn on fetal and neonatal clinical outcomes will be assessed. The PK characteristics of ATryn in the subjects will be investigated by measuring AT activity levels in the mother during treatment and in cord blood.

Detailed Description: Hospitalized PPE patients who are being expectantly managed, after initial assessment and stabilization period, will be considered for the study. After informed consent has been obtained subjects will be screened for eligibility. Screening includes obtaining the subject's medical/obstetric history and a physical examination which includes an assessment of maternal and fetal status. Blood samples for hematology, clinical chemistries, biomarkers, coagulation, immunogenicity and AT activity levels will be drawn. Urine will be collected for baseline urinalysis, protein/creatinine ratio and biomarkers. Eligible subjects who meet inclusion/exclusion criteria will be randomized in a 1:1 ratio to receive a continuous infusion of either ATryn or placebo.

Sampling for AT activity will be performed immediately prior to the first dose of study drug and at specified times thereafter.

Subjects will continue on study drug until maternal and/or fetal indications for delivery necessitate cessation of expectant management or until 34 0/7 weeks of gestation. The average extension of pregnancy with standard of care expectant management in this patient population is approximately 7 days. It is assumed that treatment with ATryn will provide an additional increase in gestational age of 5-7 days as compared to this standard of care. Total duration on study drug is therefore estimated to be approximately 7 to 14 days on average.

Post treatment assessments of the mother will be performed at hospital discharge and approximately 4-6 weeks after delivery of the neonate. Information on the neonates will be collected until they reach a post-menstrual age (PMA) of 36 weeks. If the neonate reaches 36 weeks PMA \< 28 days following delivery, the final neonatal follow-up visit should be done at the 4-6 week post-delivery visit.

After the primary study completion and follow-up period, the neonate total number of days in the Neonatal Intensive Care Unit (NICU), days on a ventilator, days requiring supplemental oxygen (FiO2 ≥21%),the neonate hospital discharge date and whether the neonate is discharged from the hospital with a requirement for supplemental home oxygen therapy will be collected to help assess health care utilization. In addition, the date of death will be collected if the neonate expires before hospital discharge. These data will be considered supplemental to the primary study data set.

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 120

Inclusion Criteria

Hospitalized female pregnant patients of gestational age of ≥23 0/7 weeks to ≤30 0/7 weeks (for subjects at gestational age 23 0/7 to 23 6/7 all standard interventions including antenatal steroids and cesarean for fetal indications must be offered).

Gestational age determination by local practice using one of the following three approaches:
- Last menstrual period (LMP) dating and confirmatory ultrasound
- Ultrasound alone when LMP is not reliable
- Known date of conception in the setting of assisted reproductive technology
At least 16 years of age (NOTE: different age restrictions may apply per local regulation and/or ethical considerations; subjects under the local age of consent may be excluded at the discretion of the reviewing Institutional Review Board (IRB)
Recent diagnosis of Preeclampsia or Superimposed Preeclampsia as defined by:

• For Preeclampsia
- Gestational hypertension defined as a recorded systolic blood pressure (BP) of
  
  ≥140 mm Hg or diastolic BP of ≥90 mm Hg on 2 occasions at least 4 hours apart (since the commencement of medical intervention in any facility) OR
- Severe gestational hypertension defined as systolic blood pressure of ≥ 160 mm Hg or diastolic blood pressure ≥ 110 mm Hg, confirmed with second assessment within a short interval (minutes) AND
- New onset of any of the following:
  - Proteinuria defined as ≥0.3 g protein per 24 hours in a 12-24 hour urine collection or protein/creatinine ratio of ≥0.3 mg/mg* (on a random sample or any collection period.)
  - Platelet count less than 100,000/μL
  - Serum creatinine concentrations greater than 1.1 mg/dL in the absence of other renal disease
  - Elevated liver transaminases to ≥ twice upper limit of normal
  - Cerebral or visual symptoms
For Superimposed preeclampsia:
- The start of antihypertensive medication, increasing the dose of a currently administered antihypertensive medication or adding a second antihypertensive medication after 20 weeks of pregnancy for systolic BP ≥ 160 or diastolic BP ≥ 105 in a patient that had a previous history of controlled hypertension before 20 weeks of pregnancy. AND
- New onset of any of the following:
  - proteinuria defined as ≥0.3 g protein per 24 hours in a 12-24 hour urine collection or protein/creatinine ratio of ≥0.3 mg/mg (on a random sample or any collection period)
  - Platelet count less than 100,000/μL
  - Serum creatinine concentrations greater than 1.1 mg/dL in the absence of other renal disease
  - Elevated liver transaminases to ≥ twice upper limit of normal
  - Cerebral or visual symptoms
In the opinion of the investigator the patient has demonstrated sufficient clinical stability to be eligible for expectant management
The patient is expected to be managed as an inpatient until delivery
Signed informed consent for both subject and neonate

Exclusion Criteria

Criteria that would likely require immediate delivery of the fetus are exclusionary if present just prior to randomization:
- Refractory hypertension despite maximal medical intervention of systolic BP ≥160 mm Hg or diastolic BP of ≥110 mm Hg
- Thrombocytopenia (platelets ˂ 100/mm3) with or without Hemolysis elevated liver enzymes low platelets (HELLP) syndrome defined as defined as Aspartate amino transferase (AST) ≥70 units/L, and platelets ˂100/mm3, and evidence of hemolysis on blood film plus either Lactic dehydrogenase (LDH) ≥600 IU/mL or total bilirubin ≥1.2 mg/dL)
- Oliguria (≤500 mL/24 hours) or evidence of progressive renal insufficiency
- Serum creatinine concentration greater than 1.1 mg/dL
- Persistent visual disturbances
- Placental abruption
- Pulmonary edema
- Nonreassuring fetal heart rate tracing
- Intractable headache unrelieved with analgesia
- Intractable right upper quadrant abdominal pain or vomiting
- If umbilical Doppler ultrasound has been performed, the presence of an abnormal umbilical artery Doppler as defined by absent or reverse end diastolic flow
- Biophysical score ≤ 4/10 on 2 occasions
- Oligohydramnios (deepest vertical pocket less than 2 x 2cm on ultrasound)
- Other maternal or fetal conditions that would preclude expectant management
Known lethal or major fetal anomaly
Recent (within 12 months) history of maternal alcoholism or drug dependence
Diagnosis of epilepsy
Has need for chronic therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) including selective cyclooxygenase (Cox)-2 inhibitors, or unwilling to abstain from use of NSAIDs during the study treatment period (low dose aspirin of 81 mg/day or less allowable)
Received within 72 hours or has requirement for heparin; low molecular weight heparins such as enoxaparin or dalteparin; fondaparinux; antiplatelet agents such as clopidogrel, prasugrel, or high dose aspirin (>81 mg/day); Direct Thrombin Inhibitors (DTI) such as dabigatran
Pre-existing renal disease, documented pre-pregnancy or in pregnancy prior to 20 weeks gestation (prior to the diagnosis of preeclampsia) or 24 hr urine of ≥0.3 gm/24 hours, documented in pregnancy, prior to 20 weeks gestation or ≥2+ dipstick or ≥ 0.3 Protein Creatinine Ratio (PCR), documented in pregnancy at the last available test prior to 20 weeks gestation. In the case of conflicting results between dipstick, PCR, and timed urine collection tests to work up an episode of proteinuria, the timed urine collection result would supersede other results
Multi-fetal pregnancy
History of Antiphospholipid antibody syndrome
Known hypersensitivity to goat and goat milk proteins
Participation in another interventional clinical trial of an investigational, unapproved therapy (drug, biologic, device) within 30 days of consent

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Normal Saline 0.9%	Normal Saline 0.9%	Placebo (Normal Saline 0.9%, matched for volume of active treatment) consisting of a loading dose over 15 minutes followed by continuous infusion.
Recombinant Human Antithrombin (ATryn)	Recombinant human antithrombin (ATryn)	ATryn 250 mg loading dose over 15 minutes, immediately followed by continuous infusion of 2000 mg per 24 hours. Total daily dose is 2250 mg for the first day and 2000 mg on subsequent days

Primary Outcome Measures

Name	Time	Method
Increase in Gestational Age in Days	Subjects will continue on study drug until maternal and/or fetal indications for delivery necessitate cessation of expectant management or until 34 0/7 weeks of gestation.	Increase in gestational age is defined as the gestational age at delivery minus the gestational age at randomization.

Secondary Outcome Measures

Name	Time	Method
Composite Measure of Specific Fetal and Neonatal Outcomes Based on Protocol Defined 5-point Scale (Scores of 0 to 4)	Neonatal outcomes were assessed from birth until the later of 36 weeks (wks) Post Menstrual Age (PMA) and the 36 wks PMA visit, or through the 4-6 weeks post-delivery visit (if both 36 wks PMA and the 36 wks PMA visit occurred < 28 days post delivery)	Composite score was calculated based on the following fetal and neonatal events: bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), cystic periventricular leucomalacia (PVL), retinopathy of prematurity (ROP), late Sepsis, necrotizing enterocolitis (NEC) and mortality (fetal and neonatal). The endpoint is measured on a 5 point scale where 0 represents no outcomes experienced and no mortality, and 4 represents death, as shown below. Should the same outcome occur more than once, it will only be counted once. Score Outcome 0 No events, no mortality 1. One event, no mortality 2. Two events, no mortality 3. Three or more events, no mortality 4. Death

Trial Locations

Locations (23): Northwestern University
🇺🇸
Chicago, Illinois, United States
University of Texas Houston School of Medicine
🇺🇸
Houston, Texas, United States
University of Oklahoma Health Sciences Center
🇺🇸
Oklahoma City, Oklahoma, United States
Tri-State Maternal Fetal Health
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Cincinnati, Ohio, United States
University of Mississippi Medical Center
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Jackson, Mississippi, United States
University of Utah Hospitals & Clinics
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Salt Lake City, Utah, United States
Saint Louis University School of Medicine
🇺🇸
Saint Louis, Missouri, United States
Saint John Hospital and Medical Center
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Detroit, Michigan, United States
Intermountain Health
🇺🇸
Murray, Utah, United States
University of Alabama
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Birmingham, Alabama, United States
University of South Alabama
🇺🇸
Mobile, Alabama, United States
Yale New Haven Hospital
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New Haven, Connecticut, United States
University of South Florida
🇺🇸
Tampa, Florida, United States
University of Arkansas
🇺🇸
Little Rock, Arkansas, United States
Norton Healthcare
🇺🇸
Louisville, Kentucky, United States
Erlanger Medical Center
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Chattanooga, Tennessee, United States
Oschner Baptist
🇺🇸
New Orleans, Louisiana, United States
Barnes-Jewish Hospital
🇺🇸
Saint Louis, Missouri, United States
Columbia University Medical Center
🇺🇸
New York, New York, United States
University of California at Irvine
🇺🇸
Orange, California, United States
University Texas Medical Branch
🇺🇸
Galveston, Texas, United States
Duke University
🇺🇸
Durham, North Carolina, United States
Women & Infants Hospital
🇺🇸
Providence, Rhode Island, United States