CClinicalTrials.gg
CompletedNCT00412464Updated Apr 15, 2015Results posted

Pilot Dose Finding and Pharmacokinetic Study of Fondaparinux in Children With Thrombosis

A Phase 1 interventional study of Fondaparinux in Thrombosis and Heparin-induced Thrombocytopenia, sponsored by Children's Hospital Los Angeles. Completed at 4 sites in United States. Open to participants aged 1 Year to 18 Years. Per ClinicalTrials.gov, last updated 2015-04-15.

Sponsored by Children's Hospital Los Angeles · Phase 1, Interventional, and Treatment

Phase
Phase 1
Study type
Interventional
Enrollment
24
Allocation
Non-randomized
Ages
1 Year to 18 Years
Sex
All
01

Study summary

This study will evaluate the use of a blood thinner, fondaparinux, which is approved for use in adults (not in children) in a children aged 1-18 years. Subject with a blood clot (thrombosis) or heparin-induced thrombocytopenia who need to be on a blood thinner will be eligible to participate. Subjects will receive a once daily dose of fondaparinux followed by blood tests at 2, 4, 12, and 24 hours after the first dose in order to determine the proper dose for this age group. The hypothesis is that children receiving fondaparinux will be able to receive a once daily dose. The currently available alternative agent, enoxaparin, needs to be given twice daily. In addition, an evaluation of the safety of this medication will be made by assessing for side effects, especially bleeding.

Read the detailed description

This clinical trial will assess the pharmacokinetics and safety of the novel anticoagulant, fondaparinux sodium (Arixtra) in pediatric patients with thromboembolism. Currently available anticoagulants have significant limitations especially as it applies to the pediatric population. Thus novel agents with improved pharmacologic properties are needed to improve the care of this increasingly recognized complication in children. Furthermore, the only available agent for long-term anticoagulation in children with heparin-induced thrombocytopenia is warfarin. Anticoagulation with warfarin in the pediatric population is problematic due to its narrow therapeutic index and the numerous drug and food interactions necessitating frequent laboratory monitoring. In addition, oral administration of warfarin (which cannot be compounded to a liquid) is difficult in young children. Thus a novel agent for this condition is needed and fondaparinux does not cross-react with heparin antibodies. The aims of the study are to determine the proper dosing regimen (dose and interval) and safety in patients less than 18 years of age with thrombosis or heparin-induced thrombocytopenia. Another aim is to assess the utility of thromboelastography as a monitoring tool for patients on fondaparinux. This will be a pilot study which will have a total of 24 patients in 3 age cohorts with 8 patients per cohort as follows: 1-5 years, 6 -12 years, and 12-18 years as the pharmacokinetics of medications differ by age. Patients will receive an initial dose of 0.1mg/kg subcutaneously daily. After the first dose, fondaparinux levels will be drawn at 2,4,12, and 24 hours after administration. Dose adjustments will be made based on the 4 hour (peak) level and trough levels at 12 and 24 hours will determine if daily dosing is feasible. Thromboelastography will be performed at 2 or 4 hours and 24 hours with the results correlated with the plasma activity level. Safety will be assessed by physical examination, laboratory testing, and if necessary diagnostic imaging to determine the incidence of minor and major bleeding. Pharmacokinetic analyses as well as safety and efficacy determinations will be made which will provide valuable information on this promising new anticoagulant for pediatric patients.

02

Conditions studied

  • Thrombosis
  • Heparin-induced Thrombocytopenia

Keywords

  • fondaparinux
  • thrombosis
  • heparin-induced thrombocytopenia
  • pediatrics
03

In context

Thrombosis

1,506 studies on the registry are indexed under Thrombosis; 238 are open to participants now.

This study's enrollment of 24 is below the median of 106 across 849 interventional studies indexed under Thrombosis.

Browse Thrombosis studies →

Lead sponsor

Children's Hospital Los Angeles is the lead sponsor of 150 studies on the registry; 46 are open to participants now.

Of its 9 completed or terminated interventional studies of FDA-regulated products, 6 (67%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
1 Year to 18 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Children between 1 year and 18 years of age.
  • The presence of documented venous or arterial thrombosis confirmed by diagnostic imaging.
  • Weight greater than 8.3 kg.
  • Signed informed consent/assent.

Exclusion criteria

Exclusion Criteria:

  • Patients with active bleeding.
  • Patients with planned invasive procedures less than 2 weeks from the time of enrollment.
  • Patients with a contraindication to anticoagulation.
  • Patients receiving thrombolytic agents.
  • Patients with an INR>1.5 or an activated partial thromboplastin time (PTT)>40 seconds.
  • Patients with a creatinine level above 1.2 times the upper limit of normal expected for age.
  • Children \<1 year of age.
05

Study design

Phase
Phase 1
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Single group
Masking
None (open label)
Enrollment
24 participants (actual)

Interventions

  • DrugFondaparinux

    Fondaparinux 0.1 mg/kg (up to 7.5 mg max initial dose) once daily for up to 21 days.

    Also known as: Arixtra

06

What researchers measure

Primary outcomes

  1. Number of Abnormal Lab Results Resulting in Adverse Events.

    The primary outcome measure was assessment of safety by reporting the number of abnormal lab results resulting in adverse events. Safety laboratory assessments are as follows: Liver and kidney toxicity will be determined by serial measurements of AST, ALT, total bilirubin, BUN and creatinine. Hematologic toxicity will be assessed by serial CBCs.

    Time frame: Study period which was up to 21 days of fondaparinux

  2. Therapeutic Plasma Concentration of Fondaparinux at 21 Days

    Subjects all had detailed pharmacokinetic measurements done which were subsequently analyzed in a population pharmacokinetic model. This model then informed the dosing recommendations that were published as a result of the study.

    Time frame: 21 days

  3. Bleeding Events

    Bleeding assessment Patients will be monitored for bleeding symptoms by physician and nursing assessment. Major bleeding will be defined as bleeding which is in a critical space (intracranial, retroperitoneal, or visceral) or leads to the need for blood transfusion. Minor bleeding will be all other bleeding and will be classified as clinically significant (i.e. If the physician has to take action to treat the minor bleed) or clinically insignificant (i.e. if the physician does not need to intervene to treat the minor bleed).

    Time frame: Study period which was up to 21 days of fondaparinux

  4. Adverse Events

    Adverse events will be defined as any untoward or unexpected event which can be a symptom, physical exam sign or laboratory abnormality. Adverse events will be classified as serious if they lead to prolonged hospitalization, re-hospitalization, transfer to an intensive care unit, or death. Adverse events will be categorized in terms of their likely association with fondaparinux as probably related, possibly related, unrelated, or unknown, and will be recorded according to standard adverse reporting guidelines for clinical trials.

    Time frame: Study period which was up to 21 days of fondaparinux

  5. Thrombocytopenic Events

    Patient's platelet counts should be kept above 50 x 10\^9/L while on study with platelet transfusions as needed with the exception of patients enrolled under the HIT/ suspicion of HIT inclusion (platelet transfusions are contraindicated in HIT). With regards to study patients who experience progressive decreases in platelet count to below 50 x 10\^9/L while receiving fondaparinux (excluding patients being treated for HIT or suspicion of HIT), fondaparinux will be discontinued.

    Time frame: Study period which was up to 21 days of fondaparinux

07

Results

Posted Dec 6, 2011

Participant flow

Subjects were recruited between September, 2006 and June, 2009 at 4 sites (Children's Hospital Los Angeles, Children's Hospital of Orange County, Texas Children's Hospital and Nationwide Children's Hospital). All subjects were in the inpatient units of these hospitals for the duration of their study participation.

Participant flow — Overall Study
MilestoneFondaparinux Group
Started24
Completed24
Not completed0

Outcome measures

PrimaryNumber of Abnormal Lab Results Resulting in Adverse Events.

The primary outcome measure was assessment of safety by reporting the number of abnormal lab results resulting in adverse events. Safety laboratory assessments are as follows: Liver and kidney toxicity will be determined by serial measurements of AST, ALT, total bilirubin, BUN and creatinine. Hematologic toxicity will be assessed by serial CBCs.

Time frame:
Study period which was up to 21 days of fondaparinux
Reported as:
Number · Adverse Events
Number of Abnormal Lab Results Resulting in Adverse Events.
Adverse EventsFondaparinux Group
Number of Abnormal Lab Results Resulting in Adverse Events.0
PrimaryTherapeutic Plasma Concentration of Fondaparinux at 21 Days

Subjects all had detailed pharmacokinetic measurements done which were subsequently analyzed in a population pharmacokinetic model. This model then informed the dosing recommendations that were published as a result of the study.

Time frame:
21 days
Reported as:
Mean · mg/dL
Therapeutic Plasma Concentration of Fondaparinux at 21 Days
mg/dLFondaparinux Group
Therapeutic Plasma Concentration of Fondaparinux at 21 Days24 ± 0.001
PrimaryBleeding Events

Bleeding assessment Patients will be monitored for bleeding symptoms by physician and nursing assessment. Major bleeding will be defined as bleeding which is in a critical space (intracranial, retroperitoneal, or visceral) or leads to the need for blood transfusion. Minor bleeding will be all other bleeding and will be classified as clinically significant (i.e. If the physician has to take action to treat the minor bleed) or clinically insignificant (i.e. if the physician does not need to intervene to treat the minor bleed).

Time frame:
Study period which was up to 21 days of fondaparinux
Reported as:
Number · Adverse Events
Bleeding Events
Adverse EventsFondaparinux Group
Bleeding Events2
PrimaryAdverse Events

Adverse events will be defined as any untoward or unexpected event which can be a symptom, physical exam sign or laboratory abnormality. Adverse events will be classified as serious if they lead to prolonged hospitalization, re-hospitalization, transfer to an intensive care unit, or death. Adverse events will be categorized in terms of their likely association with fondaparinux as probably related, possibly related, unrelated, or unknown, and will be recorded according to standard adverse reporting guidelines for clinical trials.

Time frame:
Study period which was up to 21 days of fondaparinux
Reported as:
Number · Adverse Events
Adverse Events
Adverse EventsFondaparinux Group
Adverse Events0
PrimaryThrombocytopenic Events

Patient's platelet counts should be kept above 50 x 10\^9/L while on study with platelet transfusions as needed with the exception of patients enrolled under the HIT/ suspicion of HIT inclusion (platelet transfusions are contraindicated in HIT). With regards to study patients who experience progressive decreases in platelet count to below 50 x 10\^9/L while receiving fondaparinux (excluding patients being treated for HIT or suspicion of HIT), fondaparinux will be discontinued.

Time frame:
Study period which was up to 21 days of fondaparinux
Reported as:
Number · Adverse Events
Thrombocytopenic Events
Adverse EventsFondaparinux Group
Thrombocytopenic Events0

Adverse events

Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Fondaparinux Group—0/24 (0%)0/24 (0%)

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)Fondaparinux Group
<=18 years24
Between 18 and 65 years0
>=65 years0
Age, Continuous
Age, Continuous(years)Fondaparinux Group
Mean12 ± 4
Sex: Female, Male
Sex: Female, Male(Participants)Fondaparinux Group
Female14
Male10
Region of Enrollment
Region of Enrollment(participants)Fondaparinux Group
United States24
08

Study locations

4 sites
  • Children's Hospital Los Angeles
    Los Angeles, California 90027, United States
  • Children's Hospital of Orange County
    Orange, California 92868, United States
  • Nationwide Children's Hospital
    Columbus, Ohio 43205, United States
  • Texas Children's Hospital
    Houston, Texas 77030, United States
09

References and documents

Publications

  • Young G, Yee FL, Khanna R, O'Brien D, Nugent DJ. Fondaparinux for the Treatment of Thrombosis in Children: A Prospective, Dose-Finding, Pharmacodynamic and Safety Study. Blood (ASH Annual Meeting Abstracts), Nov 2009; 114: 3130.
  • Young G, Yee DL, O'Brien SH, Khanna R, Barbour A, Nugent DJ. FondaKIDS: a prospective pharmacokinetic and safety study of fondaparinux in children between 1 and 18 years of age. Pediatr Blood Cancer. 2011 Dec 1;57(6):1049-54. doi: 10.1002/pbc.23011. Epub 2011 Feb 11. PubMed 21319285 ↗
10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 15, 2015, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT00412464
Lead sponsor
Children's Hospital Los Angeles
First posted
Dec 18, 2006
Start date
Sep 2006
Primary completion
Jun 2009
Completion
Dec 2009
Results posted
Dec 6, 2011
Last update
Apr 15, 2015

Study contacts

Guy Young, MD
principal investigator · Children's Hospital of Orange County

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Oct 2011. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion