An Early Phase 1 interventional study of Aspirin in Preeclampsia, sponsored by Rockefeller University. Recruiting at 1 site in United States. Open to female participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-10-30.
Sponsored by Rockefeller University · Early Phase 1, Interventional, and Basic science
Hypertensive disorders of pregnancy (including preeclampsia) are among the leading causes of pregnancy complications and maternal deaths worldwide. They also increase the risks to the babies. Numerous interventions have been suggested in order to reduce the rate of preeclampsia. Low-dose aspirin is the most beneficial prophylactic approach in this regard. Nevertheless, aspirin failure is not uncommon. The genetic, laboratory, and clinical factors associated with low-dose aspirin failure in the prevention of preeclampsia are largely unknown. The presence of a genetic variant in PAR4 receptor expressed on platelets, is associated with increased platelet function and possibly with aspirin failure.
Preeclampsia is among the leading causes of maternal morbidity and mortality worldwide. The pathophysiology underling the occurrence of preeclampsia is multifactorial with many suggested theories. Among the latter, enhanced platelet activation coupled with an imbalance in prostanoid levels have been postulated as being responsible for the pathophysiologic changes in preeclampsia.
Numerous prophylactic interventions have been investigated in order to reduce the rate of gestational hypertensive disorders. It is currently well-established that administration of low-dose aspirin is the most beneficial prophylactic approach.
The major effect of aspirin is to inhibit cyclooxygenase-1 (COX-1), which reduces thromboxane A2 production in platelets and the abnormally increased thromboxane A2/prostaglandin I2 imbalance.
This improves placental function by favoring systemic vasodilatation and inhibiting platelet aggregation. Despite its well-established clinical role in the prevention of preeclampsia, aspirin failure is not uncommon. Nevertheless, the ancestry/genetic, laboratory, and clinical factors associated with low-dose aspirin failure in the prevention of preeclampsia are largely unknown.
Higher rates of aspirin failure have been reported in Black women, possibly due to genetic variants. Studies among non-pregnant patients, have identified that racial differences in PAR4 (protease- activated receptor 4) expressed on platelets, are associated with increased platelet function in Blacks compared to whites. A single-nucleotide variant (rs773902) in PAR4 gene (F2RL3), which results in alanine/threonine polymorphism, was shown to largely account for the racial difference in platelet activation by PAR4. The frequency of the variant differs widely between self-declared Black individuals and non-Black individuals, with values of \~65% versus\~20%. Thus, it is possible that the variant may contribute to the higher rate of failure of low dose aspirin in the Black population.
The study aim is to evaluate these issues.
916 studies on the registry are indexed under Pre-Eclampsia; 243 are open to participants now.
This study's planned enrollment of 130 is above the median of 110 across 480 interventional studies indexed under Pre-Eclampsia.
Browse Pre-Eclampsia studies →Rockefeller University is the lead sponsor of 123 studies on the registry; 3 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 6 (43%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Women aged 18 years or older, with no other specific inclusion criteria that need to be met in order to be enrolled for the study.
Exclusion Criteria:
A. \<18 years of age. B. Participants may be excluded at the discretion of the investigator for medical, psychological or other reasons C. Rockefeller students, and Rockefeller employees in the Coller lab, are excluded from participation.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Single-dose of enteric-coated 81 mg aspirin
Drug: Aspirin
In this group, no aspirin will be given, as blood draw will not be performed at all among the healthy volunteers. The group of healthy volunteers will serve only for the SNP assay development.
Platelet assays including VerifyNow Aspirin assay, VerifyNow Base assay, platelet aggregometry, Thromboxana A2 levels- will be measured at baseline and 1 hour after administration of single-dose enteric-coated 81 mg aspirin
Allelic frequency of the PAR4 variant (rs773902) in relation to aspirin success in preeclampsia prevention
We will compare the the allelic frequency of the PAR4 variant (rs773902) between aspirin-responders (no recurrence of preeclampsia) and aspirin non responders (recurrence of preeclampsia despite aspirin)
Time frame: At study enrollment
Platelet response to aspirin as assessed by VerifyNow Aspirin Assay in relation to aspirin success in preeclampsia prevention-measured as VerifyNow Reaction Units
In the VerifyNow aspirin assay- arachidonic acid is used as the activator to measure the response of the platelet to aspirin. Aspirin irreversibly inhibits COX-1, the enzyme that catalyzes the first reaction leading to the conversion of arachidonic acid to thromboxane A2, which in turn, activates the GPIIb/IIIa receptor to bind fibrinogen, which leads to platelet aggregation. In the presence of aspirin the aggregation does not occur. This assay will demonstrate whether those who developed preeclampsia despite aspirin administration, have increased platelet aggregation at baseline, at 1 hour following aspirin administration, or both.
Time frame: 0 and 1 hours post single dose 81 mg enteric-coated aspirin
Platelet response to aspirin as assessed by VerifyNow Base Assay in relation to aspirin success in preeclampsia prevention-measured as VerifyNow Reaction Units
In the VerifyNow Base assay, platelet activation is produced by PAR1 thrombin receptor activating peptide + a PAR4 agonist peptide. Thus, this assay will be used to assess whether there is an enhanced response of the PAR4 peptide in those with the PAR4 variant, or perhaps even in those who did not have a good response to aspirin even if they do not have the variant.
Time frame: 0 and 1 hours post single dose 81 mg enteric-coated aspirin
Platelet response to aspirin as assessed by aggregometry in relation to aspirin success in preeclampsia prevention-measured as VerifyNow Reaction Units
As in the VerifyNow Base assay, the Base channel includes both PAR1 and PAR4 agonists, we will also perform platelet aggregometry with just the PAR4 agonist peptide, to avoid any confounding effect of the PAR1 peptide. This will be measured at baseline and at 1 hour after aspirin administration. Results will be compared between those who developed preeclampsia depicted aspirin and those who did not experience preeclampsia under aspirin prophylaxis.
Time frame: 0 and 1 hours post single dose 81 mg enteric-coated aspirin
Thromboxane A2 levels in relation to aspirin success in preeclampsia prevention-measured in ng/mL
Aspirin inhibits the enzyme COX-1 which converts arachidonic acid to thromboxane A2. Therefore, evaluating the end product directly-thromboxane A2 levels-may potentially detect differences between the groups (aspirin responders vs. aspirin non-responders).
Time frame: 0 and 1 hours post single dose 81 mg enteric-coated aspirin
Plan to share: No
Started Apr 2023 (actual). Primary completion is estimated for Nov 2026, 42 months after the start.
Of 20 phase 1 interventional studies under Pre-Eclampsia, half reached primary completion within 25 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 34. This study's planned 42 months is above that.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Aspirin