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RecruitingNCT07303894Updated Sep 15, 2026

A Study of Isoquercetin in People With Ovarian Cancer

A Phase 2 interventional study of Isoquercetin and Placebo in Ovarian Cancer, Epithelial Ovarian Cancer and Serous Ovarian Tumor, sponsored by Memorial Sloan Kettering Cancer Center. Recruiting at 8 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-15.

Sponsored by Memorial Sloan Kettering Cancer Center · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
90
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The purpose of this study is to test whether isoquercetin can reduce markers in the blood that may indicate the risk of blood clots in people with ovarian cancer. The effects of isoquercetin will be compared with those of a placebo.

02

Conditions studied

  • Ovarian Cancer
  • Epithelial Ovarian Cancer
  • Serous Ovarian Tumor

Keywords

  • Ovarian Cancer
  • Epithelial Ovarian Cancer
  • Serous Ovarian Tumor
  • Isoquercetin
  • Memorial Sloan Kettering Cancer Center
  • 25-060
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Participants must have histological- or cytological-confirmed ovarian cancer (epithelial, serous, or clear cell) and be receiving first-line chemotherapy (day 1 of isoquercetin should align with day 1 of cycle 1 or 2 of chemotherapy) for neoadjuvant, adjuvant, or advanced settings.
  • Minimum age 18 years
  • Life expectancy of greater than 6 months.
  • ECOG performance status \<2
  • Participants must have preserved organ and marrow function as defined below:

    • Platelet count > 50,000/mcL
    • Prothrombin time (PT) and partial thromboplastin time (PTT) \< 1.5 x institutional upper limit of normal (ULN)
    • Total bilirubin \< 3 x ULN without liver metastases and \<5 x ULN in presence of liver metastases.
    • Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \< 3 X ULN without liver metastases and \<5 x ULN in the presence of liver metastases.
    • Estimated creatinine clearance (CrCl >30 ml/min)
  • The effects of isoquercetin on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
  • Ability to understand and the willingness to sign a written informed consent document.

Exclusion criteria

Exclusion Criteria:

  • Prior history of documented venous thromboembolic event within the last 2 years (excluding central line associated events whereby patients completed anticoagulation)
  • Active bleeding or high risk for bleeding (e.g., known acute gastrointestinal ulcer)
  • History of significant hemorrhage (requiring hospitalization or transfusion) outside of a surgical setting within the last 24 months
  • Familial bleeding diathesis
  • Known diagnosis of disseminated intravascular coagulation (DIC)
  • Currently receiving anticoagulant therapy
  • Current daily use of aspirin, clopidogrel (Plavix), cilostazol (Pletal), aspirin-dipyridamole (Aggrenox) (within 10 days) or considered to use regular use of higher doses of non-steroidal anti-inflammatory agents as determined by the treating physician (e.g ibuprofen > 800 mg daily or equivalent)
  • Uncontrolled intercurrent illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
  • Known intolerance of (iso)quercetin, niacin or ascorbic acid (including known G6PD deficiency).
  • Participants with known brain metastases
  • Pregnant women are excluded from this study because isoquercetin is a PDI inhibitor with the potential for teratogenic or abortifacient effects. Because there is an unknown but potential risk of adverse events in nursing infants secondary to treatment of the mother with isoquercetin, breastfeeding should be discontinued if the mother is treated with isoquercetin.
04

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Care provider)
Enrollment
90 participants (estimated)

Study arms

  • Placebo comparator
    Cohort A: Placebo

    Other: Placebo

  • Experimental
    Cohort B: Isoquercetin daily

    Drug: Isoquercetin

  • Experimental
    Cohort C: Isoquercetin twice daily

    Drug: Isoquercetin

Interventions

  • DrugIsoquercetin

    Cohort B and Cohort C will take isoquercetin

  • OtherPlacebo

    Placebo

05

What researchers measure

Primary outcomes

  1. Level of PDI-sensitive, platelet-dependent thrombin generation measured as compared to baseline

    The primary endpoint is the maximal inhibition of PDI-sensitive, platelet-dependent thrombin generation measured at either 3 or 6 weeks (relative to baseline).

    Time frame: up to 6 weeks from baseline

06

Study locations

7 of 8 sites recruiting
  • Beth Israel Deaconess Medical Center (Data Collection Only)
    Boston, Massachusetts 02215, United States
    • Robert Flaumenhaft, MD, PhD · Contact · 617-735-4005
    Not yet recruiting
  • Memorial Sloan Kettering Basking Ridge (All Protocol Activities)
    Basking Ridge, New Jersey 07920, United States
    • Jeffrey A Zwicker, MD · Contact · 646-608-3723
    Recruiting
  • Memorial Sloan Kettering Monmouth (All Protocol Activities)
    Middletown, New Jersey 07748, United States
    • Jeffrey Zwicker, MD · Contact · 646-608-3723
    Recruiting
  • Memorial Sloan Kettering Bergen (All Protocol Activities)
    Montvale, New Jersey 07645, United States
    • Jeffrey Zwicker, MD · Contact · 646-608-3723
    Recruiting
  • Memorial Sloan Kettering Suffolk-Commack (All Protocol Activities )
    Commack, New York 11725, United States
    • Jeffrey Zwicker, MD · Contact · 646-608-3723
    Recruiting
  • Memorial Sloan Kettering Westchester (All Protocol Activities)
    Harrison, New York 10604, United States
    • Jeffrey Zwicker, MD · Contact · 646-608-3723
    Recruiting
  • Memorial Sloan Kettering Cancer Center (All Protocol Activites)
    New York, New York 10065, United States
    • Jeffrey Zwicker, MD · Contact · 646-608-3723
    Recruiting
  • Memorial Sloan Kettering Nassau (All protocol activities)
    Rockville Centre, New York 11553, United States
    • Jeffrey Zwicker, MD · Contact · 646-608-3723
    Recruiting
07

References and documents

Individual participant data

Plan to share: Yes — • Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.

08

Registry details

Key details

Study ID
NCT07303894
Lead sponsor
Memorial Sloan Kettering Cancer Center
Collaborators
National Institutes of Health (NIH)
Responsible party
Sponsor
First posted
Dec 26, 2025
Start date
Jan 22, 2026
Primary completion
Jan 2032 (estimated)
Completion
Jan 2032 (estimated)
Last update
Sep 15, 2026

Study contacts

Jeffrey Zwicker, MD
Contact
zwickerj@mskcc.org
646-608-3723
Elizabeth Jewell, MD
Contact
jewelle@mskcc.org
212-639-3366
Jeffrey Zwicker, MD
principal investigator · Memorial Sloan Kettering Cancer Center

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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