A Study of Isoquercetin in People With Ovarian Cancer
Randomized, Multi-dose, Placebo-controlled Phase 2 Trial of Oral Isoquercetin to Reduce Thrombin Generation in Ovarian Cancer
1 other identifier
interventional
90
1 country
8
Brief 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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for phase_2 ovarian-cancer
Started Jan 2026
Longer than P75 for phase_2 ovarian-cancer
8 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
December 23, 2025
CompletedFirst Posted
Study publicly available on registry
December 26, 2025
CompletedStudy Start
First participant enrolled
January 22, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
January 1, 2032
ExpectedStudy Completion
Last participant's last visit for all outcomes
January 1, 2032
April 16, 2026
April 1, 2026
5.9 years
December 23, 2025
April 15, 2026
Conditions
Keywords
Outcome Measures
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).
up to 6 weeks from baseline
Study Arms (3)
Cohort A: Placebo
PLACEBO COMPARATORCohort B: Isoquercetin daily
EXPERIMENTALCohort C: Isoquercetin twice daily
EXPERIMENTALInterventions
Cohort B and Cohort C will take isoquercetin
Eligibility Criteria
You may qualify if:
- 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.
You may not qualify if:
- 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.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (8)
Beth Israel Deaconess Medical Center (Data Collection Only)
Boston, Massachusetts, 02215, United States
Memorial Sloan Kettering Basking Ridge (All Protocol Activities)
Basking Ridge, New Jersey, 07920, United States
Memorial Sloan Kettering Monmouth (All Protocol Activities)
Middletown, New Jersey, 07748, United States
Memorial Sloan Kettering Bergen (All Protocol Activities)
Montvale, New Jersey, 07645, United States
Memorial Sloan Kettering Suffolk-Commack (All Protocol Activities )
Commack, New York, 11725, United States
Memorial Sloan Kettering Westchester (All Protocol Activities)
Harrison, New York, 10604, United States
Memorial Sloan Kettering Cancer Center (All Protocol Activites)
New York, New York, 10065, United States
Memorial Sloan Kettering Nassau (All protocol activities)
Rockville Centre, New York, 11553, United States
Related Links
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Jeffrey Zwicker, MD
Memorial Sloan Kettering Cancer Center
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- RANDOMIZED
- Masking
- DOUBLE
- Who Masked
- PARTICIPANT, CARE PROVIDER
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
December 23, 2025
First Posted
December 26, 2025
Study Start
January 22, 2026
Primary Completion (Estimated)
January 1, 2032
Study Completion (Estimated)
January 1, 2032
Last Updated
April 16, 2026
Record last verified: 2026-04
Data Sharing
- IPD Sharing
- Will share
• 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.