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A Study of the Effects of Inhibiting Platelet Function on Circulating Cancer Cells in Breast Cancer Patients

This study has been terminated.
(Stopped due to low percentage of patients with detectable CTCs at baseline.)
Barnes-Jewish Hospital
Information provided by (Responsible Party):
Washington University School of Medicine Identifier:
First received: December 6, 2005
Last updated: January 24, 2017
Last verified: January 2017
The purpose of this study is to determine the effects of Plavix and aspirin in women with metastatic breast cancer.

Condition Intervention Phase
Breast Neoplasms Drug: Plavix Drug: Aspirin Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Treatment
Official Title: The Impact Of Platelet Function Inhibition On Circulating Cancer Cells In Metastatic Breast Cancer Patients

Resource links provided by NLM:

Further study details as provided by Washington University School of Medicine:

Primary Outcome Measures:
  • Platelet Inhibition of Circulating Tumor Cells (CTCs) Measured by the Number of Patients With Detectable CTCs [ Time Frame: Week 4 ]
    Measured by number of patients who have detectable circulating tumor cells

  • Safety and Tolerability of Aspirin and Plavix Measured by the Number of Patients Who Discontinue the Study Drug [ Time Frame: Maximum of 6 months ]
    Measured by number of patients who discontinue administration of study drug because of toxicity and the incidence categorized by type.

Secondary Outcome Measures:
  • Percentage of Patients With a Given Absolute Number of Circulating Tumor Cells (Broken Into Categories) Plotted Against Time [ Time Frame: Baseline, 2 weeks and 1 month ]
    Percent of patients with a given number/range of CTCs ( 0, 1-5 >+ 5) vs. time baseline 2-weeks and 1 month for plavix & Aspirin arm and observation only

  • Mean Aspirin-Mediated Platelet Inhibition vs. Time Plotted for Plavix and Aspirin and Observation Groups [ Time Frame: Baseline, 2 weeks and 1 month ]
    Mean platelet inhibition vs. time plotted for Plavix & Aspirin Arm and Observation group. Citrated whole blood is added to a test carriage containing fibrinogen-coated beads and a platelet activator (arachidonic acid to synthesize thromboxane A2). Using a turbidimetric-based optical detection system, aggregation of activated platelets to fibrinogen-coated beads increase light transmittance which is reported in Aspirin Reaction Units (ARU).

  • Clopidogrel-Mediated Percent of Platelet Inhibition vs. Time Plotted for Aspirin and Plavix and Observation Groups [ Time Frame: Baseline, 2 weeks and 1 month ]
    Mean Clopidogrel-Mediated platelet inhibition (% inhibition) vs. time for Aspirin and Plavix and Observation groups

  • Progression Free Survival [ Time Frame: Maximum of 6 months ]

Enrollment: 48
Study Start Date: January 2006
Study Completion Date: September 2009
Primary Completion Date: September 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Plavix and Aspirin
Patients will receive a 300 mg loading dose of Plavix on day 1, followed by 75 mg/day, and aspirin 81 mg per day starting day 1. Treatment will be continued until the treating physician elects to resume systemic therapy for the treatment of breast cancer or until unacceptable toxicity is observed. A pill diary will be collected monthly to monitor patients' compliance with the medication regimen.
Drug: Plavix
Other Name: Clopidogrel Bisulfate
Drug: Aspirin
Other Name: acetylsalicylic acid
No Intervention: Observation only
Observation by treating physician


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Women with metastatic breast cancer who are completing planned course of chemotherapy with planned treatment break
  • On stable hormone therapy for at least 2 months are also eligible for the study
  • Estimated survival of at least 3 months
  • No platelet inhibitor therapy within 1 month of study entry
  • Platelets ≥ 100,000
  • Coagulation screening tests within normal range (INR between 0.81 and 1.20)
  • Normal kidney and liver function as defined by:

    • Aspartate aminotransferase(AST)/serum glutamic oxaloacetic transaminase (SGOT))/alanine aminotransferase(ALT) ≤ 2 x Institutional Normal
    • Creatinine ≤ 2 x Institutional Normal
  • Able to provide signed, informed consent.

Exclusion Criteria:

  • Patients going on to surgery
  • Patients with a serious bleeding disorder that make them inappropriate candidates for NSAID therapy
  • Patients with history of significant bleeding related to peptic ulcer disease
  • Patients on standing doses of NSAIDS or platelet function inhibitors
  • Patients on standing doses of anti-coagulants
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00263211

United States, Missouri
Washington University School of Medicine
St. Louis, Missouri, United States, 63110
Sponsors and Collaborators
Washington University School of Medicine
Barnes-Jewish Hospital
Principal Investigator: Katherine N Weilbaecher, M.D. Washington University School of Medicine
  More Information

Additional Information:
Responsible Party: Washington University School of Medicine Identifier: NCT00263211     History of Changes
Other Study ID Numbers: 05-0427 / 201107340
Study First Received: December 6, 2005
Results First Received: July 21, 2016
Last Updated: January 24, 2017

Keywords provided by Washington University School of Medicine:
Breast Cancer

Additional relevant MeSH terms:
Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Inflammatory Agents
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents processed this record on September 19, 2017