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

Condition(s) targeted: Breast Neoplasms

Intervention: Plavix/Aspirin (Drug); No Intervention (Other)

Phase: Phase 2

Status: Recruiting

Sponsored by: Washington University School of Medicine

Official(s) and/or principal investigator(s):
Katherine Weilbaecher, M.D., Principal Investigator, Affiliation: Washington University School of Medicine

Overall contact:
Jenny Edrington, Phone: 314-362-0202, Email: edringtj@ccadmin.wustl.edu

The purpose of this study is to determine the effects of Plavix and aspirin in women with metastatic breast cancer.

Official title: The Impact Of Platelet Function Inhibition On Circulating Cancer Cells In Metastatic Breast Cancer Patients

Study design: Treatment, Randomized, Single Blind (Subject), Historical Control, Parallel Assignment, Efficacy Study

Primary outcome: The primary endpoint of efficacy is the proportion of the patients who have detectable circulating tumor cells (CTC) after completion of study (at the time of either resuming systemic treatment of breast cancer or unacceptable toxicity being observed).

Detailed description: All patients will have medical history, physical exam, and standard labs at baseline, including platelets, AST/ALT, creatinine, PT/PTT. Platelet function, CTC tests, and Urine Ntx will be taken at baseline, two weeks, and then monthly. Patients may remain on study until treating physician elects to resume systemic therapy. If patients continue on study after one month, they will receive physical exam, medical history/progress notes, standard labs, platelet function (at the treating physician's discretion), and CTC tests on a monthly (q 4 week) schedule or every 3 weeks if receiving trastuzumab or other i. v. medication that necessitates returning to the clinic on an every 3 week schedule.

Plavix/Aspirin Arm

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.

No Treatment Arm

Patients randomized to the no treatment arm will receive no anti-platelet drugs but will be monitored by the treating physician. Assessment of performance status, quality of life, CTC, and platelet function will be performed. Patients will continue on the study until the treating physician elects to resume systemic therapy for the treatment of breast cancer, or until unacceptable toxicity is observed. Patients will be followed for 6 months maximum as part of the protocol.

Minimum age: 18 Years. Maximum age: N/A. Gender(s): Female.

Criteria:

Inclusion Criteria:

- Women with metastatic breast cancer

- Completing planned course of therapy with planned treatment break

- Measurable or evaluable disease

- Estimated survival of at least 3 months

- Planned to be off therapy at least 1 month

- No platelet inhibitor therapy within 1 month of study entry

- Platelets > 100,000

- Coagulation screening tests within normal range—INR between 1. 0 and 1. 4

- Normal kidney and liver function as defined by:

- AST/ALT < 2 x Institutional Normal

- Creatinine < 2 x Institutional Normal

Exclusion Criteria:

- Patients going on to endocrine therapy

- Patients going on to surgery

- Patients with a serious bleeding disorder that contraindicate the use of platelet

function inhibitors

- 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

Jenny Edrington, Phone: 314-362-0202, Email: edringtj@ccadmin.wustl.edu

Washington University, St. Louis, Missouri 63110, United States; Recruiting
Beth Grigsby, M.A., CCRP, Phone: 314-747-4112, Email: grigsbya@ccadmin.wustl.edu

Starting date: January 2006
Ending date: December 2008
Last updated: October 27, 2008