CBD for Breast Cancer Primary Tumors

April 6, 2026 updated by: Medical University of South Carolina

A Phase 1a "Window Trial" of Cannabidiol (CBD) For Breast Cancer Primary Tumors

This is a randomized placebo controlled partially blinded window of opportunity trial. A maximum of 84 patients with invasive breast cancer will be enrolled. Patients will be randomized 2:2:1:1 to either CBD low dose, CBD high dose, matching low dose placebo, or matching high dose placebo using permuted block randomization with random block sizes of 6 or 12. The time window between CBD or placebo initiation and surgery will be between 5 and 56 days.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

84

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • South Carolina
      • Charleston, South Carolina, United States, 29425
        • Recruiting
        • Medical University of South Carolina
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Patients who are able to consent for surgery.
  2. Histologically confirmed invasive breast cancer (stages I, II, or III) with Ki67 proliferation rate greater than or equal to 10%.
  3. Women 18 years of age or older at time of consent.
  4. Women of child-bearing potential (WOCBP) must agree to use an approved form of birth control and to have a negative pregnancy test result before registration. WOCBP is defined as any female who has experienced menarche and who has not undergone surgical sterilization (hysterectomy or bilateral oophorectomy) or who is not postmenopausal. Menopause is defined clinically as 12 consecutive months of amenorrhea in a woman over 45 in the absence of other biological or physiological causes.
  5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
  6. Adequate hematologic and end organ function, defined by the following laboratory results obtained within 14 days prior to registration:

    1. ANC ≥ 1.5 × 109/L
    2. Platelet count ≥ 100 × 109/L
    3. Hemoglobin ≥ 9 g/dL
    4. Albumin ≥ 2.5 g/dL
    5. Bilirubin ≤ 1.5 × the upper limit of normal (ULN)
    6. AST, ALT, and alkaline phosphatase ≤ 3 × ULN
    7. Serum creatinine ≤ 1.5 × ULN or creatinine clearance (CrCl) ≥ 40 mL/min on the basis of measured CrCl from a 24-hour urine collection or Cockcroft-Gault* glomerular filtration rate estimation:

      (140-age) × (weight in kg) × (0.85 if female)

      72 × (serum creatinine in mg/dL)

      • The Modification of Diet in Renal Disease (Levey et al. 2006) and the Chronic Kidney Disease Epidemiology Collaboration (Levey et al. 2009) formulas for estimation of glomerular filtration rate are also acceptable.
  7. Self declared ability and capacity to comply with the study and follow-up procedures.
  8. Subjects must be scheduled for surgery no less than 5 days from the planned start of day 1 and no more than 56 days from the planned start of day 1.

Exclusion Criteria:

  1. Subjects undergoing neoadjuvant chemotherapy or neoadjuvant endocrine therapy.
  2. Known allergy to sesame. Please note the study product contains sesame oil.
  3. South Carolina State employees or anyone whose work requires THC drug testing.
  4. Patients taking drugs metabolized by cytochrome p450 including warfarin, amiodarone, levothyroxine, clobazam, lamotrigine, valproate, prednisolone, hydrocortisone, clarithromycin, itraconazole, erythromycin, fluconazole, clopidogrel, rifampin, sulfamethoxazole, any opioids, and antiepileptic medications including carbamazapine, phenytoin, and valproic acid.
  5. Self reported routine use of recreational or medicinal marijuana products, including over-the-counter CBD oil, Marinol®, Delta-8 THC, or cannabis (defined as > 4 times over last 30 days) or illicit drug use including opioids, cocaine, amphetamines, PCP, LSD.
  6. Self reported concurrent use of over-the-counter CBD oil, Marinol®, Delta-8 THC, or cannabis.
  7. History of allergic reactions attributed to compounds of similar chemical or biologic composition to CBD or placebo.
  8. Underlying history of epilepsy/ recurrent seizure disorder or unexplained seizure within past 6 months.
  9. Patients with uncontrolled cardiovascular disease defined by myocardial infarction, stroke, or transient ischemic attack, or need for coronary stent placement within past six months.
  10. Patients with a medical history of psychiatric illness or psychiatric symptoms that would prevent them from completing study procedures or would disqualify them from surgical intervention (e.g., untreated schizophrenia, bipolar disorder, or suicide ideation/attempt resulting in psychiatric hospitalization within the last 30 days).
  11. Women who are pregnant or breastfeeding.
  12. Use of blood thinners at the time of registration (warfarin, rivaroxaban, clopidogrel, and apixaban) .

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: CBD Oral
CBD Oral 175mg or 350mg twice daily for 5-56 days
CBD Oral 175mg or 350mg twice daily for 5 days-56 days
Placebo Comparator: Placebo control
Placebo control Oral twice daily for 5-56 days
Placebo Control

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
CBD and cell proliferation
Time Frame: 2 months
To determine whether oral administration of cannabidiol (CBD) causes biological changes related to cell proliferation (using Ki67 expression as a marker) in primary tumors of breast cancer patients.
2 months
CBD and apoptosis
Time Frame: 2 months
To determine whether oral administration of cannabidiol (CBD) causes biological changes related to apoptosis (using Ki67 expression as a marker) in primary tumors of breast cancer patients.
2 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of participants with treatment-related adverse events as assessed by CTCAE 5.0
Time Frame: 2 months
To determine adverse event relationship to oral CBD extract in patients with breast cancer.
2 months
GAD-7 anxiety level scoring at Pre and post CBD administration
Time Frame: 2 months
To determine whether CBD administered in the period waiting for surgery reduces self-reported anxiety from baseline to time of surgery as measured by the GAD-7 patient reported outcomes scale.
2 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 15, 2026

Primary Completion (Estimated)

March 25, 2028

Study Completion (Estimated)

March 25, 2029

Study Registration Dates

First Submitted

April 17, 2023

First Submitted That Met QC Criteria

November 18, 2023

First Posted (Actual)

November 28, 2023

Study Record Updates

Last Update Posted (Actual)

April 9, 2026

Last Update Submitted That Met QC Criteria

April 6, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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