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Study of 6qc-ICG applied to the skin during breast cancer surgery to help surgeons see tumor edges in patients having breast conserving operations

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study is looking at breast cancer and how a new imaging substance called 6QC-ICG works when applied directly to tissue during surgery. Breast cancer is a disease where abnormal cells grow in the breast tissue. The study will also use a placebo for comparison. The imaging agent is designed to help surgeons see cancer cells more clearly during operations where only part of the breast is removed, not the whole breast. This type of surgery is called breast conserving surgery and aims to remove the cancer while keeping as much healthy breast tissue as possible.

The purpose of the study is to find out if 6QC-ICG is safe and well-tolerated when applied to tissue, and whether it can help doctors see any remaining cancer cells during surgery. The study has two parts. Part A involves healthy volunteers who will have the substance applied to a small wound on their skin to check for any unwanted effects. Part B involves patients who have been diagnosed with a specific type of breast cancer and are scheduled to have surgery. During their operation, the substance will be applied to the area where the tumor was removed to see if it lights up any remaining cancer cells that might need to be taken out.

Throughout the study, researchers will carefully monitor participants for any side effects or problems. They will check vital signs like blood pressure and heart rate, take blood and urine samples for laboratory tests, and perform heart rhythm tests using an ECG. For the patients having surgery, doctors will take pictures using special cameras that can see the fluorescent signal from the imaging agent, and they will compare these images with laboratory results from tissue samples to see how well the substance works at identifying cancer cells.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial screening and preparation

    Your eligibility for the study will be confirmed through various tests and assessments.

    A urine pregnancy test will be performed if you are of childbearing potential and not surgically sterile or post-menopausal.

    An electrocardiogram (a test that records the electrical activity of your heart) will be conducted.

    Blood and urine samples will be collected for laboratory tests to check your general health status.

    Your vital signs will be measured, including pulse rate and blood pressure.

    If you are premenopausal and not surgically sterile, you will need to agree to use an effective method of contraception for at least 30 days after receiving the study treatment.

  2. Step 2

    Study treatment administration during surgery

    During your breast-conserving surgery, a single dose of the study product 6qc-ICG or placebo will be applied directly onto the surgical area.

    The study product is a solution that will be applied topically, meaning it will be placed directly on the tissue surface in the surgical cavity.

    This application is designed to help visualize any remaining cancer cells during the surgery using a special fluorescent imaging technique.

    The surgical team will examine the surgical cavity walls using near-infrared fluorescence imaging to detect any fluorescent signals that may indicate the presence of cancer tissue.

  3. Step 3

    Safety monitoring during and immediately after treatment

    Your vital signs, including pulse rate and blood pressure, will be monitored at scheduled times during and after the procedure.

    The surgical team will assess the local tolerability of the study product at the application site.

    Any pain or itching at the application site will be evaluated using rating scales.

    Blood samples will be collected at specific times to measure the levels of the study product in your bloodstream.

    Urine samples will also be collected to assess how the study product is eliminated from your body.

  4. Step 4

    Follow-up assessments

    Additional electrocardiograms will be performed at scheduled times to monitor your heart's electrical activity.

    Blood and urine samples will be collected for laboratory tests at specified intervals.

    Your vital signs will continue to be measured at scheduled times.

    The status of wound closure will be assessed over time to monitor healing.

    Any side effects or adverse events will be recorded throughout the study period.

    All medications you are taking will be documented.

  5. Step 5

    Tissue analysis

    Tissue samples taken from the surgical cavity during your surgery will be analyzed in the laboratory.

    The analysis will determine whether any fluorescent areas contained cancer cells.

    The pathology results will confirm whether all cancer tissue was successfully removed during the surgery.

Who can join the trial?

13 criteria

  • You must be between 18 and 55 years old at the time of screening, which is the first visit where doctors check if you can join the study (for healthy volunteers in Part A)
  • You must be 18 years of age or older at the time of screening (for patients in Part B)
  • You must have breast cancer confirmed by biopsy, which is a test where a small piece of tissue is removed and examined under a microscope. The cancer must be Bloom-Richardson grade 3 invasive breast cancer (a type of cancer that has spread into nearby breast tissue and is fast-growing) or grade 3 ductal carcinoma in situ (a type of cancer that stays within the milk ducts but is also fast-growing). You must be scheduled for breast-conserving surgery, which is an operation to remove the cancer while keeping most of the breast (for patients in Part B)
  • You must be unable to have children due to surgery, past menopause (the natural end of monthly periods), or have a negative pregnancy test before receiving the study treatment if you are still having periods. If you are still having periods and able to have children, you must agree to use effective contraception (birth control) for at least 30 days after receiving the study treatment (for patients in Part B)
  • Your ECG (a test that measures the electrical activity of your heart) and blood test results must be normal, or if any results are outside normal ranges, your doctor must consider them not medically important (for patients in Part B)
  • You must be able and willing to follow all study procedures (for both healthy volunteers and patients)
  • You must be in good overall health based on your doctor's assessment of your vital signs (like blood pressure and heart rate), medical history, physical examination, and laboratory tests (for healthy volunteers in Part A)
  • Your body mass index (a measure of body fat based on height and weight) must be between 18 and 32, and you must weigh at least 50 kilograms (for healthy volunteers in Part A)
  • You must be unable to have children due to surgery, past menopause, or have a negative pregnancy test at screening and before receiving the study treatment if you are still having periods. If you are still having periods and able to have children, you must agree to use effective contraception (for healthy volunteers in Part A)
  • Your ECG and blood test results at screening must be normal, or if any results are outside normal ranges, they must be considered not medically important (for healthy volunteers in Part A)
  • You must test negative for drugs and alcohol (for healthy volunteers in Part A)
  • You must have a large enough area of healthy, unbroken skin on your back (more than 100 square centimeters) (for healthy volunteers in Part A)
  • You must provide written informed consent, which means you must sign a document showing you understand and agree to participate in the study, before any study activities begin

Who cannot join the trial?

8 criteria

  • The study document does not provide specific exclusion criteria, which are the reasons why someone cannot participate in this clinical trial
  • If you are interested in participating, the research team will need to review your individual medical situation to determine if you are eligible
  • General factors that often prevent participation in clinical trials may include certain allergies, which are reactions your body has to specific substances
  • Other common exclusion factors may involve taking certain medications that could interfere with the study treatment
  • Having other medical conditions besides breast cancer might also affect your ability to participate
  • Being pregnant or breastfeeding, which means nursing a baby, typically prevents participation in studies like this
  • Previous reactions to similar imaging substances or dyes may be a reason for exclusion
  • Certain skin conditions at the treatment area might prevent you from taking part
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Investigated drugs

6qc-ICG is a fluorescent probe that is applied directly to the skin surface during surgery. This medication is designed to light up or glow when it comes into contact with certain enzymes that are found in cancer cells. During breast-conserving surgery, surgeons spray this substance on the tissue to help them see if any cancer cells remain at the edges of the area they are removing. This helps the surgical team determine in real-time whether they have removed all the cancer tissue or if more needs to be taken out. The medication works by becoming activated by specific proteins called cathepsins that are more common in cancer tissue, making the cancer cells visible under special imaging equipment.

What is already known about the treatment

6qc-ICG – This is an experimental fluorescent imaging agent that is applied directly onto tissue during surgery to help surgeons see cancer cells in real time. It works by being activated by cathepsin enzymes, which are proteins found in higher amounts in cancer cells, causing the medication to glow under special light and making tumor edges visible. Currently, this substance is being tested in early clinical trials (phase I/II) to evaluate its safety and ability to help surgeons remove breast cancer completely while preserving healthy breast tissue. The medication is sprayed or applied topically onto the surgical area to identify any remaining cancer cells at the edges of the removed tissue.

Investigated diseases

Breast Cancer – Breast cancer is a disease where abnormal cells in the breast tissue grow uncontrollably and form a tumor. It typically begins in the milk ducts or lobules of the breast and can spread to nearby tissues. The cancer cells may grow slowly or rapidly depending on the type. As the disease progresses, the tumor can increase in size and may affect the shape or appearance of the breast. Without intervention, cancer cells can break away from the original tumor and spread through the lymphatic system or bloodstream to other parts of the body. This study focuses on patients undergoing breast conserving surgery, where only the tumor and surrounding tissue are removed while preserving most of the breast.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase I/IITrial ID2025-523166-24-00Protocol codeSPRAYDYE / CHDR2535Estimated enrolment22 patientsSponsorLeids Universitair Medisch Centrum (LUMC)

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