AuthorisedTherapeutic exploratory (Phase II)Interventional

DECREASE-IPC 2025-068 : De-Ecalating neoadjuvant Chemoimmunotherapy in early triple-negative BREASt cancer

Triple-negative breast cancer is usually treated with several months of intensive chemotherapy combined with immunotherapy before surgery. While effective, this intensive plan can cause substantial side effects. The DECREASE study aims to find out whether a shorter, 12-week course of treatment can clear the cancer just as well. Participants receive an immunotherapy drug called pembrolizumab alongside standard chemotherapy drugs through a drip for 12 weeks. Doctors will then check whether the tumour has gone completely using a breast MRI scan, a biopsy, and laboratory checks on the tissue removed during surgery. The main goal is to see if heavier chemotherapy drugs can be safely left out if the cancer has already cleared after 12 weeks. The study team will also monitor recovery, survival, emotional well-being, and overall quality of life for up to three years after treatment.

At a glance

Status

Authorised

Phase

Therapeutic exploratory (Phase II)

Sponsor

Institut Paoli Calmettes

Enrolment target

Start

24 Jul 2026

triple‑negative breast cancer

What is this study about?

Triple-negative breast cancer is a form of breast cancer that does not have receptors for the hormones oestrogen or progesterone, or for a protein called HER2. Because hormone therapies do not work against it, the usual standard of care involves giving a mix of chemotherapy and immunotherapy before surgery. The aim is to shrink or completely destroy the tumour before an operation takes place.

At present, standard treatments can be very intense. Patients often receive multiple chemotherapy drugs over four to six months. While this approach helps cure many people, it can also cause serious short-term and long-term side effects, such as extreme fatigue, heart strain, and nerve damage. The DECREASE study is exploring an approach known as treatment 'de-escalation'. This means carefully reducing the amount or duration of chemotherapy to spare patients unnecessary harm, without reducing their chances of being cured.

In this study, patients receive 12 weeks of chemotherapy combined with immunotherapy. After this period, doctors use an MRI scan, a tissue sample (biopsy), and the final surgical results to look for any remaining cancer cells. If no cancer is left, it suggests that shorter therapy is sufficient. The trial also tracks patient well-being, worries about the cancer returning, and overall health for three years to ensure this gentler approach remains safe in the long term.

Key takeaways

Tests whether 12 weeks of chemoimmunotherapy before surgery can completely clear early triple-negative breast cancer.
Aims to spare patients from heavier chemotherapy drugs and reduce severe side effects.
Uses breast MRI scans and tissue analysis to verify if the tumour has disappeared.
Follows participants for three years to monitor recovery, safety, and quality of life.
Open to adults aged 18 and over who have not yet started treatment for their cancer.

Who may be eligible?

This study is open to adults aged 18 and over who have been newly diagnosed with early-stage triple-negative breast cancer. It is suitable for people who have not yet had surgery or drug treatments for their current diagnosis. Both women and men can join.

To be considered, you must be in good enough general health to safely receive chemotherapy and immunotherapy drips. This means having satisfactory heart, kidney, and liver function, which your hospital team will check with simple tests.

You may not be eligible if the cancer has already spread to other distant parts of your body, or if you have an active autoimmune disease that could make immunotherapy unsafe. Your cancer specialist will go through your medical history and scans to confirm whether the trial is a safe match for you.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged 18 or older.
I have been diagnosed with early-stage triple-negative breast cancer.
I have not yet had surgery or chemotherapy for this breast cancer.
My cancer has not spread to distant parts of my body.
I am generally well enough to attend regular hospital visits for intravenous drips.

Answer every question to see your result.

What does participation involve?

If you take part, you will start with screening checks, including blood tests and a breast MRI scan. You will then receive 12 weeks of treatment given as intravenous drips at the hospital. These include an immunotherapy drug (pembrolizumab) and chemotherapy drugs (paclitaxel and carboplatin). After 12 weeks, you will have another MRI scan and a small biopsy to check your tumour, followed by your planned breast surgery. Doctors will examine the tissue removed during surgery to see if any cancer cells remain. After surgery, your active drug treatment under the study ends, but you will attend routine hospital check-ups and fill out short quality-of-life questionnaires over a three-year follow-up period.

Potential risks and benefits

The possible benefit of taking part is that your tumour may clear completely with fewer weeks of treatment, helping you avoid heavier chemotherapy drugs and their side effects. However, there is no guarantee that the 12-week course will clear all cancer cells, and some patients may still need further treatments. All cancer therapies carry risks. Common chemotherapy side effects include hair loss, nausea, tiredness, and an increased risk of infection. Immunotherapy can cause your immune system to attack healthy tissues, causing inflammation in organs such as the bowels, skin, or thyroid. Joining is entirely voluntary, and you can withdraw at any time without your regular NHS medical care being affected.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
France

Common questions

What does 'de-escalating' treatment mean?

It means reducing the amount, duration, or strength of medical treatment to spare patients unwanted side effects, while making sure the cancer is still treated effectively.

What is triple-negative breast cancer?

It is a type of breast cancer that lacks oestrogen, progesterone, and HER2 receptors. It is usually treated with chemotherapy and immunotherapy rather than hormone pills.

Will taking part delay my breast surgery?

No. The 12 weeks of treatment take place before your operation, which is a standard timeline for shrinking breast tumours before surgery.

What happens if cancer cells are still found after 12 weeks?

Your surgical team and oncologist will assess the tissue carefully and recommend standard follow-up treatments, which may include further chemotherapy, radiotherapy, or other approved medicines.

Do I have to pay to take part in this study?

No. In the UK, study drugs and trial-related hospital assessments are provided free of charge through NHS and clinical research programmes.