AuthorisedTherapeutic confirmatory (Phase III)Interventional

Premedication with dexamethasone for preventing interstitial lung disease in patients with breast cancer treated with trastuzumab deruxtecan

Trastuzumab deruxtecan (also called T-DXd) is an effective targeted treatment for certain types of breast cancer. However, one known side effect is lung inflammation, medically known as interstitial lung disease (ILD). While often mild, this lung problem can sometimes become serious and cause breathing difficulties or interrupt cancer treatment. This Phase 3 clinical trial is investigating whether taking a steroid tablet called dexamethasone before cancer treatment can lower the risk of developing lung inflammation. Researchers will monitor participants over 12 months using regular chest CT scans, breathing checks, and symptom reviews. The main aim is to discover if this simple preventive treatment keeps patients safer and allows them to continue their cancer therapy without lung complications. Anyone taking part will receive standard cancer care alongside close health monitoring.

At a glance

Status

Authorised

Phase

Therapeutic confirmatory (Phase III)

Sponsor

Istituto Di Ricerche Farmacologiche Mario Negri

Enrolment target

244

Start

11 Aug 2026

Breast Cancer

What is this study about?

Trastuzumab deruxtecan (T-DXd) is a modern, targeted medicine that has shown great success in treating certain types of breast cancer. It works by finding cancer cells and delivering chemotherapy directly into them. While it can be very effective, doctors have found that some patients develop lung inflammation, known as interstitial lung disease or ILD. For most people, this is mild, but in some cases, it can cause a dry cough, shortness of breath, and may mean cancer treatment has to stop.

This clinical trial is testing a way to prevent this lung problem before it starts. Doctors are studying whether giving a common anti-inflammatory steroid called dexamethasone can shield the lungs. Dexamethasone is already widely used in cancer care to calm swelling and control nausea, but researchers want to confirm if it can specifically protect against lung damage caused by T-DXd.

During the trial, doctors will track participants' lung health for 12 months using high-resolution chest CT scans and regular breathing tests. They will also keep track of common side effects, such as sickness, tiredness, and changes in liver blood tests. If the steroid proves successful, it could become a standard way to make breast cancer treatment safer and more comfortable for patients in the future.

Key takeaways

Tests whether a steroid tablet (dexamethasone) can stop lung inflammation in breast cancer patients.
Aimed at adults aged 18 and over who are starting trastuzumab deruxtecan (T-DXd).
Involves regular lung scans, breathing checks, and symptom tracking over 12 months.
Participation is completely voluntary and will not compromise your standard cancer treatment.
Could help make an important breast cancer medicine safer for future patients.

Who may be eligible?

This trial is open to adults aged 18 and over who have been diagnosed with breast cancer and are scheduled to receive the targeted cancer drug trastuzumab deruxtecan (T-DXd).

Both women and men can join. Because the study focuses on how the lungs respond to treatment, participants should be well enough to attend regular hospital appointments and undergo breathing tests and chest scans.

Your cancer specialist will review your overall health, current medications, and past medical history to confirm whether this study is safe and suitable 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 breast cancer.
My doctor has recommended treatment with trastuzumab deruxtecan (T-DXd).
I am able to attend regular hospital appointments for check-ups and scans.
I am willing to take steroid tablets as instructed by the study doctor.

Answer every question to see your result.

What does participation involve?

If you take part, you will take dexamethasone tablets (4 mg) as advised by the trial team before your cancer therapy sessions. You will receive your planned breast cancer treatment as normal. Over a 12-month period, you will have regular hospital visits that match your treatment schedule. During these visits, doctors will monitor your breathing, check your blood oxygen levels, and perform lung function tests. You will also have scheduled chest CT scans (at roughly 3, 6, 9, and 12 months) to look closely at your lungs. The study team will regularly ask you about any symptoms such as coughing or breathlessness, and you will have standard blood tests to check your liver function.

Potential risks and benefits

A potential benefit of joining is that the steroid medication might lower your chance of developing lung inflammation, and your lungs will be monitored very closely by specialists. However, there is no guarantee that dexamethasone will completely prevent lung issues. Dexamethasone can also cause mild, temporary side effects such as increased appetite, mood changes, difficulty sleeping, or raised blood sugar levels. Taking part involves extra chest scans and breathing checks. Taking part is entirely voluntary, and you are free to leave the trial at any time without your regular NHS 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
Italy

Common questions

What is interstitial lung disease (ILD)?

ILD is an umbrella term for swelling or inflammation in the tissues of the lungs. It can cause a dry cough and breathlessness, but it can often be managed well if caught early.

What is dexamethasone?

Dexamethasone is a widely used steroid medicine. It reduces swelling and inflammation and is often used in cancer care to help treat side effects such as feeling sick.

Will taking part delay my cancer treatment?

No. The study is designed to run alongside your planned cancer therapy with trastuzumab deruxtecan without causing unnecessary delays.

Do I have to pay to take part?

No, taking part in clinical trials in the UK does not cost you anything, and trial-specific medicines and scans are provided at no charge.

Can I leave the study if I change my mind?

Yes, you can withdraw from the study at any time and for any reason. Your usual medical team will continue to give you the best possible care.