CompletedPhase IIIInterventional

DOMENICA: Randomized phase III trial in MMR deficient endometrial cancer patients comparing chemotherapy alone versus dostarlimab in a first-line advanced/metastatic setting

Endometrial cancer starts in the lining of the womb. When it is advanced or comes back after treatment, the usual first option is chemotherapy. While chemotherapy can be effective, the cancer often returns. The DOMENICA study is testing an immunotherapy medicine called dostarlimab to see if it works better than standard chemotherapy. Immunotherapy helps your own immune system recognise and attack cancer cells. This trial is specifically for patients whose cancer cells have a feature called 'mismatch repair deficiency' (MMRd), which often makes them respond well to immunotherapy. Participants are randomly placed into one of two groups: one receives dostarlimab, and the other receives standard chemotherapy. The study lasts around five years, including treatment and regular follow-up visits. Doctors hope this study will lead to better, kinder treatments for advanced womb cancer in the future.

At a glance

Status

Completed

Phase

Phase III

Sponsor

Arcagy Gineco

Enrolment target

260

Start

01 Mar 2024

Estimated completion

30 Jun 2025

Endometrial cancer

What is this study about?

Endometrial cancer is a type of cancer that begins in the lining of the womb (uterus). When the cancer has spread to other parts of the body (advanced or metastatic) or has come back after previous treatment, standard chemotherapy is usually offered. Chemotherapy uses strong medicines to kill cancer cells, but it can cause difficult side effects and may not keep the cancer away permanently.

The DOMENICA trial is looking at a different kind of treatment called dostarlimab. Dostarlimab is an immunotherapy. Instead of attacking cancer cells directly, it helps your body's own immune system find and destroy them. This study focuses on tumours that have a specific biological marker called 'MMR deficiency' (MMRd). Tumours with this marker have trouble repairing their own DNA, which makes them easier for the immune system to spot when given immunotherapy.

Researchers want to see if giving dostarlimab on its own works better than standard chemotherapy at stopping the cancer from growing or coming back. To find out, this Phase III trial is comparing the two treatments side by side in hospital centres across several countries, including the UK.

Taking part in this study could help doctors understand whether immunotherapy should become the new first-line treatment for this specific type of womb cancer. If successful, it could offer patients a more effective treatment option and quicker access to modern cancer therapies.

Key takeaways

The DOMENICA trial compares dostarlimab (an immunotherapy) directly against standard chemotherapy for advanced womb cancer.
The trial is designed specifically for tumours that have a genetic feature called MMR deficiency (MMRd).
Participants are randomly assigned by a computer to receive either dostarlimab or chemotherapy.
Total participation lasts around five years, including treatment and regular follow-up checks.
You have the right to withdraw from the study at any point without compromising your ongoing medical care.

Who may be eligible?

This study is open to adult women (aged 18 and older) who have advanced, metastatic, or recurrent endometrial cancer that cannot be cured by surgery or radiotherapy alone. To take part, your cancer must be tested and confirmed as 'mismatch repair deficient' (MMRd) or 'microsatellite instability-high' (MSI-H). You will also need to be reasonably active and able to look after yourself in daily life.

You may not be eligible if you have already received chemotherapy for this advanced stage or recurrence of your cancer, or if your tumour does not show the MMR-deficient marker. Because the effects of the study drug on an unborn baby are unknown, you cannot take part if you are pregnant or planning to become pregnant during the trial.

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 a woman aged 18 or older.
I have been diagnosed with advanced, spread, or recurrent endometrial (womb) cancer.
My cancer cannot be cured with surgery or radiotherapy alone.
My tumour has been tested (or can be tested) and is MMR-deficient (MMRd) or MSI-H.
I have not yet had chemotherapy for this advanced stage or first recurrence.
I am not pregnant and not planning to become pregnant during the trial.

Answer every question to see your result.

What does participation involve?

Taking part in the study lasts around five years in total and is divided into clear stages. First, your doctors will check whether you are eligible using an existing sample of your tumour tissue, so you should not need an extra operation for this. If you are eligible and agree to join, a computer will randomly choose which treatment you receive: either dostarlimab or standard chemotherapy (paclitaxel and carboplatin). You have an equal (50/50) chance of being in either group.

You will receive your treatment through a drip into a vein at regular hospital visits. During treatment, your care team will monitor your health closely through blood tests, heart checks (ECGs), and regular CT or MRI scans to see how your body and the cancer are responding. After your course of treatment ends, you will enter a follow-up period with scheduled check-ups so doctors can continue tracking your health.

Potential risks and benefits

Taking part gives you the chance to receive a newer immunotherapy treatment earlier than usual, alongside very close monitoring by specialist cancer doctors. However, as with any clinical trial, there is no guarantee that your cancer will improve. Both dostarlimab and chemotherapy can cause side effects ranging from mild tiredness to more serious immune reactions or infections. You may also experience minor discomfort or bruising from blood tests and drips. Your doctor will discuss all known side effects with you, and you can leave the study at any point without it affecting your standard NHS care.

Locations (10)

Velindre Cancer Centre
Approximate
Cardiff, Wales
Royal Cornwall Hospital (treliske)
City only
Truro, England
St James University Hospital
Approximate
Leeds, England
Western General Hospital
City only
Lothian, Scotland
Addenbrookes
Approximate
Cambridge, England
Queen Elizabeth Hospital
Unverified
Birmingham, England
Guys Hospital
Unverified
London, England
University College Hospital Macmillan Cancer Centre
Unverified
London, England
Northampton
Unverified
Northampton, England
United Lincolnshire Hospitals NHS Trust
Unverified
Lincoln, England

Common questions

What is dostarlimab?

Dostarlimab is an immunotherapy medicine given through a drip. It works by boosting your body's immune system to help it recognise and attack cancer cells.

Can I choose which treatment I receive?

No. A computer randomly decides whether you receive dostarlimab or standard chemotherapy. This ensures the study results are fair and scientifically accurate.

Will taking part cost me anything?

No. The trial medication, extra tests, and study appointments are provided free of charge through the clinical trial programme.

What happens if I decide to leave the trial?

You are free to leave the trial at any time. Your decision will not affect the quality of your medical care or your relationship with your doctor.

Will I need an extra biopsy to check if I can join?

In most cases, doctors can test a sample of tumour tissue that was already collected during a previous procedure, so an extra biopsy is usually not needed.

How to find out more

Joanna Canham

DOMENICA@cardiff.ac.uk - Official trial record

Always speak to your GP or specialist before deciding to take part in a study.