A study looking at immunotherapy before usual treatment for newly diagnosed breast cancer (ECLIPSE Study)

Cancer type:

Breast cancer




Phase 2
This study is looking at whether immunotherapy in combination with targeted drugs can improve treatment for breast cancer. 
It is for people whose cancer is HER2 negative and oestrogen (ER) positive. This means the breast cancer cells:
  • don’t have receptors for HER2 Open a glossary item 
  • do have receptors for oestrogen Open a glossary item  

More about this trial

The level of immune cells in the area around a tumour shows the immune system’s Open a glossary item ability to find and fight cancer. Tumours that have a high level of immune cells around them are called inflamed type tumours. Tumours that have low levels of immune cells around them are called non inflamed type tumours. 
Immunotherapy uses the immune system Open a glossary item to fight cancer. We know from research that having one immunotherapy drug works better in inflamed tumours than in non inflamed tumours. 
We also know that most breast cancers that are ER positive are non inflamed.  So, having a single immunotherapy drug doesn’t work very well. 
Researchers want to improve treatment for people with ER positive breast cancer. They think that having an immunotherapy drug in combination with targeted drugs might help. They hope this will switch the tumours from non inflamed to inflamed tumours. And increase the chances of an immune response. 
In this study, researchers are trying to work out which combination of drugs works best to do this. They are looking at different combinations that include the following drugs:
  • atezolizumab 
  • cobimetinib
  • ipatasertib
  • bevacizumab
Atezolizumab is an immunotherapy drug. It blocks a protein called PD-L1 on the surface on cancer cells. This helps the immune system to find and kill cancer cells.
Cobimetinib, ipatasertib and bevacizumab are all targeted drugs called cancer growth blockers. They work in slightly different ways to stop signals that cancer cells use to divide and grow. 
In this study, everyone has atezolizumab. And some people have it in combination with other targeted drugs. 
The main aims of the study are to:
  • find out which combination of treatment works best to produce an immune response
  • learn more about the side effects

Who can enter

The following bullet points list the entry conditions for this study. Talk to your doctor or the study team if you are unsure about any of these. They will be able to advise you. 
Who can take part
You may be able to join this study if all of the following apply. 
  • have breast cancer that your surgeon can remove with an operation 
  • have breast cancer that is bigger than 1 cm across
  • have oestrogen positive receptor Open a glossary itembreast cancer  
  • have HER 2 negative Open a glossary itembreast cancer  
  • have tumour samples available for the study team to do some tests on
  • are well enough to carry out all your normal activities, apart from heavy physical work (performance status 0 or 1
  • have satisfactory blood test results  
  • are willing to use reliable contraception for 14 days before treatment, during treatment and for 6 months afterwards if there is any chance you or your partner could become pregnant 
  • are at least 18 years old 
Who can’t take part
You cannot join this study if any of these apply. 
Cancer related
  • have a type of breast cancer called inflammatory breast cancer  
  • have had treatment with an immunotherapy drug within 28 days of joining the study or it hasn’t cleared your body properly yet
  • have already had atezolizumab, cobimetinib, ipatasertib or bevacizumab or similar drugs in the past
  • are having treatment with an experimental drug or taking part in another clinical trial
  • have already had treatment for this diagnosis of breast cancer (you can take part if you had treatment for a previous breast cancer or any another cancer as long as you had treatment more than 1 year ago)
  • have had any other cancer in the last 5 years apart from carcinoma insitu (CIS Open a glossary item) of the cervix, non melanoma skin cancer Open a glossary item, or DCIS Open a glossary item of the breast that has been successfully treated
Medical conditions
  • have had steroid tablets or steroid treatment as a drip into a vein in the 14 days before joining the study 
  • have an autoimmune condition Open a glossary item such as rheumatoid arthritis or lupus
  • have a lung condition called pulmonary fibrosis
  • have an active tuberculosis infection
  • have had a stem cell transplant with someone else’s cells (allogeneic stem cell transplant Open a glossary item) or an organ transplant 
  • have had surgery in the last 4 weeks or you have surgery planned for a condition other than breast cancer
  • have had a severe infection in the 28 days before joining the study
  • have a heart problem such as congestive heart failure or a heart attack in the 3 months before joining the study
  • have a bleeding problem 
  • are using hormone replacement therapy Open a glossary item (you might be able to join if your doctors thinks it’s ok to stop taking it)
  • have HIV 
  • have an active hepatitis B or hepatitis C infection
  • have had a live vaccination Open a glossary item within 28 days of starting treatment study treatment or plan to have one within 5 months after the last dose of atezolizumab
  • are sensitive to any of the drugs in the study
  • are pregnant or breastfeeding
As well as the above, there are a few separate entry conditions for: 
  • atezolizumab and cobimetinib
  • atezolizumab and ipatasertib
  • atezolizumab, cobimetinib and bevacizumab
The study team will check these to see if you are suitable to have combination treatment. 

Trial design

This phase 2 study is taking place worldwide. The researchers need 160 people to take part including about 40 from the UK.
It is a randomised study. You are put into treatment groups by a computer. Neither you nor your doctor will be able to decide which group you are in. 
You have 1 of the following:
  • atezolizumab only 
  • atezolizumab and cobimetinib
  • atezolizumab and ipatasertib
  • atezolizumab, cobimetinib and bevacizumab

In each treatment group, you have 1 cycle of treatment. This cycle of treatment is 3 weeks. The first day of the treatment cycle is called day 1.
You then have the usual (standard) treatment Open a glossary item for breast cancer. For example, surgery. Or chemotherapy or hormone therapy (neoadjuvant treatment) followed by surgery. The study doctor can tell you more about this. 
From diagnosis to treatment, it is usual to wait about 3 to 4 weeks. Every effort will be made to fit this trial within this window, however, it is possible that joining this study might delay treatment by 1 to 2 weeks. Your doctor will tell you more about this. 
Atezolizumab only
You have atezolizumab as a drip into a vein. You will have a single infusion on day 1. It takes about an hour.
Atezolizumab and cobimetinib
You have atezolizumab as a drip into a vein. You will have a single infusion on day 1
Cobimetinib is a tablet. You take it once a day, everyday for 21 days. 
Atezolizumab and ipatasertib
You have atezolizumab as a drip into a vein. You will have a single infusion on day 1. 
Ipatasertib is a tablet. You take them once a day, every day for 21 days. 
Atezolizumab, cobimetinib and bevacizumab
You have atezolizumab and bevacizumab as a drip into a vein. You will have a single infusion on day 1. This takes about 2 ½ hours. 
Cobimetinib is a tablet. You take it once a day, every day for 21 days. 
Samples for research
You give some extra blood samples during treatment. You give the samples at specific times and the study team will give you more information about this. They plan to use the samples to:
  • see how well the treatment is working
  • find out what happens to the drugs in the body
  • look for biomarkers Open a glossary item to predict who will benefit from treatment
The research team take tumour samples (a biopsy Open a glossary item):
  • before treatment starts 
  • at the end of 3 weeks
This is so they can examine the samples to see how well the different treatments worked.
The doctors will ask you to collect poo samples. They will use these to look at the microbiome in your gut. This is your normal gut flora. They think that looking at this will help work out why some people respond better to treatments than others. The study team will give you a special kit to collect the samples at home. 
You don’t have to agree to give the poo samples if you don’t want to. You can still take part in the main study. 

Hospital visits

You see a doctor and have some tests before you can take part. These include:
  • physical examination
  • blood tests
  • urine tests
You have atezolizumab and bevacizumab in the hospital outpatient department. You take the cobimetinib and ipatasertib tablets at home. 
The study team will give you a diary. They’ll ask you to write in when you take your tablets each day. 
You have a check up:
  • after the 3 week treatment period 
  • at 3 months 

Side effects

As these are new combinations of drugs, there may be some side effects we don’t know about yet. The study team will monitor you during the time you have treatment and you’ll have a phone number to call if you are worried about anything. 
The most common side effects of atezolizumab are:
This treatment affects the immune system. This may cause inflammation in different parts of the body which can cause serious side effects. They could happen during treatment, or some months after treatment has finished. In some people, these side effects could be life threatening.
The most common side effects of cobimetinib are:
  • drop in the number of red blood cells (anaemia)
  • an increased risk of bleeding
  • blurred vision
  • diarrhoea
  • feeling or being sick 
  • fever and chills
  • skin rash 
  • liver changes
  • a build up of fluid under the eye
  • thickening of skin
  • high blood pressure
The most common side effects of ipatasertib are:
  • diarrhoea
  • feeling or being sick 
  • skin rash 
  • high levels of sugar in the blood
The most common side effects of bevacizumab are:
  • high blood pressure 
  • numbness or tingling in hands or feet 
  • an increased risk of infection
  • an increased risk of bleeding 
  • feeling weak and having no energy 
  • tiredness 
  • diarrhoea
  • feeling or being sick 
  • tummy (abdominal) pain
The study doctor will explain all the possible side effects before you join the study. 



Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Prof Peter Schmid

Supported by

Queen Mary University of London
F. Hoffmann-La Roche Ltd

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Harriet wanted to try new treatments

Picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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