“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”
A trial of ribociclib alongside letrozole for advanced breast cancer (MONALEESA 2)
This trial was for women whose breast cancer had come back in the same place or had spread to another part of the body (advanced breast cancer).
Their cancer also had to be:
- hormone receptor positive
- HER2 negative
Hormone receptor positive means that breast cancer cells have
More about this trial
Hormone therapy is often used to treat hormone receptor positive breast cancer. Letrozole (Femara) is one type of hormone therapy. Doctors use it as a treatment for breast cancer in women who are
Ribociclib (LEE011) is a type of targeted cancer drug called a cancer growth blocker. It stops signals that cancer cells use to divide and grow.
The researchers wanted to find out if ribociclib alongside letrozole helps women with advanced breast cancer. In this trial, women had 1 of the following:
- ribociclib and letrozole
- dummy drug (
placebo) and letrozole
The aims of this trial were to:
- find out how well ribociclib and letrozole work as a treatment
- learn more about the side effects
- find out how this treatment affects the women’s
quality of life
Summary of results
The trial team concluded that ribociclib alongside letrozole helps women with advanced breast cancer.
This was a phase 3 trial. 668 women with advanced breast cancer took part. Everyone had hormone receptor positive breast cancer and HER2 negative breast cancer.
This was a randomised trial. Women were put into 1 of the following treatment groups by computer:
- 334 women had ribociclib and letrozole
- 334 women had a dummy drug and letrozole
Neither they nor their doctor could choose which group they were in.
Everyone had treatment for as long as their cancer stayed the same and didn’t get worse. When their cancer got worse (
Some people were still having treatment at the time the study team looked at the results. So, the team looked at how well ribociclib worked for all women after 18 months of treatment.
To do this, doctors looked at the number of women who had no signs of their cancer getting worse after 18 months of treatment. This is called progression free survival. They found it was:
- around 6 out of every 10 women (63%) in the ribociclib and letrozole group
- around 4 out of every 10 women (42%) in the dummy drug and letrozole group
The team also looked at the most common side effects women had. They were:
- a drop in the number of white blood cells causing an increased risk of infection (neutropenia)
- feeling sick
The team found that women in the ribociclib and letrozole group had worse side effects than women in the dummy drug and letrozole group.
So, the trial team concluded that ribociclib alongside letrozole helps women with advanced breast cancer. They will continue to look at the results until all women finish their treatment.
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (
How to join a clinical trial
Professor David Cameron
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer