A trial looking at olaparib with chemotherapy for early breast cancer (PARTNER)

This trial showed that olaparib and chemotherapy before surgery did not work better than chemotherapy alone. This was for people with triple negative breast cancer. 

Results

The team wanted to recruit enough people with triple negative breast cancer, or BRCA gene changes, so they could test whether olaparib and chemotherapy before surgery worked better in each of these groups. 

For the group with:

• triple negative breast cancer, they recruited all the people needed 
• BRCA gene changes, they recruited enough people to help them with the first steps in testing the treatment

A total of 559 people took part in the trial. A computer put people into 1 of 2 groups at random. There were:

• 287 in the paclitaxel, carboplatin and olaparib group (research group)
• 272 in the paclitaxel and carboplatin group (control group )

The researchers were able to analyse the results for most people who took part in 2023. They looked at 543 people who’d had treatment and who were going on to have surgery.

They looked at how many people had no signs of cancer after the above treatment before having surgery. They found it was similar in the two groups:

• 141 out of 276 people (51%) in the research group
• 140 out of 267 people (52%) in the control group

They also looked at how many people’s cancer came back 3 years after they joined the trial. They found this was also similar in each group: 

• 80 out of every 100 people (80%) in the research group
• 79 out of every 100 people (79%) in the control group

The researchers looked at the percentage of people who were living at 3 years. They found it was high and similar in both groups: 

• 90 out of every 100 people (90%) in the research group
• 87 out of every 100 people (87%) in the control group

Quality of life
The researchers also looked at the quality of life of people taking part. They asked people to complete questionnaires at regular times during treatment. These asked how people were feeling and about any problems they were having.

They found that the quality of life was: 

• slightly better for the control group throughout the trial
• significantly worse for people in the research group at 3 months when they looked at physical, functional, social, and emotional wellbeing 
• lower for both groups at 4 and 6 months

Side effects
Everyone in the research group and most people (99%) in the control group had at least one side effect from treatment. But many were mild or didn’t last long. 
Some people had more severe side effects. This was:

• 181 people (64%) in the research group
• 158 people (59%) in the control group

The most common of the more severe side effects were:

• a drop in white blood cells (neutrophils) causing an increased risk of infection (neutropenia)
• a drop in red blood cells causing shortness of breath and tiredness
• a drop in blood clotting cells (platelets) causing bruising or bleeding problems
• extreme tiredness (fatigue)

These side effects were not permanent. They got better.

More people in the research group had:

• a drop in blood cells
• high blood pressure
• diarrhoea
• an increase in an enzyme in the blood called alanine aminotransferase
• blood clots
• nausea (feeling sick)
• numbness and pins and needles
• low levels of magnesium

More people in the control group had:

• extreme tiredness (fatigue)
• a sore mouth and ulcers
• fainting
• a serious complication of an infection that can be life threatening (sepsis)
• vomiting (being sick)
• infections, including sinus, throat or lung infections
• joint and muscle pain

A number of people stopped treatment when the side effects of treatment became too severe. This was:

• 21 people (7%) in the research group
• 22 people (8%) in the control group

We have more information about the side effects of carboplatin, paclitaxel and olaparib in our Cancer drugs section.

Conclusion
The trial team concluded that olaparib and chemotherapy before surgery for triple negative breast cancer was not better than chemotherapy alone.

But the team are looking into whether this treatment might be helpful for people with certain types of triple negative breast cancer.

The trial team will publish results to show if olaparib helps neoadjuvant chemotherapy for breast cancer with a change in the BRCA gene work better. We plan to update this page when more results are available.

Sometimes trials show a different treatment isn’t useful for a particular type or stage  of cancer. But these trials still add to our knowledge and understanding of cancer and how to treat it.

More detailed information
There is more information about this research in the reference below. 

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

The PARTNER trial of neoadjuvant olaparib with chemotherapy in triple-negative breast cancer
J Abraham and others
Nature, 2024. Volume 629, issue 8014, pages 1142-1148

Where this information comes from    
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.