A trial of vistusertib and paclitaxel for ovarian cancer that has come back (OCTOPUS)

Cancer type:

Ovarian cancer

Status:

Results

Phase:

Phase 2

This trial looked at adding a drug called vistusertib to paclitaxel chemotherapy for ovarian cancer that had come back.

It was for women who had ovarian cancer, primary peritoneal cancer or fallopian tube cancer. These cancers are treated in a similar way. When we use the term ovarian cancer in this summary, we are referring to all 3.

You pronounce vistusertib as vis-too-sir-tib.

Cancer Research UK supported this trial. It was open for people to join between 2015 and 2018. The team published the results in 2023.

More about this trial

When this trial was done, surgery followed by chemotherapy was a usual treatment for:

The chemotherapy often included a platinum drug Open a glossary item such as carboplatin. If the cancer got worse within 6 months of having this treatment, it is called platinum resistant cancer. At the time of this trial, the next treatment offered was a taxane chemotherapy drug called paclitaxel. Sometimes the cancer starts to grow again. So researchers were looking at ways to delay this.

In this trial, they looked at a drug called vistusertib. It was a new drug at the time of the trial. It is a type of targeted cancer drug called a cancer growth blocker. It works by blocking the action of a protein called mTOR. This stops signals that cancer cells use to divide and grow.

This was a randomised trial. The women who took part had one of the following:

weekly paclitaxel and vistusertib
weekly paclitaxel and a dummy drug (placebo )

The main aims of this phase 2 trial were to find out:

if adding vistusertib to paclitaxel is a useful treatment for ovarian cancer
more about the side effects
how treatment affects quality of life

Summary of results

A total of 140 women joined this trial:

70 had paclitaxel and vistusertib
70 had paclitaxel and a dummy drug (placebo )

The trial team looked at:

how long before the cancer started to grow again
how long people lived
how well the treatment worked

They didn’t find a difference between the 2 groups in any of these.

Side effects
Most women who took part in this trial had at least 1 side effect. Most were mild or didn’t last long. But some women had side effects that were more severe.

The team looked at the number of women who had more severe side effects. They found it was:

29 women (41%) in the paclitaxel and vistusertib group
26 women (37%) in the paclitaxel and dummy drug group

The most common severe side effects for both groups included:

an increased risk of infection
tiredness (fatigue)

More women in the paclitaxel and vistusertib group had these side effects.

Women who had paclitaxel and vistusertib also had mild to moderate problems with:

stomach acid traveling up to the throat (reflux)
a skin rash

No one in the paclitaxel and dummy drug group had these problems.

Quality of life
The trial team looked at how treatment affected quality of life. They didn’t find a difference in this between the 2 different groups.

Conclusion
The trial team found that adding vistusertib to paclitaxel didn’t improve treatment for ovarian cancer.

The team say that biomarkers Open a glossary item that predict who vistusertib could work best for should be looked at in more detail. The team found that low levels of a potential biomarker called PTEN was linked with how long before the cancer started to grow again. This was for people who had paclitaxel and vistusertib. The team say this should be looked at in separate studies using similar drugs.

Sometimes trials show a different treatment isn’t useful for a particular type or stage Open a glossary item 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.

Efficacy and Safety of Weekly Paclitaxel Plus Vistusertib vs Paclitaxel Alone in Patients With Platinum-Resistant Ovarian High-Grade Serous Carcinoma
The OCTOPUS Multicenter, Phase 2, Randomized Clinical Trial
S Banerjee and others
The Journal of the American Medical Association, 2023. Volume 9, issue 5, pages 675 – 682.

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 Open a glossary item ) 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.