A trial of vistusertib with paclitaxel for solid tumours (TAX-TORC)

The research team found the best dose to give and concluded that vistusertib and paclitaxel could be a useful treatment.

 

This trial was open for people to join between 2013 and 2016. The research team reported the results in 2018.

 

To begin with they recruited 22 people with advanced cancer. Everyone had paclitaxel through a drip into a vein once a week. They had vistusertib tablets for either 2 days or 3 days each week, for 6 weeks out of 7. Each 7 week period is one cycle of treatment.

 

The first few people who took part had the lowest dose of vistusertib. As they didn’t have any serious side effects, the next few people had a higher dose. And so on, until they found the best dose to give. This is called a phase 1 dose escalation study.

 

The most common side effects for people who had vistusertib 3 times a week were extreme tiredness (fatigue), a drop in red blood cells and diarrhoea. 

 

The most common side effects for people who had vistusertib twice a week were feeling sick, fatigue and tingling in hands and feet (peripheral neuropathy).

 

The research team decided it would be best to use a lower dose for both groups.

 

People who took part after this all had same dose of vistusertib. This is called the dose expansion phase of the trial. Of the people who had treatment:

The research team were able to assess how well treatment had worked for 21 people who had ovarian cancer. They found that it went away in 1 person and got smaller in 11 people. This means that 12 people’s cancer (57%) responded to treatment. 

 

It was just over 6 months before the cancer started to grow again. 

 

They also measured a protein called CA125 in blood samples. A drop in the level of CA125 can mean that the cancer is responding to treatment. They found that CA125 was lower after treatment in 15 out of 21 people (71%).

 

It is difficult to draw any firm conclusions from a small trial. But these results are promising compared to other trials which have looked at paclitaxel alone and some other treatments.

 

Some of the first few people who took part had some severe side effects, including fatigue and diarrhoea. And more people than expected had a lung infection. The research team reviewed the information and decided the remaining people taking part should have a lower dose of vistusertib. 

 

The research team were able to assess how well treatment had worked for 29 people who had lung cancer. The cancer:

It was just under 5 months before the cancer started to grow again. 

 

These results are better than for some other treatments for lung cancer.

 

The research team concluded that, at the right dose, the combination of paclitaxel and vistusertib didn’t cause too many side effects. And that it could be a useful treatment in the future. They suggest it is looked at in further trials to find out more about how well it works.

 

We have based this summary on information from the research team. Some of the information they sent us has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. Some of the information we quote is from the published paper, and some is from additional information which has not been published. We have not analysed the data ourselves.