A study to find out more about cabazitaxel for prostate cancer that has spread and is no longer responding to hormone therapy (GenCab)

Cancer type:

Prostate cancer

Status:

Results

Phase:

Other

This study was done to find out more about how cabazitaxel works for men whose prostate cancer has spread and is no longer responding to hormone therapy.

More about this trial

Doctors can use hormone therapy or a chemotherapy drug called docetaxel to treat prostate cancer that has spread. When this trial started they could then use a chemotherapy drug called cabazitaxel (Jevtana) if the cancer continued to grow.

We already knew from research that cabazitaxel could help men who have already been treated with hormone therapy and docetaxel. But it works better for some men than others.

In this study, researchers took blood samples and samples of prostate tissue (biopsies) from men who were having cabazitaxel. The aim of the study was to look at the genes in the cells and find out more about how cabazitaxel works.

Summary of results

The research team found that there is a change in how some genes work after treatment with cabazitaxel.

Results

They had hoped to recruit about 30 men with prostate cancer, but had to close this study earlier than planned. This is because cabazitaxel became temporarily unavailable as a treatment on the NHS part way through.

They were able to get blood and tissue samples from 3 men, and did some analysis on the samples they had.

They looked at the prostate samples, and at the genes within the cancer cells. They compared samples before and after cabazitaxel treatment.

They found that there were areas of cancer and areas that were not cancerous (benign) in the prostate biopsies. So it is important that prostate biopsies are fully analysed.

Genes are codes inside our cells, and each gene tells the cell to make a specific protein. If a gene is more active, the cell produces more of that particular protein. Each cell has many thousands of genes, some are more active than others.

The research team had already identified 5 genes associated with prostate cancer that has come back after hormone therapy. This is called a 5 gene signature.

They looked at how active these 5 genes were in the men taking part. They compared the cells before and after treatment, and found that the activity of the:

PSA gene went down in all 3 men
AR gene went down in 2 men and up in 1 man
AR-V7 gene went down in 1 man and up in 2 men
beta-tubulin III gene went down in 2 men and up in 1 man
AKT1 gene went down in 1 man, up in 1 man and stayed the same in 1 man

Conclusion

It is hard to draw firm conclusions because this was a small study. But the research team found that after cabazitaxel, certain genes can become more active in some men and less active in other men. This may help explain why it works better for some men than others.

They suggest that finding out more about genetic changes will help develop a way of deciding which treatment is best, depending on people’s genes.

We have based this summary on information from the research team. As far as we are aware, the information they sent us has not been reviewed independently (peer reviewed Open a glossary item