The trial team found that orteronel might be a useful treatment for advanced prostate cancer following docetaxel chemotherapy.
This trial was stopped early because 2 other phase 3 trials at the time did not find orteronel useful. This meant that the researchers were not able to recruit as many men as they hoped into this trial.
The trial team think that having a hormonal therapy like orteronel soon after chemotherapy (switch maintenance therapy) is a good idea. And they recommend more research into it.
This phase 3 trial recruited 47 men in the UK and Switzerland. It was randomised. The men taking part were put into one of 2 groups by a computer. Neither they nor their doctor could decide, or knew, which group they were in. This is called a double blind trial.
- 23 men take orteronel tablets
- 24 men took a dummy drug (placebo)
The results of this trial were published in 2016, about 2 ½ years after the trial closed to recruitment
Event free survival
The trial team looked at the length of time that men were free of certain events. This is called event free survival (or EFS). In this trial, an event was defined as one of the following:
- death from any cause
- the cancer has got worse shown by scan results and certain symptoms
- the cancer had got worse shown by scan results and the level of PSA in the blood
- the cancer had got worse shown by certain symptoms and the level of PSA
The doctors followed the men’s PSA levels and decided whether this was significant. Whether it was significant depended on how much the PSA level fell following treatment with orteronel and any increase after that.
On average they found that event free survival was:
- 8 ½ months for men who had orteronel
- just under 3 months for men who had a dummy tablet
So, in this trial the men who had orteronel had stable disease for longer compared to those men who had a dummy tablet.
Reasons for stopping treatment
The average time that men had treatment for was:
- just over 5 months in the orteronel group
- just under 3 months in the group taking a dummy tablet
The main reasons for stopping treatment included:
- the prostate cancer started to grow again
- the patient decided to stop treatment
- side effects were too severe or difficult to cope with
The prostate cancer started to grow again in 14 men who had orteronel and 20 men who had the placebo. 3 men from each group decided to stop treatment for various reasons.
3 men in the orteronel group stopped treatment because of their side effects. Nobody in the placebo group stopped treatment for this reason.
37 out of the 47 men taking part went on to have further treatment once they finished treatment with orteronel. This included:
- 18 men from the orteronel group
- 19 men from the placebo group
At the time of collecting the results:
- 6 men in the orteronel group were alive
- 8 men in the placebo group were alive
Information about 3 of the men could not be recorded. 14 men in the orteronel group and 11 men in the placebo group had died. The cause of death for most of the men was thought to be their prostate cancer.
The side effects that men taking orteronel had were mainly mild. One man taking orteronel developed pneumonitis (inflammation of the lungs). He recovered following treatment for this. The trial team think this was probably due to orteronel.
The researchers could not draw any firm conclusions about men’s quality of life in this trial. This was because only a small number of men completed the quality of life questionnaires. And the number of men who did this became less as the trial continued.
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed
) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.