A trial looking at docetaxel, zoledronic acid and strontium 89 for prostate cancer that has spread to the bones (Trapeze trial)

The team found strontium 89 with docetaxel increased the amount of time that people lived free of symptoms of bone spread. Zoledronic acid and docetaxel increased the length of time before new bone problems occurred. 

This was a phase 3 trial. 757 men took part in this randomised trial. They were put into 1 of 4 groups by a computer. Neither they nor their doctor chose which group they were in. 

The groups were:

• 191 men had docetaxel
• 188 men had docetaxel and zoledronic acid
• 190 men had docetaxel and strontium 89
• 188 men had docetaxel, zoledronic acid and strontium 89

The team found that strontium 89 had a moderate effect of increasing the amount of time the men lived without any clinical signs of the cancer in their bones getting worse. 

The average delay for new symptoms to appear was about a month. Strontium 89 had no effect on the total number of bone problems experienced by men in the trial.

Zoledronic acid significantly delayed the amount of time before men presented with a new bone problem due to their prostate cancer. The delay was around 2½ months. 

The total number of unpleasant bone complications were reduced by about a third in men who had zoledronic acid. These include:

• the need for radiotherapy to relieve bone pain
• bone fractures
• surgery for bone problems 

Neither strontium 89 or zoledronic acid increased the length of time the men lived after treatment. 

The side effects were the same in each treatment group. The worst side effects reported were mainly due to the chemotherapy and were:

• a drop in red blood cells and white blood cells
• high temperature (fever) and a drop in a type of white blood cells called neutrophils  (febrile neutropenia) 

In addition, many men in the trial reported bone pain and tiredness but these were due to the cancer itself and not the treatments.

The team also found that adding strontium 89 or zoledronic acid to chemotherapy increased the cost of treatment initially. But in the long term it was a cost saving measure because the men were healthier for longer. And in particular needed fewer treatments such as radiotherapy or surgery for bone complications of cancer.

The team concluded that giving strontium 89 with docetaxel increased the amount of time men lived free of their bone spread getting worse. But because similar treatments worked better the team felt these results couldn’t support the widespread use of strontium 89.  

In comparison as zoledronic acid reduces bone problems caused by advanced prostate cancer it should still have an important role in treatment. 

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 journals. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.