A trial of Alpharadin for prostate cancer that has spread to the bones and is no longer responding to hormone therapy

Cancer type:

Prostate cancer

Status:

Results

Phase:

Phase 2

This trial was looking at Alpharadin (also known as radium 223) for men with prostate cancer that had spread to their bones and was causing pain. The trial was for men whose cancer was no longer responding to hormone therapy.

Doctors often treat prostate cancer with hormone therapy. Sometimes the hormones can stop working and the cancer can spread to the bones. Cancer that has spread to the bones can cause bone pain.

To control the pain, doctors often start with painkillers. If these do not control the pain, they may use radiotherapy as well. You can have internal radiotherapy to treat the cancer cells causing pain in the bone. This uses radioactive isotopes. These are radioactive substances that target cancer in the bones and give off high energy.

Alpharadin is a new type of radioactive injection that gives off a different type of high energy to other radioisotopes. The aims of this trial were to

Find out if Alpharadin helped men with prostate cancer that had spread to the bones
Learn more about the side effects

Summary of results

The researchers found that Alpharadin may help men who have prostate cancer that is no longer responding to hormone therapy, and that it did not cause bad side effects.

The trial recruited 64 men in the UK, Norway and Sweden. The researchers planned to give half the men 4 injections of radium 223 and the other half 4 dummy injections (placebos Open a glossary item ).

All the men taking part also had external radiotherapy to the most painful areas of their bones before entering the study.

Everybody taking part had at least 1 injection. But the number of men who had all 4 injections was

28 of 33 in the group having Alpharadin
21 of 31 in the group having dummy injections

The reasons men stopped having injections in both groups included their cancer getting worse, having heart problems or being confused. And 4 men in the dummy injection group chose not to complete the treatment.

The trial team looked at how many men had bone problems such as

Pain getting a lot worse
Needing more painkillers
Bones breaking
Needing other treatment for bone pain

They found that 4 weeks after the last injection, there had been slightly fewer of these problems in the men having radium 223.

The researchers also did blood tests to measure a protein called bone-alkaline phosphatase. Bone-ALP is made by bone cells and measures bone cell activity. If you have cancer in the bones, the level of bone cell activity may be higher than normal, so the level of bone-ALP in the blood goes up. They found that the level of bone-ALP went down in men who had the Alpharadin injections.

On average, men who received Alpharadin lived longer than men who received the dummy injections (placebos).

The side effects were similar for men in both groups. Constipation was a problem for more men who had Alpharadin, but the men having the dummy injections had more bone pain.

The researchers point out that this trial may not have been big enough to show whether or not Alpharadin really helped. As Alpharadin did have an effect on bone activity and didn’t cause bad side effects, this treatment will be looked at in further clinical trials. A phase 3 trial looking into radium 223 (Alpharadin) has now started.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item ) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.