A trial looking at immunotherapy and combretastatin for advanced bowel and pancreatic cancer (A5B7-CA4P PH1/092)

Cancer type:

Bowel (colorectal) cancer

Pancreatic cancer

Status:

Results

Phase:

Phase 1

This trial was looking at combination of I-A5B7 and combretastatin (CA4P) for advanced bowel cancer and pancreatic cancer. This trial was supported by Cancer Research UK.

A5B7 is a type of biological therapy called a monoclonal antibody. Monoclonal antibodies target specific cells, and A5B7 targets cells that produce CEA Open a glossary item . This is a chemical produced by some cancer cells.

In this trial, the A5B7 had radioactive iodine attached to it, so it is called I-A5B7. The idea is that the radioactive iodine kills the cancer cells.

Combretastatin damages the blood vessels in the cancer. So it blocks the cancer’s blood supply and hopefully stops the cancer growing.

The aims of this trial were to find out

What effect I-A5B7 and combretastatin had on blood flow to the cancer
The best dose to give
More about the side effects
If I-A5B7 and combretastatin may be a useful treatment for cancer

Summary of results

This trial showed that the combination of I-A5B7 and combretastatin did change blood flow to the cancer. But even at low doses it caused serious side effects.

This trial was designed as a dose escalation study. That means that the first few people taking part have the lowest dose. The next few people have a higher dose. And so on, until the trial team find the best dose to give. But the people having the lowest dose had serious side effects, so the research team didn’t give anyone a higher dose.

The trial recruited 12 patients. Two people completed 1 cycle of treatment. But 10 people stopped treatment during the first cycle. This was usually because their cancer continued to grow and they were too unwell to have treatment.

The trial team looked at the scan results for 10 of the people who took part. They showed the cancer had stayed the same in 3 people (this is called ‘stable disease’). And it had continued to grow in 7 people.

The most common side effects were

A drop in blood cells causing an increased risk of infection, bleeding problems, tiredness and shortness of breath
Mild allergic reaction
Fast or slow pulse rate
High or low blood pressure

The research team concluded that the combination of A5B7 and combretastatin did change the flow of blood to cancer. But they had been unable to find the best dose to give because of the side effects of even a low dose. They recommended that it would be best to look at different combinations of treatments in future trials.

We have based this summary on information from the team who ran the trial. As far as we are aware, the information they sent us has not been reviewed independently (peer reviewed Open a glossary item ) or published in a medical journal yet. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.