Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.
A trial looking at the drug GSAO in people with advanced cancer (PH1 109)
This trial was done to see what happened to a drug called GSAO in the body. This trial was supported by Cancer Research UK.
Cancers need a blood supply to be able to grow. Research in the laboratory had shown that GSAO could help stop the growth of blood vessels (anti angiogenesis) in cancers. Researchers hoped that it would help stop angiogenesis and slow down or stop the growth of cancer in people.
The aims of this trial were to find out
- The best dose of GSAO to give
- The effect GSAO has on the body
- About side effects of GSAO
- How GSAO affects cancer cells
Summary of results
The research team found that GSAO didn’t cause too many side effects, and they found safe doses to use.
Everyone taking part had GSAO though a drip into a vein 5 days a week, for 2 weeks out of every 3.
The first people taking part had the lowest dose of GSAO. As they didn’t have any serious side effects, the next few people had a higher dose. And so on, until they found the best dose to give. This is called a dose escalation trial.
The trial team found that the most serious side effects were a change in how the liver works, a fast heart beat (tachycardia) and inflammation of the brain (encephalopathy). These side effects were rare, and they went away when treatment stopped.
The most common side effects were
- Tiredness (fatigue)
- Constipation and diarrhoea
- Feeling or being sick
- A drop in red and white blood cells
- Changes to heart rhythm
The research team looked at a number of things in blood samples they took from people taking part in the trial. They found that
- The amount of GSAO in the blood was low, but it was higher with the higher doses
- GSAO didn’t seem to have an effect on some of the markers in the blood which are used to measure the formation of blood vessels
- GSAO didn’t seem to have an effect on some of the markers in the blood which are used to suggest cancer cells are dying
The research team were able to assess how 19 people’s cancer responded to treatment. They found that the cancer
- Stayed the same in 8 out of 19 people
- Continued to grow in 11 out of 19 people
The research team also used a scan called a DCE-MRI scan to look at how blood flow in cancers changed with different doses of GSAO. They found that the different doses of GSAO didn’t seem to affect the blood flow.
The trial team concluded that they had found the best doses to use. And that GSAO did have some side effects, but it is safe to look at in other trials. At the time this trial was completed, a new treatment based on GSAO (called PENAO) was being developed in Australia.
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 (
How to join a clinical trial
Professor Gordon Jayson
Cancer Research UK (Centre for Drug Development)
Experimental Cancer Medicine Centre (ECMC)
This is Cancer Research UK trial number CRUKD/08/041.