A study looking at ADI PEG 20 to treat small cell lung cancer

Cancer type:

Lung cancer
Small cell lung cancer




Phase 2

This study looked at ADI PEG 20 for a type of lung cancer called small cell lung cancer (SCLC).

More about this trial

Doctors can treat small cell lung cancer with chemotherapy. Unfortunately sometimes the cancer can continue to grow during treatment or come back afterwards. When this happens it is more difficult to treat.
Researchers had found a new way of destroying small cell lung cancer cells in the laboratory, by removing an amino acid Open a glossary item called arginine. Arginine helps with many different jobs in the body, including the growth of cells.
Our bodies can usually make arginine using a protein (a particular enzyme) Open a glossary item. But this enzyme is often missing in small cell lung cancer cells. So if you remove arginine from the cancer cells, they will not be able to replace it. 
When this trial was done, ADI PEG 20 was a new treatment that had been shown to remove arginine from cells. The researchers hoped that this treatment would help stop lung cancer cells growing.
The aims of this study were to find out:
  • how well ADI PEG 20 works for small cell lung cancer
  • how safe it is

Summary of results

This trial showed that ADI PEG 20 did not help stop small cell lung cancer (SCLC) cells growing.
The research team recruited a total of 22 people into this trial. They were:
  • 9 people who’d already had treatment for their SCLC that had worked
  • 13 people who’d already had treatment for their SCLC that had not worked
Everyone taking part had an injection of ADI PEG 20 into a muscle, once a week for 4 weeks, and then a week with no treatment. The people taking part had between 1 and 16 injections, depending on how well they were.
When the trial team looked to see how well the treatment had worked, they found that the cancer had not got smaller in any of the people taking part. It had stayed the same size in 4 people (2 in each group). Doctors call this stable disease. Unfortunately it had continued to grow in the other people taking part.
The trial team also looked at side effects. The most common side effects were:
  • tiredness
  • feeling sick
  • drop in white blood cells
  • loss of appetite
  • soreness at the injection site
Because the trial team had recruited fewer people than they had hoped, and because the treatment wasn’t stopping the cancer from growing in most people taking part, they decided to stop the trial early.
The trial team concluded that although the treatment didn’t cause many serious side effects and was safe to use, it did not work as a treatment for small cell lung cancer.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Peter Szlosarek

Supported by

Barts Health NHS Trust
Ludwig Institute for Cancer Research
Polaris Pharmaceuticals Inc

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Last reviewed:

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