A trial of T-VEC (Talimogene laherparepvec) for melanoma that cannot be removed

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Cancer type:





Phase 3

This trial looked at treating melanoma with a drug called T-VEC (previously known as OncoVEX GM-CSF). It was for people with melanoma that had either not been treated, or had come back after earlier treatment, and could not be removed with surgery.

The treatment used a form of the cold sore virus that had been changed so that it was not harmful to normal cells, but destroyed cancer cells. The normal strain of the virus is changed by altering the genes that tell the virus how to behave.

More about this trial

T-VEC works in several ways

  • It puts the changed virus directly into cancer cells where it can grow and kill them
  • It tells the cancer cell to make more of a substance called GM-CSF before the virus kills it
  • It helps the body’s immune system to recognise and attack cancer cells.

GM-CSF stands for granulocyte and macrophage colony stimulating factor. It is a growth factor that can encourage the immune system to recognise and attack cancer cells. Small amounts of GM-CSF are produced naturally in the body. But you can have larger amounts by injection.

In this trial, some people had injections of GM-CSF alone and some had T-VEC.  Doctors injected T-VEC directly into the melanoma. This is called intratumoural treatment Open a glossary item. The researchers hoped the virus would kill cancer cells and the GM-CSF would boost the immune system to help fight the cancer.

The aims of the trial were to

  • See how well T-VEC worked for melanoma
  • Learn more about the side effects

Summary of results

The trial team found that T-VEC was a better treatment than GM-CSF alone for people with melanoma that either hadn’t been treated, or had come back after earlier treatment, and could not be removed with surgery.

The trial recruited 436 people.

  • 295 people had T-VEC
  • 141 had GM-CSF

On average, people in the trial stayed on treatment with T-VEC for 23 weeks. If they were having GM-CSF, they stayed on treatment for an average of 10 weeks. The trial team followed them up for around 3 ½ years. They found that T-VEC was better at controlling melanoma than GM-CSF. On average it controlled the melanoma for 5 months longer than GM-CSF alone.

32 people having T-VEC had no visible signs of any melanoma after treatment. Doctors call this a complete response. 1 person having GM-CSF had a complete response.

The researchers also looked at how long people lived with or without signs of their melanoma. Doctors call this overall survival. They found that on average

  • People who had T-VEC lived for just over 23 months
  • People who had GM-CSF lived for just under 19 months

People having T-VEC had more side effects such as tiredness and lack of energy (fatigue), chills and a high temperature (fever) than people having GM-CSF

Based on these results the trial team have stated that T-VEC is a possible new treatment option for people with melanoma who have lesions that can be directly injected and whose cancer has not spread widely.

We have based this summary on information from the research team. 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 who did the research. We have not analysed the data ourselves.

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 Kevin Harrington

Supported by

Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer

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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.

Charlie took part in a trial to try new treatments

A picture of Charlie

“I think it’s really important that people keep signing up to these type of trials to push research forward.”

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