A trial looking at imiquimod cream as treatment for an early type of melanoma skin cancer (LIMIT - 1)

Cancer type:

Melanoma

Skin cancer

Status:

Results

Phase:

Phase 2

This trial looked at imiquimod cream to treat an early type of melanoma skin cancer called lentigo maligna.

More about this trial

Lentigo maligna is a dark patch of skin which grows slowly over many years. It usually occurs on areas of the skin that have a lot of sun exposure such as the face. It grows and spreads over the outer layer of the skin.

Left untreated it might start to grow deep into the skin. It is then called lentigo maligna melanoma.

Doctors use surgery to remove lentigo maligna. But this can be stressful and unpleasant. It can also leave scarring which might be noticeable.

Surgery might also cause nerve damage. This can affect normal movement and cause an eyelid to droop for example.

Imiquimod cream works by using the body’s immune system to attack the cancer cells in the skin. We know from research that imiquimod cream might help people with early stage melanoma skin cancer.

Researchers thought that imiquimod cream could be just as good as surgery to treat lentigo maligna. In this trial people used the cream before surgery.

The aims of this trial were to find out:

how well imiquimod cream worked to treat people with lentigo maligna
how well people accepted using the cream
what people thought about using imiquimod cream
if taking a sample of tissue (biopsy) after imiquimod can tell doctors if the treatment has worked
if it would be worthwhile to do a phase 3 trial comparing lentigo malinga to surgery

Summary of results

The team found that imiquimod cream didn’t work as well as surgery for lentigo malinga.

This trial closed in 2011 and the results were published in 2017.

About this trial

This was a phase 2 trial.

28 people used the imiquimod cream for 12 weeks before having surgery to remove their lentigo malinga.

After surgery, they completed an opinion questionnaire about how likely they were to use imiquimod cream or have surgery.

To find out how well the cream worked, researchers took samples of tissue (biopsies) of the lentigo malinga after treatment with the imiquimod cream.

Results of the tissue samples

The team looked at how many people had no sign of their lentigo malinga after using the imiquimod cream.

They found that for 12 out of the 28 people (43%):

their doctor couldn’t see any sign of lentigo malinga
samples of tissue (biopsies) taken from where their lentigo maligna was showed no sign of it

11 of the 12 people went on to have surgery. Of these 7 people were found to still have some lentigo maligna left in place. The researchers said this showed that tissue samples taken after using imiquimod cream cannot be depended on to predict there is no lentigo malinga left.

For a phase 3 trial to be worth doing, the number of people who had no sign of lentigo maligna needed to be 60 out of every 100 people (60%) or more.

Results of the opinion questionnaire

There were 15 different supposed situations in the questionnaire. They ranged from:

imiquimod cream cures everyone (100%) and surgery cures 95 out of every 100 people (95%)

imiquimod cream cures 10 out of every 100 people (10%) to surgery cures 95 out of every 100 people (95%)

16 people completed the questionnaire.

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The higher the supposed cure rate of imiquimod cream the more people said it would be their first choice of treatment.

Half the people said they would choose surgery over imiquimod cream even when the cure rate of imiquimod cream was 85 out of every 100 people (85%).

Conclusion
The trial team concluded that imiquimod cream didn’t work well enough to do a larger phase 3 trial to compare it with surgery.

Where we got this information from
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.