A trial of a drug called cabozantinib for medullary thyroid cancer (EXAM)

Cancer type:

Thyroid cancer

Status:

Results

Phase:

Phase 3

This trial looked cabozantinib (also called XL184) for medullary thyroid cancer that has spread outside the thyroid gland and cannot be removed with surgery.

Doctors may use chemotherapy for medullary thyroid cancer that has spread outside the thyroid gland. But this treatment does not always work very well and researchers are looking for new drugs to treat people in this situation. In this trial, they looked at a drug called cabozantinib.

Cabozantinib is type of cancer growth blocker. It stops signals that cancer cells use to divide and grow.

Researchers wanted to see if cabozantinib slows down the growth of medullary thyroid cancer. In this trial, they compared it with a dummy drug (placebo).

The aims of the trial were to

See how well cabozantinib works for medullary thyroid cancer
Find out more about what happens to the drug in the body
Learn more about the side effects of cabozantinib

Summary of results

The research team found that cabozantinib helped stop medullary thyroid cancer growing, and not many people had serious side effects.

This phase 3 trial recruited 330 people from 23 different countries around the world. Everyone taking part had medullary thyroid cancer that had spread outside the thyroid gland and continued to grow, and couldn’t be removed with surgery.

Some people taking part had cabozantinib capsules, and some had dummy capsules (placebos). They were put into treatment groups at random, with 2 people in the cabozantinib group for every 1 person in the placebo group. So

219 people took cabozantinib capsules
111 people took dummy (placebo) capsules

The research team looked at how long it was before the cancer got any larger. They found on average it was

Just over 11 months for those who had cabozantinib
4 months for those who had the placebo

When they looked at the number of people whose cancer had not got any bigger a year after starting treatment, they found it was

Nearly half of those who had cabozantinib (47%)
Fewer than 1 in 10 people who had the placebo (7%)

They also looked at how long people in each group lived for. They found that, so far, there is no difference between the two groups, but they will continue to look at this. We plan to update this page as more results become available.

The people taking cabozantinib did have side effects, and some of them were classed as serious. The most common serious side effects were diarrhoea, redness of the hands and feet (palmar-plantar syndrome) and tiredness (fatigue).

A small number of people in the cabozantinib group did have some very rare, but serious, side effects such as developing a hole in the wall of their bowel (perforation or fistula), or serious bleeding (haemorrhage).

The trial team concluded that cabozantinib helped stop medullary thyroid cancer growing, and could be a useful treatment for this rare cancer.

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 (peer reviewed Open a glossary item ) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.