A trial of pembrolizumab for advanced cancers

The team found that pembrolizumab was a promising treatment for advanced cancers and the side effects were manageable.  

About this trial
This was a phase 1 trial. 196 people took part. Everyone had pembrolizumab. 

Everyone had had a number of other treatments for their cancer before taking part in this trial. 

Results
In each cancer group the team looked at:

• the total number of people whose cancer responded to pembrolizumab (overall response rate)
• how well pembrolizumab worked for each person 
• how long people lived without a sign of their cancer coming back (progression free survival)
• the average length of time pembrolizumab worked (response duration)
• the side effects 

Pembrolizumab can affect how the immune system  works. So the team also looked at side effects that affected the immune system. 

Breast cancer   
There were 25 people in this group.

The average length of time these people were followed up was just over 9½ months. 

When the team looked at how well pembrolizumab worked they found for:

• 3 people (12%) their cancer had shrunk (partial response)
• 4 people (16%) their cancer had stayed the same (stable disease)
• 15 people (60%) their cancer had got worse (progressive disease)

For 3 people (12%) they couldn’t tell how well pembrolizumab worked because these people didn’t have a scan before starting treatment. So the team couldn’t compare the before and after treatment scans. 

The average length of time people lived without a sign of their cancer coming back was just under 2 months (1.8 months). 

The average overall length of time people lived after treatment was just over 8½ months (8.6 months). 

The average length of time that pembrolizumab worked for people with breast cancer was a year. 

Salivary gland cancer   
There were 26 people in this group.

The average length of time these people were followed up was 20 months. 

When the team looked at how well pembrolizumab worked they found for:

• 3 people (12%) their cancer had shrunk
• 12 people (46%) their cancer had stayed the same 
• 11 people (42%) their cancer had got worse

The average length of time people lived without a sign of their cancer coming back was 4 months. 

The average overall length of time people lived after treatment was 13 months. 

The average length of time that pembrolizumab worked for people with salivary gland cancer was 4 months. 

Bowel (colorectal) cancer  
There were 23 people in this group. 

The average length of time these people were followed up was just under 5½ months. 

 When the team looked at how well pembrolizumab worked they found for:

• 1 person (5%) their cancer had shrunk
• 4 people (20%) their cancer had stayed the same
• 15 people (65%) their cancer had got worse

For 3 people the team couldn’t assess how well pembrolizumab had worked. For 1 person their cancer started to get worse before the first scan. The other 2 people didn’t continue in the trail. 

The average length of time people lived without a sign of their cancer coming back was just under 2 months (1.8 months).

The overall length of time people lived after treatment was just under 5½ months (5.3 months).

Cervical cancer  
There were 24 people in this group. 

The average length of time these people were followed up was 11 months.

When the team looked at how well pembrolizumab worked they found that for:

• 4 people (17%) their cancer had shrunk 
• 3 people (13%) their cancer had stayed the same
• 16 people (67%) their cancer had got worse 

1 person had withdrawn from the trial due to side effects before the scan was done to assess how well treatment worked. 

The average length of time people lived without a sign of their cancer coming back was 2 months. 

The overall average length of time people lived after treatment was 11 months. 

The average length of time that pembrolizumab worked for people with cervical cancer was just under 5½ months (5.4 months). 

Small cell lung cancer  
There were 24 people in this group. 

The average length of time these people were followed up was just under 10 months. 

When the team looked at how well pembrolizumab worked they found that for:

• 1 person (4.2%) there was no sign of their cancer (complete response)
• 7 people (29.2%) their cancer had shrunk
• 1 person (4.2%) their cancer had stayed the same
• 13 people (54.2%) their cancer had got worse

For 2 people the team couldn’t assess how well pembrolizumab worked because they didn’t have an initial assessment before starting treatment.
 
The average length of time people lived without a sign of their cancer coming back was just under 2 months (1.9 months).

The overall average length of time people lived after treatment was just under 10 months (9.7 months).

The average length of time pembrolizumab worked for people with small cell lung cancer was just under 19½ months (19.4 months).

Endometrial (womb) cancer   
There were 24 people in this group.

The average length of time these people were followed up was just under 18 months. 

When the team looked at how well pembrolizumab worked they found that for:

• 3 people (13%) their cancer had shrunk
• 3 people (13%) their cancer had stayed the same
• 13 people (56.5%) their cancer had got worse

For 3 people the team couldn’t assess how well treatment worked because they didn’t have a scan after treatment. 

The average length of time people lived without a sign of their cancer coming back was just under 2 months (1.8 months). 

When the team stopped collecting the information about this group of people they couldn’t work out the average length of time these people lived after treatment. This was because these people were still alive.

They also couldn’t work out how long pembrolizumab worked for people with endometrial cancer. This was because 2 people were still taking pembrolizumab and it was still working for them. 

Anal cancer
There were 25 people in this group. 

The average length of time these people were followed up was just over 10½ months. 

When the team looked at how well pembrolizumab had worked they found that for:

• 4 people (17%) their cancer had shrunk
• 10 people (42%) their cancer had stayed the same
• 9 people (38%) their cancer had got worse

1 person stopped taking pembrolizumab due to side effects before the scan after treatment was done. So the team couldn’t compare the scans before treatment and after treatment to assess how well it worked. 

The average length of time people lived after treatment without a sign of their cancer coming back was 3 months.

The overall average time people lived after treatment was just under 9½ months (9.3 months). 

The team couldn’t work out the average length of time that pembrolizumab worked for people with anal cancer. This was because at the time 2 of the 4 people were still alive. 

Mesothelioma of the lung (pleural)
There were 25 people in this group. 

The average length of time these people were followed up was just over 18½ months.

When the team looked at how well pembrolizumab had worked they found that for:

• 5 people (20%) their cancer had shrunk
• 13 people (52%) their cancer had stayed the same
• 4 people (16%) their cancer had got worse

For 3 people the team couldn’t asses how well pembrolizumab worked because:

• 2 people withdrew after having 1 treatment and didn’t have any scans 
• for 1 person they could not check how well it had worked

The average length of time people lived without a sign of their cancer was just under 5½ months (5.4 months).

The average overall length of time people lived after treatment was just over 18½ months (18.7 months). 

The average length of time that pembrolizumab worked for people with pleural mesothelioma was 12 months.  

Side effects
The most common side effects reported in all groups include:

• tiredness (fatigue)
• feeling sick
• sore muscles 
• itching
• loss of appetite
• dry mouth
• diarrhoea
• high temperature
• weakness
• cough
• difficulty sleeping
• rash
• sore, inflamed mouth

Side effects affecting the immune system
Of the 196 people in the trial, 24 people had a side effect that affected how the immune system worked. These side effects included:

• changes to the way the thyroid gland worked
• inflammation of the thyroid
• inflammation of the liver 
• a reaction at the injection site where the pembrolizumab infusion was given
• inflammation of the lungs
• rash
• inflammation of the bowel 
• Guillain-Barre syndrome
• breakdown of muscle tissue that can cause serious complications such as kidney damage
• inflammation of the iris 

Conclusion
The trial team concluded that pembrolizumab worked for the following PD-L1 positive cancers:

• salivary gland
• bowel (colorectal)
• cervical
• small cell lung
• endometrial
• mesothelioma

There are further clinical trials going on to look at pembrolizumab in these cancers.

For breast cancer and anal cancer, they concluded that pembrolizumab showed promise and further trials should be considered.

Where this information comes 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 ) 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.