A trial of SCIB1 injections for melanoma

In this small trial the team found that SCIB1 helped to boost the immune system. Most of the side effects were mild. 

About this trial
35 people took part in this phase 1/2 trial. Of those:

• 15 had melanoma present
• 20 had no signs of melanoma after their surgery 

Diagram 1]

There were 2 parts to the trial. Part 1 looked at the best dose for further treatment. Part 2 tested this dose in more people. 

People with melanoma present (Part 1)
15 people joined this part of the trial. The team looked at the best dose of SCIB1 to use in the future. To do this the first few people had a low dose. If they didn’t have any side effects the next few people had a higher dose until they found the best dose. 

The team found 2 doses they could give. One was a lower dose (4mg). During the running of the trial the researchers found it was possible to make a higher dose of the vaccine. So some people had the higher dose (8mg). 

People whose melanoma was completely removed (Part 2)
20 people joined this part of the trial. Some people had the 4mg dose and some had the 8mg dose that they found in Part 1. The dose they had depended on when they joined the trial. 

Both groups
Everybody taking part was due to have 5 injections of SCIB1 over a period of about 6 months. They had the injections into a muscle using a special device. This means that they had the injection and then a short electrical pulse . This is called electroporation, or EP. Of the 35 people who took part:

• 25 had the full course of treatment
• 10 stopped treatment early because their cancer got worse

Results
The team looked to see if SCIB1 activated cells in the immune system.

To do this the research team measured the number of T cells (cells that kill cancer cells) in blood samples. They wanted to see if the vaccine had stimulated the immune system.

They had the results for 33 out of 35 people. They found the vaccine activated the immune system in just under 9 out of 10 people (88%). 

The team also looked at the dose level that people had. They wanted to see if this affected the immune response. Some people had a lower dose (4mg) and some people had a higher dose (8mg). This depended on when people joined the trial. The team compared:

• people who had melanoma present with
• people whose melanoma was completely removed

They found the following: 

• people who had the 4mg dose had a stronger immune response if they had no signs of melanoma. This was compared to the group who still had melanoma present.
• people with melanoma present had a stronger immune response to the 8mg dose. This was compared to the group who had no signs of melanoma.
• in people who had no signs of melanoma, the higher dose (8mg) didn’t seem to improve the immune response compared to the 4mg dose

The team say that this suggests that the lower dose is good enough for people whose cancer has been completely removed. But the higher dose might work better for people who have melanoma present. 

15 people had areas of cancer that doctors could measure on a scan. The team looked to see what happened to their cancer during treatment.

They found that in:

• 1 person the cancer shrunk a little bit 
• 7 people the cancer stayed the same
• 7 people the cancer gradually grew

There was an option to continue to have the vaccine if it was working. 12 people chose to do this. They could have the vaccine every 3 months for up to 5 years. 9 out of these 12 people who chose to continue had no melanoma present.

The cancer came back in 5 out of 20 people whose melanoma was completely removed with surgery. At the end of the study, all 20 people were living. They were on the trial for between 6 months and 4 years. 

Tissue samples
The team looked at tissue samples (biopsies ) that people gave before and after treatment. They were looking for biomarkers that could predict how well treatment might work. They took samples from 21 people. 

They looked at a number of markers including 2 called MHC-I and MHC-II. These are important for encouraging immune function. They found that treatment seemed to work better in people who had these 2 markers on their melanoma cells. 

Side effects
Most people had side effects. The most common side effects related to having the SCIB1 injections were:

• pain from having the injection 
• a bruise at the injection site
• tiredness (fatigue)
• blurred vision
• headaches

Most of these were mild. 

There was no difference in the number of side effects when they compared those whose melanoma was still present. And those whose melanoma had been completely removed. 

One person found that the short electrical pulse was too uncomfortable. They had 3 doses and then decided to stop treatment because of this. 

Conclusion
The team concluded that the SCIB1 vaccine stimulated the immune system in people with melanoma. They recommend it is looked at in further studies. This includes on its own or in combination with targeted drugs  to treat people who have advanced melanoma. 

We have information about a trial looking at the SCIB1 vaccine with pembrolizumab for advanced melanoma on the CRUK trials database. 

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.