There’s a been a lot of news recently about the BRAF targeting drugs, which have been shown to be effective against melanomas containing the BRAF mutation. But the mutation only occurs in half of all melanomas. So what are the options for those without BRAF? .
This type of treatment helps the body’s immune system attack melanoma cells more effectively. Some types of immune therapy are already used to treat some melanomas.
There are three main types that we will talk about here:
1. Drugs that activate the immune system
Ipilimumab blocks a protein that normally suppresses the response of the immune systems (in particular T-cells). If T-cells are suppressed they can’t detect and kill a growing melanoma. Ipilimumab has been shown to help some people with advanced melanomas live longer.
Some studies found combining ipilimumab with another immunotherapy drug called GM-CSF helped patients with advanced melanoma live longer than with just ipilimumab.
2. Drugs that help the immune system find melanomas
Melanoma cells have a number of ways of avoiding detection by the immune system. They often have a protein called PD-L1 on their surface that helps hide.
Some new drugs can block the PD-L1 protein and can help the immune system recognise the melanoma cells and attack them.
These drugs can shrink tumours in about 1/3 of people with melanoma, which is much better than most results seen with ipilimumab. They have fewer serious side effects as well, and seem last longer.
3. Melanoma vaccines
Melanoma vaccines are still in the research stage and have yet to be proven to work.
These vaccines are relatively similar to the vaccines used to prevent diseases caused by viruses. Vaccines usually contain weakened viruses or parts of a virus that cannot cause the disease. The vaccine stimulates the body’s immune system to destroy the real virus when it attacks.
Similarly, killed melanoma cells or parts of cells (antigens) can be injected into a patient to stimulate the body’s immune system to destroy other melanoma cells in the body.
Other chemicals that help boost the body’s immune system in general are added as well.
The main difference to the viral vaccines is that a melanoma vaccine is given once the person has the cancer. It can’t be used to prevent a melanoma in the first place.
Making an effective vaccine against melanoma has proven to be hard, but there are some newer vaccines being studied now which show some promise.
4. Other immunotherapies
Other forms of immunotherapy are also being studied.
One promising field involved using tumour-infiltrating lymphocytes (TILs) in combination with chemotherapy and radiation. These are immune cells found in tumours which can shrink melanomas and may also prolong life. Some new research looks at genetically modifying the TILs to make them more effective at fighting cancer.
Most of the immunotherapies are in fact much more effective when given in combination with other treatments. Side effects from the individual drugs are also often reduced, as lower doses of each drug are needed.