In focus: targeted therapies - immunotherapy

[OvacomeSupport]

This month in our Health in Focus series, we’re looking at targeted therapies. Cancer cells behave differently from healthy cells in a number of ways. These behaviours can make them more vulnerable to damage. Targeted therapies are drugs that disrupt this abnormal behaviour, causing the cells to die.

Targeted therapies are usually given in addition to surgery and chemotherapy for ovarian cancer, as maintenance therapies. Their role is to reduce the risk of the cancer recurring and to prolong the time between treatments if it does. This can give people longer periods of feeling well before they next need treatment.

Because targeted therapies are less likely to affect healthy cells, many people find that their side effects are more tolerable than chemotherapy and become easier to manage over time. As with any drug, some people will find them easier to tolerate than others. If you’re experiencing side effects that are difficult to cope with, your team may be able to reduce the dose, which can make them more manageable

Our information booklet about targeted therapies is available at:

ovacome.org.uk/targeted-the...

In this final post in our series on targeted therapies, we will be focusing on immunotherapies, which are treatments that harness the body’s own immune system to attack cancer cells.

As well as fighting viral or bacterial infections, such as colds and stomach bugs, the immune system also has another role. That is to identify and destroy damaged or abnormal cells, including cells which have the potential to multiply out of control and grow into a tumour.

Cancer cells can evade the immune system in a number of ways. For example, they can ‘hide’ by not displaying proteins on their surface that the immune system recognises as abnormal. Some cancer cells can ‘turn off’ the immune cells that would normally destroy them. The aim of immunotherapy is to counteract some of these processes and help the immune system to find and destroy cancer cells.

Immunotherapy therefore includes a number of different treatment approaches. For example, Avastin, which we looked at in our first post in this series ( healthunlocked.com/ovacome/... ), is an immunotherapy drug. It belongs to a family of drugs called monoclonal antibodies (the names of these drugs end in ‘mab’), which work by sticking to a specific protein. As we mentioned in our post about Avastin, it targets a protein called ‘VEGF.’ Avastin is the only immunotherapy drug currently licensed to treat ovarian cancer in the UK.

Other types of immunotherapy include:

•drugs that ‘teach’ the immune system to recognise the person’s cancer cells (dendritic cell therapy/’cancer vaccines’);

•drugs that stop the cancer cells from turning off the immune cells (such as PD1 and PD-L1 inhibitors, which you can watch a video about at youtube.com/watch?v=k41b40X...(Not working as expected?);

•attaching drugs to antibodies to ‘smuggle’ them into cancer cells (antibody-drug-conjugates, or ‘ADCs’); and

•taking out the person’s own immune cells, ‘engineering’ them to destroy any cancer cells then putting them back into the body (‘CAR-T’ cell therapy).

You can read more about the different types of immunotherapy at about-cancer.cancerresearch...

Although immunotherapies are being used to treat other types of cancer, research into their effectiveness in ovarian cancer has had limited success so far. This could be to do with characteristics of ovarian cancer cells, such as the types of genetic mutations they have. It could also be related to the composition of ovarian cancer tumours, for example the types and numbers of immune cells they contain.

Researchers are therefore looking into using immunotherapy drugs in combination with other treatments for ovarian cancer such as PARP inhibitors. There are some clinical trials happening at the moment using this strategy.

All drugs have potential side effects, and developing immunotherapies presents some particular challenges. As we mentioned above, some cancer cells have the ability to ‘turn off’ the immune cells that would otherwise destroy them. These ‘off switches’ are an important part of healthy immune function, because immune cells need to stop working when they’re no longer needed. Immunotherapy therefore needs to include ways to reduce the risk of causing overactivity in the immune system.

If the immune system isn’t controlled it can attack healthy cells and tissues, causing autoimmune conditions such as type I diabetes, rheumatoid arthritis and lupus. This means therapies designed to boost the activity of the immune system have the potential to cause significant side effects.

You can watch a talk by Dr Sarah Spear about her research into how the immune system fights ovarian cancer, which includes an overview of some of the challenges of developing immunotherapies at:

youtube.com/watch?time_cont...

If you would like to share your experiences of immunotherapy or have any tips on it, please comment on this post. If you would like information or support, please contact our Support Line on 07503 682 311 or email [e-mail].

Best wishes

Julia

Ovacome Support