What is immunotherapy?
Immunotherapy is fast becoming an important treatment option for cancer types that are not very responsive to conventional treatments of chemotherapy or radiotherapy, such as chordoma.
Immunotherapy boosts the body’s immune system to help it destroy cancer cells using molecules and substances that are either naturally produced by the body or are produced in a laboratory to enhance the functioning of the immune system.
Why would immunotherapy be useful for chordoma patients?
Recent studies have shown that a molecule known as PD-L1 is expressed in chordomas and even higher amounts in chordomas which have spread elsewhere in the body. PD-L1 plays a major role in supressing the immune system by preventing the proliferation of ‘cytotoxic T-cells’ - which work to destroy cancerous cells. If PD-L1 is present in high levels, as it is in chordoma, it may allow cancer cells to evade these cytotoxic T-cells of the body’s immune response and continue to grow and divide.
How can we target PD-L1 to treat chordoma?
PD-L1 has previously been targeted by immunotherapy, and such targeted drugs have now been licensed for use in skin and lung cancer. A recent study, by Dr James Hodge and his team at the Centre of Cancer Research (USA), investigated PD-L1 in chordoma cells. This research showed that inhibiting PD-L1 increases the destruction of cancerous chordoma cells by an immune response known as ‘antibody-dependent cell-mediated cytotoxicity’.
The drug used to inhibit PD-L1 is known as ‘Avelumab’. Further investigation during this study found that a combination of Avelumab and a molecule of the immune system known as IFN-γ increased the immune response of CD8+ T-Cells and the destruction of chordoma cells.
What could the future hold for immunotherapy and chordoma?
The findings from this study suggest that while chordoma is resistant to conventional therapies such a chemotherapy or radiotherapy, the use of immunotherapy may have real clinical benefit for chordoma patients. This area will be looked into more to before it is confirmed that PD-L1 is a safe and effective target of immunotherapy, but the results so far are extremely positive.