PARP inhibitors could boost the effects of immunotherapy in cancer patients

New research from The Institute of Cancer Research (ICR), London has discovered that precision cancer drugs called PARP inhibitors have the ability to boost the immune system, and thus could help more patients benefit from immunotherapy.

PARP inhibitors, such as olaparib, work by targeting weakened cancer cells, and shutting down their ability to repair damage in their DNA. Being unable to repair themselves, the cancer cells die. The researchers in the study found that PARP inhibitors had worked to expose the cancer and ‘sparked a powerful immune response’. The buildup of DNA damage was seen to trigger the release of various molecular signals that could have helped attract immune cells to the site of the cancer.

While immunotherapy is an exciting advancement, it is still in its early stages with many cancers, ovarian included. One of the issues is helping our immune system find the cancer in the first place. According to this recent study, PARP inhibitors appear to assist here by unmasking and drawing immune cells to the cancer. This suggests that if PARP inhibitors are used in conjunction with immunotherapy, the immune response could be further enhanced to attack cancer cells more effectively. 

The research was led by Professor Chris Lord, Professor of Cancer Genomics at the ICR and Dr Sophie Postel-Vinay, Clinician Scientist and Medical Oncologist at Gustave Roussy, France, and the ICR. Their paper was published in the Journal of Clinical Investigation and the project was funded by Breast Cancer Now, Cancer Research UK, Siric Socrates, the Philanthropia Foundation and the Inserm ATIP-Avenir programme.

The research team performed experiments with breast cancers and lung cancers and will be starting a clinical trial of lung, prostate, and bladder cancers later this year. We will be watching this with great anticipation; these very promising findings could lead to advances in the treatment of ovarian cancers.