Researchers have determined that PARP inhibitors ("poly ADP ribose polymerase") can spark a powerful immune response against cancers [sciencedaily.com] that have weaknesses in repairing their DNA.
PARP inhibitors such as olaparib block one of the systems which cells use to repair their DNA. They are designed to attack tumours that are already defective at DNA repair, especially ovarian and breast cancers in women with inherited BRCA mutations.
New generations of immunotherapy treatments are effective against some cancers (10-20%), however a study [jci.org] published in the Journal of Clinical Investigation described an action of PARP inhibitors which could make additional cancers treatable in this way.
"Our study found that PARP inhibitors enlist immune cells to aid in the killing of cancer cells. This provides a rationale for using PARP inhibitors alongside immunotherapies to further stimulate the immune response to cancer cells with DNA repair defects and enhance the therapeutic benefit of the treatment."
Using PARP inhibitors to augment immunotherapies
"will be evaluated in a clinical trial of lung, prostate and bladder cancers, which is starting later this year."