A study, conducted by The Institute of Cancer Research, London (ICR) and Paris-based cancer research institute Gustave Roussy, identified that drugs known as PARP inhibitors kill cancer cells with a particular defect in the PBRM1 gene.
PARP inhibitors are a type of drug most commonly used to treat ovarian and breast cancers.
Researchers found that these drugs can kill the DNA defences of the cancer cells and prevent them from repairing the damage to their genetic code.
They have found that the PARP inhibitors could also exploit weaknesses in DNA repair in patients whose cancers have defects in the PBRM1 gene.
ICR noted that the mutations in PBRM1 gene can be observed in around half of all kidney cancer cases, in mesothelioma as well as in some lung or bile duct cancers.
Scientists have also found that treating PBRM1-defective cancer cells with PARP inhibitors such as rucaparib, olaparib or talazoparib in the lab had a ‘synthetic lethal’ effect, which causes the death of this type of cell.
ICR Cancer Genomics professor Chris Lord said: “Defects in the PBRM1 gene are common in various cancers, including half of all clear cell renal cell carcinomas, a common form of kidney cancer. Our findings suggest that cancers with faulty PBRM1 genes are sensitive to PARP inhibitors – drugs that strip cancer of its DNA defences.
“These findings are promising and our colleagues in Paris have already begun trials in patients based on this work. We’re hopeful that this could become a brand new genetically targeted approach to treating cancer and could offer hope to patients with various cancer types including a common form of kidney cancer.”
Following this study, the two Gustave Roussy-sponsored multicentre Phase II clinical trials have been developed to test a PARP inhibitor with immunotherapy in patients with a range of cancers with defective PBRM1 genes such as kidney, lung, bladder and bile duct cancers.