New drug may help women with hereditary breast cancer
A small clinical trial of a new drug designed to treat hereditary breast cancer has achieved promising results, UK scientists have said.
The scientists recruited 54 women from the UK, Europe, the US and Australia, all of whom had previously received chemotherapy for advanced breast cancer, and who carried faulty copies of the BRCA1 or 2 genes.
Half of the patients were given 100mg doses of a new drug called olaparib, while the other half received 400mg doses of the drug.
Olaparib is one in a class of drugs known as 'PARP inhibitors' and was designed to treat breast cancer in women with faulty BRCA1 or BRCA2 genes, which account for around five per cent of cases of the disease.
The drug was developed to target a specific weakness found in women whose tumours are caused by an inherited faulty BRCA 1 or 2 gene.
The results of the trial, which involved drug company AstraZeneca, were presented at a conference of the American Society of Clinical Oncology in Florida.
They showed that over 40 per cent of tumours among women treated with the higher dose shrunk by a significant amount, with one patient's tumour disappearing completely.
The women's tumours stopped growing for an average of around six months and the majority only reported minor side-effects such as fatigue and nausea.
The new drug uses an intelligent new approach called 'synthetic lethality' to target cancer cells that lack BRCA1 or BRCA2.
To do this, it blocks a protein called PARP, causing the cancer cells - but not normal cells - to lose control of the health of their DNA and die.
Unlike chemotherapy - which affects healthy cells as well as cancer cells - the new targeted treatment only kills cancer cells.
Dr Andrew Tutt, director of the Breakthrough Breast Cancer Research Unit at King's College London, led the trial.
He said: "The results of this study are very promising. It is rewarding to see our earlier laboratory findings, showing that PARP inhibitors such as olaparib specifically kill breast cancer cells with BRCA faults, now seem to be holding true for our patients in the clinic.
"We are hopeful that olaparib could provide a targeted treatment for women with BRCA-related breast cancer."
However, Dr Tutt noted: "It is important to remember this drug is at a very early stage of development, and further clinical trials are necessary to fully evaluate its potential."
Cancer Research UK's Professor Herbie Newell, from the Northern Research Institute at Newcastle University, where much of the research that led to the development of PARP inhibitor drugs was carried out, said that the charity is "extremely encouraged" by the early results.
He added that if the results are confirmed in larger trials, they may signal an "important new therapy" for women with certain types of inherited breast cancer.
"Cancer Research UK has contributed significantly over many years to the discovery of the BRCA cancer pre-disposition genes, and to studies on DNA repair which identified PARP as a therapeutic target," he revealed.
"It is gratifying to see the results of this basic research being translated into patient benefit.
"Olaparib is one of a family of PARP inhibitors currently in clinical trials and Cancer Research UK expect that this new class of anti-cancer treatments will make a significant impact in the fight against cancer."
Liz Woolf, head of Cancer Research UK's patient information website CancerHelp UK, added: "These early results are encouraging. We hope they will be confirmed in future, larger randomised trials and so become a treatment option for women with hereditary breast cancer."