Positive response to cancer trial drug

PATIENTS with hereditary cancers including breast, ovarian and prostate, have responded well in preliminary trials to a new drug after other treatments had failed.

The drug, Olaparib, either shrank or stabilised tumours in more than half of the trial group, all of whom had advanced cancers.

One patient given the treatment is still in remission after two years.

Those who took part in the trial had not responded to other standard therapies.

The 19 patients involved in the small-scale trial reported less side effects from Olaparib than from chemotherapy. This is because Olaparib targets cancerous cells while leaving healthy cells relatively unaffected.

Researcher Dr Johann de Bono called for the drug to be tested in larger trials.

“It’s giving patients who have already tried many conventional treatments long periods of remission, free from the symptoms of cancer or major side-effects,” Dr de Bono said.

Olaparib, which kills cancer cells with a faulty BRCA1 or BRCA2 gene, successfully uses a technique called “synthetic lethality” – a subtle way of exploiting the body’s own molecular weaknesses for positive effect.

Olaparib causes cancer cells with a BRCA fault to lose control of the health of their DNA. This causes the cancer cell to die and means that the tumour should either stop growing or get smaller. It does this by blocking a protein called PARP and is, therefore, known as a PARP inhibitor.

The study’s authors believe the process of drug evaluation and registration may have to be revamped to take consideration of the fact that new generation cancer drugs target specific molecular defects, rather than types of cancer.

The Olaparib study, led by the Institute of Cancer Research, features in the New England Journal of Medicine.

In Ireland, a multi-million euro cancer research scheme will bring together experts in the field to develop so-called “magic bullet” drugs to treat the disease.

Headed up by consultant medical oncologist Professor John Crown, its aim is to revolutionise treatment of cancer by co-ordinating efforts of scientists, doctors and researchers.

Prof Crown, who works at St Vincent’s University Hospital and St Luke’s Hospital, Dublin, said the €5.6 million research cluster would boost the progress already made in the search for ways to tackle the disease.