Breakthrough targeted cancer drug extending lives

Carol Clarke takes four Glivec a day and says she feels very well. Picture / Alan Gibson

Carol Clarke says she owes her life to the breakthrough cancer drug she started taking nearly six years ago.

"Most definitely," says the 58-year-old grandmother and insurance consultant from Rotorua, "I don't think I would be here today."

She was diagnosed with chronic myeloid leukaemia (CML) in April 2000 and started taking Glivec capsules six months later as part of an international clinical trial. She was the first patient in this country to join the trial.

She still swallows the capsules, four a day, and has regular blood tests.

"I've been in remission for just over five years so what more could I ask for; and I'm very well."

On Saturday, the five-year follow-up results of the trial were presented to the American Society of Oncologists meeting in Atlanta.

Novartis, the maker of Glivec, says the results show that nearly 90 per cent of CML patients on Glivec were alive at the five-year point. And of the 10 per cent who died, fewer than half died from leukaemia.

Auckland University haematologist Associate Professor Peter Browett, an investigator on the trial, considers the results amazing. Before Glivec, people with the disease survived on average for four to four and a half years, he said.

"These results are quite outstanding. I wouldn't expect to see again in my clinical career another treatment that is so effective in reducing progression in this type of cancer to zero in the majority of patients by the fourth year. In this respect, Glivec is unprecedented."

Before Glivec, the risk of a patient with CML progressing from the early to the acute stage was 20 to 30 per cent a year in years three to five after diagnosis.

Virtually no patients were now treated with interferon and chemotherapy, the alternative drug treatment, although some still had a bone marrow transplant, Professor Browett said.

He said Glivec's success supported the idea of targeted cancer therapies.

"It really validates this new approach that's being taken to cancer trials and treatment now with targeted therapies ... developing drugs targeting the gene or genes causing the cancer."

Glivec was one of the first targeted anti-cancer drugs - unlike chemotherapy, they are not toxic to healthy cells - to be tested in a clinical trial.

Another targeted therapy is breast cancer medicine Herceptin, which Government drug agency Pharmac is now considering for an extension of state funding to include patients with the targeted type of early stage breast cancer.

Pharmac decided in 2002 Glivec would be funded for CML. Around 240 CML patients are now taking it.

Like Herceptin, however, Glivec is an extremely expensive medicine. The price negotiated with Novartis in 2002 was technically $58,000 to $88,000 a year a patient, but the drug company agreed to a risk-sharing arrangement and to cut the price of other drugs.