New drugs chip away at cancer

NEW ORLEANS - New targeted therapies are helping cancer patients live longer, even if they do not offer miraculous cures.

Researchers are learning how to combine the best new targeted therapies with older drugs to eke out extra months or even years for cancer patients - which can mean a lot to a patient hoping to live long enough to see a child graduate or marry.

Each small step builds on earlier progress, so that the overall five-year survival rate for all cancers is now 63 per cent, up from 51 per cent in 1975, according to the American Cancer Society.

"It is sort of like a glacier - you have this slow but extremely powerful movement. But it's not a fast movement," said Michael Friedman, chief executive of the City of Hope Cancer Centre in California.

At first cancer researchers hoped the targeted therapies would prove to be magic bullets that could kill cancer cells without causing too many toxic side-effects, as chemotherapy and radiation do.

Dr Margaret Tempero, president of the American Society of Clinical Oncology, said targeted therapies were far too specific to affect a disease that had as many different causes as cancer. "You can't expect to hit one part of the pathway and expect everything to regress.

"Miraculous effects like Gleevec and CML are probably few and far between."

However, several studies presented at an ASCO meeting in New Orleans show the new drugs can buy time.

For instance, adding ImClone Systems' drug Erbitux to radiation therapy helped head and neck cancer patients live longer without their cancer spreading.

Combining two targeted drugs, Avastin and Tarceva, both made by Genentech with Roche and OSI Pharmaceuticals, kept 71 per cent of patients with a hopeless type of kidney cancer alive for six months or more.

Combining Avastin with Pfizer's Camptosar and an older drug called 5-FU helped colon cancer patients live 25.1 months versus 15.8 months for those on more standard therapy.

Some of the targeted drugs also have significant effects on their own when used in the right patients.

Millennium Pharmaceuticals' Velcade helped patients with recurrent multiple myeloma, a hard-to-treat blood cancer that kills 11,000 people a year in the United States.

Cancer remains the second leading cause of death in the United States behind heart disease.

- REUTERS