The drug, called Iressa, can be taken as a pill — a huge boon to patients used to being hooked up to intravenous infusions for chemotherapy. And it has very few side-effects — none of the nausea and hair loss that often makes chemotherapy patients so miserable.
Iressa takes a new approach, targeting proteins that are produced only by cancer cells, so it does not attack hair follicles and intestinal cells the way other cancer drugs do.
"Giving a drug that blocks an enzyme actually makes patients feel better," Dr. Mark Kris of the Memorial Sloan-Kettering Cancer Center in New York, who presented his findings to a meeting in Orlando of the American Society of Clinical Oncology, told a news conference.
"That is nothing short of amazing."
Iressa, being developed by Europe's second largest drugmaker, AstraZeneca Plc, is being tested in clinical trials pending approval by the U.S. Food and Drug Administration.
Kris and colleagues tested Iressa, once known by the experimental name of ZD1839, in 216 patients with advanced non-small cell lung cancer.
All had cancer that worsened despite two or more rounds of chemotherapy. "All these patients had cancer that couldn't be helped by either radiation or surgery," Kris said.
They weren't cured, but 43 percent felt better, the researchers told ASCO's annual conference in Florida. They had less shortness of breath, weight loss, cough, loss of appetite and confusion — all symptoms of lung cancer.
"What is quite amazing is that the patients who had that improvement had it within two weeks," Kris told a news conference.
And in 12 percent, the tumors shrank 50 percent or more. Average survival was about six months, so Iressa is no wonder drug, experts said. But it is the first hope to patients with what has been a very hopeless stage of cancer, they say.
"The major side-effect, it turns out, is a minor skin rash that looks like acne," Dr. Paul Bunn, president-elect of the American Society of Clinical Oncology and a cancer specialist at the University of Colorado, told reporters.
At the same meeting in Orlando, researchers on Saturday presented evidence that a cousin of vitamin A may be able to reverse some of the damage that can lead to lung cancer in smokers — offering the hope of actually preventing the disease.
Lung cancer is almost always caused by smoking, or by exposure to tobacco smoke.
People who quit smoking reduce their risk, but the precancerous damage caused by tobacco smoke does not immediately stop. Doctors have been hoping to find a way to stop the damage from getting worse.
One possible approach uses antioxidants, compounds that can both prevent and in some cases reverse the damage. Some of the most common antioxidants are vitamins such as vitamins A, C and E.
Studies have not shown taking megadoses of these vitamins can help smokers — and one study showed it may hurt. So a team led by Dr. Jonathan Kurie of the M.D. Anderson Cancer Center in Houston tried a cousin of vitamin A known as 9-cis retinoic acid.
They tested it on 226 patients who had smoked for years but who had quit. They were divided into three groups who got either the 9-cis retinoic acid, 13-cis retinoic acid plus alpha tocopherol, a form of vitamin E, or a placebo.
Biopsies — little tissue samples — of their lungs were taken before and after treatments.
"The 9-cis retinoic acid significantly decreased or reversed the precancerous state, compared to 13-cis retinoic acid or placebo," Dr. Charles Balch, executive vice president of the American Society of Clinical Oncology, which featured the study at its annual conference in Orlando, said in an interview.
"People who quit smoking are still at risk of lung cancer. Maybe we can reverse some of the damage done by smoking, with very little toxicity," Balch added.
The side-effects included headache, skin rashes and fatigue.
It will take years of follow-up to see if the changes seen in such patients translates into actually preventing cancer, but the researchers say their findings are promising enough to justify further experiments.
"This study shows that 9-cis retinoic acid is biologically active in the lung," Kurie said in a statement. "These encouraging results now deserve further study in a larger group of patients."