By Raja Mishra, Globe Staff, 6/5/2004

Cancer scientists will unveil this weekend dozens of studies demonstrating the power of new so-called smart drugs against a wide array of lethal tumors, perhaps the strongest sign to date that cancer treatment is shifting from toxic chemotherapies into a new era of precision-guided medicines with far fewer side effects.

The drugs have had isolated successes in recent years, but in numerous studies to be presented at a conference in New Orleans, these new therapies, which capitalize on recent strides in genetics, proved better than traditional treatments for cancers of the lung, kidney, intestines, and head and neck, among others.

The conference is expected to hasten their use across the nation: 20,000-plus cancer doctors are attending.

Smart cancer drugs home in on specific molecules within cancer cells. Traditional chemotherapy attacks cancer cells and healthy ones alike. Many doctors call it poison. Patients curse its miserable side effects.

"We have this idea of the cancer patient being bald, losing weight, being sick. Now it's clear it doesn't have to be that way," said Dr. Daniel Haber of Massachusetts General Hospital.

Every year at the American Society of Clinical Oncology conference, cancer specialists confer marquee status on a handful of studies they say will dramatically improve cancer care, presenting them at well-attended news conferences and symposia. This year, nine of 30 of these highlighted studies will involve smart drugs. Just five years ago, none was picked for this select group. Among the 3,700 studies to be released in New Orleans starting today, smart drugs are ubiquitous.

Take one much-publicized type, antiangiogenesis drugs, based on the pathbreaking work of Dr. Judah Folkman of Harvard. These drugs starve cancer tumors by cutting off their blood supply. For five years, patients have been anxiously awaiting their arrival. But progress has been slower than hoped.

In New Orleans, 62 antiangiogenesis studies will be unveiled, on treatments for a wide range of cancers. Seven of the studies involve new drugs. Nine involve late-stage clinical trials, meaning the drugs could be in hospitals soon.

These developments suggest that the steady improvements in fighting cancer during the past 30 years will continue and may accelerate. This week, the federal government reported that overall cancer rates dropped 0.5 percent per year from 1975 to 2001. This seemingly small drop indicates that tens of thousands fewer people developed cancer, results researchers credit to advances in cancer screening, reductions in smoking, and other lifestyle shifts.

The government also reported increases of 10 percent or more in the survival rate five years after diagnosis of male patients with cancer in their prostate, colon, kidney, skin, lymph nodes, or blood. More modest gains were posted for bladder, stomach, liver, and brain cancers.

In women, the survival rate for colon, kidney, and breast cancers increased significantly. More modest gains occurred in bladder, mouth, stomach, brain, and ovarian cancers.

Smart cancer drugs were not in wide use during the years studied, but their impact is expected to be felt as their use expands. A report found that progress has been slow in fighting lung, pancreas, and liver cancers. Data demonstrating the effectiveness of the smart drug Iressa in treating lung cancer, the most lethal in the United States, will be discussed in New Orleans.

Another striking example is kidney cancer. About 32,000 new kidney cancer cases, and 12,000 deaths, are reported annually in the United States, according to federal government statistics. Most cases are diagnosed late. Current therapies help about 18 percent of patients, and most only marginally.

Kidney tumors are filled with blood vessels -- a ripe target for antiangiogenesis drugs, which cut off blood to tumors. One such drug, called Avastin, combined with another type of smart drug, Tarceva, was tested against standard kidney cancer treatment, and the results will be presented this weekend.

Another experimental antiangiogenesis drug, called SU11248, attacks multiple targets in kidney tumors. Dr. William Li, president of the Cambridge-based Angiogenesis Foundation, described the drug as "a smart bomb with multiple warheads." The drug also appears to work on intestinal tumors.

Avastin is effective against colon cancer, and Tarceva helps lung cancer patients. Smart drugs are proving quite flexible, especially when combined, specialists said.

Dr. George D. Demetri of Dana Farber, who cowrote one of the SU11248 studies to be unveiled in New Orleans, said his next step will be to see whether the drug works against more common cancers, like colon and lung.

"We're going to take those lessons [from SU11248] and extrapolate them to common cancers," he said. "We are excited about moving the field forward."

Demetri tested SU11248 as a backup to the star of the smart drug pantheon, Gleevec. That medication was unveiled at a similar conference four years ago, and many doctors praised its power against a bone marrow cancer.

Many studies that will be on display this weekend follow a similar pattern, mixing and matching smart drugs to halt tumor growth. In this way, cancer medicine is becoming more like HIV treatment, which has effectively used similar drug "cocktails."

Raja Mishra can be reached at rmishra@globe.com.

This story ran on page A3 of the Boston Globe on 6/5/2004. © Copyright 2003 Globe Newspaper Company.

Back to the E-Zine Archives | Main Menu