'Smart' cancer drugs under way

CHICAGO -- New research shows a sharp escalation in the weapons race against cancer, with several high-tech approaches long dreamed of but not possible or successful until now.

At a weekend conference of more than 30,000 cancer specialists, scientists reported:

New "smart" drugs that deliver powerful poisons directly to cancer cells while leaving healthy ones alone.

A new tool that helps the immune system attack a broad range of cancer types.

Treatments aimed at new genes and cancer pathways, plus better tests to predict which patients will benefit.

"I see major advances being made in big diseases" such as breast and prostate cancers, said Dr. Richard Pazdur, cancer drug chief at the federal Food and Drug Administration. The field continues to move toward more precise treatments with fewer side effects and away from old-style chemotherapy, he said.

In fact, an emerging class of "smart bombs" was one of the most hopeful developments reported at the meeting of the American Society of Clinical Oncology.

These are two-punch weapons that combine antibodies, which bond with specific cancer cells, and toxins held together by a chemical link.

"This is a classic example of the magic bullet concept," first proposed more than 100 years ago but only now possible with advances in technology, said Dr. Louis Weiner of Georgetown Lombardi Comprehensive Cancer Center.

Yesterday, a large study showed that one such drug, Genentech's T-DM1, delayed the progress of cancer in very advanced breast cancer.

Dozens of similar "smart bomb" drugs are in development. Today, Pfizer Inc. plans to report on one it is testing for certain types of lymphoma and leukemia. Only one such drug is on the market now -- Adcetris, sold by Seattle Genetics Inc. for some less common types of lymphoma.