Endostatin Cancer Trials Begin

Volunteers began signing up in Boston on Tuesday for the first human trials of endostatin, an experimental cancer drug that has been shown to shrink tumors in mice, reports CBS News Correspondent Christopher Glenn.

Endostatin is believed to "starve" the tumor by destroying its ability to sprout the new blood vessels that support its growth.

Dana-Farber/Partners Cancer Care was seeking 15 to 30 Boston volunteers over age 17 with solid tumors that have not benefited from other treatment. Patients with leukemia, lymphoma, myeloma or primary brain tumors are not eligible for the study.

A telephone number for applicants was printed in local newspapers Tuesday and the response this morning was heavy, with four nurses answering calls, said Steve Singer, spokesman for the Dana-Farber Cancer Institute. Dana-Farber/Partners Cancer Care is a collaboration of the institute and several local hospitals.

Endostatin and a sister protein, angiostatin, destroy a tumor's ability to sprout new blood vessels. In research done in the lab or Dr. Judah Folkman at Children's Hospital, cancer went dormant or disappeared altogether in test animals treated with the drug.

There was no certainty the same thing will happen in people.

The first phase of the trial will check for adverse side effects, though researchers will also look for signs that the drug is halting progress of tumors. If the drug is found to be safe, a second phase will evaluate the drug's effectiveness.

"It is important to stress that this is a Phase I clinical trial that seeks to determine dose levels for endostatin treatment," said Dr. Donald Kufe, principle investigator of the study. "It may take up to a year before we complete the study, and even then, only future studies can determine the effectiveness of the drug."

Two other sites also will enroll patients for the study in the near future: the University of Texas M.D. Cancer Center in Houston and the University of Wisconsin Comprehensive Cancer Center.

Fewer than 100 people are expected to receive the drug at the three locations.

The initial tests are being sponsored by EntreMed Inc., a Maryland-based biotech company that licensed the right to develop endostatin from Boston's Children's Hospital.

Endostatin and angiostatin have been the subject of a roller coaster of speculation ever since an enthusiastic front-page story on Folkman in The New York Times last year. But doubts cropped up when it was reported that scientists from the National Cancer Institute had not been able to reproduce Folkman's results. Then in February, an NCI team said it had at last duplicated Folkman's work by having the NCI scientists conduct the experiments at his laboratory in Boston.

CBS News Medical Consultant Dr. Bernadine Healy suggests other researchers were unable to duplicate Dr. Folkman's results because endostatin is difficult to maniplate.

"I don't think it's an issue of the credibility of the work, but more an issue that this is a pretty tricky protein to be working on," she says.