Washington, May 23 : Researchers at East Carolina University (ECU) have developed a monoclonal antibody that could play a vital role in treating the most common form of ovarian cancer, breast cancer and other cancers.
They are working with two major drug firms, ImmunoGen Inc. and sanofi-aventis, that have the expertise in formulating antibodies into cancer therapies and taking them to clinical trials in humans.
Dr. Anne Kellogg, an associate professor of pathology and laboratory medicine at the Brody School of Medicine at ECU, created the antibody, called DS-6, that attaches to cancer cells.
DS-6 will serve as a delivery vehicle for a highly potent cell-killing agent developed by ImmunoGen specifically for delivery to cancer cells by antibodies.
The antibody latches on to tumour cells and enables the whole compound, the antibody and the attached cell-killing agent, to enter the cancer cell.
Once inside, the cell-killing agent becomes activated and kills the tumour cell as it divides.
"We can't give such a potent chemotherapy agent on its own because it would be too toxic, but if we can link it to an antibody, it goes inside the tumour cell and is released inside the tumour cell, which is really an amazing feat," Kellogg said.
The antibody with the cell-killing agent attached to it circulates in the body in an inactive state.
The agent becomes active only when it reaches the tumour cell, so ImmunoGen refers to its technology as Tumour-Activated Prodrug, or TAP, technology.
Sanofi-aventis has rights to develop specific anticancer agents using ImmunoGen's TAP technology and is in charge of advancing the TAP compound containing the DS-6 antibody licensed from ECU into human clinical testing.
Monoclonal antibodies are manufactured proteins, produced from a single parent cell, that bind to a specific substance.
They can be used to detect or purify that substance and are widely used in hospital and pathology laboratories as components of diagnostic tests.
Kellogg began working with monoclonal antibodies in the early 1990s looking for ones pathologists could use to diagnose cancer.
A few years later, Kellogg turned her attention to identifying an antibody that could not only recognize tumours but also be useful in treating them.
She isolated DS-6 in the late 1990s and then began characterizing the antibody for its ability to recognize various types of cancer.
"Drugs that are developed from monoclonal antibodies are potentially more specific for tumours and risk less in the way of toxicity to the patient," said Dr. Adam Asch, associate director of the Leo W. Jenkins Cancer Center at ECU.