Clay Siegall – the man behind antibody drug conjugates

After graduating with a Ph.D in genetics from George Washington University, Dr. Clay Siegall worked in a series of jobs as a senior researcher. He spent this period of his career working on a new line of drugs broadly referred to as targeted cancer therapies. He found the corporate environment to be somewhat stifling and decided to set out on his own.

In 1998, Dr. Siegall founded Seattle Genetics, with a few researchers that he had pulled away from the corporate world. Within three years, Dr. Siegall led the firm in its IPO, which generated an astounding $1.2 billion. Now awash with capital, Dr. Siegall directed the company’s energies towards the intensive research of a new line of drugs, what Seattle Genetics called antibody drug conjugates. Over the next ten years, Seattle Genetics took out hundreds of patents and began the development of 12 new drugs. In 2011, it was granted FDA approval for its first marketable drug, Adcetris.

Cancer’s new drug

Antibody drug conjugates are a revolutionary new drug which specifically target the tumor cells without harming any other cells in the body. Dr. Siegall and Seattle Genetics are largely responsible for the advent of this new type of cancer treatment that promises to radically further the treatment of many types of cancer.

Antibody drug conjugates are a fairly simple concept in theory, but, in practice, they present immense technical hurdles. The drug is designed with two parts, an antibody, which seeks out and attaches itself to the tumor sites and a cytotoxin, a lethal substance which kills cells, that is conjugated or chemically bound to the antibody. When the antibody comes into contact with the tumor cell, it is brought inside the cell, where it releases the cytotoxin.

This has one main benefit and many others which stem from it. The cytotoxin is not released into the patient’s system, it’s only released into the malignant cells. This means that all of the side effects of chemotherapy that result from the death of healthy tissues can be avoided.

These drugs promise to revolutionize cancer treatment. And Dr. Siegall and his company are at the vanguard of that revolution.