Clay Siegall makes major contributions to targeted therapies

Dr. Clay Siegall, the founder of revolutionary drug company Seattle Genetics, has been at the forefront of the development of targeted cancer therapies since the beginning. After first becoming aware of the new class of drugs, while working at the National Cancer Institute, Dr. Siegall went on to lead a team of researchers at Bristol-Meyer-Squibb that gave birth to an entirely new form of targeted therapy, a class of drugs known as antibody drug conjugates.

Tinkering with nature’s most basic mechanics

The field of targeted therapy first started becoming an accepted part of the cancer research world throughout the late 80s and early 90s. During this time, great leaps forward in things like genomics and molecular biology allowed for techniques that were not previously possible. Targeted therapy, as a concept, developed as a way by which increased knowledge of genetic sequencing, protein structure and other detailed, molecular-level knowledge of microbiological processes could be used to specifically target malignant cells.

Many different methods of creating drugs that used the principles of targeted therapy were developed. There were two main branches of the targeted therapy approach, the creation of drugs that were cytotoxic and the creation of those which were cytostatic. Cytotoxic drugs involve delivery of an agent which kills cells into the tumor site and its cells. This is usually accomplished by use of enzymes or antibodies which specifically target the tumor cells using a sort of molecular handshake. By contrast, cytostatic drugs are agents which prevent further growth of the malignancy but don’t actually kill the tumor’s cells. The two approaches both have their respective merits, but each one uses radically different mechanisms to work its desired effects. Of the two, the class of cytotoxic drugs holds the most promise for developing a bona fide cure, but they also are the most difficult drugs to develop.

Dr. Siegall and his company have developed a class of cytotoxic drugs known as antibody drug conjugates. With one drug, Adcetris, already approved by the FDA for treatment of classic Hodgkin’s lymphoma, Seattle Genetics is well on its way to becoming the leading company in the search for cancer’s eventual cure.