Clay Siegall blazes trails in exciting new field of targeted cancer therapies

Today we take for granted that the medical establishment is fully capable of treating many types of cancers, improving survivability at the five-year benchmark to almost 100 percent, with many types of cancers. Far from a pedestrian accomplishment, this is a quite remarkable achievement, one that humanity lived without for the first 200,000 years of its existence.

It wasn’t until the 1930s that cancer really even became treatable. Before that, surgeries were occasionally done in an attempt to excise tumors, but these often had dismal results, with the patient being about as likely to die from the intervention as they were from the cancer itself.

However, that began to change with the advent of radiation therapy, as well as chemotherapy. But these treatments had absolutely brutal side effects, often leaving the patient with permanent paresthesia, sensory deficits and even dementia. Still, five-year survival rates for a wide array of cancer types did begin to dramatically improve and continued to do so throughout the ‘50s and ‘60s.

But then, the cancer treatment field began running into a period of stagnation. Most of the low-hanging fruit, the dramatic improvement in survival rates, was already harvested. The cancer treatment industry needed to find new methods to continue making significant strides in the five-year survival rates for most types of cancer.

Then along came Clay Siegall, a researcher for Bristol-Myers Squibb in the area of targeted drugs. In 1998, Dr. Siegall founded Seattle Genetics, a company dedicated to the research and development of a class of targeted cancer therapy called antibody drug conjugates. The principle behind antibody drug conjugates is simple enough. They use the body’s own immune system to target malignant growths and then bombard them with cytotoxic agents. The difference between this class of drugs and traditional chemotherapy is that, at least in theory, antibody drug conjugates can completely eliminate the systemic release of highly lethal and dangerous chemotherapeutic agents.

With antibody drug conjugates, a cytotoxic agent is chemically bound to the antibody, only being released upon direct contact with or ingestion into the tumor tissue. This dramatically increases the therapeutic window, that is, the amount of a drug that can be given at any one time. This allows for amounts of cytotoxic chemicals to be pumped into the tumor site that will kill all malignant tissue with almost total certainty.