Dr. Clay Siegall is living legend of targeted cancer therapies
Today, it is largely taken for granted that if someone develops cancer, there’s a very good chance they’ll be able to survive, with a high degree of certainty, at the five-year survival benchmark. This is largely due to advancements that have taken place over the last 70 years. The advent of both radiation treatment and chemotherapy mark the beginning of modern cancer treatment, with real improvements in survivability seen across a wide swath of cancer types.
But in the mid-1980s, these advancements had become stagnant. Many types of cancers were no longer seeing the momentous gains and survivability that had been a staple of the ‘30s through the ‘60s. The cancer treatment industry needed to find new inroads to improving survivability.
Another aspect of the old treatment regimen was the sheer brutality of the side effects. The mainstays of cancer treatment had long been excision, radical surgery and both radiation and chemotherapy. All of these treatment modes had severe side effects associated with them. For example, people undergoing chemotherapy often times end up with permanent paresthesia, sensory deficits and other neurological conditions, including severe dementia. While not all patients experience these side effects at a high degree, they are bad enough that they represent a serious obstacle to the return to total health of the patient.
Beginning in the mid-‘90s, a man by the name of Clay Siegall became interested in a new field of cancer research called targeted cancer therapies. As a senior researcher at Bristol-Myers Squibb, Dr. Siegall first started working on a new class of targeted drugs called antibody drug conjugates. Antibody drug conjugates use the immune system to create antibodies, which are bound to cytotoxic agents. The major benefit of this method of cancer treatment is that there is no systemic release of the cytotoxic agents into the bloodstream, dramatically increasing the therapeutic window and allowing for highly lethal doses to be delivered directly to the site of the tumor. Whereas traditional chemotherapy may have taken six courses to reduce the tumor size by 25 percent, antibody drug conjugates can reduce the tumor size to nothing in just one treatment. And they have minimal associated side effects.