Clay Siegall creates biotech giant from scratch

One of the most exciting developments to take place in the cancer research space throughout the last 30 years has been the development of so-called targeted cancer therapies. These drugs enable doctors to go after malignant tissues directly, potentially leading to dramatically reduced side effects and dramatically increased effectiveness of the treatments. Although there are many different types of targeted cancer therapies, one type, so-called antibody drug conjugates, has dominated the industry. No one has been more important in the development of these innovative new types of drugs then Clay Siegall.


After working for Bristol-Myers Squibb for more than 10 years as a senior researcher, in 1998, Dr. Siegall decided to break off, founding his own biotech startup. He called the company Seattle Genetics. Over the next three years, Dr. Siegall built Seattle Genetics from a tiny start up struggling to raise any capital at all to a viable biotech research firm, with dozens of full-time staff and a healthy supply of venture capital.


By 2001, Dr. Siegall was ready to take Seattle Genetics public. In an initial public offering that smashed all previous records for biotech firms, he was able to raise more than $1.2 billion on the open market, suddenly infusing Seattle Genetics with enough cash to sustain long-term research efforts in the development of some of the most promising drugs the world had ever seen.


Throughout the 2000’s, Dr. Siegall made ample use of this new influx of capital, developing some of the most innovative drugs that had ever been developed in the cancer treatment industry. One of those was called ADCetris, an antibody drug conjugate that was able to specifically target the malignant tissues involved in the disease called non-Hodgkin’s lymphoma. By 2011, ADCetris had been put through many different drug trials and was on the brink of being approved by the FDA as the first antibody drug conjugate ever to be generally available to the public.


That year, the FDA did finally approve ADCetris as the first antibody drug conjugate ever. Today, ADCetris is indicated for the treatment of refractory non-Hodgkin’s lymphoma as well as a few other off-label uses. Dr. Siegall believes that within five years, Seattle Genetics will have dozens of other antibody drug conjugates approved by the FDA.