Dr. Clay Siegall’s Immense Contribution to Oncology

Clay Siegall, Ph.D currently serves as the president and CEO of Seattle Genetics, Inc, a company that’s focused on development and commercialization of anti-body based therapies to be used in treatment of cancer. He has lead Seattle Genetics in development of antibody-drug conjugates and securing the 2011 FDA approval for ADCETRIS, its first ADC product. Working with Takeda Pharmaceutical Company, the company convinced over 65 countries to approve the drug. Dr. Siegall also oversees the company’s capital raising activities. Seattle Genetics has been able to raise over $1.2 billion through private and public financing.

Why Dr. Siegall started Seattle Genetics

Dr. Siegall started his company to help cancer patients. Seeing his father suffer and die from cancer when he was just 24 made him aware of the limited treatment options available to cancer patients. He wanted to improve tools available to oncologists, and to treat cancer patients with better drugs. He says that’s the reason he’s been doing his job for 30 years.

Dr. Siegall’s background

Prior to co-founding Seattle Genetics in 1998, Dr. Siegall worked at Bristol-Myers Squibb Pharmaceutical Research Institute, the National Cancer Institute, and National Institutes of Health. He received a Bachelor of Science in Zoology from the University of Maryland, and a Doctorate in Genetics from George Washington University.

In 2013, Clay Siegall was appointed as an outside director to biotechnology company, Mirna Therapeutics. Dr. Siegall uses his experience in the pharmaceutical industry to guide Mirna as it develops microRNA-based therapeutics. Dr. Siegall was also appointed to the board of directors of Ultragenyx Pharmaceutical Inc, a biopharmaceutical company focusing on developing novel products for rare diseases, in 2014. He also serves as director of Alder Biopharmaceuticals.


Dr. Siegall has been able to grow his business by working with others who are also developing cancer drugs. He attributes his success to partners who have extended reach of their technology and resources to Seattle Genetics, giving the company an opportunity to discover new ways of helping patients. Dr. Siegall advices all entrepreneurs to learn as much as they can, and to interact with people who are experts in diverse fields.