Our Leadership Team
At Exelixis, we believe that leadership happens at all levels across the company. We lead by example, fostering shared purpose and a heartfelt passion for giving patients hope as the core driver of business performance. Together, we are resilient in the face of adversity, relentless in delivering results and unwavering in our commitment to excel for patients through the work we do and medicines we bring to market. We strive to create sustained value by translating science and opportunity into impact.
Michael M. Morrissey, Ph.D.
President and Chief Executive Officer
Michael M. Morrissey, Ph.D., has served as a director and as Exelixis’ President and Chief Executive Officer since July 2010. Dr. Morrissey has held positions of increasing responsibility at Exelixis since he joined the company in February 2000, including serving as President of Research and Development from January 2007 until July 2010. From 1991 to 2000, Dr. Morrissey held several positions at Berlex Biosciences, last holding the position of Vice President, Discovery Research. Earlier in his career, Dr. Morrissey served as a Senior Scientist and Project Team Leader in Medicinal Chemistry at CIBA-Geigy Corporation. Dr. Morrissey serves as a member of the board of directors of XWPharma Ltd., a privately held, clinical-stage biopharmaceutical company. He is the author of numerous scientific publications in medicinal chemistry and drug discovery and an inventor on 70 issued U.S. patents and 25 additional published U.S. patent applications. Dr. Morrissey holds a B.S. (Honors) in Chemistry from the University of Wisconsin and a Ph.D. in Chemistry from Harvard University.
Peter Lamb, Ph.D.
Executive Vice President, Scientific Strategy and Chief Scientific Officer
Peter Lamb, Ph.D., has served as Executive Vice President, Scientific Strategy and Chief Scientific Officer since February 2016. Previously, he served as Executive Vice President, Discovery Research and Chief Scientific Officer from September 2009 to February 2016, as Senior Vice President, Discovery Research and Chief Scientific Officer from January 2007 until September 2009, as Vice President, Discovery Pharmacology from December 2003 until January 2007 and as Senior Director, Molecular Pharmacology and Structural Biology from October 2000 until December 2003. Prior to joining Exelixis, from June 1992 until September 2000, Dr. Lamb held positions of increasing responsibility at Ligand Pharmaceuticals, a pharmaceutical company, most recently serving as Director of Transcription Research. Dr. Lamb has held post-doctoral research fellowships at the Carnegie Institution, Department of Embryology, with Dr. S.L. McKnight and the University of Oxford with Dr. N.J. Proudfoot, working in the field of gene regulation. He has authored numerous articles in the fields of gene expression, signal transduction and oncology, and is an author on multiple issued and pending U.S. patents. He has a Ph.D. in Molecular Biology from the ICRF/University of London and a B.A. in Biochemistry from the University of Cambridge.
Christopher J. Senner
Executive Vice President and Chief Financial Officer
Christopher J. Senner, has served as Executive Vice President and Chief Financial Officer (and in such capacity, as our principal financial officer and principal accounting officer, as defined under applicable securities laws) since July 2015. Prior to joining Exelixis, Mr. Senner served as Vice President, Corporate Finance for Gilead Sciences, Inc., a biopharmaceutical company, from March 2010 to July 2015, where he was accountable for controllership, tax, treasury and corporate and operational financial planning. Mr. Senner previously spent eighteen years at Wyeth, a pharmaceutical company acquired by Pfizer Inc. in 2009, in a variety of financial roles with increasing responsibility, most notably as Chief Financial Officer of Wyeth’s U.S. pharmaceuticals business and the BioPharma Business Unit. Since 2019, Mr. Senner has served as a member of the board of directors of Cortexyme, Inc., a publicly held clinical-stage biopharmaceutical company. Mr. Senner holds a B.S. in Finance from Bentley College.
Dana T. Aftab, Ph.D.
Executive Vice President, Business Operations
Dana T. Aftab, Ph.D., is Executive Vice President, Business Operations at Exelixis. Since February 2016, Dr. Aftab’s responsibilities in this role have included corporate site development, management and operations, in order to ensure that Exelixis’ work environments are well-suited to empower the company’s teams in their collective quest to help patients with cancer. Dr. Aftab joined Exelixis in 1998, starting in the company’s drug discovery group, where he helped build the company’s foundational discovery programs in oncology and metabolic diseases. He then moved into the clinical development organization in 2007, where he implemented a broad translational medicine platform. Prior to joining Exelixis, Dr. Aftab held senior scientist positions at several biotech start-ups. Dr. Aftab holds B.A. and Ph.D. degrees in pharmacology from the University of California, Santa Barbara and Yale University, respectively, and did postdoctoral work at the University of California, Berkeley in the field of oncogene signaling.
Executive Vice President, Human Resources
Laura Dillard is Executive Vice President of Human Resources at Exelixis. In this role since February 2020, Ms. Dillard is responsible for assembling a driven, talented and inspired workforce that works together to help Exelixis in its goal of helping patients with cancer achieve remission. As a part of the Exelixis human resources team since 2005, Ms. Dillard has spearheaded significant initiatives along the company’s growth trajectory, including its transition from a drug discovery company to a full-scale commercial organization following the FDA approval of CABOMETYX in 2016. Prior to joining Exelixis, Ms. Dillard served as Vice President of Human Resources and Real Estate at Leapfrog from 2002 to 2005, and in several positions of increasing responsibility at AT&T Consumer/Northpoint Communications from 1999 to 2001. She also held various human resources management positions at Hasbro and Sega of America, where she established the human resources function for the Japanese video game company’s U.S. and Canadian-based operations. Ms. Dillard holds a B.S. degree in Human Services Administration from Notre Dame de Namur University and is certified as a Senior Professional in Human Resources (SPHR) by the Society for Human Resource Management.
Executive Vice President, Commercial
P.J. Haley, has served as the company’s Executive Vice President, Commercial since February 2020 and has held positions of progressive commercial leadership since September 2010, serving as Senior Vice President, Commercial from December 2016 to February 2020, Vice President, Commercial from November 2014 to November 2016, Executive Director, Sales & Marketing from September 2013 to October 2014, Senior Director, Marketing from March 2012 to August 2013, and as Director, Marketing from September 2010 to February 2012. Prior to joining Exelixis, from 2007 to 2010, he held positions of increasing responsibility at Genentech, Inc., on the Avastin marketing team, most recently Group Product Manager. Between 2003 and 2007, Mr. Haley served in various sales and marketing roles at Amgen, Inc. He served as an analyst at PWC Securities, Lehman Brothers and Accenture from 1998 to 2001. Mr. Haley holds a Masters of Business Administration from University of Michigan, Ross School of Business, and a Bachelor of Arts in Art History and Medieval and Renaissance Studies from Duke University.
Jeffrey J. Hessekiel, J.D.
Executive Vice President and General Counsel
Jeffrey J. Hessekiel, J.D., has served as Executive Vice President and General Counsel since February 2014 and as its Secretary from October 2014 to September 2017. From 2012 to 2014, he held the position of Senior Counsel at Arnold & Porter Kaye Scholer LLP, where he advised emerging growth and public companies, primarily in the life sciences sector, on complex legal issues connected with strategic transactions, healthcare compliance programs and investigations, and regulatory matters. Prior to working with Arnold & Porter, from 2002 to 2012, he held positions of increasing responsibility at Gilead Sciences, Inc., most recently as Chief Compliance & Quality Officer where he was responsible for the creation and management of Gilead’s Corporate Compliance & Quality department. From 1998 to 2002, Mr. Hessekiel held the position of Associate, working on both litigation and corporate matters for Wilson Sonsini Goodrich and Rosati PC. Mr. Hessekiel also worked as an Associate focusing on litigation matters for Heller Ehrman LLP from 1996 to 1998. Prior to joining Heller Ehrman LLP, Mr. Hessekiel also worked for several international non-governmental organizations. Mr. Hessekiel received his J.D. from The George Washington University Law School and is admitted to practice in California. Mr. Hessekiel received a B.A. in Political Science from Duke University.
Susan T. Hubbard
Executive Vice President, Public Affairs and Investor Relations
Susan T. Hubbard is Executive Vice President of Public Affairs and Investor Relations at Exelixis. In this role since December 2016, Ms. Hubbard is responsible for developing the company’s global corporate brand marketing and communications strategy to build Exelixis’ reputation among diverse corporate audiences. Ms. Hubbard led the company’s 2017 rebrand to codify its mission, culture and core values and built out Exelixis’ corporate communications function with a team whose charter includes bringing to life the significant contributions the company has made to the treatment of cancer. Ms. Hubbard oversees all aspects of the company’s corporate, partnership and product communications, as well as employee, investor and advocacy relations to reinforce Exelixis’ unrelenting commitment to the field of oncology and bold vision for the future. A public relations and investor relations consultant to Exelixis since 2014, Ms. Hubbard was instrumental in developing Exelixis’ communications strategy around the launch of CABOMETYX, as well as managing the announcements of several other major milestones for its partnered programs. Previously, Ms. Hubbard spent over two decades at Gilead Sciences, Inc., where she occupied a variety of roles of increasing responsibility, concluding her tenure as Vice President of Investor Relations. Ms. Hubbard holds a B.A. in Psychology from the University of California, Los Angeles.