Bassil I. Dahiyat, Ph.D. has served as our President and Chief Executive Officer since February 2005 and as a member of our Board since August 1997. He has led the Company in creating a diverse clinical-stage portfolio of engineered antibodies for the treatment of cancer and serious diseases, and has established alliances with leading biopharmaceutical companies that have resulted in three marketed drugs. Dr. Dahiyat has more than 25 years of experience in the biotechnology business, having co-founded Xencor in 1997. From 1997 to 2003, he served as our Chief Executive Officer, and from 2003 to 2005, served as our Chief Scientific Officer. Dr. Dahiyat currently serves on the board of directors of Kodiak Sciences Inc., a publicly traded biopharmaceutical company, and Terray Therapeutics, Inc., a privately held biotechnology company. In 2017, Dr. Dahiyat was awarded the Ernst & Young Entrepreneur of the Year in Technology for the Los Angeles Region and in 2005 was recognized as a technology pioneer by the World Economic Forum. Additionally, Dr. Dahiyat was named one of 2003’s Top 100 Young Innovators by MIT’s Technology Review magazine for his work on protein design and its development for therapeutic applications and has received awards from the American Chemical Society, the Controlled Release Society and the California Institute of Technology. Dr. Dahiyat holds a Ph.D. in chemistry from the California Institute of Technology (“Caltech”) and B.S. and M.S.E. degrees in biomedical engineering from Johns Hopkins University. We believe that Dr. Dahiyat’s experience in the pharmaceutical industry and as one of our founders qualifies him to serve on our Board.

Raymond J. Deshaies, Ph.D. joined our Board in July 2025. Dr. Deshaies has more than 40 years of experience in biotechnology as a biochemist and cell biologist. He is currently Professor Emeritus of Biology and Biological Engineering (“BBE”) at Caltech, since December 2025. Dr. Deshaies currently serves on the board of directors of Site Therapeutics and Lyterian Therapeutics, both privately held biotechnology companies. Prior to his role at Caltech, he served as Distinguished Fellow at Amgen Inc. (“Amgen”), from January 2025 to June 2025, Senior Vice President from August 2024 to January 2025, Senior Vice President of Global Research from July 2018 to July 2024, and Senior Vice President of Discovery Research from May 2017 to July 2018. Prior to joining Amgen, he was a member of the professorial faculty of the BBE Division at Caltech from 1994 to 2017. During his tenure at Caltech, he also served as Executive Officer of the Division, and from 2000-2017 was an investigator of the Howard Hughes Medical Institute. He co-founded the biotechnology companies Cleave Biosciences in 2011 and Proteolix in 2003. He is an elected member of the American Academy of Arts and Sciences and the National Academy of Sciences. Dr. Deshaies received a B.S. in Biochemistry from Cornell University, a Ph.D. from the University of California, Berkeley (“Berkeley”) and performed postdoctoral studies at Berkeley and subsequently at the University of California, San Francisco. We believe that Dr. Deshaies’ significant scientific and leadership expertise in drug development and biotechnology and his educational background qualify him to serve on our Board.

Ellen G. Feigal, M.D. joined our Board in November 2018. Dr. Feigal has more than 30 years of drug development and healthcare regulatory experience. Dr. Feigal has served as a partner at NDA Partners, a strategy consulting firm, since November 2014, where she leads efforts in designing and executing product development and regulatory strategies in the product areas of biologics, including antibodies, cell and gene therapies, medical imaging, across a broad spectrum of disease areas, with a particular focus on hematology and oncology. She also currently serves as a member of the board of directors of NextCure, Inc., a publicly traded biopharmaceutical company, which she joined in October 2021, and as a member of the board of directors of Prescient Therapeutics Limited, a publicly traded biopharmaceutical company, which she joined in May 2023. Dr. Feigal is also adjunct faculty at the Sandra Day O'Connor College of Law, Arizona State University, a position she has held since April 2015, where she teaches Food & Drug Administration drug law and medical research ethics and law. Dr. Feigal previously served as senior vice president of research and development at the California Institute for Regenerative Medicine from 2011 to 2014; executive medical director, global development, at Amgen from 2008 to 2011; and chief medical officer at Insys Therapeutics from 2007 to 2008. She was a founding director of the American Course on Drug Development and Regulatory Sciences at the University of California, San Francisco (“UCSF”), which she began in 2006 and directed through 2011. Dr. Feigal’s positions also included director of medical devices and imaging at the Critical Path Institute from 2006 to 2007, and vice president of clinical sciences at the Translational Genomics Research Institute from 2004 to 2007. From 1992 to 2004, she held leadership roles at the National Cancer Institute, where she directed the Division of Cancer Treatment and Diagnosis after serving as deputy director of the division and as a senior investigator in the Cancer Therapy Evaluation Program. Dr. Feigal received her B.S. in biology and M.S. in molecular biology and biochemistry from University of California, Irvine, her M.D. from the University of California, Davis School of Medicine, completed an internal medicine residency at Stanford University and a hematology/oncology fellowship at UCSF. We believe that Dr. Feigal’s leadership and experience in regulatory affairs and drug development and her educational background qualify her to serve on our Board.

Kevin C. Gorman, Ph.D. joined our Board in April 2017. He has more than 30 years of experience in the life science business including senior roles in finance, business development and operations. Dr. Gorman is a founder of Neurocrine Biosciences, Inc., a publicly traded biotechnology company (“Neurocrine”), and has served as a member of the board of directors of Neurocrine, since January 2008, From January 2008 to October 2024, he served as President and Chief Executive Officer of Neurocrine. Previously, Dr. Gorman served as Executive Vice President and Chief Operating Officer of Neurocrine from September 2006 to January 2008 and Senior Vice President of Business Development. From 1990 until 1993, Dr. Gorman was a principal of Avalon Medical Partners, L.P., where he was responsible for the early-stage founding of the company and several other biotechnology companies such as Onyx Pharmaceuticals, Inc., Metra Biosystems, Inc., Idun Pharmaceuticals, Inc. and ARIAD Pharmaceuticals, Inc. Dr. Gorman received his Ph.D. in immunology and M.B.A. in finance from the University of California, Los Angeles and did further post-doctoral training at The Rockefeller University. We believe that Dr. Gorman’s experience in biotechnology company leadership roles and his educational background qualify him to serve on our Board.

Barbara J. Klencke, M.D. joined our Board in September 2023. Dr. Klencke has more than 20 years of biopharmaceutical product development experience. She has served as Chief Medical Officer of ALX Oncology, Inc., a publicly traded biopharmaceutical company, on an interim basis from September 2025 and on a permanent basis since February 2026. Dr. Klencke also served on the board of directors of ALX Oncology from January to September 2025 and currently serves on the board of directors of TScan Therapeutics, Inc., a publicly traded biopharmaceutical company, which she joined in April 2023. She previously served as the Chief Medical Officer and Chief Development Officer of Sierra Oncology, Inc. (“Sierra”), a publicly traded clinical-stage biopharmaceutical company from July 2015 to June 2023, where she built a highly effective clinical development organization and led its strategy and execution, culminating in the approval of OJJAARA® for myelofibrosis after Sierra’s acquisition by GSK. While at Sierra, she concurrently served as a member of the board of directors of Lexent Bio, Inc., a publicly traded biopharmaceutical company, from May 2017 to June 2020. From 2011 to 2015, Dr. Klencke served as senior vice president of global development at Onyx Pharmaceuticals, where she led development and execution for Onyx’s pipeline programs, including the approval of KYPROLIS® for multiple myeloma, through the company’s acquisition by Amgen Inc. in 2013. Between 2003 and 2011, she served as a group medical director at Genentech, where she led product development strategies for several early- and late-stage oncology programs, including KADCYLA®, AVASTIN® and TARCEVA®. Dr. Klencke completed Internal Medicine and Hematology/Oncology training at the University of California, San Francisco and remained there as an Assistant Professor of Medicine in Oncology focusing on clinical research from 1995 to 2002. She holds a B.S. from Indiana University and an M.D. from the University of California, Davis. We believe that Dr. Klencke’s significant scientific expertise in drug development and biotechnology and her educational background qualify her to serve on our Board.

A. Bruce Montgomery, M.D. joined our Board in March 2015. Dr. Montgomery has more than 35 years of drug development, operations and financing experience, including positions at Genentech, Inc., Pathogenesis Corporation, Corus Pharma and Gilead Sciences, Inc. (“Gilead”). In October 2022, he retired as Chief Executive Officer and a member of the board of directors of Avalyn Pharma (formerly Genoa Pharmaceuticals), a private biotechnology company, which he joined in February 2017. From April 2011 to December 2016, he was Chief Executive Officer and a member of the board of directors of Cardeas Pharma Corporation, a private biotechnology company that he founded in 2010. From August 2006 to May 2011, Dr. Montgomery served as Senior Vice President of Gilead and prior to that, served for six years as Chief Executive Officer of Corus Pharma, Inc., a specialized biotechnology company that he founded, which was acquired by Gilead in 2006. While at Gilead, Dr. Montgomery successfully led the development of CAYSTON® as a treatment for cystic fibrosis patients. Dr. Montgomery also served as Executive Vice President of Research and Development at PathoGenesis Corporation until its acquisition by Chiron Corporation in 2000. Dr. Montgomery previously served as a board member for the following publicly traded companies: ZymoGenetics, Inc. (acquired by Bristol-Myers Squibb Company in 2010), Alder BioPharmaceuticals, Inc. (acquired by Lundbeck A/S in 2019) and Cytodyn, Inc. Dr. Montgomery is a board-certified internist and pulmonologist. Dr. Montgomery received his B.S. in chemistry (magna cum laude, Outstanding Chemistry Major (Merck Award)), and M.D. (Alpha Omega Alpha Honor Medical Society) from the University of Washington, Seattle. We believe that Dr. Montgomery’s executive leadership experience in pharmaceutical and biotechnology company drug development and his educational background qualify him to serve on our Board.

Todd E. Simpson joined our Board in March 2025. Mr. Simpson has more than 40 years of experience serving in chief financial officer and other financial roles at multiple biopharmaceutical companies and in public accounting. Most recently he served as Chief Financial Officer at Seagen Inc. (“Seagen”) from October 2005 through its acquisition in December 2023. During his eighteen years as Chief Financial Officer of Seagen, Mr. Simpson played an important role in the development, launch, and commercialization of four oncology drugs across more than a dozen labeled indications in the United States. He was also instrumental in Seagen’s international expansion, leading to the commercialization of medicines in the Americas and Europe. Mr. Simpson has led a range of functions including global finance, strategic planning, tax, treasury, corporate real estate, facilities, investor relations, corporate communications and information technologies, among others. Prior to joining Seagen, he served in executive roles at Targeted Genetics, Aastrom Biosciences and Telios Pharmaceuticals. Mr. Simpson currently serves on the board of directors of Shape Therapeutics Inc., since June 2024, a privately held biotechnology company, and he previously served on the boards of directors of Neoleukin Therapeutics, Aquinox Pharmaceuticals, and Life Science Washington (formerly Washington Biotech and Biomedical Association). Mr. Simpson is a certified public accountant (inactive), and early in his career he practiced public accounting with Ernst & Young LLP for nearly a decade. He received a B.S. in Accounting and Computer Science from Oregon State University. We believe Mr. Simpson’s experience in biotechnology company leadership and finance qualify him to serve on our Board.