Diem Nguyen, Ph.D.
Chief Executive Officer

Diem Nguyen, Ph.D., began serving as Chief Executive Officer and as a Director in January 2024. Dr. Nguyen joined SIGA from Xalud Therapeutics, a clinical stage biotechnology company developing treatments for inflammatory diseases, including pain associated with osteoarthritis, and neurodegenerative diseases, where she served as CEO. Prior to Xalud, Dr. Nguyen served as executive vice president of biopharma at PPD Inc., a leading global clinical research organization providing integrated drug development services. From 2009-2018, she served in several roles at Pfizer including global president, Americas, Pfizer Essential Health, where she was responsible for diverse commercial businesses in the U.S., Latin America, Canada, and Puerto Rico representing more than $11 billion in annual revenue. She earned a Ph.D. in biochemistry and molecular genetics at the University of Virginia, as well as an M.B.A. from Darden Graduate School of Business Administration.

Daniel J. Luckshire
Executive Vice President and Chief Financial Officer

Daniel J. Luckshire joined as Executive Vice President and Chief Financial Officer in February 2011. Prior to joining SIGA, Mr. Luckshire was a strategic advisor and private investor for a broad range of companies who are leaders within specialized market segments. Between 1998 and 2008, Mr. Luckshire was an investment banker at Merrill Lynch & Co., where he held various positions of increasing responsibility. Prior to Merrill Lynch, Mr. Luckshire was a member of the management team that built USI Insurance Services into a national insurance brokerage and was a CPA at Price Waterhouse LLP. Mr. Luckshire has a Master of Business Administration degree in Finance and Strategic Management from The Wharton School of the University of Pennsylvania and a Bachelor of Science degree in Accountancy from Villanova University.

Dennis E. Hruby Ph.D.
Executive Vice President and Chief Scientific Officer

Dennis E. Hruby, Ph.D. has served as Vice President - Chief Scientific Officer since June 2000. From April 1, 1997 through June 2000, Dr. Hruby was our Vice President of Research. From January 1996 through March 1997, Dr. Hruby served as a senior scientific advisor to SIGA. Dr. Hruby is a Professor of Microbiology at Oregon State University, and from 1990 to 1993 was Director of the Molecular and Cellular Biology Program and Associate Director of the Center for Gene Research and Biotechnology. Dr. Hruby specializes in virology and cell biology research, and the use of viral and bacterial vectors to produce recombinant vaccines. He is a member of the American Society of Virology, the American Society for Microbiology and a fellow of the American Academy of Microbiology. Dr. Hruby received a Ph.D. in microbiology from the University of Colorado Medical Center and a B.S. in microbiology from Oregon State University.

Jay K. Varma, MD
Executive Vice President and Chief Medical Officer
Jay K. Varma, MD, joined SIGA as the Executive Vice President and Chief Medical Officer in September 2023. He has also served on the SIGA Board of Directors since November 2022.  Dr. Varma was previously a Professor of Population Health Sciences and Director of the Cornell Center for Pandemic Prevention and Response at Weill Cornell Medicine. Dr. Varma is an expert on the prevention and control of diseases, having led epidemic responses, developed global and national policies, and led large-scale programs that have saved hundreds of thousands of lives in China, Southeast Asia, Africa, and the United States.  From 2001-2021, he worked for the U.S. Centers for Disease Control and Prevention with postings in Atlanta, Thailand, China, Ethiopia, and New York City. Recruited by the Mayor of New York at the peak of the COVID epidemic, Dr. Varma served from April 2020 to May 2021 as the principal scientific spokesperson and architect for New York City’s COVID-19 pandemic response, including the largest diagnostic testing and contact tracing programs in the country, the phased re-opening of businesses, the health policies and practices for the safe re-opening of the largest public school system in the country, and vaccination campaigns. In September 2021, Dr. Varma joined Weill Cornell Medicine to conduct research, training, and programs on public health and direct a new center focused on pandemic prevention, preparedness, and response.  Dr. Varma graduated with highest honors from Harvard for his undergraduate education, and completed medical school, internal medicine residency, and chief residency at the University of California, San Diego School of Medicine.
Larry Miller
General Counsel

Larry Miller began serving as General Counsel in March 2024.  He brings over twenty years of experience in the biopharmaceutical industry. Most recently, he served as General Counsel and Secretary at Phathom Pharmaceuticals, Inc., where he provided strategic legal advice on securities, corporate governance, mergers and acquisitions, intellectual property, regulatory strategy, clinical development, and commercialization. Larry previously served as General Counsel and Secretary at Blue Buffalo Company, where he advised the company through its $8 billion sale to General Mills. Earlier in his career, he held increasingly senior roles at Pfizer Inc., and served as an Associate attorney at both Arnold & Porter and Weil, Gotshal & Manges. He earned his bachelor’s degree from Dartmouth College and law degree from Columbia Law School.