LeadershipHBV-experienced, results-driven, and accomplished leadership team

Meet the team leading the charge in the fight against hepatitis B virus (HBV)

Greg Mayes


Mr Mayes is the Chief Executive Officer and a board member of Antios Therapeutics. Prior to Antios, and drawing on inspiration from his son’s epilepsy diagnosis, he raised $40 million from prominent investors and founded the clinical-stage pharmaceutical company, Engage Therapeutics, to develop a product candidate for seizures. Upon approval, Staccato® Alprazolam will be the first and only drug-device combination for the rapid termination of an active epileptic seizure. Engage was sold to UCB in 2020 in a deal valued at $270 million following the successful completion of its randomized, phase 2b clinical study.

Prior to Engage, Mr Mayes played an integral role in the growth of Advaxis Immunotherapies (NASDAQ: ADXS), a biotech company developing immuno-oncology therapies for patients with hard-to-treat cancers through its bacterial vector system, Lm Technology. As its Chief Operating Officer, he was instrumental in helping to secure in excess of $200 million in follow-on funding and developing partnerships with companies such as Amgen, AstraZeneca, and Merck & Co.

From 2004 to 2010, Mr Mayes served as Vice President, General Counsel and Chief Compliance Officer at ImClone Systems Corporation. During his tenure at ImClone, Mr Mayes supported the clinical development and commercialization of ERBITUX® and contributed significantly to activities that resulted in its acquisition by Eli Lilly for $6.5 billion in 2008.

Mr Mayes is a cum laude graduate of Syracuse University where he was recognized as a Remembrance Scholar and he earned his Juris Doctor degree magna cum laude from the Temple University School of Law where he was the Articles Editor on the Temple Law Review.

Doug Mayers, MD


Dr Mayers is the Chief Medical Officer and a cofounder of Antios Therapeutics. He was most recently Chief Medical Officer at Cocrystal Pharma (NASDAQ: COCP) developing antiviral drugs against hepatitis B, hepatitis C, and influenza viruses. Notably, in 2007, Dr Mayers was named Executive Vice President and Chief Medical Officer at Idenix Pharmaceuticals where he was responsible for drug safety and clinical development for therapies targeting HIV, hepatitis B, and hepatitis C. After Idenix was acquired by Merck Pharmaceuticals (NYSE: MRK) in 2014, he served for a year as a Principal Investigator at the United States Army Medical Research Institute of Infectious Diseases coordinating efforts to develop drugs against Ebola and MERS coronavirus. Dr Mayers was commissioned into the United States Navy in 1981 and retired after 38 years of service as a Captain, initially serving as a Staff Internist and rising to Department Head, Division of Retrovirology, where he was responsible for directing HIV natural history studies and clinical trials at Army, Navy, and Air Force sites domestically. In 1998, Dr Mayers left Navy active duty to become the Head of the Division of Infectious Diseases at Henry Ford Hospital. He served as Principal Investigator for the clinical trials unit funded by The National Institutes of Health (NIH) and conducted NIH-funded clinical trials of antiviral drugs and the clinical implications and management of HIV drug resistance. In 2001, he moved to Boehringer Ingelheim Pharmaceuticals as the International Head/Vice President of the Therapeutic Area Virology where he was responsible for the therapeutic area strategy and global clinical development and support for antiviral drugs including nevirapine and tipranavir.

Dr Mayers has served as a consultant to the Food and Drug Administration, as a member of numerous Federal and NIH committees, study sections, and advisory groups. He has authored numerous publications and is the editor for the 2-volume textbook, Antimicrobial Drug Resistance, and is a Fellow of the American College of Physicians and the Infectious Disease Society of America.

He received the Jay P. Sanford Award for lifetime professional achievement from the Armed Forces Infectious Disease Society. He holds a Bachelor’s Degree in Electrical Engineering from Pennsylvania State University, and a Doctor of Medicine from the University of Pennsylvania.

Tamra Adams


Ms Adams has more than 25 years of experience in accounting and financial management. Before joining Antios, she founded Accounting Concepts, Inc., a firm that provided CFO, accounting, and financial services to emerging growth companies in the biopharmaceutical and information technology industries, including Engage Therapeutics, a company that was sold to UCB in 2020. Before that, Ms Adams was a senior financial executive at Silverstorm Technologies, Inc., where she was responsible for financial and human resources functions and participated in an acquisition of the company by QLogic. Prior, she was the Controller of Starcite, Inc., an internet company, where she was responsible for financial reporting, business model development, and internal control systems. Ms Adams began her career at Ernst & Young, LLP, as a Senior Auditor specializing in entrepreneurial services, and later at Goldman Sachs as a Senior Accounting Officer.

Ms Adams earned her Bachelor of Science degree in Accounting at State University of New York, Albany and was a certified public accountant in New York.

Katie Laessig, MD


Dr Laessig has more than 20 years of experience in pharmaceutical regulatory roles both in industry and for the United States Food and Drug Administration (FDA). Before joining Antios, she served as Vice President, Therapeutic Strategy, Strategic Drug Development at IQVIA where she delivered strategic regulatory and clinical development planning for pharmaceuticals and biologics, including support for regulatory interactions, across a range of therapeutic areas for the IQVIA’s biotechnology and pharmaceutical customers. Before that, she was Senior Vice President, Regulatory Affairs, Medical Safety, and Quality Assurance at RRD International, LLC, where she provided strategic and tactical regulatory, clinical, and development evaluation and direction to product development programs undertaken by RRD for its client companies. From 1999 to 2015, Dr Laessig served in multiple roles of increasing responsibility at the US FDA including Medical Review Officer and Medical Team Leader, Division of Antiviral Products, and Deputy Director, Division of Anti-Infective Products. From 2000 to 2016, she volunteered once weekly at the Whitman Walker Clinic in Washington, DC, the city’s largest provider of HIV/AIDS care.

Dr Laessig earned her Doctor of Medicine from the University of Maryland School of Medicine and a Bachelor of Arts degree in Biology from Cornell University.

Karen Fusaro


Ms Fusaro spent more than 20 years managing and leading execution of clinical trials from phase 1 through phase 3 in several therapeutic areas including infectious disease. Prior to joining Antios, she held several positions of increasing responsibility at Melinta Therapeutics where she oversaw all clinical, regulatory, and pharmacovigilance activities for 4 antibiotic programs. Before that, she was responsible for clinical operations and clinical project management at The Medicines Company and contributed to the US FDA approvals of 2 antibiotics, Orbactiv® and VABOMERE®. Additional experience included managing global clinical development of diabetes and cardiovascular programs at Novartis and managing global clinical trials for neuropathic pain, HIV, liver fibrosis, and migraine candidates for GlaxoSmithKline.

Ms Fusaro earned a Bachelor of Arts degree in Psychology from State University of New York at Binghamton.

Mark Lockwood, PhD


Dr Lockwood has 20+ years of experience in the pharmaceutical industry in both process and medicinal chemistry. He began his pharmaceutical career at Abbott Laboratories, where he was part of the process chemistry group responsible for bringing Kaletra to market. He moved from large pharma to be a part of several startup biotech companies in the Atlanta area, including Somatacor Pharmaceuticals, AtheroGenics, Metastatix, and the Emory Institute for Drug Development, where he developed a process for the manufacture of molnupiravir, an antiviral drug licensed to Ridgeback (and later Merck). Molnupiravir is currently in phase 2/3 clinical trials for the treatment of COVID-19. Dr Lockwood is currently Director of Process Research and Manufacturing at Antios Therapeutics and is the coauthor on numerous scientific publications and patents.

Dr Lockwood received his PhD from Purdue University and was a post-doctoral associate at the University of Washington.

Katherine Squires, PhD


Dr Squires started as a Research and Development Project Manager at Antios before her current position as Director of Research and Development. Prior to joining Antios, she served as an Associate Project Manager at Q2 Solutions, where she managed over $43 million in phase 1 to 3 clinical trial startup projects and led global project teams through the design phase of study-specific databases with a focus on Alzheimer’s disease. Since joining Antios, Dr Squires has managed the preclinical development program of the company’s lead molecule, ATI-2173, and recently led the acquisition of a novel HBV capsid assembly modulator program.

Dr Squires earned a PhD in Molecular Pharmacology at Emory University and a Bachelor of Arts degree in Textile Engineering at North Carolina State University.

Catherine Coffey Ross


Ms Coffey Ross has more than 25 years of experience with global pharmaceutical companies, developing and executing medical marketing plans for antiviral products, including programs for hepatitis C (HCV). She joins Antios following a distinguished 17-year career at Abbott Labs and then AbbVie, where she served as an integral part of the HCV franchise in various roles helping to bring multiple products through preclinical development, FDA approval, and launch. Ms Coffey Ross held positions of increasing responsibility, where she eventually rose to Marketing Director, US Commercial HCV. She was responsible for the professional and medical marketing for AbbVie’s HCV franchise, including the successful launch of MAVYRET®, which in 2020 was ranked by FiercePharma as the most successful launch since 2017. During her tenure, Ms Coffey Ross helped make AbbVie a leader in HCV therapeutics, leading external engagement and medical education. Prior to joining AbbVie, she held medical marketing positions at Roche Pharmaceuticals, Bristol-Myers Squibb, and Merck & Co.

Ms Coffey Ross earned her Bachelor of Science degree in Dietetics from Texas Christian University in Fort Worth, Texas where she practiced as a critical care dietitian at Baylor All Saints Hospital.

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