Jeff Lamothe, President and Chief Executive Officer
Jeff Lamothe is President and Chief Executive Officer of Aptevo Therapeutics and a member of the Board of Directors. He leads the development and execution of corporate strategy as Aptevo advances differentiated immuno-oncology therapies built on its proprietary ADAPTIR™ and ADAPTIR-FLEX™ platforms.

Jeff brings deep executive leadership experience to the role, including more than 20 years serving in C-suite positions as Chief Executive Officer, Chief Operating Officer, and Chief Financial Officer across multiple industries.

As a founding member of Aptevo’s leadership team, Jeff progressed from Chief Financial Officer to Chief Operating Officer and now Chief Executive Officer, bringing financial discipline, operational leadership, and strategic vision. As COO, he oversaw Clinical, Research and Development, Quality, Manufacturing, and Operations, advancing multiple programs in parallel. Earlier, as CFO, he led Finance, Business Development, Investor Relations, and Information Technology, helping to establish the strategic and financial framework that supported the company’s growth. Prior to joining Aptevo, he served as Vice President Finance, Biosciences Division at Emergent BioSolutions following its acquisition of Cangene Corporation, where he was Chief Financial Officer.

Daphne Taylor, Senior Vice President and Chief Financial Officer
Daphne Taylor is Senior Vice President and Chief Financial Officer of Aptevo Therapeutics, providing strategic direction to financial operations including audit, tax, accounting, purchasing, treasury, forecasting, budgeting, risk management, and ensuring regulatory compliance. She also oversees Investor Relations, and Information Technology, aligning performance with long-term growth.

Before joining Aptevo, Daphne served as Chief Financial Officer at BioLife Solutions and held senior finance roles at Cardiac Science Corporation, LookSmart, SpeedTrak, Core-Mark International, and Pacific Telesis. She began her career at Coopers & Lybrand in San Francisco. Daphne serves as a leader at Executive Women in Bio (Seattle chapter), holds a B.A. from Sonoma State University and is Certified Public Accountant in Washington and California.

Dirk Huebner, M.D., Senior Vice President and Chief Medical Officer
DDr. Dirk Huebner is Chief Medical Officer and brings three decades of academic and industry-based clinical drug development experience across the biotech and pharmaceutical sectors. He leads Aptevo’s clinical strategy and execution from early-stage studies through late-stage development.

Previously, Dirk served as Chief Medical Officer and Senior Medical Advisor at Mersana (2018–2021), where he built the clinical development department and oversaw the ADC pipeline. Earlier, as Vice President and Head of Development at Boston Biomedical, he assembled a robust clinical team and led multiple early-stage programs, including the napabucasin Phase 3 program. At Millennium/Takeda Oncology, he was Executive Medical Director and global clinical lead for ADCETRIS® (brentuximab vedotin), guiding its European regulatory approval and subsequent registration-enabling studies. He also served as clinical lead for clofarabine in acute myeloid leukemia at Genzyme and held roles of increasing responsibility at Roche and Bristol-Myers Squibb. Dirk holds an M.D. from Freie Universität Berlin and completed his medical residency at the Department of Urology, University Hospital Eppendorf (Hamburg).

SoYoung Kwon, Senior Vice President and General Counsel, Business Development and Corporate Affairs
SoYoung Kwon is Senior Vice President and General Counsel of Aptevo Therapeutics. She leads Legal, Compliance, Business Development, Human Resources and Facilities, overseeing corporate governance, securities, compliance, contractual and intellectual property matters, talent and organizational development, facilities and safety. SoYoung brings more than 30 years of legal and business leadership across regulated and innovation-driven industries.

Prior to Aptevo, SoYoung served as Global Senior Vice President, General Counsel, and Corporate Secretary and business development leader at AGC Biologics, a global contract development and manufacturing organization with facilities in the U.S., Europe, and Asia. She also served as Vice President, General Counsel, and Corporate Secretary and Head of Human Resources at Onvia, Inc.; Senior Counsel at Safeco Corporation; and Corporate Associate at Graham & Dunn PC. Her experience spans insurance, high-tech, biologics, and cell and gene therapy. SoYoung is a Trustee of the Seattle Art Museum, where she serves as a member of the Executive Committee. She also serves as President of the Washington Scholarship Foundation.

Miriam Weber Miller, Vice President, Investor Relations and Corporate Communications
Miriam Weber Miller is Vice President of Investor Relations and Corporate Communications at Aptevo Therapeutics. She leads investor engagement and enterprise communications across investors, employees, partners, media, and the Board of Directors, shaping corporate narrative and market positioning.

Miriam brings more than 20 years of experience in investor relations, public relations, and corporate communications within healthcare. She has worked with early-stage biotech and publicly traded pharmaceutical organizations, with deep expertise in investor strategy, clinical data positioning, and corporate storytelling in high-visibility environments. Prior to Aptevo, she held senior leadership positions at Tiberend Strategic Advisors and Finn Partners and helped build the life sciences communications practice at Porter Novelli, leading programs around IPOs and strategic transactions and managing high-performing teams. Miriam holds a M.B.A. (Finance) from Fordham University and a B.A. (Journalism) from Rowan University.