Senior Management

PACT Pharma

Terry Rosen, Ph.D.


Dr. Rosen has been leading successful drug discovery and development organizations in the biotechnology and pharmaceutical industries for over 30 years. In 2015, he co-founded Arcus Biosciences, a drug discovery company focused on the treatment of cancer by blocking tumor-induced immunosuppression. Previously, he was co-founder and CEO of Flexus Biosciences, a company created to develop small-molecule drugs to reverse tumor immunosuppression, which was acquired by Bristol-Myers Squibb early in 2015 for $1.25 billion. Prior to Flexus, Terry served as Vice President, Therapeutic Discovery (TD) at Amgen and as the site head for Amgen South San Francisco, having joined Amgen with the acquisition of Tularik in 2004. He was named Amgen Washington site head in 2006, transitioned to a leadership role heading Chemistry Research and Discovery in 2007 and became the head of Protein Sciences in 2011. He and his leadership team were responsible for the creation of the TD organization, a group of 550+ staff responsible for all of Amgen’s large and small molecule drug discovery efforts.

Prior to joining Amgen, Terry held several executive positions at Tularik, including Executive Vice President, Operations, Vice President, Research Operations, and Vice President, Medicinal Chemistry. He has also held scientific and management positions at Pfizer and Abbott Laboratories. Terry serves on the Salk Institute Board of Trustees, the leadership committees of the University of Michigan Undergraduate Research Opportunity Program and Life Sciences Institute, the Berkeley Chemistry Advisory Board, the Caltech Biology & Bioengineering Chair’s Council and the Board of the California Life Sciences Association.

Juan Jaen, Ph.D.


Dr. Jaen has been engaged in all aspects of drug discovery and development for more than 30 years. In 2015, he co-founded Arcus Biosciences together with Terry Rosen. Prior to that, he was co-founder and President/Head of R&D at Flexus Biosciences, until its acquisition by Bristol-Myers Squibb for $1.25 billion. Previously, he was Chief Scientific Officer and Senior Vice President of Drug Discovery at ChemoCentryx. During his tenure there of just under 7 years, Juan led the discovery and progression into the clinic of 8 novel drug candidates in the immunology space. At ChemoCentryx, Juan led the discovery efforts for the multi-year collaboration with GSK, which generated over $100M in non-dilutive milestones and fees. From 1996 to 2006, Juan held various scientific management positions at Tularik (responsible for about 100 scientists in Medicinal and Computational Chemistry, as well as Structural Biology) and then Amgen Inc. (after its acquisition of Tularik in 2004), most recently as Vice President of Chemistry.

From 1983 to 1996, Juan held various scientific leadership positions at Parke-Davis/Warner-Lambert. Juan holds a Visiting Scholar appointment (ChEM-H) at Stanford University and is a member of the Scientific Advisory Board at Cleave Biosciences. Juan obtained a B.S. degree in Chemistry from Universidad Complutense in Madrid (Spain) and a Ph.D. degree in Organic Chemistry from the University of Michigan. He has co-authored over 100 scientific papers and is an inventor on 50 issued U.S. patents. Juan has been responsible for the advancement of over 20 novel molecules into clinical development for diseases including cancer, Alzheimer’s, Crohn’s, RA, diabetes and diabetic nephropathy, psoriasis, asthma, and vasculitis, among others.

Alex Franzusoff, Ph.D.

SVP Research and Product Development

Dr. Franzusoff joined PACT Pharma in January 2017. Previously, he was consulting for several private and public biotech/pharma companies in the I-O space, in addition to his role as founder and CEO of Krypton Immuno-oncology. At Bavarian Nordic, he worked at the forefront of the electrified I-O space as SVP R&D, which resulted in the $1B deal with BMS for Prostvac, its Ph3 cancer immunotherapy product. He had returned to California for that role, from Boston, after serving as Chief Executive Officer and Board Director for AZTherapies, developing Alzheimer’s therapies based on re-purposing previously approved drugs via the 505(b)2 pathway for Phase 3 studies. He previously led the venture-backed Permeon Biologics as President and a member of the board of directors. Dr. Franzusoff’s career in the biotechnology industry was launched with the co-founding of the biotech GlobeImmune, Inc., where he served as Vice President of Research & Development for immunotherapy against cancer & infectious diseases.

Dr. Franzusoff received his PhD in Biochemistry from SUNY at Stony Brook, NY. Dr. Franzusoff trained as a Postdoctoral Fellow with the Nobel Laureate, Dr. Randy Schekman, at the University of California, Berkeley. He was a tenured Associate Professor at the University of Colorado, School of Medicine until 2004.

According to the terms of the PACT Pharma founding agreement with Arcus Biosciences, PACT is supported by the efforts of the following Arcus executives:

Jennifer Jarrett, M.B.A.

Chief Business & Finance Officer, Arcus Biosciences (supporting PACT)

Ms. Jarrett most recently served as Chief Financial Officer of Medivation, where she was responsible for finance, accounting, information technology, investor relations, strategy and business development and played a significant role in the sale of Medivation to Pfizer.

Prior to Medivation, Jennifer spent 20 years in investment banking, most of that time covering biotechnology companies. Most recently, Ms. Jarrett served as a Managing Director at Citigroup where she headed up their west coast life sciences investment banking group. Prior to Citigroup, Ms. Jarrett worked in the investment banking divisions of Credit Suisse, Donaldson, Lufkin & Jenrette, Merrill Lynch and Kidder Peabody. Jennifer received her M.B.A from the Stanford Graduate School of Business and her undergraduate degree in Economics from Dartmouth College.

Steven Chan

VP Finance, Arcus Biosciences (supporting PACT)

Steve is a seasoned financial executive with over 20 years of experience managing the finance and accounting functions at companies in varying stages of growth, including two start-ups that successfully went public. Prior to joining Arcus, Steve was the VP Finance, Corporate Controller for MyoKardia, Inc. where he helped lead the company public in 2015 and built out the finance and accounting infrastructure and teams. Before MyoKardia, Steve was at Solta Medical, Inc., a global medical device company, where he was a Vice President and Corporate Controller, responsible for leading day-to-day company-wide accounting and finance operations from 2010 to 2014 until it was sold to Valeant Pharmaceuticals. Prior to Solta Medical, Steve was Vice President, Finance at Moody’s Analytics Inc. from 2007 to 2010, where he focused heavily on international expansion and M&A activities in addition to leading a 25 person finance team, Worldwide Revenue Director at Polycom from 2006 to 2007, and a Regional Controller at Logitech International S.A. from 2002 to 2006.

Steve started his career at KPMG LLP, is a Certified Public Accountant in California (inactive status) and holds a B.S. in Business Administration from the Haas School of Business at the University of California, Berkeley.

Tim Sullivan, Ph.D.

VP, Business Development, Arcus Biosciences (supporting PACT)

Tim has been involved in multiple aspects of drug discovery and development in pharmaceutical and biotechnology companies in the U.S. for more than 15 years, leading discovery and pharmacology teams in a variety of therapeutic areas (e.g., oncology, autoimmune, inflammatory, metabolic and CNS diseases) as well as being involved in groups focused on the external identification of novel technologies and assets suitable for in-licensing and/or acquisition. Prior to joining Arcus, Tim was a Senior Director in the External R&D Innovation (ERDI) group at Pfizer where he focused on identifying new Immuno-Oncology opportunities across all therapeutic modalities, as well as managing the global alliances with Servier and Cellectis focused on the discovery and development of allogeneic CAR-T cell products. Before Pfizer, Tim was a Director in the New Frontier Science group at Takeda, where he primarily focused on identifying and funding very early-stage technologies being developed in academic settings to determine utility in accelerating drug discovery and development.

Prior to Takeda, Tim held various scientific management roles, first at Tularik/Amgen and then as Director of Biology at ChemoCentryx. Tim holds a B.A. degree from the University of Notre Dame and a Ph.D. degree in Cellular and Molecular Biology from the University of California, Berkeley where he trained in the laboratory of Dr. James Allison.