Meet our Team
Matthew P. Jacobson, Ph.D.
Co-Founder
Matthew P. Jacobson, Ph.D. - Co-Founder
Matt Jacobson, Ph.D., is the Chair of the Department of Pharmaceutical Chemistry at UC San Francisco. He earned his Ph.D. in physical chemistry at MIT, and completed post-doctoral research at Oxford and Columbia. Matt’s research focuses on computational biophysics and computer-aided drug design; he is the author of over 120 publications. Software written by Matt and his collaborators is widely used in the pharmaceutical industry; he serves on the Scientific Advisory Board of Schrödinger, LLC, and is also a co-founder of Global Blood Therapeutics (NASDAQ: GBT), Relay Therapeutics and Cedilla Therapeutics. Matt received the NSF CAREER award, an Alfred P. Sloan Fellowship, and a School of Pharmacy teaching award. He has served on the editorial boards of several journals, including Biochemistry and PLoS Computational Biology.
David J. Earp, J.D., Ph.D.
President & CEO
David J. Earp, J.D., Ph.D. - President & CEO
David J. Earp, J.D., Ph.D., has served as the President & CEO of Circle since October 2013. Previously, David held various roles at Geron Corporation (GERN), including chief patent counsel, chief legal officer and senior vice president of corporate transactions, building a broad IP portfolio and playing an integral role in numerous partnering, licensing and collaboration deals. He led the spin-out of Geron’s nuclear transfer technology into StART Licensing, Inc., and its subsequent acquisition by Viagen Corp. (Austin, Texas). He served on the boards of StART and Viagen, including as executive chairman of Viagen and led the sale of the company to TransOva Genetics (subsequently acquired by Intrexon). David was also a member of the board of directors of TA Therapeutics Ltd. (Hong Kong, PRC). He was previously a partner in the intellectual property law firm of Klarquist Sparkman, LLP (Portland, Oregon). He currently also serves as a board member of Sienna Cancer Diagnostics (Melbourne, Australia).
David received his B.Sc. (with first class honours) in microbiology from the University of Leeds, his Ph.D. in biochemistry and molecular biology from the University of Cambridge, and his J.D. (magna cum laude) from the Northwestern School of Law of Lewis and Clark College. He was a postdoctoral research fellow at the University of California, Berkeley / USDA PGEC.
Rajinder Singh, Ph.D.
Chief Science Officer
Rajinder Singh, Ph.D. - Chief Science Officer
Rajinder Singh, Ph.D., has served as our Chief Scientific Officer since July 2020. From 2016 to 2020, Dr. Singh held the position of Senior Vice President of Research & Pharmaceutics at ChemoCentryx – where he worked on the complement system (C5aR inhibition with avacopan), diverse chemokine receptors (such as CCR1, CCR2, CCR6, CXCR2, CXCR7) and immune-oncology with small molecules targeting PD-1/PD-L1. From 1998 to 2016, Dr. Singh held various management positions including Vice President, Chemistry at Rigel Pharmaceuticals, Inc., where he oversaw the advancement of numerous drug candidates from discovery to clinical development, which included the filing of numerous Investigational New Drug applications leading to the approval of Tavalisse (fostamatinib) a Syk kinase inhibitor in the areas of immunology and oncology. Prior to joining Rigel, Dr. Singh was a lead chemist at Chiron Corporation from 1994 to 1998. From 1992 to 1994, Dr. Singh was a Postdoctoral Fellow at Eli Lilly & Company. Dr. Singh received his Ph.D. degree in Organic Chemistry from the University of Oxford and B.Sc in Chemistry from University of Cardiff.
David C. Spellmeyer, Ph.D.
Advisor, Informatics and Computational Chemistry
David C. Spellmeyer, Ph.D. - Advisor, Informatics and Computational Chemistry
David Spellmeyer brings over 25 years of scientific leadership experience to Circle, having served in senior positions at several drug development and life science services companies. These roles include CTO & CIO at Nodality, CSO at Signature BioScience, and vice president of computational sciences at CombiChem(acquired by DuPont). David was involved in the development of peptoids as therapeutics at Chiron. He serves as an Executive-in-Residence at ShangPharma Innovation, which is an investor in Circle. He heads Interlaken Associates, a life sciences advisory company, and is Adjunct Associate Professor in the Department of Pharmaceutical Chemistry at U.C. San Francisco, where he completed his postdoctoral studies. David received his PhD in theoretical organic chemistry at U.C. Los Angeles and a BS in computer science and chemistry from Purdue University.
Pablo D. Garcia, Ph.D.
Sr. Director, Biology Research
Pablo D. Garcia, Ph.D. - Sr. Director, Biology Research
Pablo D. Garcia, Ph.D., is a cellular and molecular biologist with extensive experience in oncology drug discovery and preclinical development. With over 17 years of experience at Chiron Corporation and the Novartis Institutes for Biomedical Research in Emeryville, he made significant contributions to the areas of target identification and validation, the implementation of diverse discovery platforms and the management of a cancer biology discovery group. Pablo has led several drug discovery projects, including the PIM kinase inhibitor project at Chiron/Novartis. As the project leader, he oversaw all stages of preclinical development, from the initial validation of relevance to human disease to delivery of a drug candidate to clinical development. Pablo has a B.A. in Biology, a Masters in Genetics from Universidad Católica de Valparaíso (Chile) and a Ph.D. in Biochemistry from the University of California, San Francisco (UCSF).
Amy Cowgill
Director, Business Operations and Administration
Amy Cowgill - Director, Business Operations and Administration
Siegfried S.F. Leung, Ph.D.
Sr. Scientist II, Computational Chemistry
Siegfried S.F. Leung, Ph.D. - Sr. Scientist II, Computational Chemistry
Siegfried Leung, Ph.D., specializes in computational drug design and has over a decade of experience in macrocycle design and modeling. He joined Circle after undertaking postdoctoral research in the laboratory of Circle founder Matt Jacobson at UC San Francisco. His work there focused on the development of physics-based predictive models for passive membrane permeability and the application of these methods in designing cell permeable cyclic peptides. He was a key member of the Pfizer / Jacobson laboratory collaboration investigating the engineering of permeability into macrocyclic peptides, developing computational protocols for target-based design of permeable macrocycles. Siegfried received a B.S. (cum laude) from University of San Francisco and his Ph.D. in chemistry from Yale University under the mentorship of Prof. William Jorgensen.
Andrew T. Bockus, Ph.D.
Sr. Scientist II, Chemistry
Andrew T. Bockus, Ph.D. - Sr. Scientist II, Chemistry
Andrew T. Bockus, Ph.D., leads Circle’s chemistry team. Andrew is a chemist with over a decade of experience in the field of passively-permeable peptidic macrocycles. Prior to joining Circle Pharma, Andrew worked in the lab of Prof. Scott Lokey, a co-founder of Circle, where he synthesized natural product-like cyclic peptides and identified drivers of structure-permeability relationships in diverse peptidic scaffolds. He then developed applications for synthetic receptors and taught undergraduate courses in organic chemistry as a postdoc for Prof. Adam Urbach at Trinity University. Andrew holds a B.A. in Chemistry and Biochemistry from Skidmore College and a Ph.D. in Chemistry from the University of California, Santa Cruz.
Catherine Gleason, Ph.D.
Sr. Scientist I, Biology Research
Catherine Gleason, Ph.D. - Sr. Scientist I, Biology Research
Catherine Gleason, Ph.D., received her B.S. in biochemistry from the University of Washington and earned her Ph.D. from the University of Pennsylvania under the mentorship of Prof. Morris Birnbaum. She trained as a postdoctoral research fellow with Prof. Philip Cohen at the Medical Research Council’s Protein Phosphorylation Unit at the University of Dundee, UK, where she studied the interplay of protein phosphorylation and ubiquitylation in Toll-like receptor signaling and the innate immune response. Before joining Circle Pharma, she was an Adjunct Assistant Professor at the University of California San Francisco, investigating the mTOR signaling pathway in regulation of renal metabolism and ion transport.
Luis Hernandez
Manager, Chemistry
Luis Hernandez - Manager, Chemistry
Luis Hernandez is a member of Circle’s chemistry team. Luis has applied his continuous improvement and management experience from his previous role in a manufacturing facility to streamline macrocycle production and information workflows for Circle. Luis previously held positions at Ingredion, Inc. and Formulation Technology, Inc. He holds a B.S. in Chemical Biology from the University of California, Berkeley.
Breena Fraga
Scientist I, Chemistry
Breena Fraga - Scientist I, Chemistry
Breena Walton earned a B.S. in Molecular Synthesis at the University of California, San Diego. After studying total synthesis at the University of Pennsylvania under Prof. Madeleine Joullie and earning an M.S., she went on to work at E.I Dupont de Nemours in the Crop Protection division where she was a co-inventor on several patent applications for bicyclic azoles and helped move a product towards market. She subsequently worked in medicinal chemistry at Theravance Biopharma, and now at Circle Pharma in the chemistry team where her work focuses on advanced chemical synthesis and design.
Miles W. Membreno
Research Associate II, Biology
Miles W. Membreno - Research Associate II, Biology
Miles Membreno has worked in both the Biology and Chemistry teams at Circle and currently focuses on developing and running assays for hit identification and lead optimization. Miles previously worked at CS Bio, where he focused on peptide purification. He holds a B.S. in Pharmacology from the University of California, Santa Barbara.
Miguel P. Baldomero
Sr. Research Associate, Chemistry
Miguel P. Baldomero - Sr. Research Associate, Chemistry
Miguel Baldomero is a member of Circle’s chemistry team where he focuses on macrocycle synthesis. Miguel previously held positions at CS Bio and Bachem Americas. He holds a B.S. in Chemistry from the University of Wisconsin, Oshkosh.
Bryan M. Lent
Research Associate II, Chemistry
Bryan M. Lent - Research Associate II, Chemistry
Bryan Lent works with the chemistry team at Circle Pharma and manages lab operations. Bryan holds a B.S. in Biochemistry from California Polytechnic University, San Luis Obispo and undertook post-graduate studies in Biological Chemistry at Ohio State University with Prof. Jen Ottesen.
Frances Hamkins-Indik
Research Associate, Biology
Frances Hamkins-Indik - Research Associate, Biology
Frances Hamkins-Indik is a research associate at Circle Pharma working with the Biology and Chemistry teams. Frances previously worked in Prof. Phil Crews’ group at UC Santa Cruz as an undergraduate researcher and received their B.S. in Chemistry from UC Santa Cruz.
Nick Vaquera
Laboratory Technician
Nick Vaquera - Laboratory Technician
Cayla M. McEwen
Business Operations Consultant
Cayla M. McEwen - Business Operations Consultant
Cayla McEwen has been responsible for the administrative and operational needs of Circle Pharma since its inception. She was previously the laboratory manager for Scott Lokey’s group at UC Santa Cruz and a Grants Officer at UCSC. Cayla received her B.S. (Summa cum Laude) in Chemistry from Washington State University.
Board of Directors
John Josey, Ph.D.
Chairman of the Board
John Josey, Ph.D.
Peter Svennilson, Ph.D.
The Column Group
Peter Svennilson, Ph.D.
Thilo Shroeder, Ph.D.
Nextech Invest
Thilo Shroeder, Ph.D.
Walter H. Moos, Ph.D.
ShangPharma Innovation / Pandect Bioventures
Walter H. Moos, PhD - Board Chair
Walter holds Ph.D. and A.B. degrees in chemistry from UC Berkeley and Harvard, respectively.
Founders
R. Scott Lokey, Ph.D.
Co-Founder
R. Scott Lokey, Ph.D. - Co-Founder
Scott Lokey , Ph.D., has been a faculty member in the department of Chemistry and Biochemistry at the University of California Santa Cruz since 2002. He received his Bachelor’s of Science in Chemistry from Trinity University in San Antonio, Texas in 1989, and a Ph.D. in Chemistry from University of Texas, Austin in 1997 under the mentorship of Dr. Brent Iverson. Dr. Lokey held a NIH postdoctoral fellowship at the Harvard Institute of Chemistry and Cell Biology in Boston, Massachusetts, where he worked with Professors Timothy Mitchison and Marc Kirschner on the identification of cyclic peptide modulators of actin dynamics. His current research interests include the basic science underlying cell permeability of cyclic peptides. He has developed methodologies for synthesizing backbone-modified cyclic peptides. Dr. Lokey and Dr. Jacobson have collaborated on the application of computational approaches for predicting membrane permeability in non-Lipinski Rule-of-5 molecules, with a particular focus on macrocyclic peptides. Dr. Lokey co-founded Circle Pharma with Dr. Jacobson.
Key Advisors
Barbara Weber, M.D.
Senior Advisor, Oncology Therapeutics
Barbara Weber, M.D. - Senior Advisor, Oncology Therapeutics
William G. Kaelin, Jr. M.D.
Advisor
William G. Kaelin, Jr. M.D.
Dr. Kaelin is a Professor in the Department of Medicine at the Dana-Farber Cancer Institute, Harvard Medical School, and Associate Director, Basic Science, for the Dana-Farber/Harvard Cancer Center. He obtained his undergraduate and MD degrees from Duke University and completed his training in internal medicine at the Johns Hopkins Hospital, where he served as chief medical resident. He was a clinical fellow in Medical Oncology at the Dana-Farber Cancer Institute, during which time he was a McDonnell Scholar. He was elected to the National Academy of Sciences, has been a Howard Hughes Medical Investigator since 1998, and has received numerous recognitions for his work, including the Albert Lasker Basic Medical Research Award (2016), the Princess Takamatsu Award (AACR, 2016), the Science of Oncology Award (ASCO, 2016) and the Canada Gairdner International Award (2010). Dr. Kaelin’s research seeks to understand how, mechanistically, mutations affecting tumor-suppressor genes cause cancer. His long-term goal is to lay the foundation for new anticancer therapies based on the biochemical functions of tumor suppressor proteins.
Richard Kriwacki, Ph.D.
Advisor
Richard Kriwacki, Ph.D.
Zaneta Nikolovska –Coleska, Ph.D.
Advisor
Zaneta Nikolovska –Coleska, Ph.D.
Dr. Nikolovska-Coleska is an Associate Professor of Pathology and Director of the Molecular and Cellular Pathology Graduate Program at the University of Michigan. Her research group focuses on the discovery, design and development of new molecularly targeted therapies for cancer, particularly protein-protein interactions that are involved in programmed cell death and epigenetic regulation. Dr. Nikolovska-Coleska was the recipient of several awards including the Chemical Structure Association Trust (CSA Trust), New Investigator Award from Leukemia Research Foundation and Innovator Award from Harrington Discovery Institute. She is an inventor on more than 13 international and US patents and patent applications, contributing to the discovery and development of clinical candidate AT-406, an XIAP inhibitor, which is in Phase I clinical trial for the treatment of human cancer. Currently she serves on the Board of Directors of the International Chemical Biology Society. Dr. Nikolovska-Coleska received her PhD in pharmaceutical chemistry at the Ss. Cyril and Methodius University, Skopje, Republic of Macedonia, and was a post-doctoral fellow in drug discovery at the University of Michigan.
Steven Olson, Ph.D.
Advisor
Steven Olson, Ph.D.
Dr. Olson is an Adjunct Professor in the Institute for Neurodegenerative Diseases at the University of California, San Francisco, where he leads drug discovery research into neurodegenerative diseases. He was previously a medicinal chemist at Merck Research Laboratories and Amgen where he was the chemistry lead for Amgen’s MDM2:p53 project, deploying structure based design to develop small moleciule inhibitors of this protein-protein interaction, leading to the discovery of AMG-232, which is currently in clinical studies. Dr. Olson holds a PhD from Yale University, where he worked in the laboratory of Dr. Samuel Danishefsky, and conducted postdoctoral research at U.C. Berkeley.
Ronald Zuckerman, Ph.D.
Advisor
Ronald Zuckerman, Ph.D.
Dr. Zuckerman is the Facility Director of the Biological Nanostructures Facility at the Molecular Foundry, Lawrence Berkeley National Laboratory. The focus of his research team there is on sequence-defined peptoid polymers. He received his PhD from UC Berkeley in bioorganic chemistry with Dr. Peter Schultz, and became a founding chemist at Protos Corp, a combinatorial chemistry company, where he developed robotic combinatorial library synthesizers and a novel class of heteropolymers called peptoids. Following the acquisition of Protos by Chiron, he continued his work at Chiron until joining Lawrence Berkeley National Laboratory.