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Andrew Koff, PhD


Founder and Director

Andrew has been at Memorial Sloan Kettering Cancer Center for over 25 years, where he started the Laboratory of Cell Cycle Regulation and holds the title of full Member (equivalent to tenured full professor). Andrew is internationally recognized for his work describing the mechanism by which cells make the decision to proliferate or withdraw from the cell cycle into a non-proliferative state, and the outcome of losing this control during normal development and in cancer in all tissues.  His earlier discoveries surrounding the identification and function of the cyclins and cyclin-dependent kinase inhibitors resulted in more than 90 peer-reviewed papers, as well as 12 patents and have opened up a number of additional fields of research and drug development. 

Andrew founded Atropos and became an entrepreneur because he is passionate about the science behind it. Over the last few years, Andrew’s attention has turned to understanding the decision made by cells after they withdraw from the cell cycle. Andrew has published on the first genes and proteins controlling this differentiation process called senescence after growth arrest (SAGA, or geroconversion). He firmly believes the molecular understanding of this pathway is important for improving upon the effectiveness of CDK4 inhibitors to treat patients with cancer, and might allow for the identification of compounds that could also limit the onset of many age-related morbidities. Through Atropos, Andrew has taken his seminal discoveries further to devise a proprietary, phenotypic screening drug discovery platform called FATES.

Andrew has received approximately $12M in funding from various sources including the National Institute of General Medicine, the National Cancer Institute, and philanthropic agencies.  His current distinctions include the Pew Foundation and Irma T. Hirschl Scholar. Andrew was also a past recipient of the Boyer Young Investigator Award and the Frederick R. Adler Chair at his academic institution. Andrew has been named as one of the top 250 highly cited researchers in Molecular Biology and Genetics by the Institute for Scientific Information.


William D. Tap, MD


Co-founder and Director

William D. Tap, MD is the Chief of the Sarcoma Medical Oncology Service at Memorial Sloan Kettering Cancer Center in New York. He is a medical oncologist who specializes in the treatment of patients with soft tissue and bone sarcomas. Bill has extensive experience in translational medicine as it applies to oncology and early drug development. He is an expert in developing therapeutic strategies in rare diseases and neoplasms, incorporating basic science research, correlative science, clinical medicine, and health outcomes tools. Bill’s academic research interests are focused on understanding the genetic and molecular nuances of sarcoma with an emphasis on identifying and validating therapeutic targets, treatment biomarkers, and modeling drug resistance. He is also focused on understanding cellular gerocoversion and its application to clinical medicine. Bill received his Medical Degree from Jefferson Medical College in Philadelphia and performed his residency in Internal Medicine at the Vanderbilt University Medical Center in Nashville, and his fellowship in Hematology and Medical Oncology at the UCLA Medical Center in Los Angeles.


Pauline Jen Ryan


CEO and Director

Pauline Jen Ryan is a CEO and a member of the Board of Directors of Atropos Therapeutics.  From 2014 to 2021, Pauline was a Partner at Red Sky Partners where she served in interim C-level roles (CEO, CBO, COO) and advised biotech clients on corporate and business development matters.  Her particular expertise is with small- to mid-size therapeutics companies, including startups and companies leveraging “virtual” operating models. Recently, Pauline partnered with the academic founder of ZielBio and determined the corporate strategy and corporate development plan that resulted in a successful $25.1M Series A raise with multiple competing terms sheets.  Pauline also served as interim co-CEO of Harbour Antibodies, an Atlas Venture portfolio company, which included management of consultants/employees, starting a US subsidiary and leading business development transactions, a long-term engagement which resulted in a successful exit, an acquisition by Harbour BioMed.  Pauline has also served as part-time CBO for a number of private and public companies in growth or transition.

Previously, Pauline helped lead investor Healthcare Ventures raise a $45M Series A round to launch Proteostasis Therapeutics.  In addition to setting intellectual property and business development strategy, she was responsible for establishing and growing all business operations functions such as finance, human resources and communications from launch to 50 employees.  Previously, Pauline was Senior Vice President, Corporate Development & Operations at ImmunoGen (NASD:  IMGN), where secured numerous corporate partnerships including the one with Genentech that created Kadcyla® for breast cancer and with Aventis (now Sanofi) for Sarclisa® for multiple myeloma.  As a corporate officer and member of the executive team, she headed corporate strategic planning, business development and alliance management during her tenure there and was also responsible for human resources, manufacturing, and program management during growth and transition stages.  She was responsible for raising over $150M in direct funding from corporate partnerships and was also instrumental in completing a $125M secondary offering.

Pauline has volunteered as a Trustee of the Advanced Math and Science Academy Charter School where she served as Board Chair for three years during a period of organizational growth and transition and she is a member of the Board of Directors of Distinguished Young Women, the national scholarship program previously known as America’s Junior Miss.  She is one of the inaugural Ambassadors for the New England Region’s American Cancer Society ResearcHERs campaign to support women-led cancer research.  She has previously served as an advisor for the Delta V accelerator program at the Martin Trust Center for Entrepreneurship at MIT, advising startups ReviveMed and Lumio. Earlier, she was on the Business Advisory Board of Solmap Pharmaceuticals, a wholly-owned subsidiary of Mercury Computer Systems, until its acquisition by Forma Therapeutics.  Pauline was also a founding member of the Biotechnology Industry Organization’s Business Development Advisory Committee and launched the BIO Business Development Fundamentals Course in 2003.

Pauline has an MBA from the Kellogg Graduate School of Management at Northwestern University, and a BA in Psychology from Northwestern University.

Dan Garza, PhD


VP, Drug Discovery Biology

Dan Garza is a Vice President of Drug Discovery Biology at Atropos Therapeutics. 

Dr. Garza has more than 25 years of drug discovery experience in academic, pharma, biotech. and CRO environments.   Most recently, Dan has been serving as a Scientific Coordinator at Scripps Research Institute, coordinating drug discovery-related activities for the laboratory of Jeffery Kelly and more than a dozen collaborating laboratories.

Previously, Dan was the Head of Biology and founding scientist at Proteostasis Therapeutics, a biotechnology start-up company focused on the development of small-molecule treatments for diverse diseases associated with expression of misfolded proteins.  Dr. Garza also served as a Senior Unit Head in the Department of Functional Genomics at the Novartis Institutes for Biomedical Research, where he led the Model Systems team and the Stress Response Pathways program focused on applying genome-scale screening technologies to the discovery of new targets and hit compounds for drug development.

Dan received his B.S. Biochemistry from SUNY Stonybrook and Ph.D. from Washington University Medical School Department of Genetics and carried out postdoctoral research at Stanford University Medical School Department of Developmental Biology/Biochemistry.

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Nathanie Trisnadi, PhD


Director of Laboratory Operations & Research Scientist

Nathanie established the lab at Atropos and is currently conducting research to translate discoveries in senescence after growth arrest into therapeutic drugs. She has experience in developing assays, particularly in imaging, and adapting these methods for different systems. Her work with advanced microscopy techniques and quantitative image analysis helped progress Atropos’ FATES platform towards drug discovery. Nathanie received her B.A. from the University of California - Berkeley and her Ph.D. from the California Institute of Technology. Prior to joining Atropos, she was a postdoctoral fellow at the National Institutes of Health.

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