Our Leadership

Mr. Paterson was appointed President and Chief Executive Officer of Verastem Oncology in 2023, following more than a decade of increasing leadership roles and responsibilities within the Company since joining in 2011. He has more than 30 years of experience across oncology drug and diagnostic development, business development, and launch planning.

Before joining Verastem, Mr. Paterson was the co-founder and Chief Operating Officer of On-Q-ity, a developer of technology to capture and analyze circulating tumor cells, and the founding Chief Executive Officer of The DNA Repair Company (merged to form On-Q-ity), which developed oncology-focused molecular diagnostics. Prior to that, Mr. Paterson was Head of Global Strategy for Specialty Market and Patient-Level Data at IMS Health, after playing a key role in the acquisition of PharMetrics by IMS Health as Vice President, Marketing and Corporate Development. While at PharMetrics, Mr. Paterson led the development of an innovative suite of pharmaceutical product launch tools that became the basis of the company’s product line. Earlier in his career, Mr. Paterson led clinical development and regulatory initiatives in academic, industry, and Contract Research Organizations.

Mr. Paterson holds a Bachelor of Arts in Biology from Boston University and attended the Northeastern University Graduate Pharmacology program.

Mr. Calkins is the Chief Financial Officer of Verastem Oncology, a role he was promoted to in October 2023 after steadily advancing within the Company since joining in 2018. He has been instrumental in supporting Verastem’s strategic transformation, providing financial leadership through key phases of growth and change.

With a deep background in finance and accounting, including a prior role as a Technical Accounting Consultant at CFGI, Mr. Calkins advised companies across various industries on complex technical accounting matters, financial reporting, IPO readiness, and internal controls. Mr. Calkins began his career with the Assurance practice at PwC in Boston.

Mr. Calkins received his Bachelor of Science in Accounting from Bryant University and his Master of Science in Accounting from Northeastern University.

Ms. Carew is the Chief Organizational Effectiveness Officer at Verastem Oncology and has been a key member of the Company since 2012, providing consistent leadership and deep institutional knowledge through the Company’s evolution and growth. Her longstanding commitment and adaptability have made her a trusted advisor and catalyst for change during pivotal moments in the Company’s history. During her tenure at Verastem, she has held interim roles, including Head of Human Resources, where she played a critical role shaping the Company’s people strategy and leadership development program.

With nearly two decades of management and consulting experience in the biopharma industry, including work with Dicerna Pharmaceuticals, Catamaran Bio, Aquinnah Pharma, and OvaScience, Ms. Carew is a proven organizational effectiveness leader. She has led organizations through major transitions, from early research phases to full commercialization and helped engage individuals and teams to deliver their highest levels of performance.

Mr. Crowther joined Verastem Oncology in October 2023 and currently serves as the Chief Commercial Officer. He is an accomplished marketing and commercialization leader with more than 20 years of experience leading commercial, marketing, and business operations, and has launched more than 10 leading oncology therapies in multiple geographies, including the U.S., Europe, and other emerging markets.

Prior to joining Verastem, Mr. Crowther was the Chief Business Officer at Minerva Biotechnologies, where he drove business success in immune-oncology through strategic planning, business development, and commercial operations. Before Minerva, Mr. Crowther was the Interim U.S. Lead and Vice President of U.S. Marketing at Kite Pharma where he was responsible for strategic marketing and business operations. Prior to Kite Pharma, he held positions of increasing responsibility within Global Marketing at Celgene where he led commercial strategy and execution across several therapeutic areas. Over the course of his career, Mr. Crowther has launched 10 oncology products, including Velcade^®, Xgeva^®, Istodax^®, Revlimid^®, Onureg^®, Inrebic^®, Reblozyl^®, Yescarta^®, and Tecartus^®.

Mr. Crowther received his Bachelor of Science at the Manchester Metropolitan University in Manchester, United Kingdom.

Dr. Hayslip, M.D., joined Verastem Oncology as Chief Medical Officer in April 2024. He has more than 25 years of oncology research and development experience across industry and academia, most recently serving as Chief Medical Officer at I-MAB Biopharma. Prior to that, Dr. Hayslip was the Vice President of Clinical Development at Nektar Therapeutics and led clinical development activities for multiple therapies while at AbbVie Oncology. Prior to joining AbbVie Oncology, Dr. Hayslip led numerous cancer research studies at the University of Kentucky’s Markey Cancer Center. Dr. Hayslip served as the Chief of Hematology and Bone Marrow Transplant and the Director of Clinical Research and Data Management at the University of Kentucky’s Markey Cancer Center, with responsibilities including leading protocol review teams and mentoring of junior faculty.

Dr. Hayslip received his medical degree from Northeast Ohio Medical University and a master’s degree in clinical research from the Medical University of South Carolina. Following his residency in internal medicine, Dr. Hayslip completed his fellowship in hematology-oncology at the Medical University of South Carolina, leading to dual board certifications in both hematology and medical oncology. Dr. Hayslip holds multiple U.S. and international patents and has published dozens of scientific papers and reviews in renowned journals including Lancet Haematology, Clinical Cancer Research, Leukemia Research, Blood, and Journal of Clinical Oncology.

Ms. Horvat is Senior Vice President, Corporate and Portfolio Strategy at Verastem Oncology bringing nearly 25 years of commercialization experience in the biopharmaceutical industry. including support for 12 product launches and building cross-functional teams in growing and established organizations. She joined the Company in February 2025 as the Chief of Staff of Operations.

Before Verastem, Ms. Horvat served as a Senior Consultant at The NemeztGroup, a strategic consulting firm where she executed over 50 commercialization projects spanning corporate strategy, launch planning, and asset valuation. She provided thought partnership to C-suite members across several organizations and served in various fractional/interim Commercial roles. Prior to consulting, Ms. Horvat was the Vice President of Global Marketing at ARIAD pharmaceuticals, with responsibilities for Global and US Marketing, Global Commercial Analytics, and Strategic Planning and ROW Alliance Management. 

Previously, Ms. Horvat held positions of increasing responsibility within ARIAD Pharmaceuticals, GPC Biotech and Bristol-Myers Squibb, where she helped build fully integrated commercial organizations to support successful drug and indication launches, as well as led geographic prioritization initiatives and supported strategic collaborations.

In addition to her biotech/pharmaceutical experience, Ms. Horvat was a Captain in the United States Marine Corps. She received her Bachelor of Science in Ocean Engineering from the US Naval Academy and an MBA from Harvard University.

Dr. Kauffman joined Verastem Oncology in December 2025 as President of Development after serving as the Company’s Lead Director of Verastem’s Board of Directors since June 2016. Dr. Kauffman has a deep understanding of the Company’s strategy, clinical development plans, and operations.

Previously, Dr. Kauffman served as the Chief Executive Officer of Nereid Therapeutics. He was co-founder and Chief Executive Officer of Karyopharm, where he guided the Company’s transition from a discovery stage biotechnology company to a commercial stage organization and the global approvals of XPOVIO®. Prior to co-founding Karyopharm, Dr. Kauffman was Chief Medical Officer of Onyx Pharma, where he led the development of Kyprolis® following the Onyx acquisition of Proteolix Inc., where he served as a board member and then Chief Medical Officer. Previously, Dr. Kauffman was President and Chief Executive Officer of EPIX Pharmaceuticals, Inc. (previously Predix Pharmaceuticals, Inc.). Before that, he was the leader of the Velcade® development program at Millennium Pharmaceuticals. He also held a number of senior positions at Millennium Predictive Medicine and Biogen Inc.

Dr. Kauffman received his M.D. and Ph.D. from Johns Hopkins Medical School, trained in Internal Medicine at Beth Israel (Deaconess) Medical Center and in Rheumatology at Massachusetts General Hospital, and is board certified in Internal Medicine.

Ms. Mockbee joined Verastem Oncology as the Global Head of Regulatory Affairs and Development and brings more than 25 years of drug development experience in the pharmaceutical and biotech industry with expertise in clinical development and regulatory strategy.

Before her role at Verastem, she was the Chief Development Officer and Senior Vice President of Regulatory at OncXerna Therapeutics. Ms. Mockbee established her distinguished career at Eli Lilly and Company, where she spent 20 years in oncology drug development in various leadership positions. Ms. Mockbee led the Verzenio^® global development program, where she combined innovation with speed to create and execute a development strategy that led to Verzenio’s approval and launch for metastatic breast cancer as well as the first positive Phase 3 study (monarchE) in early breast cancer for a CDK 4 & 6 inhibitor. Prior to that, Ms. Mockbee was the Head of Global Regulatory for Lilly Oncology where she was instrumental in original and supplemental NDA/BLA submissions and approvals for Gemzar^®, Alimta^®, Erbitux^®, and Cyramza^®, in addition to providing regulatory direction for the overall oncology portfolio.

Ms. Mockbee holds Bachelor of Science degrees in Chemistry and Pharmacy from Butler University and a Master of Business Administration from Purdue’s Krannert School of Business.

Dr. Pachter, Ph.D., is the Chief Scientific Officer at Verastem Oncology with over 30 years of experience leading discovery and translational research for small molecule and monoclonal antibody anti-cancer therapeutics.

Previously, Dr. Pachter was Head of Cancer Biology at OSI Pharmaceuticals, where his team was responsible for development of tumor cell EMT (epithelial-mesenchymal transition) models and discovery of drugs disrupting this process. At OSI, he advanced five small molecules into development for treatment of cancer, including OSI-906 – a selective IGF-1R/insulin receptor kinase inhibitor, which progressed to Phase 3 clinical trials – and OSI-027, a selective mTOR kinase inhibitor. Prior to OSI, Dr. Pachter held positions of increasing responsibility at Schering-Plough, where he progressed three agents into development including the monoclonal antibody robatumumab, which advanced to Phase 2 clinical evaluation in cancer patients. He also made key contributions to the regulatory approval of temozolomide for treatment of glioblastoma.

Dr. Pachter is an author of over 50 peer-reviewed publications and inventor on numerous patents. He completed his postdoctoral work in pharmacology at Yale University School of Medicine and he holds a Ph.D. from Baylor College of Medicine.

Mr. Sanburn is the Chief Business Officer at Verastem Oncology with nearly 30 years of experience across discovery, clinical development, portfolio strategy, business development, and collaborations. Since joining Verastem in 2022, Mr. Sanburn has played key roles in strategic business development and external engagement initiatives, supporting alliance management, clinical operations, and field medical functions. His leadership has been instrumental in securing Verastem’s exclusive rights to avutometinib in the EU and Japan, receiving the inaugural PanCan Therapeutic Accelerator Award, establishing a discovery and development agreement with GenFleet for multiple RAS pathway-targeted programs, and facilitating a strategic commercial collaboration with IQVIA for the launch of AVMAPKI™ FAKZYNJA™ CO-PACK.

Prior to Verastem, Mr. Sanburn served for more than 20 years in multiple scientific, clinical, and business leadership roles at Eli Lilly and Company where he owned key responsibilities across key licensing deals, research and development collaborations, clinical trial agreements, and strategic pharma and biotech transactions, including the acquisitions of Imclone and Loxo Oncology. He initiated Lilly’s collaboration with Merck on the KEYNOTE-189 trial (KEYTRUDA^® plus Alimta^® and platin) leading to subsequent cross-promotional activities for Alimta^® and Lilly’s collaboration with AstraZeneca for cross label promotion of Verzenio^® plus Faslodex^® . Earlier in his career, Mr. Sanburn helped establish the National Gene Vector Laboratory at Indiana University Medical Center, which played a significant role in advancing some of the earliest clinical development programs for gene therapies.

Mr. Sanburn received his undergraduate degree from Indiana University and his graduate degree from Purdue University.

Mr. Wanda joined Verastem Oncology in January 2025, with more than 30 years of life sciences experience and currently serves as Senior Vice President, Legal and Chief Compliance Officer.

Prior to Verastem, Mr. Wanda served in multiple legal and compliance leadership roles, including Deputy General Counsel at Sepracor, General Counsel and Corporate Secretary at Sunovion, Global Head of Anti-Bribery/Anti-Corruption compliance at Astellas, Head of Legal-Regulatory at Dicerna/Novo Nordisk, and General Counsel and Chief Compliance Officer at Defender Pharmaceuticals. In these roles he supported highly successful product launches including Prograf^®, Lunesta^®, and Xtandi^® and led legal teams across a range of business development transactions, including in-licensing, acquisitions, and divestitures.

Mr. Wanda received his undergraduate degrees in Finance and Economics with high honors from the University of Illinois and a J.D. from the University of Illinois College of Law. He is also a certified public accountant (CPA). He currently serves as Vice President of the Board at COOL Ministries, which operates a food pantry, provides transitional housing, and supports homeless veterans in the Lake County, IL, community.

Dr. Weinberg is a founding member of the Whitehead Institute for Biomedical Research and the Daniel K. Ludwig Professor for Cancer Research in the Department of Biology at MIT. Dr. Weinberg is also a founder of Verastem Oncology.

Dr. Weinberg is the internationally recognized authority on the genetic basis of human cancer development. Dr. Weinberg is the author or editor of five books and more than 350 articles. Three of the books are intended for a lay audience: One Renegade Cell, Racing to the Beginning of the Road: The Search for the Origin of Cancer, and Genes and the Biology of Cancer, the latter co-authored with Dr. Harold E. Varmus, former Director of the National Institutes of Health. More recently, Dr. Weinberg has published the textbook The Biology of Cancer, which is intended for doctoral students learning about this disease.

Dr. Weinberg is a member of the National Academy of Sciences and the Institute of Medicine and is a Fellow of the American Academy of Arts and Sciences.

Dr. Sznol is Professor of Internal Medicine, Leader of the Melanoma/Renal Cancer Disease-Associated Translational Research Team, and Co-Leader of the Cancer Immunology Program. Dr. Sznol is also the current President of the Society for Immunotherapy of Cancer (SITC). He has an international reputation in cancer drug development. Dr. Sznol graduated from Rice University and Baylor College of Medicine (BCM) in Houston, Texas. He trained in internal medicine at BCM and completed a medical oncology fellowship in the Department of Neoplastic Diseases, Mount Sinai Hospital, New York. He spent the next twelve years in the Biologics Evaluation Section (BES), Investigational Drug Branch (IDB), Cancer Therapy Evaluation Program of the National Cancer Institute, and was Head of the BES from 1994-1999. He attended on the inpatient units of the Biological Response Modifiers Program, NCI, from 1988-1996 and the Immunotherapy Service of the Surgery Branch, NCI, from 1997-1999. From 1999-2004, he served as Vice President of Clinical Development and Executive Officer of Vion Pharmaceuticals in New Haven, Connecticut.

Dr. Der is the Sarah Graham Kenan Distinguished Professor of Pharmacology at the University of North Carolina at Chapel Hill (UNC). Since his initial discovery of RAS oncogenes in human cancer, his research has centered on the study of RAS and RHO oncoproteins in cancer. His research has been funded by grants from the National Cancer Institute, Department of Defense, Lustgarten Foundation, and Pancreatic Cancer Action Network/AACR. Dr. Der is a member of the NCI RAS Working Group, the Frederick National Laboratory Advisory Committee, and he served previously on the NCI Board of Scientific Counselors. He is currently a member of the Scientific and Medical Advisory Board of the Pancreatic Cancer Action Network and previously on the scientific advisory board of the Lustgarten Foundation. His honors include Fellow of the AAAS, the recipient of an NCI Outstanding Investigator Award, the Battle Distinguished Cancer Research Award, the Mentorship Award for Lifetime Achievement, the University of California, Irvine Distinguished Alumnus Award, and the Einstein BIH Visiting Fellow Award.

He received his Ph.D. from the University of California, Irvine and completed his postdoctoral studies at Harvard Medical School and the Dana-Farber Cancer Institute.