Leadership
Theseus is led by targeted oncology pioneers with a proven track record in developing and commercializing targeted cancer therapeutics.
Our management team brings together leaders with extensive experience in the discovery, development and commercialization of cancer therapeutics – specifically, in developing tyrosine kinase inhibitors (TKIs) that target cancer-causing and resistance mutations in key driver oncogenes. Several members of our leadership team applied similar methodology in bringing three TKIs to market while at ARIAD, a global commercial-stage oncology company that was acquired by Takeda in 2017.
Kristine Callahan, CPA
Vice President, Controller
Kristine Callahan, CPA, is Vice President, Controller of Theseus Pharmaceuticals. Kristine most recently served as Senior Director of Accounting at Finch Therapeutics where she led the finance team from the transitional stages of start-up, to emerging growth and IPO. Previously Kristine worked with Danforth Advisors leading operational and finance functions in various life science companies, as the Controller of Flagship Pioneering, and Director of Financial Reporting at Winthrop Realty Trust. She began her career in public accounting at Deloitte & Touche where she successfully worked as a Senior Manager in each of the audit, tax, and technology groups within the firm. Kristine received a B.S. in Accountancy from Bentley University, an M.S. in Taxation from Northeastern University and is licensed as a CPA in the state of Massachusetts.
Tim Clackson, Ph.D.
President & Chief Executive Officer
Tim Clackson, Ph.D., is President and Chief Executive Officer of Theseus Pharmaceuticals. Tim most recently served as President and Chief Technology Officer at Xilio Therapeutics, a privately held oncology company developing tumor-selective immunotherapies, where he led the development of the company’s technology and product strategy. From 1994 to 2018, Tim was with ARIAD Pharmaceuticals, where he was President of Research & Development and Chief Scientific Officer. He played a key role in the company’s evolution from early research to a global commercial oncology company, and its subsequent acquisition by Takeda. He led the multi-disciplinary R&D team that internally discovered and developed five clinical-stage product candidates, including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Prior to ARIAD, Tim was a postdoctoral research fellow at Genentech. He received his Ph.D. in Biology from the University of Cambridge, and his B.A. in Biochemistry from the University of Oxford. Tim serves as a director on the boards of Forma Therapeutics, Elevation Oncology and the Massachusetts Biotechnology Council (MassBio).
Claire Coleman, Ph.D.
Vice President, Program Management
Claire Coleman, Ph.D., is Vice President of Program Management at Theseus Pharmaceuticals. Dr. Coleman has 16 years of experience in the pharmaceutical, biotechnology and complex generics industries. She most recently served as Executive Director, Head of Program Management at Allena Pharmaceuticals where she managed cross functional program teams through preclinical, Phase 1, Phase 2, and Phase 3 studies. Prior to that from 2006 through 2018, Dr. Coleman held positions of increasing responsibility at Momenta Pharmaceuticals including Director of Program & Alliance Management, Program leader and CMC team leader for multiple biosimilar programs across numerous indications. She holds a Ph.D. in Organic Chemistry from the University College Dublin, Ireland, and completed a Postdoctoral Fellowship in Organic Chemistry at the University of Pittsburgh.
Katie Dahlstrom
Vice President, Clinical Development Operations
Katie Dahlstrom is Vice President of Clinical Development Operations at Theseus Pharmaceuticals. Katie was previously a Senior Director of Clinical Operations at Agios Pharmaceuticals where she oversaw the operational execution of the TIBSOVO® (ivosidenib) program from IND through full approval from a Phase 1 clinical trial in R/R acute myeloid leukemia (AML), including a successful FDA inspection with no 483s. She also oversaw the successful execution of Phase 3 pivotal trials with mitapivat and was the Clinical Operations lead on the subsequent NDA/MAA filings in a rare hematologic disorder, pyruvate kinase deficiency, as well as clinical development planning and startup of pivotal programs in thalassemia and sickle cell disease. Katie has prior clinical operations experience from Takeda Oncology and pharmacovigilance experience from Genzyme, a Sanofi Company. Katie received a B.S. in Biology from Stonehill College and an M.A. in Clinical Investigation from Boston University Medical School.
Brad Dahms
Chief Financial Officer
Brad Dahms is Chief Financial Officer of Theseus Pharmaceuticals. Brad most recently served as Chief Financial Officer of Selecta Biosciences, Inc. (NASDAQ: SELB), where he oversaw financial operations, investor relations, and business development activities. He led Selecta through several significant financing and strategic transactions, including a $730 million licensing agreement. Previously, Brad was a Senior Vice President in the Healthcare Group at Cantor Fitzgerald & Co., focused on providing strategic and financial advice to life sciences companies. Prior to Cantor, Brad held several other investment banking roles, including at RBC Capital Markets in the Healthcare Group, and at J.P. Morgan. Brad earned a B.S. in Economics, with honors, from The Ohio State University.
Benjamin Enerson
Vice President, Legal Affairs
Ben Enerson is Vice President, Legal Affairs at Theseus Pharmaceuticals. Mr. Enerson has over 18 years of experience counseling clients in the medical device, pharmaceutical, and biotech industries. Before joining Theseus, he served as General Counsel at Tremeau Pharmaceuticals, Inc. and Finch Therapeutics Group, Inc., where he was responsible for all legal and intellectual property matters. Prior to that, he was corporate counsel at Moderna, Inc. and Sunovion Pharmaceuticals Inc., where he focused on complex transactions and intellectual property litigation, prosecution, and licensing. Mr. Enerson has a J.D. from Cornell Law School (2004, cum laude), and a B.A. in Chemistry from Vanderbilt University.
Wei-Sheng Huang, Ph.D.
Co-Founder, Senior Vice President, Chemistry
Wei-Sheng Huang, Ph.D., is Co-Founder and Senior Vice President of Chemistry at Theseus Pharmaceuticals. As Director, Discovery Chemistry at ARIAD Pharmaceuticals, where he served for 14 years, Wei-Sheng led the medicinal chemistry team that was the engine behind the discovery of ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Previously, as Senior Scientist at UCB Pharma, he focused on discovering sigma receptor agonists and opioid receptor-like-1 antagonists. Wei-Sheng conducted postdoctoral research at University of Virginia and Massachusetts Institute of Technology; he has co-authored over 60 publications in peer-reviewed journals; and is co-inventor of over 30 granted patents or patent applications. Wei-Sheng received his Ph.D. from Shanghai Institute of Organic Chemistry, Chinese Academy of Science and his B.S. from Huazhong University of Science and Technology.
David Kerstein, M.D.
Chief Medical Officer
David Kerstein, M.D. is Chief Medical Officer at Theseus Pharmaceuticals. David is a physician and an experienced oncology clinical research and development leader. Prior to joining Theseus, David served as Chief Medical Officer and Senior Vice President at Anchiano Therapeutics, a clinical-stage oncology company. He previously served as Senior Medical Director of Oncology Clinical Research at Takeda Pharmaceuticals, where he was the lung cancer clinical portfolio strategy lead and global clinical lead for ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC), as well as oversaw the initiation of clinical development for EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC.. Prior, David was Senior Medical Director of Clinical Research at ARIAD Pharmaceuticals, where he led the clinical development program, and New Drug Application and Marketing Authorization submissions for ALUNBRIG® (brigatinib). Previously, at Boston Biomedical, he was Director of Clinical Development and Regulatory Affairs. David received his M.D. from Tufts University School of Medicine and his B.S. in Biology from Tufts University.
Ron Knickerbocker, Ph.D.
Senior Vice President, Biometrics & Clinical Development Strategy
Ron Knickerbocker, Ph.D., is Senior Vice President, Biometrics and Clinical Development Strategy at Theseus Pharmaceuticals. Dr. Knickerbocker has over 25 years’ experience in the biotechnology and pharmaceutical industries. He most recently served as Vice President, Biometrics at EQRx where he built a biometrics team within a startup and was part of a Development Leadership Team that led global regulatory submissions for two oncology compounds. Prior to that Ron has led organizations, focusing primarily on oncology development, at companies including Ariad Pharmaceuticals, Anchiano Therapeutics, Genzyme, Pfizer, and Eli Lilly and Company. Ron has a Ph.D. in Statistics from Texas A&M University.
Nachu Narasimhan, Ph.D.
Senior Vice President, Drug Metabolism & Preclinical Safety
Narayana (Nachu) Narasimhan, Ph.D., is Senior Vice President, Drug Metabolism & Preclinical Safety at Theseus Pharmaceuticals. Nachu has over 30 years of expertise in Drug metabolism, Bioanalytical disciplines and over 10 years in preclinical safety and clinical pharmacology. He has contributed to the development and approval of abamectin and eprinomectin, two anthelminthic drugs while working at Merck. During his tenure at Bristol-Myers-Squibb, Nachu worked on Entecavir, a HepB drug which was approved. During his employment at ARIAD, Nachu was a key member of the discovery and development teams of three approved oncology drugs, ICLUSIG® (ponatinib), ALUNBRIG® (brigatinib), and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Most recently, Nachu served as Vice president for Drug Metabolism and Clinical Pharmacology at Verastem Oncology and worked on the successful approval of Copiktra® (duvelisib) in EU. Nachu received his M.S in Chemistry from Indian Institute of Technology, Chennai, and then completed his Ph.D. in chemistry at Vanderbilt University. Nachu conducted post-doctoral research at the University of Kansas. Nachu has published over 40 articles in peer reviewed journals in the areas of medical chemistry, drug metabolism, and Clinical pharmacology and has authored over 100 technical reports and regulatory submission documents.
Victor Rivera, Ph.D.
Co-Founder, Chief Scientific Officer
Victor Rivera, Ph.D., is Co-Founder and Chief Scientific Officer at Theseus Pharmaceuticals. Vic is an accomplished drug discovery and translational research leader. In over two decades at ARIAD Pharmaceuticals, beginning as a postdoctoral scientist and most recently as Vice President, Preclinical and Translational Research, he co-led discovery and led the translational research for the company’s programs including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC, ridaforolimus, and rimiducid. He has authored or co-authored over 75 peer-reviewed publications. Vic earned his Ph.D. in Microbiology and Molecular Genetics from Harvard Medical School and his A.B. in Molecular Biology from Princeton University.
Len Rozamus
Senior Vice President, Technical Operations
Len Rozamus is Senior Vice President, Technical Operations at Theseus Pharmaceuticals. An organic chemist with more than three decades of pharmaceutical discovery and development experience, Len began his career in medicinal chemistry at SmithKline Beecham and later transitioned to process development and the management of outsourced contract manufacturing for clinical programs at ARIAD Pharmaceuticals. As Sr. Director, Manufacturing Operations at ARIAD, Len provided leadership in every aspect of CMC, from pre-clinical programs through commercial products, primarily in support of ARIAD’s fast-track and breakthrough medications, including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); EXKIVITY® (mobocertinib), approved for EGFR Exon 20 insertion+ NSCLC. Most recently, Len served as the Founder and President of Rozamus and Associates, Inc., leading a team of seasoned consultants providing strategic and operational guidance to small and large companies for product life-cycle management. Len holds a Master’s in Organic Chemistry from the University of Virginia and a B.S. in Chemistry from The College of William and Mary in Virginia.
William Shakespeare, Ph.D.
Co-Founder, President of Research & Development
William Shakespeare, Ph.D., is Co-Founder and President of Research and Development at Theseus Pharmaceuticals. Bill is a renowned leader in chemistry and drug discovery, previously serving as the Vice President, Drug Discovery at ARIAD Pharmaceuticals. During his tenure of over two decades at ARIAD, he led multi-disciplinary teams in the discovery of three FDA-approved oncology drugs, ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Bill conducted his postdoctoral studies at the University of Pennsylvania; he is the author or co-author of more than 70 publications in peer-reviewed journals and is a co-inventor on more than 40 patents and patent applications. He received his Ph.D. in Chemistry from the University of New Hampshire and his B.S. in Chemistry from Gettysburg College.
Shouryadeep “Deep” Srivastava, M.D., Ph.D.
Vice President, Clinical Development
Deep Srivastava, M.D., Ph.D., is Vice President of Clinical Development at Theseus Pharmaceuticals. Dr. Srivastava has 13 years of clinical research experience in the biotechnology and pharmaceuticals industry. He most recently served as Vice President, Clinical Development at iTeos Therapeutics where he led the clinical development activity for immunotherapies being developed for solid tumors. In his role at iTeos, he led successful IND clearance by the FDA for a Phase 2 lung cancer trial and was responsible for the clinical strategy, monitoring, and oversight activities. Prior to that from 2018 through 2021, Deep held positions of increasing responsibility at Takeda and played a pivotal role in sNDA approval, Phase 3 initiation, and pediatric development for a leukemia drug, ICLUSIG® (ponatinib), as the Global Clinical Lead. Earlier in his career, he was a member of the Baxalta/Shire Hematology clinical team and also held medical writing and other roles in different companies. Dr. Srivastava received his M.D. from B.R.D. Medical College, India, and his Ph.D. from Texas Tech University.
Steve Tuller
Vice President, Quality Assurance
Steve Tuller is Vice President of Quality Assurance at Theseus Pharmaceuticals. Steve has 24 years of experience in the pharmaceutical and biotechnology industries. He most recently served as Vice President, Head of QA at Epizyme, Inc. where he initiated the GxP QA organization. In his role at Epizyme he led a successful FDA Pre-Approval Inspection for Tazverik and was responsible for clinical/commercial QA functions and Computer Systems Validation compliance. Prior to that from 2014-2016 Steve was Head of QA at Bind Therapeutics and held positions of increasing responsibility in QA, QC, and Analytical Development at Vertex, Advancis Pharma, and Shepherd Chemical. Steve has a B.S. in Chemistry from East Tennessee State University.
Kristine Callahan, CPA
Vice President, Controller
Kristine Callahan, CPA, is Vice President, Controller of Theseus Pharmaceuticals. Kristine most recently served as Senior Director of Accounting at Finch Therapeutics where she led the finance team from the transitional stages of start-up, to emerging growth and IPO. Previously Kristine worked with Danforth Advisors leading operational and finance functions in various life science companies, as the Controller of Flagship Pioneering, and Director of Financial Reporting at Winthrop Realty Trust. She began her career in public accounting at Deloitte & Touche where she successfully worked as a Senior Manager in each of the audit, tax, and technology groups within the firm. Kristine received a B.S. in Accountancy from Bentley University, an M.S. in Taxation from Northeastern University and is licensed as a CPA in the state of Massachusetts.
Tim Clackson, Ph.D.
President & Chief Executive Officer
Tim Clackson, Ph.D., is President and Chief Executive Officer of Theseus Pharmaceuticals. Tim most recently served as President and Chief Technology Officer at Xilio Therapeutics, a privately held oncology company developing tumor-selective immunotherapies, where he led the development of the company’s technology and product strategy. From 1994 to 2018, Tim was with ARIAD Pharmaceuticals, where he was President of Research & Development and Chief Scientific Officer. He played a key role in the company’s evolution from early research to a global commercial oncology company, and its subsequent acquisition by Takeda. He led the multi-disciplinary R&D team that internally discovered and developed five clinical-stage product candidates, including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Prior to ARIAD, Tim was a postdoctoral research fellow at Genentech. He received his Ph.D. in Biology from the University of Cambridge, and his B.A. in Biochemistry from the University of Oxford. Tim serves as a director on the boards of Forma Therapeutics, Elevation Oncology and the Massachusetts Biotechnology Council (MassBio).
Claire Coleman, Ph.D.
Vice President, Program Management
Claire Coleman, Ph.D., is Vice President of Program Management at Theseus Pharmaceuticals. Dr. Coleman has 16 years of experience in the pharmaceutical, biotechnology and complex generics industries. She most recently served as Executive Director, Head of Program Management at Allena Pharmaceuticals where she managed cross functional program teams through preclinical, Phase 1, Phase 2, and Phase 3 studies. Prior to that from 2006 through 2018, Dr. Coleman held positions of increasing responsibility at Momenta Pharmaceuticals including Director of Program & Alliance Management, Program leader and CMC team leader for multiple biosimilar programs across numerous indications. She holds a Ph.D. in Organic Chemistry from the University College Dublin, Ireland, and completed a Postdoctoral Fellowship in Organic Chemistry at the University of Pittsburgh.
Katie Dahlstrom
Vice President, Clinical Development Operations
Katie Dahlstrom is Vice President of Clinical Development Operations at Theseus Pharmaceuticals. Katie was previously a Senior Director of Clinical Operations at Agios Pharmaceuticals where she oversaw the operational execution of the TIBSOVO® (ivosidenib) program from IND through full approval from a Phase 1 clinical trial in R/R acute myeloid leukemia (AML), including a successful FDA inspection with no 483s. She also oversaw the successful execution of Phase 3 pivotal trials with mitapivat and was the Clinical Operations lead on the subsequent NDA/MAA filings in a rare hematologic disorder, pyruvate kinase deficiency, as well as clinical development planning and startup of pivotal programs in thalassemia and sickle cell disease. Katie has prior clinical operations experience from Takeda Oncology and pharmacovigilance experience from Genzyme, a Sanofi Company. Katie received a B.S. in Biology from Stonehill College and an M.A. in Clinical Investigation from Boston University Medical School.
Brad Dahms
Chief Financial Officer
Brad Dahms is Chief Financial Officer of Theseus Pharmaceuticals. Brad most recently served as Chief Financial Officer of Selecta Biosciences, Inc. (NASDAQ: SELB), where he oversaw financial operations, investor relations, and business development activities. He led Selecta through several significant financing and strategic transactions, including a $730 million licensing agreement. Previously, Brad was a Senior Vice President in the Healthcare Group at Cantor Fitzgerald & Co., focused on providing strategic and financial advice to life sciences companies. Prior to Cantor, Brad held several other investment banking roles, including at RBC Capital Markets in the Healthcare Group, and at J.P. Morgan. Brad earned a B.S. in Economics, with honors, from The Ohio State University.
Benjamin Enerson
Vice President, Legal Affairs
Ben Enerson is Vice President, Legal Affairs at Theseus Pharmaceuticals. Mr. Enerson has over 18 years of experience counseling clients in the medical device, pharmaceutical, and biotech industries. Before joining Theseus, he served as General Counsel at Tremeau Pharmaceuticals, Inc. and Finch Therapeutics Group, Inc., where he was responsible for all legal and intellectual property matters. Prior to that, he was corporate counsel at Moderna, Inc. and Sunovion Pharmaceuticals Inc., where he focused on complex transactions and intellectual property litigation, prosecution, and licensing. Mr. Enerson has a J.D. from Cornell Law School (2004, cum laude), and a B.A. in Chemistry from Vanderbilt University.
Wei-Sheng Huang, Ph.D.
Co-Founder, Senior Vice President, Chemistry
Wei-Sheng Huang, Ph.D., is Co-Founder and Senior Vice President of Chemistry at Theseus Pharmaceuticals. As Director, Discovery Chemistry at ARIAD Pharmaceuticals, where he served for 14 years, Wei-Sheng led the medicinal chemistry team that was the engine behind the discovery of ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Previously, as Senior Scientist at UCB Pharma, he focused on discovering sigma receptor agonists and opioid receptor-like-1 antagonists. Wei-Sheng conducted postdoctoral research at University of Virginia and Massachusetts Institute of Technology; he has co-authored over 60 publications in peer-reviewed journals; and is co-inventor of over 30 granted patents or patent applications. Wei-Sheng received his Ph.D. from Shanghai Institute of Organic Chemistry, Chinese Academy of Science and his B.S. from Huazhong University of Science and Technology.
David Kerstein, M.D.
Chief Medical Officer
David Kerstein, M.D. is Chief Medical Officer at Theseus Pharmaceuticals. David is a physician and an experienced oncology clinical research and development leader. Prior to joining Theseus, David served as Chief Medical Officer and Senior Vice President at Anchiano Therapeutics, a clinical-stage oncology company. He previously served as Senior Medical Director of Oncology Clinical Research at Takeda Pharmaceuticals, where he was the lung cancer clinical portfolio strategy lead and global clinical lead for ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC), as well as oversaw the initiation of clinical development for EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC.. Prior, David was Senior Medical Director of Clinical Research at ARIAD Pharmaceuticals, where he led the clinical development program, and New Drug Application and Marketing Authorization submissions for ALUNBRIG® (brigatinib). Previously, at Boston Biomedical, he was Director of Clinical Development and Regulatory Affairs. David received his M.D. from Tufts University School of Medicine and his B.S. in Biology from Tufts University.
Ron Knickerbocker, Ph.D.
Senior Vice President, Biometrics & Clinical Development Strategy
Ron Knickerbocker, Ph.D., is Senior Vice President, Biometrics and Clinical Development Strategy at Theseus Pharmaceuticals. Dr. Knickerbocker has over 25 years’ experience in the biotechnology and pharmaceutical industries. He most recently served as Vice President, Biometrics at EQRx where he built a biometrics team within a startup and was part of a Development Leadership Team that led global regulatory submissions for two oncology compounds. Prior to that Ron has led organizations, focusing primarily on oncology development, at companies including Ariad Pharmaceuticals, Anchiano Therapeutics, Genzyme, Pfizer, and Eli Lilly and Company. Ron has a Ph.D. in Statistics from Texas A&M University.
Nachu Narasimhan, Ph.D.
Senior Vice President, Drug Metabolism & Preclinical Safety
Narayana (Nachu) Narasimhan, Ph.D., is Senior Vice President, Drug Metabolism & Preclinical Safety at Theseus Pharmaceuticals. Nachu has over 30 years of expertise in Drug metabolism, Bioanalytical disciplines and over 10 years in preclinical safety and clinical pharmacology. He has contributed to the development and approval of abamectin and eprinomectin, two anthelminthic drugs while working at Merck. During his tenure at Bristol-Myers-Squibb, Nachu worked on Entecavir, a HepB drug which was approved. During his employment at ARIAD, Nachu was a key member of the discovery and development teams of three approved oncology drugs, ICLUSIG® (ponatinib), ALUNBRIG® (brigatinib), and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Most recently, Nachu served as Vice president for Drug Metabolism and Clinical Pharmacology at Verastem Oncology and worked on the successful approval of Copiktra® (duvelisib) in EU. Nachu received his M.S in Chemistry from Indian Institute of Technology, Chennai, and then completed his Ph.D. in chemistry at Vanderbilt University. Nachu conducted post-doctoral research at the University of Kansas. Nachu has published over 40 articles in peer reviewed journals in the areas of medical chemistry, drug metabolism, and Clinical pharmacology and has authored over 100 technical reports and regulatory submission documents.
Victor Rivera, Ph.D.
Co-Founder, Chief Scientific Officer
Victor Rivera, Ph.D., is Co-Founder and Chief Scientific Officer at Theseus Pharmaceuticals. Vic is an accomplished drug discovery and translational research leader. In over two decades at ARIAD Pharmaceuticals, beginning as a postdoctoral scientist and most recently as Vice President, Preclinical and Translational Research, he co-led discovery and led the translational research for the company’s programs including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC, ridaforolimus, and rimiducid. He has authored or co-authored over 75 peer-reviewed publications. Vic earned his Ph.D. in Microbiology and Molecular Genetics from Harvard Medical School and his A.B. in Molecular Biology from Princeton University.
Len Rozamus
Senior Vice President, Technical Operations
Len Rozamus is Senior Vice President, Technical Operations at Theseus Pharmaceuticals. An organic chemist with more than three decades of pharmaceutical discovery and development experience, Len began his career in medicinal chemistry at SmithKline Beecham and later transitioned to process development and the management of outsourced contract manufacturing for clinical programs at ARIAD Pharmaceuticals. As Sr. Director, Manufacturing Operations at ARIAD, Len provided leadership in every aspect of CMC, from pre-clinical programs through commercial products, primarily in support of ARIAD’s fast-track and breakthrough medications, including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); EXKIVITY® (mobocertinib), approved for EGFR Exon 20 insertion+ NSCLC. Most recently, Len served as the Founder and President of Rozamus and Associates, Inc., leading a team of seasoned consultants providing strategic and operational guidance to small and large companies for product life-cycle management. Len holds a Master’s in Organic Chemistry from the University of Virginia and a B.S. in Chemistry from The College of William and Mary in Virginia.
William Shakespeare, Ph.D.
Co-Founder, President of Research & Development
William Shakespeare, Ph.D., is Co-Founder and President of Research and Development at Theseus Pharmaceuticals. Bill is a renowned leader in chemistry and drug discovery, previously serving as the Vice President, Drug Discovery at ARIAD Pharmaceuticals. During his tenure of over two decades at ARIAD, he led multi-disciplinary teams in the discovery of three FDA-approved oncology drugs, ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Bill conducted his postdoctoral studies at the University of Pennsylvania; he is the author or co-author of more than 70 publications in peer-reviewed journals and is a co-inventor on more than 40 patents and patent applications. He received his Ph.D. in Chemistry from the University of New Hampshire and his B.S. in Chemistry from Gettysburg College.
Shouryadeep “Deep” Srivastava, M.D., Ph.D.
Vice President, Clinical Development
Deep Srivastava, M.D., Ph.D., is Vice President of Clinical Development at Theseus Pharmaceuticals. Dr. Srivastava has 13 years of clinical research experience in the biotechnology and pharmaceuticals industry. He most recently served as Vice President, Clinical Development at iTeos Therapeutics where he led the clinical development activity for immunotherapies being developed for solid tumors. In his role at iTeos, he led successful IND clearance by the FDA for a Phase 2 lung cancer trial and was responsible for the clinical strategy, monitoring, and oversight activities. Prior to that from 2018 through 2021, Deep held positions of increasing responsibility at Takeda and played a pivotal role in sNDA approval, Phase 3 initiation, and pediatric development for a leukemia drug, ICLUSIG® (ponatinib), as the Global Clinical Lead. Earlier in his career, he was a member of the Baxalta/Shire Hematology clinical team and also held medical writing and other roles in different companies. Dr. Srivastava received his M.D. from B.R.D. Medical College, India, and his Ph.D. from Texas Tech University.
Steve Tuller
Vice President, Quality Assurance
Steve Tuller is Vice President of Quality Assurance at Theseus Pharmaceuticals. Steve has 24 years of experience in the pharmaceutical and biotechnology industries. He most recently served as Vice President, Head of QA at Epizyme, Inc. where he initiated the GxP QA organization. In his role at Epizyme he led a successful FDA Pre-Approval Inspection for Tazverik and was responsible for clinical/commercial QA functions and Computer Systems Validation compliance. Prior to that from 2014-2016 Steve was Head of QA at Bind Therapeutics and held positions of increasing responsibility in QA, QC, and Analytical Development at Vertex, Advancis Pharma, and Shepherd Chemical. Steve has a B.S. in Chemistry from East Tennessee State University.
Iain Dukes, D.Phil.
Co-Founder and Chairman of Theseus;
Venture Partner, OrbiMed Advisors
Iain D. Dukes, D.Phil., is a Venture Partner with OrbiMed Healthcare Fund Management. Iain also serves on the Board of Lion Biotechnologies. Most recently Iain was a Senior Vice President, Business Development & Licensing Merck where he oversaw all licensing deals for Merck Research Laboratories, including external research, out-licensing, regional deals and academic alliances. Iain has more than 20 years of experience in pharmaceutical research, drug discovery, scientific and technology licensing, start-up company leadership, as well as consulting for numerous biotech and venture capital organizations. Before joining Merck, he served as Vice President of External Research and Development at Amgen. He has also held positions as President and CEO of Essentialis Therapeutics and as Vice President, Scientific and Technology Licensing at GlaxoSmithKline. Iain received his D.Phil. from the University of Oxford where he also received a B.A. in Jurisprudence.
Tim Clackson, Ph.D.
President and Chief Executive Officer
Tim Clackson, Ph.D., is President and Chief Executive Officer of Theseus Pharmaceuticals. Tim most recently served as President and Chief Technology Officer at Xilio Therapeutics, a privately held oncology company developing tumor-selective immunotherapies, where he led the development of the company’s technology and product strategy. From 1994 to 2018, Tim was with ARIAD Pharmaceuticals, where he was President of Research & Development and Chief Scientific Officer. He played a key role in the company’s evolution from early research to a global commercial oncology company, and its subsequent acquisition by Takeda. He led the multi-disciplinary R&D team that internally discovered and developed five clinical-stage product candidates, including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Prior to ARIAD, Tim was a postdoctoral research fellow at Genentech. He received his Ph.D. in Biology from the University of Cambridge, and his B.A. in Biochemistry from the University of Oxford. Tim serves as a director on the boards of Forma Therapeutics, Elevation Oncology and the Massachusetts Biotechnology Council (MassBio).
Carl Gordon, Ph.D., CFA
General Partner, OrbiMed Advisors
Carl L. Gordon, Ph.D., CFA, is a founding Partner and Co-Head of Global Private Equity at OrbiMed Healthcare Fund Management. For the last six years (2014 to 2019) Forbes® Magazine named Dr. Gordon one of the top 100 venture capitalists in the world when it placed him on the "Forbes Midas List.” He received a Ph.D. in Molecular Biology from the Massachusetts Institute of Technology and a B.A. from Harvard College, and was a Fellow at The Rockefeller University from 1993 to 1995.
Don Hayden, M.B.A.
Chair of Otsuka America Pharmaceuticals Incorporated
Don Hayden is an accomplished biopharmaceutical executive and board member, having served earlier in his career at the highest levels in big pharma and thereafter as Chair or Director of multiple innovative biotechnology companies. He is passionate, knowledgeable, and conversant in the world of drug discovery and development, and he has helped successfully build multiple biotechnology companies by developing innovative business strategies, assembling high-performance teams, guiding organizations through key transformations, and mentoring senior leaders. During his 25-year career at Bristol-Myers Squibb, Mr. Hayden held a series of key leadership roles such as President of Global Pharmaceuticals, Executive Vice President and President of the Americas, Executive Vice President of the Health Care Group, President of Oncology and Immunology, and Senior Vice President of Worldwide Franchise Management and Business Development. At BMS, he consistently drove high levels of strategic change, superior business performance and successful development of future leaders. Since leaving Bristol-Myers Squibb, Mr. Hayden has dedicated his career to building high science biotechnology companies both private and public. He has served as Board Chair at a wide range of companies, including REGENXBIO, Amicus Therapeutics, Insmed, Vitae Pharmaceuticals, Gloucester Pharmaceuticals, and Dimension Therapeutics. From early-2019 until mid-2021, he served as Chair and CEO of the oncology cell therapy company WindMIL Therapeutics. He continues to serve as Chair of Otsuka America Pharmaceuticals and Avanir Pharmaceuticals. Mr. Hayden received an M.B.A. from Indiana University and his undergraduate degree from Harvard University.
Michael Rome, Ph.D.
Managing Director, Foresite Capital
Dr. Michael Rome is Managing Director at Foresite Capital, where he co-leads the therapeutics investing practice. Michael is a board director at Kinnate Biopharma, Pharvaris, and Remix Therapeutics, with board observer roles (past and present) at Turning Point Therapeutics, Maze Therapeutics, PACT Pharma, and Nurix Therapeutics. Michael served as Vice President for Foresite Development Corporation (FSDC) and has led investments in several public companies across the portfolio. Prior to Foresite Capital, he was an analyst at DAFNA Capital Management, covering and formulating investment ideas for small/mid-cap biotech companies. Michael previously worked in early-stage drug development for an academic start-up out of the California NanoSystems Institute at UCLA. He received his Ph.D. in Biochemistry from Caltech as an NSF graduate research fellow, and his B.S. in Molecular, Cell and Developmental Biology from UCLA. He has more than 12 years of experience as a research scientist and has authored numerous publications in biomedical research journals.
Steven Stein, M.D.
Executive Vice President & Chief Medical Officer, Incyte Corporation
Dr. Stein has served as a member of our Board of Directors since October 2022. Dr. Stein currently serves as Executive Vice President, Chief Medical Officer of Incyte Corporation. Dr. Stein joined Incyte as Senior Vice President and Chief Medical Officer in March 2015, and has over 15 years of experience in clinical development and regulatory interactions. Dr. Stein joined Incyte from Novartis Pharmaceuticals Corporation, where he most recently served as Senior Vice President, U.S. Clinical Development & Medical Affairs at Novartis Oncology. Dr. Stein previously worked at GlaxoSmithKline as Vice President, Global Oncology, Clinical Development and as Head of Medicines Development for Hematology and Supportive Care. Dr. Stein earned his M.D. from the University of Witwatersrand in Johannesburg, South Africa.
Kathy Yi, M.B.A.
Chief Operating Officer, Affini-T Therapeutics
Kathy Yi, M.B.A. has served as a member of our board of directors since June 2021. Ms. Yi serves as Chief Operating Officer, Affini-T Therapeutics. Previously, Ms. Yi served as Chief Financial Officer of Cerevel Therapeutics Holdings, Inc. (Nasdaq: CERE) from June 2019 to September 2021, and Executive Vice President, Chief Financial Officer and Secretary of Sangamo Therapeutics, Inc. (Nasdaq: SGMO), from February 2017 to June 2019. Prior to Sangamo Therapeutics, Ms. Yi was Head of Finance at Novartis Pharmaceutical Corporation (NYSE: NVS) from February 2014 to February 2017. From 2007 to 2014, Ms. Yi held various financial management positions of increasing seniority at Life Technologies Corp., which was acquired by Thermo Fisher Scientific in 2014, including Finance Leader, Corporate FP&A from 2012 to 2014, Director of Finance, M&A/Corporate Development, from 2010 to 2012, and Director of Finance, Global Manufacturing Operations, from 2007 to 2010. From 2001 to 2007, Ms. Yi held increasing roles of responsibilities in corporate finance at Intel Corporation. Ms. Yi holds a Bachelor of Science in Chemical Engineering from the University of California at Berkeley and a Master of Business Administration from Columbia Business School. We believe Ms. Yi is qualified to serve on our board of directors due to her extensive business, financial and accounting experience as an executive in the pharmaceutical industry.
Iain Dukes, D.Phil.
Co-Founder and Chairman of Theseus;
Venture Partner, OrbiMed Advisors
Iain D. Dukes, D.Phil., is a Venture Partner with OrbiMed Healthcare Fund Management. Iain also serves on the Board of Lion Biotechnologies. Most recently Iain was a Senior Vice President, Business Development & Licensing Merck where he oversaw all licensing deals for Merck Research Laboratories, including external research, out-licensing, regional deals and academic alliances. Iain has more than 20 years of experience in pharmaceutical research, drug discovery, scientific and technology licensing, start-up company leadership, as well as consulting for numerous biotech and venture capital organizations. Before joining Merck, he served as Vice President of External Research and Development at Amgen. He has also held positions as President and CEO of Essentialis Therapeutics and as Vice President, Scientific and Technology Licensing at GlaxoSmithKline. Iain received his D.Phil. from the University of Oxford where he also received a B.A. in Jurisprudence.
Tim Clackson, Ph.D.
President and Chief Executive Officer
Tim Clackson, Ph.D., is President and Chief Executive Officer of Theseus Pharmaceuticals. Tim most recently served as President and Chief Technology Officer at Xilio Therapeutics, a privately held oncology company developing tumor-selective immunotherapies, where he led the development of the company’s technology and product strategy. From 1994 to 2018, Tim was with ARIAD Pharmaceuticals, where he was President of Research & Development and Chief Scientific Officer. He played a key role in the company’s evolution from early research to a global commercial oncology company, and its subsequent acquisition by Takeda. He led the multi-disciplinary R&D team that internally discovered and developed five clinical-stage product candidates, including ICLUSIG® (ponatinib), approved for patients with treatment-resistant Ph+ leukemias; ALUNBRIG® (brigatinib), approved for ALK+ non-small cell lung cancer (NSCLC); and EXKIVITY® (mobocertinib), approved for EGFR Exon20 insertion+ NSCLC. Prior to ARIAD, Tim was a postdoctoral research fellow at Genentech. He received his Ph.D. in Biology from the University of Cambridge, and his B.A. in Biochemistry from the University of Oxford. Tim serves as a director on the boards of Forma Therapeutics, Elevation Oncology and the Massachusetts Biotechnology Council (MassBio).
Carl Gordon, Ph.D., CFA
General Partner, OrbiMed Advisors
Carl L. Gordon, Ph.D., CFA, is a founding Partner and Co-Head of Global Private Equity at OrbiMed Healthcare Fund Management. For the last six years (2014 to 2019) Forbes® Magazine named Dr. Gordon one of the top 100 venture capitalists in the world when it placed him on the "Forbes Midas List.” He received a Ph.D. in Molecular Biology from the Massachusetts Institute of Technology and a B.A. from Harvard College, and was a Fellow at The Rockefeller University from 1993 to 1995.
Don Hayden, M.B.A.
Chair of Otsuka America Pharmaceuticals Incorporated
Don Hayden is an accomplished biopharmaceutical executive and board member, having served earlier in his career at the highest levels in big pharma and thereafter as Chair or Director of multiple innovative biotechnology companies. He is passionate, knowledgeable, and conversant in the world of drug discovery and development, and he has helped successfully build multiple biotechnology companies by developing innovative business strategies, assembling high-performance teams, guiding organizations through key transformations, and mentoring senior leaders. During his 25-year career at Bristol-Myers Squibb, Mr. Hayden held a series of key leadership roles such as President of Global Pharmaceuticals, Executive Vice President and President of the Americas, Executive Vice President of the Health Care Group, President of Oncology and Immunology, and Senior Vice President of Worldwide Franchise Management and Business Development. At BMS, he consistently drove high levels of strategic change, superior business performance and successful development of future leaders. Since leaving Bristol-Myers Squibb, Mr. Hayden has dedicated his career to building high science biotechnology companies both private and public. He has served as Board Chair at a wide range of companies, including REGENXBIO, Amicus Therapeutics, Insmed, Vitae Pharmaceuticals, Gloucester Pharmaceuticals, and Dimension Therapeutics. From early-2019 until mid-2021, he served as Chair and CEO of the oncology cell therapy company WindMIL Therapeutics. He continues to serve as Chair of Otsuka America Pharmaceuticals and Avanir Pharmaceuticals. Mr. Hayden received an M.B.A. from Indiana University and his undergraduate degree from Harvard University.
Michael Rome, Ph.D.
Managing Director, Foresite Capital
Dr. Michael Rome is Managing Director at Foresite Capital, where he co-leads the therapeutics investing practice. Michael is a board director at Kinnate Biopharma, Pharvaris, and Remix Therapeutics, with board observer roles (past and present) at Turning Point Therapeutics, Maze Therapeutics, PACT Pharma, and Nurix Therapeutics. Michael served as Vice President for Foresite Development Corporation (FSDC) and has led investments in several public companies across the portfolio. Prior to Foresite Capital, he was an analyst at DAFNA Capital Management, covering and formulating investment ideas for small/mid-cap biotech companies. Michael previously worked in early-stage drug development for an academic start-up out of the California NanoSystems Institute at UCLA. He received his Ph.D. in Biochemistry from Caltech as an NSF graduate research fellow, and his B.S. in Molecular, Cell and Developmental Biology from UCLA. He has more than 12 years of experience as a research scientist and has authored numerous publications in biomedical research journals.
Steven Stein, M.D.
Executive Vice President & Chief Medical Officer, Incyte Corporation
Dr. Stein has served as a member of our Board of Directors since October 2022. Dr. Stein currently serves as Executive Vice President, Chief Medical Officer of Incyte Corporation. Dr. Stein joined Incyte as Senior Vice President and Chief Medical Officer in March 2015, and has over 15 years of experience in clinical development and regulatory interactions. Dr. Stein joined Incyte from Novartis Pharmaceuticals Corporation, where he most recently served as Senior Vice President, U.S. Clinical Development & Medical Affairs at Novartis Oncology. Dr. Stein previously worked at GlaxoSmithKline as Vice President, Global Oncology, Clinical Development and as Head of Medicines Development for Hematology and Supportive Care. Dr. Stein earned his M.D. from the University of Witwatersrand in Johannesburg, South Africa.
Kathy Yi, M.B.A.
Chief Operating Officer, Affini-T Therapeutics
Kathy Yi, M.B.A. has served as a member of our board of directors since June 2021. Ms. Yi serves as Chief Operating Officer, Affini-T Therapeutics. Previously, Ms. Yi served as Chief Financial Officer of Cerevel Therapeutics Holdings, Inc. (Nasdaq: CERE) from June 2019 to September 2021, and Executive Vice President, Chief Financial Officer and Secretary of Sangamo Therapeutics, Inc. (Nasdaq: SGMO), from February 2017 to June 2019. Prior to Sangamo Therapeutics, Ms. Yi was Head of Finance at Novartis Pharmaceutical Corporation (NYSE: NVS) from February 2014 to February 2017. From 2007 to 2014, Ms. Yi held various financial management positions of increasing seniority at Life Technologies Corp., which was acquired by Thermo Fisher Scientific in 2014, including Finance Leader, Corporate FP&A from 2012 to 2014, Director of Finance, M&A/Corporate Development, from 2010 to 2012, and Director of Finance, Global Manufacturing Operations, from 2007 to 2010. From 2001 to 2007, Ms. Yi held increasing roles of responsibilities in corporate finance at Intel Corporation. Ms. Yi holds a Bachelor of Science in Chemical Engineering from the University of California at Berkeley and a Master of Business Administration from Columbia Business School. We believe Ms. Yi is qualified to serve on our board of directors due to her extensive business, financial and accounting experience as an executive in the pharmaceutical industry.
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