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Stephen Leong, MD

Associate Professor

Fred Hirsch 


Current Positions

Director, Developmental Therapeutics Clinical (Phase I) Program
Chair, Protocol Review and Monitoring Systems
Director, Oncology Teaching Service  

Education and Training

Fellowship - University of Colorado Cancer Center

Residency - Albert Einstein Medical Center (Philadelphia PA)
Beaumont Hospital (Dublin, Ireland)

Medical School - MB BCh BAO LRCSI&PI, Royal College of Surgeons in Ireland, (Dublin, Ireland)

Postgraduate Eduation - Masters in Medical Science, University College Dublin (Dublin, Ireland)
Certificate in Palliative Care Education and Practice, Harvard Medical School


Dr. Leong joined the University of Colorado School of Medicine faculty as an Assistant Professor of Medicine in July 2007.  He graduated from the Royal College of Surgeons in Ireland and did his internship at Beaumont Hospital (Dublin, Ireland).  He subsequently completed his Masters in Medical Science (Physiology) from University College Dublin.  He then trained in internal medicine at Albert Einstein Medical Center, where he also served as chief resident.  He then completed his medical oncology / drug development fellowship at University of Colorado Cancer Center.  He also completed a certificate in Palliative Care Education and Practice, Harvard Medical School in 2012.  Currently he is the Director, Developmental Therapeutics Clinical (Phase I) Program; Chair of the Protocol Review and Monitoring Systems (University of Colorado Cancer Center’s Scientific Review Committee) and the Director of Oncology Teaching Service. 


Dr. Leong is a member of the Developmental Therapeutics (Phase I), Gastrointestinal (GI) Medical Oncology and Adrenal Cancer Programs.  His research endeavors include both laboratory and clinical research.  His laboratory interests focus on novel targeted therapies.  Clinically, he serves as the principal investigator on numerous Phase I, Phase II and Phase III clinical trials.

Dr. Leong is a member of multiple national committees, including the National Cancer Institute (NCI) Esophageal and Gastric Task Force; National Comprehensive Cancer Network (NCCN) Committee on Esophageal and Gastric Cancers (which sets treatment guidelines used internationally) and American Society of Clinical Oncology (ASCO) Editorial Board.  He also serves as the Associate Editor for the ASCO’s Gastrointestinal Cancers Symposium Daily News. 

Selected Publications

1.    A Phase I Dose-Escalation Study of the Safety and Pharmacokinetics of Pictilisib in Combination with Erlotinib in Patients with Advanced Solid Tumors. Leong S, Moss RA, Bowles DW, Ware JA, Zhou J, Spoerke JM, Lackner MR, Shankar G, Schutzman JL, van der Noll R, Voest EE, Schellens JHM. Oncologist. 2017 Aug 10

2.    Patterns of Care for Locally Advanced Pancreatic Adenocarcinoma Using the National Cancer Database. Amini A, Jones BL, Stumpf P, Leong S, Lieu CH, Weekes C, Davis SL, Messersmith WA, Purcell WT, Ghosh D, Schefter T, Goodman KA. Pancreas. 2017 Aug;46

3.    Gastric Cancer, Version 3.2016, NCCN Clinical Practice Guidelines in Oncology.  Ajani JA, D'Amico TA, Almhanna K, Bentrem DJ, Chao J, Das P, Denlinger CS, Fanta P, Farjah F, Fuchs CS, Gerdes H, Gibson M, Glasgow RE, Hayman JA, Hochwald S, Hofstetter WL, Ilson DH, Jaroszewski D, Johung KL, Keswani RN, Kleinberg LR, Korn WM, Leong S, Linn C, Lockhart AC, Ly QP, Mulcahy MF, Orringer MB, Perry KA, Poultsides GA, Scott WJ, Strong VE, Washington MK, Weksler B, Willett CG, Wright CD, Zelman D, McMillian N, Sundar H. J Natl Compr Canc Netw. 2016

4.    Phase I trial of vandetanib in combination with gemcitabine and capecitabine in patients with advanced solid tumors with an expanded cohort in pancreatic and biliary cancers. Kessler ER, Eckhardt SG, Pitts TM, Bradshaw-Pierce EL, O'byrant CL, Messersmith WA, Nallapreddy S, Weekes C, Spratlin J, Lieu CH, Kane MA, Eppers S, Freas E, Leong S. Invest New Drugs. 2016

5.    Dual pharmacological targeting of the MAP kinase and PI3K/mTOR pathway in preclinical models of colorectal cancer. Pitts TM, Newton TP, Bradshaw-Pierce EL, Addison R, Arcaroli JJ, Klauck PJ, Bagby SM, Hyatt SL, Purkey A, Tentler JJ, Tan AC, Messersmith WA, Eckhardt SG, Leong S. PLoS One. 2014 

6.    From bench to bedside: lessons learned in translating preclinical studies in cancer drug development. Lieu CH, Tan AC, Leong S, Diamond JR, Eckhardt SG. J Natl Cancer Inst. 2013 Oct

7.    A phase 1, open-label, dose-escalation study of BIIB022 (anti-IGF-1R monoclonal antibody) in subjects with relapsed or refractory solid tumors. von Mehren M, Britten CD, Pieslor P, Saville W, Vassos A, Harris S, Galluppi GR, Darif M, Wainberg ZA, Cohen RB, Leong S. Invest New Drugs. 2014 Jun;32

8.    Overcoming IGF1R/IR resistance through inhibition of MEK signaling in colorectal cancer models. Flanigan SA, Pitts TM, Newton TP, Kulikowski GN, Tan AC, McManus MC, Spreafico A, Kachaeva MI, Selby HM, Tentler JJ, Eckhardt SG, Leong S. Clin Cancer Res. 2013 Nov 15

9.    Patient-derived tumour xenografts as models for oncology drug development. Tentler JJ, Tan AC, Weekes CD, Jimeno A, Leong S, Pitts TM, Arcaroli JJ, Messersmith WA, Eckhardt SG. Nat Rev Clin Oncol. 2012 Apr 17;9

PubMed Articles​​​​