Dr. Klempner completed his residency in internal medicine at Brigham and Women’s Hospital/Harvard Medical School, followed by a combined hematology-oncology fellowship at Beth Israel Deaconess Medical Center/Harvard Medical School.  While at Harvard Dr. Klempner studied the mechanisms of resistance to targeted therapies in tumor cells in the lab of Dr. Lewis Cantley, PhD.  Dr. Klempner is board certified in medical oncology, hematology, and internal medicine, and belongs to several oncology research societies including the American Society of Clinical Oncology (ASCO), European Society of Medical Oncology (ESMO), the American Association for Cancer Research (AACR).  His work has been published in multiple journals including Journal of Clinical Oncology (JCO), Cancer Discovery, Lancet Oncology, JAMA Oncology, Annals of Oncology and others.   He is an active member of the ASCO TAPUR trial molecular tumor board and serves on the editorial board of JCO Precision oncology.  

As a member of the gastrointestinal cancer group at MGH Dr. Klempner works in a multidisciplinary team to optimize and individualize treatment using molecular characterization across all stages of GI cancers.  He conducts clinical trials and translational research with new targeted agents and immune therapies, and is active in the gastroesophageal cancer community where he serves on the advisory board of Debbie's Dream Foundation and Hope for Stomach Cancer.  He has received several awards for his care of patients with GI cancers.  Originally from Wayland, MA he is an avid Boston sports fan.