Ivan Bergstein, MD

Chief Executive Officer and President

Dr. Bergstein is Chief Executive Officer and Founder of Stemline Therapeutics. Dr. Bergstein has managed the company’s evolution from early-stage research and development to the FDA approval of its lead product, ELZONRIS.

Prior to founding Stemline, Dr. Bergstein was Medical Director of Access Oncology, Inc., a clinical-stage oncology-focused biotechnology company. He was a key member of a small team responsible for the acquisition and development of the company’s clinical-stage assets and ultimately the sale of the company to Keryx Biopharmaceuticals, Inc. (Nasdaq: KERX).

He received a BA in mathematics from the University of Pennsylvania, was elected to the Pi Mu Epsilon National Mathematics Honor Society, and was captain of the varsity wrestling team. He then received an MD from the Mount Sinai School of Medicine where he was elected to the Alpha Omega Alpha Honor Medical Society, received the Merck Award for Clinical Excellence, and subsequently completed an internship in general surgery. He became the Jerome A. Urban Post-Doctoral Research Fellow at the Cornell University Medical College where he studied and published work relating to Wnt genes in human breast cancer. He completed an internal medicine residency and hematology-oncology fellowship at the New York Presbyterian Hospital—Weill Medical College of Cornell University, where he studied and published work on gene therapy manipulations of the sonic hedgehog pathway.


Mr. Hoberman has served as the Chief Operating Officer of Stemline Therapeutics since 2013. He has extensive experience in finance, accounting, investor relations, corporate governance, and business development including mergers and acquisitions, strategic alliances, and partnerships, both domestic and international. His operational expertise includes regulatory oversight, human resources, manufacturing, and clinical development.

Prior to his current role, Mr. Hoberman was Vice President of Corporate and Business Development of Keryx Biopharmaceuticals, Inc., where he was instrumental in the success of the company. He helped secure multiple sources of capital, including over $200 million in equity investments through public and private offerings. He also initiated and executed a $100 million strategic alliance and originated, negotiated, and closed dozens of licensing and operational contracts, helping to grow the company’s market capitalization to over $1 billion.

Mr. Hoberman also led the team that originated, in-licensed, and developed Auryxia™ (ferric citrate), which was approved by the US Food and Drug Administration. He is on the Board of Directors of TG Therapeutics (Nasdaq: TGTX). He received a BSBA in Finance from Boston University and completed post-baccalaureate studies at Columbia University.

Ken Hoberman

Chief Operating Officer


David Gionco

Senior Vice President of Finance and Chief Accounting Officer

Mr. Gionco is the Senior Vice President of Finance and Chief Accounting Officer at Stemline Therapeutics. Mr. Gionco was previously Vice President, Chief Financial Officer, and Chief Accounting Officer at Savient Pharmaceuticals, Inc., where he oversaw the financial function of the organization and was instrumental in helping to grow the company, raising over $350 million.

Prior to this, Mr. Gionco held audit, corporate accounting, financial planning, finance, and controller roles at companies including Merck & Co., Inc. and, previously, Medco Health Solutions, Inc., which was acquired by Merck during his tenure. At Merck, Mr. Gionco held various financial and accounting positions of increasing responsibility. Mr. Gionco also held senior financial positions at Progenics Pharmaceuticals, Inc. and Odyssey Pharmaceuticals, Inc. (a subsidiary of Pliva, Inc., now Teva Pharmaceutical Industries Ltd.).

Mr. Gionco previously spent 7 years in financial auditing with a major public accounting firm. Mr. Gionco holds a BS in accounting from Fairleigh Dickinson University and an MBA in finance from Rutgers University. Mr. Gionco is a Certified Public Accountant in the state of New York.