Bristol Myers Squibb announced the appointment of Cristian Massacesi, M.D., as executive vice president, chief medical officer and head of development, effective August 1, 2025. In this role, Dr. Massacesi will oversee the company’s early-stage and late-stage product development across all therapeutic areas.
“We are thrilled to welcome Cristian to Bristol Myers Squibb,” said Christopher Boerner, Ph.D., board chair and CEO, Bristol Myers Squibb. “His deep scientific expertise, strong focus on clinical execution and proven track record of regulatory approvals will be instrumental as we continue to advance our pipeline and deliver breakthrough medicines to even more patients around the world. Cristian also has a very strong track record of building and developing world-class teams.”
“I am on a mission to discover new medicines — unlocking innovative approaches to researching and treating challenging diseases so that one day, no patient will hear that all options have been exhausted,” said Dr. Massacesi. “I am excited to join BMS in this shared purpose, with its storied history, vast pipeline across therapeutic areas, exceptional reputation and culture deeply committed to making a difference.”
Dr. Massacesi began his career in the health care field as a medical oncologist, bringing the ethos of putting patients first into his more than 20 years of global biopharmaceutical experience. He has a proven track record of advancing breakthrough science, from early through late-stage development and global regulatory approvals, inspiring and encouraging his teams to identify novel strategies and take smart risks.
He most recently served as chief medical officer of AstraZeneca and Alexion, and as oncology chief development officer at AstraZeneca, where he led a global organization of more than 3,000 employees.
Under his leadership, AstraZeneca advanced over 150 clinical studies and secured multiple regulatory approvals. Before his tenure at AstraZeneca, Dr. Massacesi held senior R&D positions at Pfizer and Novartis, where he oversaw development programs across solid tumors and hematologic malignancies.
Samit Hirawat, M.D., Bristol Myers Squibb’s executive vice president, chief medical officer and head of development for the past six years, is stepping down to pursue new professional opportunities. Dr. Hirawat will transition from his current role, effective August 1, 2025, and will remain an advisor to the company through November 1, 2025, to ensure a seamless transition.
“We sincerely thank Samit for his leadership and dedication to innovative drug development at BMS over the past six years,” said Boerner. “Under his guidance, we have advanced groundbreaking science that has culminated in the approval of many new products across oncology, hematology, immunology, cardiovascular and neuroscience. His commitment and visionary approach have driven our progress and positioned us at the forefront of impactful medical innovation.”
Dr. Massacesi will be based in Princeton and report directly to Boerner.
