Bristol Myers Squibb has appointed Cristian Massacesi, M.D., as Executive Vice President, Chief Medical Officer, and Head of Development, effective August 1, 2025. The appointment marks a significant leadership transition as the pharmaceutical giant faces mounting challenges from patent expirations and generic competition for key revenue drivers.
Massacesi, who served as Chief Medical Officer at AstraZeneca and Alexion for the past four years, will replace Samit Hirawat, M.D., who is stepping down after six years in the role to pursue new professional opportunities. Hirawat will remain as an advisor through November 1, 2025, to ensure a seamless transition.
Leadership Transition Amid Strategic Challenges
The executive change comes at a critical juncture for Bristol Myers Squibb, which announced plans to deepen cost cuts earlier this year as it confronts generic competition for its cancer medicine Revlimid and the looming patent expirations of cancer immunotherapy Opdivo and blood thinner Eliquis.
"We are thrilled to welcome Cristian to Bristol Myers Squibb," said Christopher Boerner, Ph.D., Board Chair and CEO. "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."
Hirawat's Legacy of Drug Development Success
Under Hirawat's leadership since 2019, Bristol Myers brought to market several significant drugs including Sotyktu, Reblozyl, Camzyos, Opdualag and Cobenfy. Of these, Reblozyl has already achieved blockbuster status, generating nearly $1.8 billion in revenue in 2024.
The company also expanded its pipeline through strategic acquisitions under Hirawat's tenure, entering the radiopharmaceutical space with its buyout of RayzeBio, forming an alliance with BioNTech on bispecific antibodies, and adding KRAS therapies through its purchase of Mirati Therapeutics. The schizophrenia medicine Cobenfy joined the portfolio via the 2023 acquisition of Karuna Therapeutics.
"Samit's commitment and visionary approach have driven our progress and positioned us at the forefront of impactful medical innovation," Boerner stated.
Massacesi's Extensive Industry Experience
Massacesi brings over 20 years of global biopharmaceutical experience, having begun his career as a medical oncologist. At AstraZeneca, he led a global organization of more than 3,000 employees, advancing over 150 clinical studies and securing multiple regulatory approvals during his tenure.
His experience at AstraZeneca included overseeing the company's multi-pronged approach to building its oncology drug portfolio, with investments in areas that align with Bristol Myers' strategic interests, including radiopharmaceuticals, antibody-drug conjugates, and cell therapy.
Before joining AstraZeneca in 2019 as head of late development oncology, Massacesi held senior R&D positions at Pfizer and Novartis, where he oversaw development programs across solid tumors and hematologic malignancies. He was promoted to oncology chief development officer when appointed CMO of AstraZeneca and Alexion.
Strategic Vision for Future Development
Massacesi will be based in Princeton, New Jersey, and report directly to CEO Christopher Boerner. In his new role, he will oversee the company's early-stage and late-stage product development across all therapeutic areas.
"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," Massacesi remarked. "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."
The appointment positions Bristol Myers to leverage Massacesi's proven track record in clinical execution and regulatory approvals as the company navigates the challenges of patent cliffs while advancing its diverse pipeline of breakthrough medicines.
