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Pfizer Names Bill Sessa, Ph.D., Chief Scientific Officer to Lead Internal Medicine Research

Sessa, a leading vascular biologist from Yale University, will join the company in 2022 to lead research focused on discovering potential treatments for cardiovascular and metabolic diseases

NEW YORK, N.Y., November 12, 2021 — Pfizer Inc. (NYSE: PFE) today shared that Bill Sessa, Ph.D., will join the company as Senior Vice President and Chief Scientific Officer of its Internal Medicine Research Unit (IMRU), an organization focused on discovering potential treatments for cardiovascular and metabolic diseases. He will join in February 2022 from Yale University and report to Mikael Dolsten, M.D., Ph.D., Chief Scientific Officer and President, Worldwide Research, Development and Medical.

“Bill Sessa is an eminent leader in his field, a groundbreaking scientist and a celebrated innovator with entrepreneurial spirit,” said Dr. Dolsten. “As a long-time member of our Therapeutic Area Scientific Advisory Panel, I am confident he will spearhead and expand our existing Internal Medicine research capabilities and portfolio — driving transformative science to treat some of the fastest-growing and most burdensome diseases in modern society.”

“I am thrilled to work alongside world-class scientists to potentially deliver numerous medicines that could improve the lives of billions of people, given Pfizer’s global footprint and the Internal Medicine group’s focus on finding potential treatments for some of the world’s most widespread, deadly diseases,” said Dr. Sessa.

Sessa currently serves as Vice Chairman, Pharmacology; Alfred Gilman Professor, Pharmacology; Professor, Medicine (Cardiology); and Director, Vascular Biology & Therapeutics Program at Yale School of Medicine.

He will succeed Morris Birnbaum, M.D., Ph.D., who will retire in 2022 following seven influential years as CSO building an Internal Medicine research program defined by a strong, science-driven clinical and pre- clinical portfolio and a team of experts dedicated to collaboration. Under his leadership, the IMRU developed and brought into the clinic first-in-class potential therapies for nonalcoholic steatohepatitis and cachexia (unintentional weight loss), as well as the first orally available, small molecule GLP-1 receptor agonist. The unit is also working to advance an innovative preclinical portfolio for the treatment of metabolic diseases such as heart failure and obesity. As of November 2021, Pfizer’s Internal Medicine pipeline includes 12 programs from Phase 1 through Registration.

About Pfizer: Breakthroughs That Change Patients’ Lives
At Pfizer, we apply science and our global resources to bring therapies to people that extend and significantly improve their lives. We strive to set the standard for quality, safety and value in the discovery, development and manufacture of health care products, including innovative medicines and vaccines. Every day, Pfizer colleagues work across developed and emerging markets to advance wellness, prevention, treatments and cures that challenge the most feared diseases of our time. Consistent with our responsibility as one of the world's premier innovative biopharmaceutical companies, we collaborate with health care providers, governments and local communities to support and expand access to reliable, affordable health care around the world. For more than 170 years, we have worked to make a difference for all who rely on us. We routinely post information that may be important to investors on our website at In addition, to learn more, please visit us on and follow us on Twitter at @Pfizer and @PfizerNews, LinkedIn, YouTube and like us on Facebook at

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