Today, Jeff builds and guides start-ups at the frontiers of medicine. He is founding chairman of Philadelphia-based Dispatch Biotherapeutics, whose novel immunotherapy could unlock a universal treatment strategy for most cancers, and serves as a board member and special advisor to the CEO of Nava Therapeutics, another Philadelphia company whose delivery technology can carry RNA-based medicines to parts of the body once beyond reach. He is also executive chairman of Prime Medicine, which is developing a “search and replace” gene-editing platform, and chairman of nChroma Bio, whose technology can switch genes on or off without changing the underlying DNA. Across these companies, Jeff's work could lead to cures in five areas of medicine: cancer and genetic disease, autoimmune and infectious disease, and diseases of the kidney.

Jeff also serves as a trustee of CHOP, sitting on the board's executive committee and chairing its research committee. In 2022, he and his wife launched the Marrazzo Family Foundation to foster creativity in Philadelphia's youth.

Jeff holds two bachelor's degrees — in systems science and engineering and in economics — from the University of Pennsylvania, and two master's degrees in business and public administration from Wharton and Harvard University, a dual-degree program he founded.

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