Seven is a pleasantly uncorporate number. It suggests a dinner reservation, perhaps a band with an unusually generous brass section. At Arcellx, it became a way of remembering the beginning: David Hilbert and the first six people who joined the company. By December 2024, as Arcellx approached its tenth anniversary, the group had acquired a nickname, the “Super 7.” A company with investors and a public-market identity was still keeping count of the people who had arrived early.
Hilbert was its founder. He had been its president and chief executive, then its chief technical officer. In the years before those titles, he had worked inside other research organizations, helped direct them, and advised young businesses on getting started. Arcellx gave that accumulated experience a new address. The founding date was 2014. The preparation occupied considerably more calendar space.
There is a useful way to read his career through those changing jobs. A scientist can contribute an idea. A research leader must organize the work around it. A founder must persuade people to give that work some portion of their lives. Hilbert’s professional history passes through all three assignments. The interesting part is how much company building had already happened before he put his name beside the word founder.
“He took a chance on me and gave me the opportunity of a lifetime.”
Jeffrey Swers, recalling joining Hilbert’s Arcellx
The years that came with him
His education took him through two Pennsylvania institutions: a bachelor of science at Haverford College and a doctorate at the University of Pennsylvania. Those credentials supplied the formal beginning. His subsequent career would require him to move between the language of research and the practical demands of directing an organization. The distance between a good question and a functioning business can be measured in quite a few meetings.
In 1996, Hilbert joined Human Genome Sciences. He spent eight years there, eventually serving as vice president of research. It was a substantial stretch inside one organization, preceding the shorter chapters and new beginnings that followed. Research management gave him responsibility for work performed by other people, a different proposition from being responsible only for one’s own experiments.
By 2004, he had moved to Cellective Therapeutics as vice president of research and a member of its senior management team. MedImmune acquired Cellective in October 2005. His résumé now included a young company that had passed into a larger organization. An acquisition can be compressed into a line of biography; working through the period before it is an extended education in how a small business operates.
From 2006 through 2009, Hilbert worked as a consultant with scientists, executives and venture firms. The assignment put him alongside startups facing strategic and operational questions. It is a revealing interval in the chronology. Before founding Arcellx, he had already spent time helping other people negotiate the distance between an early proposal and an organization capable of pursuing it.
In October 2009, he joined Zyngenia as vice president of research and development. A December 2011 promotion made him chief scientific officer. The distinction between those dates matters: the senior title followed an earlier period leading the work. His path to founding ran through appointments, responsibilities and promotions, with consulting fitted between them. The career had acquired several beginnings before Arcellx supplied another.
- 1996Human Genome Sciences
- 2004Cellective Therapeutics
- 2009Joins Zyngenia
- 2014Founds Arcellx
Selected appointments, not a continuous employment chart.
An incubator, then a company
Arcellx began with a different name. The business was incorporated in Delaware in December 2014 as Encarta Therapeutics; the change to Arcellx followed in January 2016. Companies have a legal childhood as well as a public one. An incorporation date and a name change rarely become the parts anyone remembers, but they fix the beginning more accurately than the later shorthand.
The company launched out of the Germantown Innovation Center on Montgomery College’s Pinkney Innovation Complex for Science and Technology campus. That setting gives the founding story a physical scale. Before there was a company name recognized by public investors, there was an incubator location in Germantown. A venture begins somewhere specific, even when its later ambitions require an international cast of partners and investors.
Arcellx later moved to West Watkins Mill and expanded into Rockville. Those locations form a short Maryland itinerary behind a much longer corporate story. The offices and laboratories changed as the business grew. For a founder, such changes make growth concrete: an organization eventually needs room for work that could once fit into a smaller space, and decisions that a handful of colleagues could once settle together.
The early employees remained part of the company’s account of itself. In 2024, its leadership recognized Hilbert and the first six team members together. Jeffrey Swers later remembered the personal decision underneath his own appointment: Hilbert had taken a chance on him. That recollection gives an employment relationship its human scale. A headcount has individual names, and joining a young organization is a decision made one person at a time.
The growing guest list
On October 3, 2019, Arcellx announced an $85 million Series B financing. Hilbert was president and CEO. The round brought new investors together with existing backers, adding financial commitments to the work already under way. The company that had started in an incubator was now managing a much larger circle of expectations.
Aju IB and Quan Capital co-led the financing. Other participants included Mirae Asset Venture Investment, Mirae Asset Capital, LG Technology Ventures, JVC Investment Partners and funds managed by Clough Capital Partners. Existing investors Novo Holdings, SR One, NEA and Takeda Ventures also participated. The list is long enough to make a business card feel inadequate. It also shows how many separate organizations had become involved in the company’s progress.
Financing announced while Hilbert was president and CEO.
The board changed alongside the financing. Hugo Beekman of Aju IB and Lewis “Rusty” Williams of Quan Capital joined as directors. That is another stage in a founder’s working life: responsibility extends beyond the original colleagues to investors and a board with its own obligations. A company’s growing guest list brings experience and resources, along with more people entitled to ask how things are going.
A different chair at the same table
In January 2021, Arcellx announced a change at the top. Rami Elghandour became chairman and chief executive, effective January 22. Hilbert moved into a newly created chief technical officer role. The founder was changing jobs inside the business he had started. His connection to Arcellx remained; the executive assignment had changed.
It is tempting to make a leadership handoff carry a whole philosophy of entrepreneurship. The actual sequence is more useful. One person took responsibility for leading the company as CEO. Another moved into a technical leadership position. The board publicly acknowledged Hilbert’s contribution to building the organization and welcomed his continued involvement. These were distinct roles within an enterprise that was entering another stage.
Hilbert’s next transition took effect on January 2, 2022, when he moved from employee and chief technical officer to consultant. That February, Arcellx completed its initial public offering. The proximity of those events makes the chronology worth preserving. The founder’s full-time executive chapter ended before the public-company chapter began. His founding role and the company’s subsequent progress belong to the same history, with different people holding responsibility at different times.
By December 2024, a profile of Human Genome Sciences alumni identified him as an independent consultant. The early Arcellx group, meanwhile, remained a point of reference for its later leadership. In a June 2024 interview, Elghandour had discussed retaining the original scientific core after the founder’s departure. Institutional memory can be unusually practical: people remember why a decision was made because they were there to make it.
What travels with a founder
On April 28, 2026, Gilead completed its acquisition of Arcellx. The transaction carried an announced total implied equity value of approximately $7.8 billion at closing. The terms included $115 per share in cash and a non-transferable contingent value right of $5 per share. That figure describes the company transaction. Hilbert’s own career had already moved into its next phase.
The distance from December 2014 to April 2026 is more than eleven years. Between those dates sit a name change, early appointments, financing rounds, a leadership transition and an IPO. The acquisition gives the chronology an easily remembered endpoint. The earlier entries explain how an organization acquired enough substance to reach it. A purchase price takes a moment to read; a company takes years to assemble.
In 2026, Hilbert appeared on the program for The Next Helix in Germantown, with an opening talk titled “What and Who Got Us Here?” The wording suits a career spent moving among research organizations and young businesses. It leaves room for the people alongside the milestones. At Arcellx’s beginning, the count was small enough to preserve in a nickname. Years later, seven still tells us something useful about how the company started.