A financier who never left the lab, now betting on the hardest problem in cancer
Filippo Petti runs a company that lives in three places at once: a research legacy at a London university, a set of labs and clean rooms inside a working hospital, and a CEO who logs in from the New York area. Holding those pieces together is the job, and the payoff would be a cell therapy that finally works against solid tumours.
Petti has been Chief Executive Officer of Leucid Bio since July 2023, when he joined the board and took the top seat at the clinical-stage biotech. The company builds next-generation CAR-T cell therapies - treatments that re-engineer a patient's own immune cells to recognise and attack cancer. CAR-T has been transformative in blood cancers. In solid tumours, the tumour microenvironment tends to exhaust or block the engineered cells before they can do their work. That gap is precisely the territory Leucid has chosen to fight on.
Leucid's answer is a design idea it describes in four blunt words: "build out, not down." Conventional CAR molecules extend outward from the cell in a linear stack. Leucid's lateral CAR platform repositions the receptor's functional components so they sit in a more natural configuration next to the cell membrane. The lead asset, LEU011, targets NKG2D stress ligands - markers found on more than 80% of tumour cell types - and co-expresses a chemokine receptor to help the cells push deeper into the tumour. Two mechanisms, one cell: recognition and infiltration.
Leucid's unique approach to the field of CAR-T has tremendous potential to help cancer patients around the world. I look forward to working with its exceptionally talented team to advance LEU011.
Three seats at the same table
What Petti brings is a career that has circled the biotech industry rather than climbed a single ladder. He started at the bench, working as a research scientist at OSI Pharmaceuticals on drug discovery and translational research before moving into the company's corporate development side. From there he crossed to finance, covering US biotechnology as an equity research analyst at William Blair & Company and Wedbush Securities, then working as a healthcare investment banker at Wells Fargo Securities and William Blair, where he specialised in cell and gene therapy companies.
Then came the operating years. Before Leucid, Petti was CEO, CFO and Executive Director of Celyad Oncology, a CAR-T company where he ran both the strategy and the balance sheet. Few biotech leaders have sat in the scientist's chair, the analyst's chair, the banker's chair and the executive's chair. Petti has occupied all four, and in a field where the distance between a promising molecule and a funded, trial-ready programme kills most companies, that range is the point.
His academic path is similarly stacked: a Bachelor of Science from Syracuse University, a Master of Science from St. John's University, and an MBA from Cornell University. Science first, then the business that pays for it.
The AERIAL test
The clearest measure of Petti's tenure so far is the AERIAL trial, a multi-centre Phase I/IIa dose-escalation study evaluating a single intravenous dose of LEU011 in patients with relapsed or refractory solid tumours. In November 2025, Leucid presented early data at the annual meeting of the Society for Immunotherapy of Cancer, reporting that the therapy had been well tolerated and had shown functional activity.
Although preliminary, we are highly encouraged by these initial data from the AERIAL trial which establish proof-of-concept for LEU011 in the treatment of solid tumours.
Proof-of-concept is a careful phrase, and Petti uses it carefully. It does not mean the drug works; it means the biology behaved the way the design predicted - the cells recognised tumours through the stress-ligand mechanism and used chemokine signalling to move into the tumour microenvironment. The company has said additional data are expected in the first half of 2026. For a lead asset carrying an entire platform's credibility, that readout matters.
Science born at King's, built at Guy's
Leucid did not start with Petti. The company was founded in 2014 by Dr. John Maher, now its Chief Scientific Officer, to commercialise roughly two decades of CAR-T research from King's College London, where Maher established CAR T-cell work in 2004. Leucid operates from Guy's Hospital in London with dedicated R&D and manufacturing, and is backed by life-science investors including Epidarex, Sofinnova Partners, 2Invest, Vulpes Investment Management and the British Business Bank's Future Fund.
That inheritance frames Petti's actual assignment. His job is not invention - it is translation, the unglamorous work of turning academic science into a medicine that survives regulators, manufacturing and the clinic. It is the stage where the most biotech ventures fail, and it happens to be the stage Petti has spent his whole career learning to navigate from every angle.
The company has also looked beyond its own walls for the next steps. Leucid struck a partnership with Syenex to explore in vivo delivery of its CAR-T assets through the VivoCell Platform, a route Petti framed as enabling "precise in vivo delivery" - a nod to where cell therapy manufacturing may be heading. For now, though, the story rests on one molecule, one trial and one readout, run by an executive who has learned to speak fluently to scientists and investors alike, and who is asking both to be patient a little longer.