Eli Lilly acquires Kelonia in $7B deal to revolutionize cancer treatment

Eli Lilly announced Monday that it is acquiring Kelonia Therapeutics, a developer of gene therapies with a particular focus on cancer treatment, in a deal valued at up to $7 billion in cash.

Per our website data, the high end of the purchase price represents the largest acquisition of a venture-backed biotech company in years. It's a testament to the perceived potential of Kelonia's pipeline of genetic medicines, including a treatment targeting multiple myeloma that has produced promising clinical trial results.

It's also a quick progression by biotech standards. Boston-based Kelonia launched from stealth mode just four years ago, with $50 million in Series A funding led by Alta Partners, Horizons Ventures and Venrock. Two years later, it entered a research and licensing partnership with Xyphos Biosciences, a subsidiary of Japan's Astellas Pharma, that included funding to develop immuno-oncology therapeutics using its in vivo gene placement system.

Per Lilly, Kelonia's platform promises to not just improve outcomes for patients, but to do so in a rapid, simpler 'off-the-shelf format' compared to currently available CAR T-cell therapies. Its approach has been described as enabling the reprogramming of patients' T-cells inside the body so those cells can attack cancer.

Kelonia's vision is ambitious enough, and early results encouraging enough, to warrant what ranks as the largest acquisition of a venture-backed, private biotech company in the past 10 years, per our website data. To put that in context, below we ranked the next-largest deals valued at up to $2 billion or more.

The list does not include venture-backed biotechs that went public, which would broaden the ranks considerably. This includes companies that sold to acquirers shortly after IPO, such as Metsera, a developer of therapeutics for obesity and metabolic disease that went public in February 2025 and sold to Pfizer later in the year in a deal valued at around $10 billion.

In vivo acquisitions on the rise

Acquirers of late have been paying particularly handsomely for startups developing in vivo therapeutics. Just two months ago, Lilly purchased another high-profile venture-backed company in the space, Orna Therapeutics, dedicated to engineering immune cells in vivo, in a deal valued at up to $2.4 billion. Cambridge, Massachusetts-based Orna had previously raised over $320 million in venture funding, per our website data.

Last June, meanwhile, pharma giant AbbVie snapped up Capstan Therapeutics, a biotech advancing in vivo engineering of cells through RNA delivery, for $2.1 billion. San Diego-based Capstan had previously secured $340 million in venture funding.

Another big deal, announced in October, was Bristol-Myers Squibb's acquisition of Orbital Therapeutics, a Cambridge, Massachusetts-based developer of RNA medicines that reprogram the immune system in vivo, for $1.5 billion.

Of course, Kelonia's purchase price dwarfs all its predecessors, and by a hefty sum. Under the terms of the agreement, Lilly will acquire Kelonia for $3.25 billion up front, plus up to $3.75 billion in subsequent payments tied to meeting clinical, regulatory and commercial milestones.