Eli Lilly has agreed to acquire Massachusetts-based gene therapy developer, Kelonia Therapeutics, for up to $7bn – marking the pharma’s second foray into the in vivo space this year.
Through a $3.25bn upfront cash investment, Lilly will secure the rights to Kelonia’s lentiviral-based in vivo gene therapy platform, iGPS, which is designed to prompt the body’s immune cells to produce therapeutic anti-B-cell maturation antigen (BCMA) CAR-Ts independently.
The buyout will also see Lilly absorb Kelonia’s pipeline of oncology medicines – including its single-dose, BCMA-directed in vivo multiple myeloma asset, KLN-1010, which is currently in the Phase I inMMyCAR trial (NCT07075185) for refractory disease.
Alongside its focus on KLN-1010, Kelonia is working on a preclinical bispecific CAR-T therapy targeting both BCMA and CD19, as well as an asset with an undisclosed mechanism at the discovery stage.
With these medicines under its wing, Lilly is also pledging up to $3.75bn in clinical, regulatory and commercial milestone payments based on their success.
According to Jacob Van Naarden, executive VP and president of Lilly Oncology, Kelonia’s in vivo platform could have the potential to overcome the safety, manufacturing and access hurdles associated with autologous CAR-T therapies.
"The early clinical data for KLN-1010 are highly encouraging, both as a potential step forward for patients with multiple myeloma and as proof of concept for Kelonia's platform,” Van Naarden said.
In vivo’s future in the CGT space
As in vivo therapies burst onto the scene, many experts are touting them as a way to bring down the cost and complexity of the cell and gene therapy (CGT) manufacturing process, thus potentially lowering the barriers to global access.
With several big pharma companies hedging their bets on the in vivo approach over the past year, the race to potential commercialisation is on.
According to Jack Cuthbertson, senior oncology analyst at GlobalData, Lilly’s Kelonia buyout could be a sign of the Indiana-based pharma covering all bases following its $2.4bn acquisition of Orna Therapeutics in February 2026.
“There are currently two major types of in vivo CAR-T technologies: lipid nanoparticles (LNPs) loaded with transient expression systems as used by Orna, and lentiviral vectors with stable expression systems employed by Kelonia,” Cuthbertson commented.
Comparing the LNP and lentiviral approaches
At this point in time, Cuthbertson noted that it’s still unclear which type of system will take the lead. “A lot of the early data shows that lentiviral systems can effectively deliver complete responses with good prognoses. However, there are some safety concerns around immune responses when high lentiviral doses are given to deliver a therapeutic effect," he said.
This is evidenced by a Phase I readout from AstraZeneca’s lentiviral in vivo CAR-T therapy, which uncovered some safety signals GlobalData analysts call “concerning”. In the small trial, all five patients experienced adverse events rated Grade 3 or above. This prompted the study authors to suggest stricter risk stratification when running in vivo CAR-T trials in the future.
When it comes to LNP-based alternatives, Cuthbertson noted that they are often more tolerable, but may not be able to deliver the sustained, complete responses that ex-vivo CAR-Ts can.
In vivo therapy developers must also tackle the technical and logistical challenges around commercial viability as these therapies progress to the clinic. At the 2026 Advanced Therapies conference in London, investors stressed the importance of devising a commercial strategy for CGT products early.
