Johnson & Johnson, which was part of the wave of the first cell therapies, is now getting a next-generation contender by paying $785 million to start a partnership on a Sail Biomedicines cell therapy in development for autoimmune disorders.
In addition to gaining access to Sail’s lead program and the platform technology that created it, J&J secured an exclusive option to acquire the startup. The deal announced after Wednesday’s market close puts J&J squarely in the mix of large pharmaceutical companies working to expand the reach of cell therapy to immunology with treatments that achieve immune system reset: depleting pathogenic cells to enable the immune system to repopulate with cells that do not attack healthy tissue.
The science of Cambridge, Massachusetts-based Sail comes from Flagship Pioneering, an investment firm that creates startups around platform technologies. In 2023, Flagship formed Sail by merging two of its portfolio companies, Laronde and Senda Biosciences.
The most advanced program listed on Sail’s pipeline is SAIL-0839, an in vivo cell therapy designed to target T cells that are positive for CD4 and CD8. This therapy delivers RNA that reprograms those cells to express a chimeric antigen receptor (CAR) for CD19, a protein expressed on the surface of B cells. Sail describes this RNA as “endless,” offering a long-lasting effect. The first generation of cell therapies, including J&J’s multiple myeloma CAR T therapy Carvykti, go after B cells that express CD19, but these therapies are made in a lengthy and expensive multi-step ex vivo manufacturing process that also requires the patient undergo an intensive preconditioning drug regimen.
In vivo cell therapies could bring patients an off-the-shelf alternative that does not require preconditioning. Biopharmaceutical companies have been developing such therapies for autoimmune diseases. Sail has not disclosed disease targets for its programs, but B cell activity drives many immunological disorders. J&J’s announcement said the Sail agreement strengthens the pharma company’s “opportunities to advance future programs across a range of complex diseases.”
“Sail’s innovative platform represents an exciting new approach that seeks to harness the power of CAR-T therapy in a simpler, more scalable way,” John Reed, executive vice president, innovative medicine research & development, Johnson & Johnson, said in prepared statement. “By working together with Sail, we aim to accelerate the development of innovative therapies that have the potential to fundamentally transform how immune-mediated diseases are treated.”
Sail started building the case for its technology with data presented at the American Society of Gene & Cell Therapy annual meeting in May. Preclinical results for a CAR T-therapy named SAIL-0804 showed efficient in vivo reprogramming of T cells that was durable. Those cells also led to depletion of B cells. At the time, Sail said it would advance SAIL-0804 to the clinic. SAIL-0804 is no longer listed in the pipeline, which currently shows the CD4- and CD8-targeting SAIL-0839 as the lead program. Sail did not respond to an email asking about the differences between SAIL-0804 and SAIL-0839.
J&J’s agreement with Sail continues a flurry of dealmaking for in vivo cell therapies. Last year, AstraZeneca, AbbVie, Bristol Myers Squibb, and Gilead Sciences each acquired biotech companies for their in vivo cell therapy technologies and programs with potential applications in immunology. Eli Lilly joined in this year through the acquisition of Orna Therapeutics. The cohort of companies pursuing immune reset via T cell engagers includes UCBhttps://medcitynews.com/2026/05/ucb-candid-therapeutics-acquisition-t-cell-engager-autoimmune-immunology/ and Gilead, both of which added their contenders through deals this year.
Immunology is one of six key therapeutics areas for J&J, and it’s the second-largest in revenue behind only oncology. But the company’s top immunology product, Stelara, has already lost patent protection. The Sail deal helps build the pharma company’s pipeline. Under the Sail agreement, $465 million of the $785 million payment is an equity investment in the startup. Milestone payments could add another $140 million to the payout.
The deal also grants J&J an exclusive option to buy the biotech for an additional $2.85 billion. The trigger for exercising that option was not disclosed, but it could come soon. In a research note, Leerink Partners analyst David Risinger pointed out that J&J’s announcement states how much an acquisition would dilute earnings per share. While it’s not unusual for an acquiring company to state that, the announcement includes figures for both 2026 and 2027. Overall, Risinger views the Sail agreement as “an important step for JNJ’s immunology R&D efforts.”
J&J Closes Billion-Dollar Deal That Builds Its Cancer Drug Pipeline
Separate from the Sail announcement, J&J said it has completed the $1 billion acquisition of Firefly Bio, a startup developing a new type of targeted cancer therapy. The pharma company initially announced this deal in June.
Firefly was part of a group of biotech companies developing drugs in a new class of medicines called degrader antibody drug conjugates (DACs). Building on antibody drug conjugates (ADCs) for cancer, DACs employ a drug payload that degrades a disease-driving protein. Firefly launched in 2024, backed by $94 million in Series A financing. J&J said Firefly brings capabilities to address tumors that have been challenging to drug, including cancers driven by elusive KRAS mutations.
Photo: Mario Tama, Getty Images
