Lilly to Buy Diabetes Cell Therapy Partner Sigilon for Just Over $300M

 Lilly Biotechnology Center in San Diego, CAPictured: Lilly Biotechnology Center in San Diego, CA / iStock, JHVEPhoto

Eli Lilly is sealing the deal with its diabetes partner Sigilon Therapeutics. The companies announced Thursday that the pharma giant will acquire its smaller collaborator in a cash deal worth over $300 million. 

The two companies have been working together on a functional cure for Type 1 diabetes (T1D) for five years. In 2018, Lilly gave Sigilon $63 million upfront plus an equity investment to develop its “living therapeutics” into a functional cure for T1D.  

Under the terms of the acquisition, Lilly will buy Sigilon for a purchase price of $14.92 per share plus one non-tradeable contingent value right for an additional $111.64 per share in cash. Shares of Sigilon rocketed up 470% pre-market on Thursday after the announcement. The transaction is expected to close in the third quarter of this year. 

Sigilon’s platform encapsulates engineered cells using the biopharma’s proprietary Afibromer technology, which is designed to shield them from immune rejection. Unlike many cell therapies, the off-the-shelf products do not require patient gene modification or suppression of the immune system, according to Sigilon.  

For T1D, the stem cells are engineered into insulin-producing pancreatic beta cells—the cells the immune system destroys in diabetic patients, causing hyperglycemia. The goal is to “free patients from constant disease management” by restoring insulin production in their bodies long term, the companies stated in Thursday's press release. 

SIG-002, the heart of the original collaboration with Lilly and Sigilon’s current lead asset, is expected to complete IND-enabling studies this year, with a clinical trial application anticipated in 2024.  Additionally, Sigilon has a handful of candidates in discovery for lysosomal and liver diseases. 

Sigilon had a hemophilia A candidate in the mix, but its Phase I/II trial was placed on clinical hold in 2021. The company announced fibrosed spheres were retrieved from the third patient treated with SIG-001. The spheres were created with Sigilon’s Shielded Living Therapeutics platform, and the fibrosis rendered the encapsulated cell therapy no longer viable. The cause was unknown. SIG-001 is no longer included in the company’s pipeline

Lilly has been strengthening its diabetes position for years, investing in its domestic insulin manufacturing operations, listing eight molecules in the pipeline for diabetes, and its Type 2 diabetes drug now on the market—Mounjaro (tirzepatide). Since its June launch, Mounjaro brought in $483 million in 2022 and $568.5 million during the first quarter of this year alone.  

The T1D market is projected to reach over $7 billion by 2030.  

Thursday, the FDA approved the first cell therapy for T1D. CellTrans’ Lantrida is approved for adults with “brittle” Type 1, a rare form of insulin-dependent diabetes characterized by repeated episodes of severe low blood glucose. The allogeneic cell therapy is made from pancreatic cells from deceased donor patients.  

Last week, Vertex Pharmaceuticals released follow-up Phase I/II trial data from its investigational stem cell-based therapy for T1D. Two patients no longer needed insulin injections one year after treatment with VX-880. According to its clinical trial listing, the trial enrollment was 17. The therapy requires immunosuppressive treatments for recipients. 

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at and on LinkedIn.   

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