Lilly Invests in Cell Encapsulation Technology


Sigilon Therapeutics is a small company in Boston that, up until this point, has been relatively quiet about their work in the type 1 diabetes treatment effort. Today, Eli Lilly and Company announced an investment partnership with Sigilon—an upfront payment of $63 million and up to $410 million more as the Sigilon’s research hits development and commercialization milestones.

Lilly’s investment will fuel Sigilon’s work in developing encapsulated cell therapies as a potential treatment or even functional cure for type 1 diabetes.

A quick background on cell encapsulation

In type 1 diabetes, the person’s own immune system is the rogue destroyer of beta cells. Damaged beta cells of a person with type 1 diabetes cannot be replaced with functioning insulin-secreting cells because the patient’s immune system will attack and destroy these cells as well. It’s flagged them as dangerous intruders, just like it did the original beta cells.

This poses a challenge for cell replacement therapies. Pancreas transplants available today require immunosuppressive drugs to avoid beta cell destruction, but this comes with high risk and potentially damaging side effects. Transplants are only available in extreme cases.

If cell replacement therapy is the route to a cure for type 1 diabetes, cell encapsulation (or some other mechanism of avoiding an immune attack) will play a key role.

So what does Sigilon Therapeutics do?

Sigilon’s research and development until now has focused primarily on developing and testing their Afibromer™ technology. This Afibromer is designed to contain implanted cells while avoiding triggering an immune reaction.

Sigilon is named for the Spanish word “sigilo” meaning stealth, because they design materials that can “fly under the radar” of the immune system. Avoiding an immune response allows the cells inside the encapsulation to function as intended.

If this technology were to work, the implant would fly under the radar of the immune system. Insulin-producing cells would be free to do their job: regulate blood glucose levels.

How does today’s announcement fit into the path to a cure?

As many in the type 1 diabetes community know, the path to a “cure”—or to a future free from daily injections—is filled with unexpected challenges. Researchers have been working on numerous cure concepts, including cell replacement therapies, for many years. They frequently face unexpected challenges, need to pivot away from their original research, or run out of funding.

In a field where so many fail, there is significance in Sigilon winning this degree of support from industry. Lilly is a multinational pharmaceutical company that makes strategic investments. The choice to invest in Sigilon’s cell therapy research reflects both the promise of this specific technology and that cell encapsulation is an area of strategic value to Lilly.

Under the terms of this new agreement, Lilly will receive an exclusive worldwide license to Sigilon’s Afibromer technology (should it make it eventually to market) for islet cell encapsulation. Sigilon will be responsible for development activities until submission of an investigational new drug (IND) application—after that, Lilly would be responsible for clinical development and commercialization of the cell replacement therapy. Investigational new drug (IND) applications are typically required before a Phase 1 clinical trial—the first phase of human trials.

The path to a cure is a long one. JDRF has been investing in early development of beta cell replacement materials for over a decade. In fact, past grants from JDRF and Helmsley Charitable Trust to Sigilon were used to fund research that lead to the discovery of Sigilon’s Afibromer technology, which seems to be the spark for Lilly’s investment.

Now, Sigilon has partnered with Lilly “to apply Sigilon’s game-changing technology to the area of insulin-dependent diabetes” says Sigilon CEO Paul Totten. The partnership with Lilly signifies the next phase of development—creating products containing insulin-producing beta cells encapsulated in the Afibromer technology. The goal? Restored insulin production over prolonged periods with no immune reaction.

What does “cure” really mean?

The technology developed by Sigilon provides a vision for a “cure” that looks something like this: encapsulated insulin-secreting cells will be implanted surgically. This transplant will require no immunosuppressants and will eliminate the need for insulin therapy over “sustained periods”—maybe a year, maybe more.

The cure for type 1 diabetes is unlikely to take the form of a magic pill able to restore full pancreas function. Short of that, there remains questions of what a “functional cure” or “practical cure” truly means. These questions are further complicated with a simple reality: the notion of a “cure” may mean one thing to patients, another thing to caregivers, another thing to researchers and yet another thing to industry.

More practically speaking, would a once-a-year surgical procedure constitute a cure? Regardless of that answer, it certainly constitutes progress.

What happens next?

Research focused on cell-based drug delivery dates back decades. Sigilon Therapeutics is only a 2-year-old company, but their technology originated from previous research being done at Massachusetts Institute of Technology and Harvard Medical School.

Sigilon, partnered with Lilly, will now apply the Afibromer technology to applications for type 1 diabetes. This likely means further preclinical testing. If research progresses successfully and milestones are hit, Sigilon will receive additional funding from Lilly—up until the point that human trials commence. From there on out, Lilly will spearhead clinical development and commercialization. This process is one that takes years, but today’s announcement confirms that Sigilon will avoid at least one common pitfall—financial support.

Beyond Type 1 will continue to cover developments of Sigilon + Lilly, of other cell therapies and of the broader path to a cure. We look forward to learning more about what today’s announcement means for this technology.

Read more diabetes news coverage from Beyond Type 1.