The best treatment for any disease, says Sigilon Therapeutics CEO Rogerio Vivaldi, M.D., is the body’s own cells.
“If we allow cells to do what they are designed to do, that is the best treatment,” Vivaldi told FierceBiotech. These could be islet cells that make insulin in the case of Type 1 diabetes or cells that make clotting factors in the case of hemophilia.
Some companies are working on gene therapies to restore production of clotting factors, while others aim to transplant working cells into patients. But previous efforts to give patients functioning cells failed because scar tissue formed around them and the immune system attacked them, he said.
To solve these problems, Sigilon is developing encapsulated cell treatments—and it’s just raised $80.3 million toward its mission. The series B round brings the company’s war chest to more than $195 million and will push its lead program, a treatment for hemophilia A, into the clinic in the first half of this year, Vivaldi said.
“It will be the first time this technology platform will be tested in humans after being extensively tested preclinically in many different species,” he said. “In parallel, we will be starting IND-enabling studies in other indications, particularly in lysosomal storage disorders.”
People with hemophilia A make a faulty version of a blood clotting factor called factor VIII, or too little of it. A treatment that restores patients’ ability to make that clotting factor would free them from lifelong treatment that requires regular infusions. And Vivaldi, who’s worked at Spark Therapeutics and Bioverativ—both of which worked on hemophilia treatments—thinks Sigilon's encapsulated cells can go where other new treatments like gene therapy cannot.
“When you think about new modalities like gene therapy, they will have a big limitation in terms of the eligibility of patients,” he said. Those include patients with antibodies against the adenovirus-associated vectors commonly used to deliver gene therapy as well as people with liver disease.
“The number of reasons why a patient with hemophilia could not be a candidate for gene therapy are tremendous,” he said. “With our technology, patients are eligible—period … And unlike with gene therapy, we can re-dose with our technology.”
The Cambridge, Massachusetts-based company launched in 2017 with $23.5 million from Flagship Pioneering and Afibromer technology developed by MIT’s Bob Langer and Daniel Anderson. The technology encases cells that have been engineered to produce a therapeutic protein—like insulin—forming implantable spheres to treat diseases like diabetes.
“The Afibromer does two things. One: It shields the cells from immune attack and fibrosis,” Vivaldi said. “Two: It allows the cells inside to receive oxygen and nutrients from the body and allows the protein to go out, but it doesn’t allow cell-to-cell contact. That is the key point: Without that cell-to-cell contact, the body doesn’t initiate an immune response.”
Besides its hemophilia A candidate, Sigilon is working on treatments for factor VII deficiency and hemophilia B as well as for the lysosomal storage disorders Fabry disease and Mucopolysaccharidosis type 1. In 2018, the company joined forces with Eli Lilly to develop encapsulated cell therapies for Type 1 diabetes.