At a Glance
- OPF-310 is a new Practical Cure project that began human trials in June.
- The phase I/II trial tests pig islets transplanted in a protective encapsulation device.
- Transplanting non-human insulin-producing cells was actively explored from the mid-1900s to the early 2000s, with some success in mice but not humans.
- If successful, pig islets could offer an unlimited supply of insulin-producing cells.
August 7, 2025
A new clinical trial initiated in June is testing the combination product OPF-310, the latest addition to JDCA’s Practical Cure project list. It has been identified as a new project along the Cell Transplantation and Encapsulation research pathways. The trial is unique, employing a vintage approach to cell replacement: Xenotransplantation. It is led by the Tokyo-based company Otsuka Pharmaceutical Factory and conducted at the University of Illinois.
Xenotransplantation is similar to classic human-to-human islet transplantation in that it directly replaces lost insulin-producing cells in someone with T1D. Unlike typical islet transplantation, these cells are derived from other animal species—in this case, pigs.
During the mid-to-late 1900s and into the early 2000s, porcine xenotransplantation was a major focus of research to solve the cell supply shortage. While there were some successes in animal models, this was not replicated in human testing. Ultimately, xenotransplantation as a source of cells gave way to stem cell-derived beta cells.
OPF-310 marks the first xenotransplantation-based project on the Practical Cure list in over a decade.
About OPF-310
The phase I/II clinical trial is investigating the safety, efficacy, and optimal dosage of the combination product OPF-310. The product is comprised of two key elements:
- Insulin-producing pig islets.
- A microencapsulation device.
The encapsulation device acts as a physical barrier to shield the new cells from the immune system attack.
The therapy is being tested in adults with established T1D (diagnoses ≥ 5 years) and with severe hypoglycemia. The study began on June 10th of this year and is estimated to conclude on June 30, 2027.
There are two parts to this trial. Part 1 tests two different doses of transplanted islets (6,000 or 12,000 per kilogram of body weight) to gauge initial safety, efficacy, and the optimal dose. Part 2 will enroll additional subjects to evaluate further dosage expansion.
The sponsor of this research is Otsuka Pharmaceutical Factory, a Tokyo-based company that manufactures and distributes a variety of products in the pharmaceutical, nutrition, and related sectors. Though owned by Otsuka, the trial is conducted at the University of Illinois Hospital & Health Sciences System.
Xenotransplantation: Brief History and Significance
Brief History
Utilizing tissues and organs from non-human animals is not a new venture—and T1D is no exception. In fact, the creation of the first lifesaving insulin in 1921 was solely derived from pigs and cows, and a human version was not available until 1982. Pigs are the preferred non-human source as the insulin structure is almost identical, they breed quickly, and it is easier to ensure islet health.
Xenotransplantation in general has been explored for over a century, though xeno-islets were not seriously investigated until the 1960s/1970s. It was not until 1993 that the first clinical pig islet transplantation was conducted in a human. Though the procedure failed long-term, there was a temporary increase in detectable C-peptide.
Cell Supply
Currently, the go-to cell source for insulin-producing cells is from cadavers; limited in availability, expensive to procure, and without guaranteed quality. Though effective, they are hard to get.
In comparison, pig islets offer a potentially unlimited supply if successful. Through strategic and purposeful breeding, healthy cells can be cultivated quickly and on a large scale.
Popularity Today
Non-human animal-derived islets are much less common than they were twenty years ago. Today, there is only one T1D xenotransplantation trial registered as active on the US clinical trial database.
OPF-310 is the first xenotransplantation trial that has been on JDCA’s potential Practical Cure list in almost a decade. 2016’s State of the Cure for Type 1 Diabetes profiled the most recent xenotransplantation, Diabecell, which also tested pig islets inside a protective encapsulation device. Notably, that project was co-owned by Otsuka Ltd., a subsidiary of Otsuka Pharmaceutical Factory.
JDCA will keep you up to date with the latest developments in OPT-310 as they unfold.
Appendix: Additional Trial Details
“A Study to Investigate Safety and Effectiveness of Porcine Pancreatic Cells (OPF-310) in Patients With Type 1 Diabetes Mellitus” is a phase I/II clinical trial testing the OPF-310 combination product, encapsulated porcine-islets, in patients with established T1D.
Purpose: To evaluate the safety, efficacy, and optimal dose of OPF-310 combination product in individuals with established T1D.
Dose: Single transplant of OPF-310.
Estimated Enrollment: 13 participants.
Locations: University of Illinois Hospital & Health Sciences System, Chicago, IL.
Estimated Study Completion Date: June 2027.
