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.
- An encapsulation device.
The encapsulation device acts as a physical barrier to shield the new cells from the immune system attack. Details regarding the type of encapsulation device (e.g., size and material) have not yet been disclosed.
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.
