The purpose of this study is to establish the efficacy and safety of xenotransplantation of DIABECELL \[immunoprotected (alginate-encapsulated) porcine islets\] in patients with established type 1 diabetes mellitus
Intraperitoneal islet transplantation has the potential to ameliorate type 1 diabetes mellitus and avert the long-term consequences of chronic diabetes which cannot be achieved by conventional insulin treatment. As donor human islets are not available in sufficient numbers, porcine islets are the best alternative source as they are recognised as the most physiologically compatible xenogeneic insulin-producing cells. Although the use of pig-derived cells raises the risk of xenotic infections, this can be minimised by obtaining cells from designated pathogen-free (DPF) animals bred in isolation and monitored to be free of specified pathogens. The worldwide experience to date in more than 200 patients who have received transplants of pig tissue has not demonstrated evidence of transmitted xenotic infections. As animal-derived tissues have to be protected from immune rejection when transplanted into humans, transplants are usually accompanied by immunosuppressive therapy. However, porcine islets are preferably transplanted without the use of immunosuppressive drugs which cause significant morbidity. To protect them from immune rejection, the islets can be encapsulated in alginate microcapsules which permit the inward passage of nutrients and glucose and the outward passage of insulin. Alginate-encapsulated porcine islets transplanted without immunosuppressive drugs have survived rejection for many months in animal studies. DIABECELL comprises neonatal porcine islets encapsulated in alginate microcapsules. DIABECELL has been safely transplanted in healthy and diabetic mice, rats, rabbits, dogs and non-human primates. Following DIABECELL transplants, the requirement for daily insulin was significantly reduced in diabetic rats and non-human primates. The optimal dose and frequency of transplantation of the current DIABECELL preparation for the treatment of type 1 diabetes in humans can only be determined in clinical trials. The intention of this phase IIb clinical trial is to obtain at least 52 weeks safety and preliminary efficacy data in type 1 diabetic patients following transplantation of two effective doses of DIABECELL into the peritoneal cavity.
two transplants of 10,000 IEQ/kg DIABECELL (administered at least 12 weeks apart)- total of 20,000 IEQ/kg
San Martín, Buenos Aires, Argentina