VANCOUVER, British Columbia — An implant which secretes insulin could one day replace the constant need for injections for people with diabetes. An international team of scientists says the device, created using human stem cells, could help countless patients keep their blood sugar levels in check.
People with type 1 diabetes do not produce enough insulin, a hormone which helps the body convert sugar (or glucose) into energy. They therefore have to take insulin injections on a regular basis – often between two and four times a day, to regulate their blood sugar levels. Now, scientists have developed cells that produce insulin for more than a year after implantation in the patient’s body.
“A landmark has been set. The possibility of an unlimited supply of insulin-producing cells gives hope to people living with type 1 diabetes,” says co-author Professor Eelco de Koning from Leiden University in a media release.
Researchers tested the implant, made from pluripotent human stem cells, in 26 patients with type 1 diabetes. While they did not have a clinical effect on the patients’ blood sugar levels, the implants did successfully produce insulin.
“Despite the absence of relevant clinical effects, this study will remain an important milestone for the field of human PSC-derived cell replacement therapies as it is one of the first to report cell survival and functionality one year after transplantation,” Prof. Koning continues.
Keeping patients healthier with less insulin
The team conducted a phase I/II clinical trial where they loaded the cells into specially designed protective capsules before implanting them under the patient’s skin. The cells survived and began secreting insulin 26 weeks after implantation, the study finds. Patients with the implant spent 13 percent more time in the “healthy” blood glucose range and needed 20 percent less insulin when they went for a check-up a year later.
“For the first time, we provide evidence that stem cell-derived PEC-01s can mature into glucose-responsive, insulin-producing mature β-cells in vivo in patients with type 1 diabetes,” says co-author Dr. Timothy Kieffer from the University of British Columbia. “These early findings support future investment and investigation into optimizing cell therapies for diabetes.”
Study authors do note that two patients did experience serious adverse side-effects related to the surgical implant.
In another study, scientists found the implants were successfully secreting insulin in 63 percent of cases, three to 12 months after implantation. While scientists again observed adverse side-effects among some patients, the risk of infection from the operation was exceedingly low, even among patients whose wounds struggled to heal.
“The present study demonstrates definitively for the first time to our knowledge, in a small number of human subjects with type 1 diabetes, that PSC-derived pancreatic progenitor cells have the capacity to survive, engraft, differentiate, and mature into human islet-like cells when implanted subcutaneously,” adds co-author Dr. Howard Foyt of ViaCyte, the company producing the cells.
What’s causing implant side-effects?
Around 1.6 million people are living with type 1 diabetes in the United States, including around 187,000 children. In both studies, the insulin producing cells survived for up to 59 weeks after implantation.
“An ideal and sunny possible future scenario would be the wide availability of a safe and efficacious stem cell-based islet replacement therapy without the need for these immunosuppressive agents or invasive, high-risk transplantation procedures,” notes co-author Dr. Françoise Carlotti of Leiden University.
Most of the nasty side-effects stemmed from the immune suppressing drugs which are taken alongside the treatment. Study authors say using these drugs over long periods of time could prove to be a major hurdle for those wanting to get the implant.
“The clinical road to wide implementation of stem cell-derived islet replacement therapy for type 1 diabetes is likely to be long and winding. Until that time, donor pancreas and islet transplantation will remain important therapeutic options for a small group of patients,” de Koning concludes. “But an era of clinical application of innovative stem-cell based islet replacement therapy for the treatment of diabetes has finally begun.”
South West News Service writer Tom Campbell contributed to this report.