Beta Cells vs. Closed-Loop Pumps – Which is Better?

Advocates argue for both treatments at the ADA 77th Scientific Sessions.



It was slated to be a good-natured rumble between two futuristic Type 1 diabetes treatments – islet transplantation and closed-loop pump therapy – for the mantle of “the future of diabetes care.” Instead, it seemed a mismatch, as the closed-loop pump camp had one trump card – FDA-approval and a device already on the market.

During the opening session of the American Diabetes Association 77th Scientific Sessions, Millman Labs founder Jeffrey Millman and JDRF Chief Mission Officer Aaron Kowalski held court about which of the two therapies will provide the most value to the Type 1 diabetes community, with Millman championing islet cell transplants and Kowalski taking the side of closed-loop pumps.

Millman, perhaps suspecting he would already be at a disadvantage, spent much of his portion of the talk highlighting how the viability of islet cell replacement therapy has improved in recent years. The concept of harvesting working islet cells and transplanting them into people with Type 1 diabetes seems simple enough, he said, but in practice there have been major hurdles.

Until recently, the cells for transplant were taken from cadavers, and there were issues of both quantity and quality. In recent years, researchers have shifted to growing islet cells from stem cells in labs. That has upped the quantity, but not always the quality, he argued. Lab-grown cells did not go through stages of cell development necessary to have them perform consistently well in trials, he said.

That is changing now that Dr. Douglas Melton of the Harvard Stem Cell Institute has found a way to speed up the process of stem cell growth and to grow beta cells so they would develop in stages. Millman has studied under Melton, and he says the process is much easier now than before Melton’s breakthrough.

“We can actually make these cells from patients now,” Millman said.

Read more: How to Grow Beta Cells in 40 Days

However, this seemingly large supply of beta cells still doesn’t solve all problems with the transplant process. People with Type 1 diabetes who undergo islet therapy must take drugs to suppress their immune systems or their bodies will destroy the transplanted beta cells. There also is still room for improvement in quality of the grown cells. Currently, the best beta cells grown in the lab match the poorest quality of beta cells made naturally in the body. Millman believes the quality of cells grown in the lab will only improve in the coming years.

“Making beta cells is pretty much figured out,” he said. “These cells will be quite good just a few years from now.”

But while Millman can point to successful transplants involving individual patients, the number of patients who have successfully worn closed-loop insulin pumps number in the thousands, and that made Kowalski’s case much easier to argue.

Kowalski’s argument was simple – closed loop pumps work and they make the lives of people with Type 1 easier right now. To buoy his case, he came armed with statistics that JDRF advocates often cite, including that studies have shown that most people with Type 1 diabetes aren’t meeting the A1C goals necessary to avoid long-term complications. Kowalski and others at JDRF say that this isn’t because people aren’t trying; it’s just that the task of being one’s own pancreas is extremely difficult.

Hybrid closed loop pumps make that task easier, he said. In trials, the pumps, which still require individuals to bolus for meals, have been shown to significantly reduce glucose variation and improve A1C scores. These trials have also shown that closed loop pump technology had the greatest impact when people with Type 1 were asleep and can’t manage their glucose levels. Teenagers, who seem more prone than other groups to forget to bolus or test, also saw the greatest improvement in glucose control among the populations tested.

Currently, the only hybrid closed loop system on the market is the Medtronic 670G; Medtronic launched commercial sale of the pump system just days before the 77th sessions began. Kowalski understands that the hybrid pump is neither an artificial pancreas, nor a cure. However, he argues that incremental benefit is extremely beneficial, especially because it’s available now.

Read more: Medtronic Launches 670G

“If the goal would be to create a machine that functions like an islet, that’s a lofty goal,” he said. “To fly like a hummingbird is hard.”

Now that Medtronic has broken through with FDA approval, JDRF wants to see others enter the market with closed loop pump systems. He also would like to see the pump systems get smaller, as wearing bulky medical technology can also be a bit a burden.

“No one…wears an insulin pump for kicks,” Kowalski said. He later added, “If you’re going to harness the benefits of these technologies, you’ve got to minimize the burden of wearing these technologies.”

Hei didn’t seem as bullish as some on dual-hormone pump systems that use insulin to bring glucose levels down and glucagon to bring those levels up. Dual-hormone pumps have been seen by some as an enticing way to curb the risk of hypoglycemia, but Kowalski didn’t sound overly impressed in his remarks. JDRF invests in many different types of innovations for Type 1 diabetes, and dual-chamber pumps didn’t sound high on his list of priorities.

“To justify the additional complexity and cost, we need to see the superiority,” he said. “I actually see hyperglycemia being the bigger problem (than hypoglycemia).”

Kowalski delivered his half of the argument with the good-natured air of one who knows they have the better case. However, he left the door open in his talk that beta cell transplants, or another therapy, might soon best closed-loop pumps for future supremacy of Type 1 therapy.

“Devices will be obsoleted, the question is when,” he said.

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Craig Idlebrook is a past editor for Insulin Nation, Type 2 Nation, and Información Sobre Diabetes. He is now the community engagement and content manager for T1D Exchange.