The Artificial Pancreas is Coming, and Other Highlights from ADA 2016

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After taking a 15-month-break from writing about diabetes (15 months being the age of my daughter—coincidence?), I recently jumped back on the diabetes bandwagon and went to New Orleans for the American Diabetes Association’s 2016 Scientific Sessions. I’m glad I did. It was an interesting meeting, and gave me hope that the next few years are going to hold some very exciting developments for people with diabetes. Here are my top five takeaways:  

1. The artificial pancreas is coming

It wasn’t so long ago that the idea of having a closed loop system—that is, a continuous glucose monitor and insulin pump working in tandem to regulate your blood sugar for you—was a far-off dream. In fact, I actually had a dream recently in which I was wearing one, and was pretty disappointed when I woke up. But it was clear at ADA that the pace of development is accelerating quickly, and that the first version of such a system may be closer than I thought. Most tangibly, after presenting tantalizing data at ADA, Medtronic announced on June 27 that it has submitted its Hybrid Closed Loop System (otherwise known as the MMT-670G system) to the FDA for approval. The system consists of two parts: an insulin pump and a continuous glucose monitor. Once the system has been calibrated, the pump uses the readings from the CGM (which are taken every five minutes) to deliver insulin, with the goal of keeping blood sugars within a target range. If the 670G is approved, it would be the first pump to be able to actually give insulin doses—an enormous step toward a truly closed loop system. It’s not technically an “artificial pancreas” because it still requires user input (so watch out for news articles that erroneously refer to it as an AP). But still—very exciting. What’s more, Medtronic isn’t the only company working on a closed loop system. As Melissa Lee wrote about in her Artificial Pancreas roundup in January, multiple companies are racing toward the development of hybrid and, eventually, fully closed loop systems.   I’m particularly intrigued by the iLet, which is being developed by a team led by Ed Damiano, whose teenage son has type 1. It’s a dual-hormone pump, meaning that it can deliver both insulin (which lowers blood glucose) and glucagon (which raises it), and it aims to be a true closed-loop, with no need to warn it about impending meals, or to take pre-meal boluses. In fact, the only thing you’d have to do would be to enter your body weight, and the system would take it from there. That simplicity is obviously fantastic from a quality of life standpoint (can you even imagine?), but Damiano also pointed out another benefit: it evens the playing field when it comes to who can achieve tight blood sugar control. In other words, right now, maintaining a low A1c means that you have to know a heck of a lot about diabetes and your body. But the iLet wouldn’t require knowing anything about carbohydrates, or correction factors, or insulin-to-carb ratios. With the machine doing the math, everyone could achieve the same blood sugar results regardless of how well educated about diabetes they are. Some important caveats: this system is further off than the 670G, in large part because there’s not yet a stable form of liquid glucagon. But the fact that they have moved beyond a jerry-rigged iPhone/Dexcom/pump combo to an actual commercial prototype is very exciting, and Damiano hopes to have an insulin-only version of the system approved for sale in the United States within the next few years. I hope that they succeed.  

2. The FreeStyle Libre is getting closer to the US market

Those of you who have not spent the past year figuring out how to take care of a baby may already have heard of the Abbott FreeStyle Libre (like, for example, Mike). I, however, only found out about it at ADA, when I met a Croatian guy who was wearing one and who absolutely loved it. So here are the basics for anyone else not already in the know. The FreeStyle Libre is a fascinating hybrid between a traditional glucometer and a continuous glucometer that’s based on the technology of the Abbott Navigator CGM system.  It relies on a coin-sized sensor that you wear on your upper arm (for up to 14 days) that collects glucose readings every few minutes, just like a CGM. But unlike a traditional CGM, it doesn’t automatically beam the data anywhere. Instead, it does one of two things: -the straight-up FreeStyle Libre, which is already available in Europe (and is what my Croatian acquaintance was wearing), allows you to see your blood sugar level any time you want simply by waving a receiver over the sensor. It also stores 90 days’ worth of data, and can tell you which direction your blood sugar is moving.  Most excitingly, it doesn’t require any calibration, which means you don’t need to do any finger sticks. Let me repeat: NO FINGER STICKS. How does it do this? I do not know. But it’s pretty freaking cool, especially for kids, and I hope Abbott submits this patient-friendly version to the FDA soon.   -the FreeStyle Libre Pro, which is currently under review by the FDA, doesn’t let the patient see his or her glucose data. Instead, your doctor sets up the system for you, you live your normal life for a few days, you go back to the doctor, and she or he downloads all your glucose readings. Then you and your doctor use the information to fine-tune a treatment/management plan. Personally, I prefer the version where people get to see their own glucose levels. But the Pro could be a great tool for people with either type 1 or type 2 who want to get a sense of their daily blood glucose fluctuations without having to commit to wearing (and paying for) a continuous glucometer. It also may be easier to get reimbursement for.    

3. People are still working on a cure for type 1!

Better pumps, CGMs and glucometers have the potential to greatly improve quality of life for people living with type 1 diabetes, but they’re definitely not a cure. So I was very happy to attend a press conference featuring researchers who are actually trying to figure out how to reverse type 1 diabetes. Caveat: these approaches are not coming to your doctor’s office any time soon; they’re in very early stages of research. But they’re interesting to be aware of nonetheless. Let’s start with a quick review: in type 1 diabetes, the body’s immune system mistakenly kills off the cells in your pancreas that produce insulin. (These cells are called beta cells or islet cells.) This makes it seem like curing the disease would be quite simple: you just need to replace the cells that have been killed off. But unfortunately, this is much trickier than you’d think. First of all, our immune systems are designed to reject foreign invaders. So if you were to give someone an islet cell transplant—say, from a cadaver—his or her immune system would recognize the cells as foreign, and would kill them off. In order to keep the replacement cells alive, recipients would have to take a yet-to-be-perfected cocktail of anti-rejection drugs for the rest of their lives, just like people who receive full organ transplants. Second, if you’ve got type 1 diabetes, it means that your immune system will attack insulin-producing cells even if they aren’t foreign invaders (that’s what caused you to develop type 1 to begin with). Curing type 1 diabetes therefore requires figuring out how to avoid two types of attacks from your immune system. And as if that’s not enough, there simply are not enough replacement cells available. There are close to three million people with type 1 diabetes and nearly 30 million with type 2 in America alone, but there are only about 7,000 to 8,000 deceased human donors available per year. Even if we did figure out how to get past the immune issues, the numbers will never add up. The press conference, titled “Beta-Cell Replacement,” highlighted two possible solutions to these problems. The first, described by Dr. David Cooper, MD, PhD, FRCS, Professor of Surgery at the University of Pittsburgh, had to do with pigs.  Or, more specifically, pig-derived beta cells. Humans and pigs share a lot in common when it comes to our internal organs—that’s one of the reasons they’re so often used in research.  We also have very similar insulin; in fact, before scientists figured out how to make insulin analogues, people with diabetes depended on insulin from pigs. Unfortunately, you can’t just give someone pig beta cells because our immune systems would recognize them as foreign invaders and kill them off. Cooper’s solution? He wants to genetically engineer pigs to produce beta cells that wouldn’t trigger their recipients’ immune systems. Theoretically, this would remove the need to tamp down a recipient’s immune system with immunosuppressive drugs, because the pigs’ beta cells would be wearing the biological equivalent of a Harry Potter invisibility cloak. Just as Harry and Hermione can sneak around Hogwarts unnoticed, these genetically modified pig cells would be able to produce insulin and regulate blood sugar without the recipient’s immune system noticing that they were there. What’s particularly unusual and clever about this approach is that it would modify the donors of the cells (the pigs), rather than the recipients’ immune systems, thereby removing the need for immunosuppression. Cooper also pointed out that as opposed to human donor cells, which can transmit illnesses carried by the donor, the pigs could be raised in sterile, biosecure housing that would prevent them from getting infected in the first place. And these pigs could be raised in virtually unlimited numbers—which would provide an endless source of cells to transplant. “I believe that one day we’ll look back and say, ‘You know, they used to use dead people for this purpose,’” said Cooper at the end of this presentation. “And I think that that will be seen as very odd because we’ll have gotten used to using pigs.” As intriguing as this approach is, no one is going to be receiving a pig beta cell transplant any time soon—Cooper is seeking funding for his research. But I look forward to following the story. The second speaker in the conference was Chad Cowan, PhD, from the Harvard Stem Cell Institute. Chad Cowan, associate professor in stem cell and regenerative biology at Harvard and Massachusetts General and co-founder of CRISPR Therapeutics. Cowan and his team are also working on ways to hide transplanted cells from human beings’ immune systems. But instead of using beta cells from genetically modified pigs, his team is working on creating genetically modified human stem cells that would be invisible to the immune system. Cowan compares these cells to the O-negative “universal donor” blood type: since the immune system wouldn’t react to them, they could be given to anyone without any risk of rejection. In the case of diabetes, the idea would be to first coax the stem cells into becoming insulin-producing beta cells, and then to transplant them into the bodies of people with diabetes. Since the immune system wouldn’t be triggered, there’d be no need for immunosuppressive drugs. What’s more, the fact that the cells would be designed to be invisible to everyone’s immune system would mean that there would be no issues with supply: the same cell line could be used to make replacement beta cells for an unlimited number of people without need for individualization (this would greatly reduce the cost). Again, this research is in its early stages, and any treatments derived from it won’t be available any time soon. But nonetheless, it’s nice to know that there are people out there working hard on finding a cure.  

4. Finally: someone is paying attention to cannulas!

Everyone who wears an insulin pump knows that your blood glucose control is only going to be as good as the pump and the insulin itself. That’s why there’s so much work going into developing better pumps and faster, more efficient insulins. But what about the tubing and cannula that actually get the insulin from the pump into your body? Who’s paying attention to that? The answer, until recently, has been “basically nobody.” That’s partially because pump infusion sets are made by a third-party manufacturer (and therefore aren’t typically researched/developed directly by pump or insulin companies), and partially because no one really thought they needed much improvement. I mean, it’s just a tube and a cannula, right? What’s the big deal? I have long thought that infusion sets are a big deal, and am feeling very satisfied that they’re finally attracting attention. I used to get into arguments with my former endocrinologist in which I’d tell him that my insulin boluses from my pump didn’t start working until an hour or two after I’d given them, and that I thought the insulin might be getting stuck in the tubing or pooling under my skin. He would tell me that this wasn’t physiologically possible and would dismiss my complaints, especially when I admitted that I hadn’t been getting any “no delivery” alarms on my pump. It was extremely frustrating. But guess what, former doctor? I WAS RIGHT! At ADA, I learned about the BD FlowSmart infusion set. Technically called the Medtronic Pro Set with BD FlowSmart Technology, its cannula has two holes in it. One’s at the cannula’s tip (like a normal cannula). But there’s also a hole higher up on the side of the cannula, meant to relieve pressure when the tip of the cannula is blocked—not necessarily enough to set off an occlusion alarm, but enough to impact the insulin’s delivery. Apparently this type of occlusion (sometimes called a “silent occlusion” since it doesn’t set off any alarms) happens way more often than most people think.   The new infusion set is still in trials, but BD hopes it’ll be on the market in the near future. It will work with all pumps, not just Medtronic. I cannot wait.  

5. The FDA wants to help people with diabetes

  If you’ve noticed that the speed of device development seems to have picked up in the past few years, you should give some thanks to FDA itself. The leadership of the division that regulates medical devices such as insulin pumps has made a point of listening to and working with patients. It’s also been very communicative with industry about what sorts of data and information the FDA will be looking for when deciding whether or not to approve or clear new devices. The result is a much more efficient process, which is good for the FDA, for device manufacturers and, most of all, for people with diabetes whom the devices are designed to help. So on behalf of all the people with diabetes who use these devices, I want to send them a big thank you. Please keep it up.

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