Two weeks ago today for Spring Break I was in gorgeous, palm-studded Santa Barbara, CA. And what does a diabetes technology geek like me do on vacation? Visit the local research clinic, of course!
Lucky for me, the Sansum Diabetes Research Institute in Santa Barbara (home to the legendary Drs. Lois Jovanovic and Howard Zisser) just happened to be running a clinical trial they were calling "Party Study 2." I am not making this up.
It was Part 2 of a first-of-its-kind Artificial Pancreas outpatient study, a collaboration with UC Santa Barbara, that had the participants strolling out of the clinic to visit restaurants, the beach, the mission-style courthouse and other local points of interest. It consisted of just four patients, but nevertheless marked "the largest group to date in the United States being tested in the real world with an AP system," Dr. Zisser tells me.
Quite a departure from earlier studies where patients were anchored to hospital beds via a tangle of tech cables, and hooked up to an IV drip!
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I was only able to watch this study "in action" while the group was doing its initial setup the first evening. This part was a little underwhelming -- just four nice type 1's donning fanny packs full of D-gear, no real-time data yet -- however, I did learn some pretty exciting things about what is happening in AP research overall, especially toward making this stuff more practical for everyday use. (I also learned that "phlebotomy" means the science of drawing blood - eww! hate it!)
Sansum is an interesting center, since its core focus is research (they do about 170 clinical trials each year), and it looks something like a fortress from the outside. I literally could not find the front door. When I did get in, I encountered Dr. Zisser with several assistants and four patients in a small technology-strewn room at basement level, with several yet-smaller rooms with hospital beds adjacent. It's an area they fondly refer to as "The Sansum Inn" since study participants spend the night there.
I met the patients, all looking delighted to be there:
- Jim, from Orange County CA, who's had type 1 since he was a kid for a total of 47 years
- Mark, from Santa Barbara, who's been type 1 since 2000
- Larry, from Santa Barbara, who was diagnosed with type 1 in 1989 at age 35
- and Bryan, a 32-year-old type 1 veteran from Los Angeles who just recently got married
They were all in the process of getting hooked up to three devices: a Tandem t:slim pump and TWO Dexcom G4 sensors. Yes, two -- because a backup was required for the study. The receivers were loaded into a chunky fanny pack for each patient. On the table along with adhesive backings and medical prep wipes, I noticed a box of See's Awesome Peanut Brittle and Tagalong Girl Scout Cookies (for lows). Party study, indeed!
While we stood watching the infusion site preps, Dr. Zisser explained that two of the patients would remain in full control of their own insulin delivery, while the other two patients would be on the automatic, closed-loop system for the next 48 hours. They would still pre-bolus for meals, but they could rely on a "safety system" that attenuates (or reduces) insulin or even shuts off the pump if needed. To be clear, this is not the same as low-glucose suspend because it is predictive, Dr. Zisser said. "This system attenuates insulin if it predicts that the subject will go low, whereas the LGS shuts off the pump once the glucose crosses a threshold and stays suspended for a set time unless the patient intervenes."
They were setting up a system to monitor patients' glucose levels via a pretty impressive data dashboard that was projected on a screen on one wall of the room, and that the researchers could later access via laptops while the group was out and about.
The group spent a lot of time talking about what they'd order for dinner at the restaurant they were about to head to. They were instructed to eat the exact same thing they did in the first session of this study a few weeks back. The purpose of this study is of course to compare the results of the 'automated' folks to those making basal adjustments and corrections on their own.
Everyone was still guesstimating carbs and making bolus doses, however. "If the system has to react to incoming carbs, it will always be a little behind the curve as opposed to 'announced meals' where the system is told what's coming," explained Dr. Eyal Dassau, an Israeli researcher assisting with the study.
btw, Zisser, Dassau, and their other colleague Dr. Frank Doyle who collaborate on these JDRF-backed AP studies recently won the Wyss Institute IEEE EMBS Award for Translational Research, which recognizes projects with potential to make "transformative impact on healthcare safety, quality, effectiveness, accessibility and affordability." Kudos!
"Zone Control" & Inhaled Insulin
One interesting bit that Dr. Zisser talked about was dropping the notion of "treating to target" in favor of "treating to zone."
"If you're always shooting for a perfect number, say 120, then the system has to constantly make adjustments and can never really catch up. But if you think about staying in a reasonable zone, or 'zone control' as we call it, you can achieve better results, and then you can make the zone tighter as treatment progresses," he said.
He's using this concept in other AP studies, including one that kicked off Feb. 12 using Afrezza inhalable insulin from MannKind. That study includes a total of 12 people (studied 2 at a time) hooked up to a similar AP tech system, who are given a small dose of the inhaled insulin at the start of each meal to mimic the cephalic, or first-phase insulin secretion. As we all know, speed of insulin action is a barrier to improved glucose control, and the Afrezza apparently kicks in very quickly.
So inhaled insulin is far from dead, Friends! It's only approved for use investigationally right now, but Dr. Zisser says the results are impressive.
In the Afrezza study, they're also testing a 45-60 minute exercise session "without telling the controller," to see how well it reacts to unexpected glucose changes.
DiaPort, and Going to the Moon
Another AP study underway is using the Roche DiaPort device to speed up insulin action. That one's taking place in France, where the device is approved. It's a surgically implanted tube that reaches further into the body, allowing insulin delivered via an external pump to work as efficiently as if it were delivered via IV.
"With DiaPort, the insulin starts working with 4-5 minutes, and peaks at 25 minutes, versus 45 minutes delivered the regular way," says Rem Laan, the brand new executive director of the Sansum Diabetes Research Institute, who was previously with Roche.
He's clearly very excited about the AP research underway, and says, "the algorithms are good -- the issues are with speed of insulin action and where to inject it." He also expressed some familiar frustration: "The FDA is pushing for products to be close to 100% safe, but diabetes is unsafe! Insulin on its own can cause serious harm, so we need to accelerate access to these tools that help people use it better."
Meanwhile, setting patients loose from the lab environment for these studies -- to actually get some data on what happens when PWDs move about in the real world -- is a huge milestone.
Apparently, the patients and Dr. Z played a little bocce ball after dinner (I missed it, dang!):
They also took a "field trip" to the local Apple store the next day:
This is all very exciting! Although when you think about it, 48 hours is a pretty short timeframe to get a realistic read on any PWD's ongoing patterns of glucose swings. I wondered how realistic the algorithm patterns were...
"We're just dipping our toes in the stream right now," Dr. Zisser said. "We're going with our 'best guess' until we can do week-long studies."
Meanwhile, patient Jim wasn't complaining a bit over 48 hours of long-awaited freedom. "It's soooo nice -- I don't have to do anything!" he crooned, with his eyes all a'twinkle.
Dr. Zisser just grinned. "We're learning and developing things along the way," he said. "It's like the space program. We're going to the moon, and along the way we get Tang, kerbal, and who knows what other innovations that come out of the process?"
Read more about JDRF's Insulin Initiative (DiaPort, Afrezza, "smart insulin," etc.)