Hello everybody and welcome to this edition of the Taking Control of Your Diabetes podcast. I am one of your hosts, Dr. Jeremy Pettis, joined as always with my good friend and colleague Steve Edelman. If you're just tuning in, Steve and I are both endocrinologists. We work at University of California San Diego. We both have type 1 diabetes since we were 15. Steve just about 20 years after me. We both work at Taking Control of Your Diabetes, which just celebrated on Friday our 30th anniversary of Steve basically creating this wonderful organization. So, we have a very special podcast today and a very special guest. What you might not know is that our TCO office here in San Diego is maybe half a mile from Dexcom. So Steve and I, and especially Steve, have been very close with Dexcom over the years. The evolution of not just Dexcom but sensors in general, how they've been made, the accuracy, the clinical use of them, is something that we should talk about. This is such a cornerstone of all diabetes care now, but it didn't used to be that way. So we have who better of a guest than Jake Leech. Jake, say hi, tell us a little bit about yourself, and then I thought we'd go through the history.
Of course. Yeah, it's a pleasure to be here with you guys and congrats on the 30-year milestone. That's really incredible. So, yeah, excited to be here. Jake Leech, I've actually been a part of Dexcom for 21 years. Started as one of the initial engineers working on the sensing system and have been part of just an incredible development of technology and patient impact, clinical data, all the things that we've done over the years. It has always kind of really been focused on the idea of the user experience, making sure users are getting the most out of the technology. But I just have to say the growth and the opportunity that CGM has to impact the world is just not something I think we contemplated when we first started. We were really just trying to solve this hard problem of putting a glucose sensor under the skin and accurately measuring glucose. That was just an exciting engineering project. But then as we learned more and the technology improved, we started to see the tremendous impact that CGM can have, starting with type 1 diabetes but through the whole spectrum through pre-diabetes and beyond.
Yeah. Whoever would have thought that it'd be now standard of care for people with type 2 on insulin and pretty soon it's going to be standard of care for all type 2s no matter what they're on because you just mentioned the importance of the feedback you get from looking at it for people with pre-diabetes. But we were just talking before we started the podcast for the listeners and viewers that Dexcom started off as an implantable sensor and then quickly transitioned to the subcutaneous patch. And you were with Dexcom the whole way and you told me that you were with Medtronic for eight years before that. Correct.
I was. Yeah, I was actually with MiniMed up in Los Angeles. We were focused on insulin pumps and then we started building glucose sensors. It was my first job out of college. I was working in the chemistry lab actually as an intern before I even graduated. I didn't really know a lot about diabetes, but I just needed the best internship I could find and that was at MiniMed, and then it turned into an engineering job after I graduated. Then I went into the engineering group working on sensors. Then this little company called Dexcom came around and they said, 'Hey, we got this really cool technology. We're trying to implant glucose sensors continuously measuring glucose under the skin for 6 to 12 months.' I was really intrigued by it. I went down to Dexcom here in San Diego where it was founded. The company was about 5 years old at this point. Didn't have any products on the market but was a really incredible engineering team and really focused on this idea of a continuous sensor. I joined thinking I was going to be working on these implants and then we rapidly at the time pivoted to the architecture with the sensor under the probe and the patch and making it more of a subcutaneous disposable sensor, which has basically been our architecture since the very first product that we launched.
What year was that when that was 2004 when I joined and Steve you said you were involved in those clinical trials which I actually didn't know so that was a good story.
Yeah, they we in the cadaver lab and no one should ever donate their body to science. No, it was a great experience and I think it was part of a learning curve for Dexcom. They realize that the body just gunks up anything and it turns out to be a win-win-win with the transcutaneous sensors and you've come Dexcom's come such a long way and I think the G7 such major advance over the G5. Well then tell us that history.
So implanted these devices didn't really work that great. You pivot to subcutaneous sensors. What was the first sensor on the market? When did that happen? So fantastic question. 2006, March of 2006 we got approval for the STS 3-day. What that basically was is we taken all the learnings from the implant sensor which in general we had got about 70% of those implants to work reliably but then the other 30% we just couldn't quite get them to accurately measure glucose for the long run. So we kind of said that's probably not going to work out as a product especially an implant. Also the other thing too is just the engineering time it would take to determine if a 12-month implant was going to work for 12 months is 12 months. With these short-term sensors, we started doing these turnaround studies that were 3 days old. We could do a study, we could learn from it, and then we could start another study the next week. So the rapid evolution of the technology really occurred when we changed the architecture to something that was much shorter duration. That first product, the STS 3-day, there were so many things in that product that we just had to figure out how to do it as fast as possible. We had this receiver device. Funny note about these receivers. This is before smartphones had Bluetooth. Before smartphones existed, we had the display device kind of looked like a finger stick meter that showed you your glucose. When we first started building those, we actually took Motorola pagers and we took the electronics out of them and we developed our own version of the circuitry that could read the readings from our sensory implant and put those inside these Motorola pagers because we didn't have an engineer that could design a new whole housing. We were a scrappy little startup trying to save money. So yeah, the original receivers that people used in some of the studies look like a pager. Then we went into a new design sequence and we built this oval-shaped receiver. Some people called it the Tylenol just because it was reminiscent of a round Tylenol capsule. That product in 2006 we launched it and it worked well for some people and others it really wasn't accurately measuring glucose. I think the MARD on that product was about 26%. So that really means that it was within 26% of the reference on average. So it could really tell you if your glucose was changing, whether it was going up or down, but it was not accurate enough to make a lot of treatment decisions.
Did you use that, Steve? Yeah, I was on the short-term sensor, the 3-day, the little Tylenol pill, and I remember clearly that it may not have been as accurate as I would have wanted, but you have to remember where I was coming from. Pricking my finger 10 to 12 times a day. So I just thought it was incredible that I could just put the sensor on and get a blood sugar every 5 minutes. And you know what? I did double check with a finger check because I was used to doing that and it worked pretty well, I would say, the majority of the time. For me, it was the beginning of continuous glucose monitoring. It was amazing. So yeah, you have to remember where people were coming from. Nowadays, people get diagnosed like last week and they're so freaking spoiled. They get put on a CGM in 24 to 48 hours.
Well, you know, I was thinking my first experience was in 2010ish with the 7 Plus, which was still kind of like the oval looking receiver. And how long did that sensor last?
So we started with the STS 3-day, which by the way stood for short-term sensor. That's what when the engineers get the name of the product, that's what we that was our marketing. Then we did a 7 which was basically extending the wear life to seven days. Then we did a 7 Plus which was taking a bunch of feedback from users on the performance of the product and also the user interface of the receiver. So we added some enhancements there. So 7 Plus was a really nice upgrade from 7 and it was at the time a 7-day sensor and no one had really done at that point in time these subcutaneous type products like the infusion cannulas used for insulin pumps was one of the things that we looked at. No one had done anything more than three days and I remember just sitting around going why don't let's try and make it last a week, seven days, let's try it and it turned out it worked well.
Yeah, so I was telling the story before this that it was actually when I first met Steve and I was in my internal medicine residency and I was thinking I wanted to do cardiology mostly because I had massive student loans and endocrinologists don't make that much. I met Steve and he said you know you have type 1 and we chatted for a while and he was like you know you on a CGM and I literally said, you know, what is that? And he about lost his mind and then told me all the stuff that was going on. Honestly, I had no idea that sensors were happening, updates and pumps were a little bit behind that. But I kind of went through my medical training feeling like type 1 diabetes was stagnant. There wasn't much going on. It wasn't an exciting area. My care had not changed for a decade at least. Yours had like multiple decades. So that was a big reason for me to actually go into endocrinology. Like, there's actually stuff happening and stuff happening here in San Diego. So I got on the 7 Plus, but I think it's also interesting that to get it prescribed and to get it covered was just a nightmare. First of all, I had to go see a physician who didn't know what it was. It was tough to get covered. They gave me this huge log book to fill out, times that I had blood sugars less than 50 to kind of justify getting it. I'm saying this because that obviously has changed. When these sensors first came out, I think they were viewed as niche, like you don't really need that information. And actually on the medical side, it was very much patients shouldn't have this information. It's too much information. They're going to be looking at their glucose all the time. Oh my gosh, they're going to be adjusting their own insulin doses. Heaven forbid. They're going to have car crashes and all these things. We didn't know at the time how that would pan out. Of course, we know now that CGM helps people stay safe and less hypoglycemia and all these kinds of things. So what was the company's or your feeling when these products first launched? One from kind of the technical side and two from the headwind you were facing in diabetes care.
Yeah, I remember vividly the day that we unveiled some internally in the company unveiled some clinical data that just basically when we saw it we were like we got it. It was a study where we blinded the sensors for a week. So people wore multiple sensors and the data was blinded. So they didn't get to see it. They just knew they were wearing a continuous glucose monitor. They had no idea what the data was. Then we unblinded it and started showing them real time glucose data and the dramatic increase in time in range and the reductions of the hypos and the hypoglycemic events in just the matter of a couple days when you turned on the real-time data and we didn't give them any education. We were just cobbling them together. But when they got the real-time feedback and started adjusting their therapies and the food and everything they were doing, having data they'd never had before, this real-time glucose data, we knew that this was going to work.
Switch study. Is that what that was called? I remember seeing these slides from a bunch of them. But let me just say, Jake, that that's one thing that drove me nuts with the Medtronic CGMS, the 3-day blinded sensor. I was so adamantly against blinding data. And they said, 'Well, you know, if a patient sees their number, they're going to change their behaviors and it's going to improve their numbers and we won't know what improved it.' I said, 'Well, there you go.' And I remember debating Ian Bloomer.
Well, and real quick, just to make sure people know, blinding means that people would wear these sensors, but they wouldn't see the numbers and they would have to take it to father or doctor to interpret and see their information and then tell them what to do. That was kind of the initial use of this, like as a way to poke them in the eye. So there was a huge debate. We actually wrote several articles about it, blinded versus unblinded. Our stance was always that blinding was unethical even, like why not show people this information, but that was a huge debate.
No, that's it. I remember having to debate this issue. There's one paper in the medical literature about the first recorded passing away of a type 1 called dead in bed syndrome. I don't want to get too morbid on the podcast here, but he was wearing a blinded CGM and sure enough they documented him going down and his body tried to fight back a little bit. Blood sugar came up a little bit and then he passed away. So that's the ultimate if it was unblinding. If he saw the information he would have been alerted to it. That's just crazy. So anyway, it's all part of the evolution. And you're right, Jeremy, people were writing, 'Oh, it's way too much information for patients.' And that actually occurred when fingerstick chemstrips came out from urine testing. They thought about blinding the meters, the little finger stick devices. So I remember Jay Skyler, a big leader in diabetes for so many decades, and he wrote an op-ed against that. So it's just tough to change the way we do things in medicine.
It took a while and I think early days to Jeremy's point around access and how hard it was to get a CGM. I had a friend that had actually worked with me at Dexcom in the early days and he'd gone on to do some other medical technology projects and he was diagnosed with type 1. He called me and said, 'Look, my doctor's not going to give me a Dexcom till I prove that I have hypoglycemic problems. So I'm going to go and record a bunch of hypoglycemic data, but I would like to have a CGM. Can you just get me one for now until I get my insurance to pay for one?' I was like, yeah, of course. I got him one. But just the fact that he had to go through this hoop of I'm going to prove that I have hypoglycemia and have to document it to be able to get the tool he needs. It was crazy.
That's exactly what I had to do. And of course, I made up a bunch of numbers, like, well, yep, I was 50 yesterday and 45. I gave them different colored pens and crayons, so it wouldn't look it was the same. On the flip side, if you want me to have a severe hypoglycemic episode right now I could. Why should I have to force myself to do that to get this therapy? But anyways, early days and a lot of work to be done. Honestly, Steve, I think a big thanks to Steve. I would say outside of Dexcom employees maybe nobody as important as Steve Edelman is in really being a voice for getting CGM going and an advocate for that. We're talking about it like it was these old crazy days, but it kind of was in the sense that this was a technology that was not quickly adopted and here we are just not being able to live without it now.
Yeah. Well, thank you for that. But having type 1 myself, I think I really could realize the importance of it probably more than someone that doesn't have diabetes. So then I don't know, maybe catch us up, Jake, between, let's say, 2010 and now there's all these iterations, G4, G5, G6. More clever naming by the way. So anything jump out at you in that evolution that we should highlight?
You know funny thing about the G's, we actually called the first product G1 and G2 and G3 and so G4 was finally internally we called it that as an engineering team but finally the marketing team then adopted the engineering speak with G4. G4 was a huge product for us because it was the first CGM that had the accuracy and performance. It was still calibrated, but it really met the needs of a much broader population than say what 7 Plus did just because of some of the fiddle factor and some of the usability and the reliability of the product. Funny enough, G4 started out as mainly a manufacturing project in terms of how do we make sensors in a little bit more scalable way in terms of the way we put membranes on the sensor wire. It turned out that the better we got at making the sensors, the better the performance we got out of them. We made some changes in the materials. It was a big leap and really the fundamental material stack that we use even on the G7 today, a lot of its roots trace back to that original G4 development. That product again, it's still before we have smartphone integration, but that along with access and insurance coverage, people were really starting to listen to the Steve Edelmans of the world around the advocacy and how this product works. Insurance companies started paying for it and so those two things really started broadening the adoption of CGM, the better technology and the access. It's really just from there it's grown and grown. G5 was a big advancement to smartphones.
The thing I remember about a couple things about the G4. First of all, it was a cooler looking receiver. It was like a square kind of a rectangle one versus the oval which was pretty big and bulky. I mean, you had to calibrate it. We forget now that that was a thing, twice a day you had to actually enter a blood sugar. Then everybody wanted it to go to the smartphone. Everybody wanted it to go to the cloud that didn't exist yet. So you could get this little dock for the G4, which was like the initial share, right? That you could plug it into at night and it could go to people to kind of follow your blood sugars. So I remember that being kind of a big deal.
It was the share cradle and we developed it and it was the first time that a class 3 medical device, which is basically like the highest level of oversight at the FDA for medical devices. These are things like heart valves and brain implants are all in that class 3. At the time CGM was also in that category because they were still trying to figure out exactly how to treat the technology. It was the first time that type of class had ever been connected to a smartphone and it was very purposeful for us. We knew we wanted to get to full display on a smartphone. You don't have to carry your receiver device. You just everything on the smartphone because we knew we could do the remote monitoring, the convenience, all the computing power. But we knew we couldn't get there in one step. So we went and we did the cradle, which was the idea was you can charge your receiver, but it also pulls the information out of the receiver and puts it on your phone so it can go to the cloud so then loved ones could follow you. That technology we really only sold about 1,800 of those cradles because we quickly built the cradle technology right into that cool new receiver and so you didn't need the cradle. But I remember a funny story when we first started doing clinical studies with that receiver cradle, one of the kids that was wearing it was in college and he said, 'Hey, I love this thing. My mom really likes it because every time I plug it in the data just suddenly populates on her phone and she knows what time I got home.'
Yeah, that's the thing with share, right? It goes both ways. People can see your blood sugars. But yeah, so to me the next big thing was then the G6 losing calibrations, but it seems like you wanted to talk about G5. What stands out there?
So G5 was the first time we connected the CGM directly to a smartphone and it was your, as we call it in engineering speak, primary display. There was no other device. The big thing around that was you had to prove that you could reliably do the glucose alerts that alert users when their glucose is low or high, that you could really reliably do that on a smartphone. That was no small task. That really was the big development of G5 was how do we ensure that the safety and effectiveness is in this product that is on really a platform that we don't totally control. iPhone at first and then Android quickly after that. I remember when we launched that product, we launched it globally all at the same time, actually September 2015, we were at EASD and I got to stand on the stage like Steve Jobs and talk all about this new technology. It really was the beginning of unlocking the power of what a smartphone can do for users that have their device connected to it. In the development of that product, we made a very conscious decision that's worked really well over time, which was the idea that the device on your body, the patch, the wearable, is where all the intelligence is for glucose. So what that allows you to do is it allows your CGM on the Dexcom to connect to your smartphone, to an insulin pump for automated insulin delivery because we also were doing insulin pump integrations at the time starting to get towards closed loop. So we knew that was important but people still wanted to share and follow. Ultimately it led to our ability to connect directly to the Apple Watch so people have that extra convenience of just having the glucose on your watch and not having your phone with you. That was all really foundationally developed in the G5 days, which was way before the smartwatch.
Yeah. And I remember this too because this was back in the day, this was pre-COVID still. TCID, we would travel around the country and we would put on workshops, in-person conferences, a Saturday in Kansas City or different cities like we did one a month. This was such a big issue. Something that we take for granted now, your CGM of course it goes to your phone. But people were like, why doesn't this go to my phone? People were mad about it. I remember thinking that yes, there did seem to be this discrepancy between how quickly smartphones and things were moving and kind of how relatively slow it was to connect with it a lot because of these regulations and the clinical trials and things that were required. So that seems interesting to me then that must be something you struggle with as a company is like yes we can do this tomorrow but we need to go through the proper steps and things like that.
Yeah. I remember even before people were getting angry they couldn't connect to their iPhone, we'd ask how many of you have a CGM and out of maybe 200 type 1s maybe 15%. And now you couldn't even see the hands of the type 1s that don't have one. Folks on MDI they all have one, it's standard of care now.
But what I remember too was the autoinserter. Answer my question. You always do that. You chime in with a second question. Did you have... Yeah, I had a question. What was your question? Does technology kind of interface? No, it's... I thought that was a comment. Sorry.
No, it actually does. You guys remember the Blackberries? That was the smartphone before there was the iPhone. We actually had a project working on trying to integrate with one of those and the Bluetooth required so much battery power to communicate with the phone that we ended up with these wearables that were just too big. So we really went and we talked to Apple, we talked to Samsung and even Sony at the time was making Android phones. We were advocating for a lower power connection to the phones so that we could build a wearable that worked. Ultimately Apple was the first to adopt what's called low energy Bluetooth and that was the unlock for connectivity to smartphones because then you could do it at a low power and your battery could be small and the wearable could be small. I never envisioned that as someone who's involved in CGM development that I'd be going around to Samsung in Korea and going up to Cupertino to meet with Apple to try and convince them to do this. I think there were others doing the same time for other technologies or other industries and it was a big unlock for us when Apple adopted that low energy Bluetooth.
Yeah, what a cool progression of things. I don't know what sales and use look like but it must be this kind of steep curve of all these things coming together. The technology is getting better so it's more accurate, people trust it, eventually you don't have to use your meter anymore because it's accurate enough by the FDA, you can actually use it to control insulin pumps and things. As these uses become more and more and people have adopted it, insurance companies cover it. All these things took time to come together. But again, now we are here where it's just such a standard of care and Dexcom has been a huge leader in this. So let's jump forward to today's sensor and then want to talk about what's next with Dexcom. We unfortunately had to jump over the G6 again. For me that was huge getting rid of calibrations. That was just monumental in terms of I don't poke my finger at all like ever.
I'll just say one quick thing, last thing about the development. The auto inserter was kind of a nice feature. The guillotine, the G6, boom. Of course, that's so much better with the G7. But that was nice because I had no problem with the G4 pushing that thing in, but some people did.
We had a video that we used as a motivational tool and really to help engineers understand what we were trying to do when we were developing the auto applicator. It was a video that was on YouTube of a mom chasing a little girl around holding an applicator trying to hold her down to get the sensor in. She was crying and running around. Her mom was chasing her. I said, 'This is the problem we're trying to solve, team.'
Yeah. And the G4, the previous ones, was that giant like syringe. It didn't look like fun. You're like pushing this needle into you. So yeah. Going to the applicator freed up where you could put it. I know you like to put it all over your... He's got like 17 on right now. My favorite sensor spot. All right, so we get to G7 and I want to talk about obviously there are many advantages to it, but there has been at least anecdotally people having issues with it. For me, I would say it's like one third, a third of my patients are like, this is a superior product. I love it compared to the G6. It's a huge positive. The other third in the middle are kind of like, there's some bugs, there's some issues, but it's no big deal. And there is a third or so in my opinion that they're losing connectivity or there's accuracy issues and they just can't wear it. So what is this issue? How do you quantify it? What's Dexcom's kind of opinion and approach to it?
Yeah, it's super important because if you think about user experience and CGM is such an important part of managing diabetes for so many people, we are very focused on making enhancements every generation. We've made the product more accurate, more reliable, but as we've seen larger and larger populations of users, we learn lots. One of the things we pride ourselves in is listening to users and taking the feedback. As we've scaled G7, as you mentioned, the large volume of new people using CGM, we've had certain struggles in trying to ensure we could build enough products. Towards the end of last year, beginning of this year, we had some supply shortages. We had some deployment reliability problems that started kind of earlier this year with G7 that I think really amplified some of the frustrations out there. We were very aware of it. We're working super hard to fix it. At the scale we operate at, people were having those experiences and getting those sensors. So we spent a lot of time focusing on how do we make this system as reliable as possible. There definitely have been users who experienced some challenges. As you mentioned, there are lots of users having a fantastic experience. But our focus right now is making sure we know everything that people run into and that we're on top of resolving it. The other thing too that we've learned, that idea of continuous learning, is when people call in when they have an issue, how our tech support talks to users and manages that and makes sure that they have a great experience. If they need a replacement, they get the replacement in the time frame. I think we've made some mistakes in the way that we rolled out some of the support policies around how we replace sensors. With good intent we always had the positive intent, but just the way it came across and we learned a ton from that. One of the things I want users to know is that we will replace any sensor that doesn't work for you. There's no limit, there's no cap on those. If you need a sensor overnight, we're going to ship it overnight. I think that's also been something where users have had a hard time accessing sensors. It's my last sensor. I've got an AID system. We understand how critical it is if you need a replacement to get it to you. That's something that I'm ensuring our teams are doing everything necessary to ensure people can get the sensor replacements they need.
