It's official: Tandem Diabetes Care has made its filing with the U.S. FDA for an integrated insulin pump and continuous glucose monitor -- a new device that combines their sexy t:slim touchscreen pump with a Dexcom G4 Platinum CGM.

News of the FDA filing came out publicly during the company's 2nd quarter earnings call held this past Thursday (July 31), in which San Diego, CA-based Tandemtslim G4 reported on its current financial standing. The big news of the combo device filing comes just ahead of the 2014 American Association of Diabetes Educators (AADE) conference starting this week -- and it coincides with the two-year anniversary of the t:slim hitting the U.S. market.

Note that this integrated device is not the much-rumored "t:sensor" from Tandem... Instead, we're told it will officially be named the "t:slim G4 Insulin Pump." Not much of a creative ring to it, is there? We can only assume that's a strategic move, as Tandem has its eyes on future partnerships, possibly with other CGM devices that are not yet on the market.

It's way too early to be talking details on cost or availability, but it's obvious the integrated device would eliminate the need for a separate G4 receiver (although Dexcom has pointed out that receivers will still be available, for those who want them).

It's anyone's guess how long it might take the FDA to review and approve the integrated t:slim G4 device, but the company's talking about an expected 12-18 month timeline. We can only hope the process moves quickly and smoothly, as Tandem keeps up a good dialogue with the FDA (which some other device makers have failed to do in the past, resulting in delays). The current guesstimate is for this new device to hit market sometime in mid-to-late 2015, which we're hoping will happen!

Inside Tandem's Lair

Shortly before this news went public (on my way out to the ADA Scientific Sessions in San Francisco in June), I was fortunate to have a chance to visit Tandem's headquarters in San Diego, CA. I met with some high-level execs and got an inside look at the company's headquarters -- which is made up of three buildings in the Sorrento Valley area of San Diego and houses many of the 500 employees handling everything from manufacturing, customer service, administrative and behind-the-scenes aspect of pump manufacturing and commercialization.

{Disclosure: Tandem paid for my flight on the San Diego to San Francisco leg of the trip, and also covered my hotel room there and took me out to lunch one day.}

Tandem HQ

At the time, we thought the t:slim G4 filing would happen in conjunction with the ADA conference, based on what Tandem originally said publicly about its timeline. So naturally, that was a key point of conversation I had there with our gracious hosts.

Leading my tour were Tandem marketing director Aymeric Lecanu-Fayet, senior manager of marketing and communications Eric Shearin, chief administration officer Susan Morrison, VP of operations Jim Leal, and new product planning lead Jim Berkebile. Also joining in was public relations consultant Steve Sabicer, formerly of Medtronic, who now works with Tandem.Tandem Visitor Badge

While there, I got a sneak peak at the t:slim G4 device, but since it was still pre-filing, most of that conversation was off the record and of course I wasn't permitted to snap photos of product images or of the manufacturing floor process. I had to sit on the information until the embargo lifted at the time of their July 31 earnings call, which has been tough! ;)

Getting an inside look at t:slim G4 device was pretty cool, and the design looks awesome! Instead of the Dexcom G4 wheel that we've all come to know, this integrated device uses the t:slim touchscreen -- so to see your hourly line graphs, you simply tap the little button below the BG Arrow "3-HRS" to navigate between the multiple hour screens and glimpse those graphs.

I was practically jumping up and down to hear that Tandem will be weaving the much-anticipated Reverse Correction function into the t:slim G4! Yes, this feature means that if you're lower than your target number when dosing for food, then the t:slim will give you the option to reverse correct you back up to where you want to be. For example, if you're 70 mg/dL and want to be at 100 mg/dL, then it will lop off some of the suggested food bolus to bring you back to that target number. This is huge, and something many of us in the D-Community have been calling for since the t:slim was first introduced. Thanks, Tandem, for listening to us!

Integration of a fingerstick meter is a big deal for many people who wear these D-devices, and so I asked about that, too: Will the t:slim G4 wirelessly connect with any meters, like the Verio IQ that comes with the t:slim currently, or the Bluetooth-enabled VerioSync? Short answer: No. Apparently in designing this integrated pump-CGM, they had to replace the Bluetooth chip in the t:slim (the one that communicates with the meter) with Dexcom's chip that talks to the transmitter. So, without a complete redesign and potential risk of losing legacy t:slim and G4 users, they decided to stay with what they have for now. Of course, all these meters can still be included in the t:connect software, so users can still share access and share information online.

I mentioned the issue of how confusing the carb and BG buttons can be on the t:slim, and how I've heard many users say they often mistakenly enter blood glucose amounts as food boluses -- that could cause dangerously large amounts of insulin if delivered... yikes! With the screens looking so much the same and the touchscreen making it so quick and easy to tap through the many confirmations, it's easy to see how this mistake happens. Sitting face-to-face with the Tandem execs, I echoed what others in the DOC have told me: Tandem should swap the two icons, or try to make them a little more creative with a blood drop and food icon to better distinguish the two options. That would at least make it more easy to tell the difference, IMHO.

I also mentioned some other DOC-generated feedback on the t:slim, such as interest in having it OK for use with Apidra insulin, and the fact that it takes soooo long to do a cartridge and infusion set change compared to other pumps. No promises could be made as to future tech or upgrades, of course, but at least the Tandem execs listened and seemed receptive to what I was saying.

We also can't forget that in 2012 Tandem acquired ownership or licensing rights over 51 patents from Smith's Medical, makers of the now-defunct Deltec Cozmo insulin pump. Many of the beloved features of the Cozmo could very well be making their way into the t:slim at some point, but the powers-that-be are tight-lipped about what those might be.

Making the t:slim

It was also fascinating to tour the manufacturing facilities and see how the t:slim is put together.

There's a U-shaped room with 15 people assembling the pumps at all hours, and each pump moves along the assembly line where the motor is inserted, the face is put on, the siding is skillfully glued together, and then the t:slim goes through a computer verification process testing all the functions. The glue aspect is the most meticulous and skill-tapping task of the operation. Once the siding is glued on, each pump sits for two hours on a two-level rack with many compatriots as the glue cools.

tslim testing

In total, it takes about a day and half to make one of the 300-unit t:slims, I was told. VP of Operations Jim Leal, who's a D-Dad himself, says about two or three pumps are pulled from the line each week for things as minor as a scratch on the surface, and those "seconds" are then offered to endos to use as clinical demo devices.

The packaging area is in the same room where the t:slims are made, and it was amazing to see how the units are loaded into the shiny packages and boxes we eventually see as customers.

This facility is also where the new t:slim G4 will be made, Tandem says. In a separate room with "in development" signs posted all over, they will eventually be able to house three production lines that could manufacture 6 million t:slim devices; but at the time of my visit they only had one of those lines set up. I found it interesting to walk through the facility, hearing that some of the machines they use are the same technology that's used to make cell phones.

My hosts explained how they did thorough testing to make sure the G4 transmitter signal could actually penetrate the metal trim around the insulin pump. Yep, no issue there, I was told.

Recalling the Recall

Of course, we also talked about the t:slim cartridge recall at the start of 2014, affecting 130,000 cartridges (or 13,000 boxes) and costing the company $1.6 million. Remember, Tandem voluntarily recalled those cartridges because of the potential for leaking -- first on Jan 10 and then expanding that recall 10 days later.

I'm convinced this was the key issue that got me an invite to Tandem's HQ. After I reported in March about my decision to not purchase the t:slim because of some lingering concerns, I received word that they wanted to "reassure us" of the quality of the device -- making it clear that I wouldn't be visiting as a customer per se, but as a journalist for this site. So quality control was definitely on the agenda.

I was told emphatically that the issue then was an internal machine part that caused the whole problem. It had some strange machine name, but essentially it was designed like a giant drill, with the drill bit fitting into the little white hole where you stick in the needle to fill the t:slim cartridge with insulin. Basically, that drill bit was going in too far and created the potential for insulin to leak out of the cartridge.

At the time of the recall, I was using the t:slim but none of my cartridges were included in the problem batches -- those shipped before Oct. 16, 2013, and after Dec. 17. So naturally, I wondered what happened during that month inbetween. Tandem says it was a matter of changing out that drill part, and that none of the cartridges made during that month-long period were affected.

It was good to hear how quickly they caught the problem and made a change, alerting customers and the general public about the recall ASAP without waiting for official responses and extra eyes to sign off on everything. That's happened with other diabetes recalls, but not this one -- and whether I'm a customer or not, that makes me feel safe and confident in the people behind this device.

What's Next?

Now that Tandem Diabetes has filed the t:slim G4 with the FDA, they've started moving forward with the larger-reservoir insulin pump dubbed the t:flex. This is the pump that will have a bigger cartridge holding 480 units of insulin for those who require larger doses, and the cartridge will extend out slightly on one side to accommodate the extra volume while staying true to all the other t:slim benefits.

On the July 31 earnings call, Tandem execs said they've finalized the design and are doing final testing before submitting the t:flex to the FDA sometime during this 3rd quarter. That's a 510(k) submission, meaning the FDA could potentially review it within six months, so Tandem is expecting a mid-2015 launch of the t:flex device here in the States.

Tandem's also continuing to develop the t:dual, a double-chamber insulin pump that could hold insulin and another medication, like glucagon. No news has surfaced on this since the Tandem-JDRF partnership was first announced in early 2013, but we were able to get an image of what the device might look like (below); it's a prototype design and the final concept could change.

Tandem tdual

Personally, I appreciate how Tandem is moving ahead and working with the Diabetes Community in so many ways -- from sponsoring our Innovation Project here at the 'Mine, to supporting GlucoLift and Insulindepenence (as seen in their front lobby, where a tin of glucose tabs sits alongside a Tandem-customized surf board), to their support of efforts like the Big Blue Test (I saw a BBT flyer posted in the hallway of one manufacturing facility). These people really care and are trying to make a difference, and whether I use their pump or not, I'm happy to have them "on our team" working to make life with diabetes better.

Disclaimer: Content created by the Diabetes Mine team. For more details click here.


This content is created for Diabetes Mine, a consumer health blog focused on the diabetes community. The content is not medically reviewed and doesn't adhere to Healthline's editorial guidelines. For more information about Healthline's partnership with Diabetes Mine, please click here.