It’s official: Tandem Diabetes Care now has approval from the FDA for its t:slim G4 combo system, which is integrated with the Dexcom G4 continuous glucose monitor. On Wednesday morning, the California pump company announced that the FDA had approved its first combo device on Sept. 8 — about 14 months after Tandem Diabetes submitted the system for review. This marks Tandem’s third device approval since debuting in August 2012 (first the t:slim, then the larger t:flex pump and now the combo system).

In the past year while Tandem was awaiting approval, competitor J&J’s G4-combo Animas Vibe system got the FDA green light and hit the market in January. That makes this t:slim G4 the second pump to offer built-in Dexcom CGM integration and the third combo system overall behind Medtronic’s line of CGM-pumps.

Welcome, t:slim G4!

The good news is that it’s always exciting to see our Diabetes Community get another option as far as tools to help us pursue improved health outcomes.

The bad news is the timing: Tandem’s new combo device is nearly obsolete on arrival given that last Fall, Dexcom rolled out an advanced algorithm that’s more accurate than its original G4 and that new algorithm is not included here. Moreover, Dexcom’s G5 direct-to-smartphone sensor was also just approved by FDA and will be available in the coming weeks — putting Tandem another square behind the latest tech.

What Is the t:slim G4 Combo Device?

So here’s a look at what this new t:slim G4 has to offer:

  • Basics: The pump holds 300 units of insulin housed in a unique micro-delivery infusion and “cartridge bag” system. Sexy color touchscreen. Rechargeable battery, and many of the traditional insulin pump functions and features. 
  • Youth: Approved for ages 12 and older, although Tandem hopes the FDA will lower that age to 6 or 7 within the next year. Of course, doctors are able to prescribe this off-label to younger kids if they choose. (For comparison, the Animas Vibe with G4 is approved for ages 18+ while the Medtronic Paradigm Revel with its Sof-sensor can be used at any age, and the Minimed 530G with Enlite sensor is for 16+).
  • New Features: Aside from the new CGM integration, this combo device will have newer software than the first-generation t:slims, and will include the new features added in April 2015. Some of those key improvements include:
  1. Correction Bolus – Users will now be offered the option to reduce their bolus amount when a BG entered is below their target, but above 70 mg/dL. A reduction is still forced when BG is below 70 mg/dL.
  2. Bolus Workflow – Users can now enter a manual bolus directly in the suggested bolus window without first entering a carb value.
  3. Fill Estimate – The pump will now display an estimated fill amount (indicated by a “+”) until 10 units have been pumped, at which point a more specific volume will be displayed.
  4. Change Cartridge/Fill Tubing – Users can now fill their cartridge prior to installing it on the pump. Additionally, the tubing fill time has been decreased, and there is an audible tone during tubing fill to help prevent inadvertent filling.
  5. Pump History – now includes Total Daily Dose values for individual days broken down into units and percent.
  6. Alerts – The alarm and reminder tones have been enhanced with multiple frequencies.
  7. Status Screen – Users can now view the Status Screen without unlocking their pump.
  • New Improved t:connect: This is Tandem’s current Mac and PC-compatible software, which will now be expanded to include data from the t:slim G4. When a CGM-enabled Tandem pump is linked to a t:connect account, a new CGM hourly report will be available to summarize CGM readings. t:slim G4 customers will have access to all existing t:connect content as well as this new report, additional logbook stats, and a CGM summary dashboard.
  • Availability: Tandem is taking orders now and pumps will start shipping in October. But no access overseas, as Tandem says it will be focused on U.S. commercialization for the foreseeable future. ***UPDATE:*** Tandem announced it would start shipping this t:slim G4 on Sept. 23, 2015.
  • Cost: Pre-insurance retail list price is $7295. And that doesn’t include the $599 for the G4 transmitter plus $299 for each box of G4 sensors, sold separately by Dexcom.
  • Reimbursement: Tandem says the pump component of the t:slim G4 should have the same insurance reimbursement as the t:slim pump and YIMV (Your Insurance May Vary).
  • Exchange Offer: Earlier this year, Tandem irked many in the D-Community with a No-Upgrade policy. But now it’s modified that stance with an exchange policy: if you’ve bought a t:slim or t:flex on or after Aug. 1, 2015, you’ll be able to get a no-cost exchange to the t:slim G4 combo. If that’s something you’re interested in, you have until Oct. 2 to apply. But there’s a caveat… (read on).
  • Future Upgrades:Tandem is talking to the FDA about its so-called Project Odyssey, which it hopes to file with the agency by year’s end to allow plug-in, at-home upgrades of t:slim technology and software — similar to updating your smartphone from home. The aim is that in the near future, Tandem customers will be able to simply plug in their t:slims for system updates, including the Bluetooth chip inside that could allow for compatibility with the Bluetooth-enabled Dexcom G5 Mobile that’s recently FDA approved. But customers who upgrade to the t:slim G4 version now will be getting a system that doesn’t have that capability, since it’s connected to the G4 sensor using an older wireless signal… This might be a reason to hold off on upgrading to the t:slim G4.

To clarify, neither the t:slim G4 nor G4-integrated Animas Vibe is compatible with the new G5, nor do they include the latest G4 advanced algorithm.

You can actually play around with the t:slim G4 using the very cool t:simulator app that Tandem Diabetes has for both iOS and Android devices. We checked it out following the approval news, and thought the pump-CGM device really does seem to be intuitively-designed (assuming the demo reflects how the device will be in real life).

Predicting the Pump-CGM Future

We asked Tandem spokesman Steve Sabicer about the potential impact of the Dexcom G5 approval on those weighing this new device.

“Right now the t:slim G4 pump offers the most accurate pump-integrated CGM available. We think the approval of the G5 adds a great option for people with diabetes who want more flexibility with their CGM access with fewer devices. Now people have choices and can decide if they prefer to see their data on their pump or their phone,” Sabicer says, noting that the t:slim G4 uses Dexcom’s older proprietary antenna so it’s actually a different pump than the t:slim and t:flex that have dormant Bluetooth capability built in. 

As to future upgrades through its still-uncertain Project Odyssey, Sabicer says this: 

“The initial plan for Odyssey is to allow original t:slim customers to update their pumps to the newer software that started shipping in April 2015. We plan to submit this for review to the FDA by the end of this year. We are investigating the potential of remotely updating existing t:slim pump software to enable communication with Bluetooth-enabled CGM systems, however it is too early at this point to speculate on whether this will be possible. The current t:slim model is a 510k product, and all CGM-enabled pumps are PMA products.”

The difference there being that 510(k) submissions are only required to demonstrate that a device is “substantially equivalent” to a predicate device (one that has been cleared by the FDA or marketed before 1976), whereas PMA (Pre-Market Approval) submissions require proof that a new or modified device is safe and effective, so the standard is higher for receiving clearance.

So, while nothing is 100% sure yet, there’s a chance that if you have a t:slim or t:flex pump, you might soon have the ability to remotely update your device from home for newer software, and possibly CGM integration on the screen. Hmmm. A lot to think about.

We can’t imagine how difficult this must be for Tandem, balancing the forces of business while trying to best protect and serve patients with existing tech. all while not knowing what the immediate future holds. This makes for an incredibly challenging stance… one that’s probably going to make some people mad no matter how they decide to proceed.

We feel for you, Tandem. The timing, in large part because of how quickly diabetes device tech and mobile health has started moving in the past two years, has put you in a tough spot.

Obviously, it’s up to each individual customer to decide for themselves based on cost and their own diabetes management needs. These are just some important considerations we would want to know about, if we were considering the Tandem devices right now.

Still, as Tandem says, it’s another great choice for those who want and need it. And we have to applaud that.