Remember when we had to calibrate our glucometers? Each vial of strips came with a “code” that we had to put into the meter. The “code” was the calibration for that batch of strips. Then as the manufacturing tolerances became better the code was always 19 or 20, and later the code was always 20, and after that they advertised “no coding” meters which just means they put the 20 in at the factory.
The same progression is happening with CGM sensors. The study supporting the G6 has 30,000 pairs of data points comparing the G6 sensor with the YSI laboratory instrument, and Dexcom believes that the data already show that the G6 works as a no-calibration sensor. They had filed with the FDA for the G6 with smaller transmitter and easier inserter and 1 calibration per day because they thought that would be needed to get approval for insulin dosing without fingerstick confirmation in the first half of '18. The Libre approval for insulin dosing with no calibrations has changed the landscape. Now Dexcom is talking to the FDA to figure out what is possible and how to get there. At the December conference call we may hear the plan, but right now it looks like the most likely path is G6 with 1 daily calibration earlier in the year, and toward the end of 2018 approval for 0-calibration use. However, if talks with the FDA show a path to approval for a 0-calibration G6 well before year-end, Dex may go directly there.
Dexcom is eager to get to 0-calibration. We know they lost their position as CGM supplier to Bigfoot Medical’s hybrid closed loop pump because Bigfoot believes calibration errors are too great a safety hazard. And with a good enough sensor that’s absolutely true. Dexcom believes that 0-calibration is quite important for expanding their market to the many T1 and T2 who are not highly-motivated elite diabetics. And it will help when selling against the Libre.
Rather than allowing an optional calibration, I think it more likely they will say that if you don’t believe your CGM and your fingerstick shows the CGM is wrong, take another fingerstick to confirm it, and if the CGM really is wrong, the proper conclusion is that the sensor is broken, it should not be relied upon, and it needs to be replaced. xDrip+ could be the workaround for people who feel as you do.
Other tidbits from the conference call:
With respect to the collaboration with Google, look for a 0-calibration Verily CGM with disposable transmitter by the end of '18. This product will be marketed to people not on intensive insulin therapy, as something to be worn from time to time, perhaps for a month or two, while learning about the effect of diet and exercise on BG, and to help the physicians adjust medications and doses. They don’t know whether the Verily sensor will be approved for 10 days or 14 days, but the transmitter is built-in, disposable, and won’t have a long life. So don’t anticipate the ability to restart the Verily.
For the G6 Dexcom hasn’t decided on the sensor lifetime (the initial PMA said 10 days, but it may possibly be revised to 14 days or to 10 days but 0 calibrations.) They have not decided whether or not to use a suicide timer to kill the sensor and prevent restarts.
The Dexcom business approximately doubled in Europe and Canada over the last year. Dex competes well with the Libre despite a higher price because of the alerts, and the continuous flow of data which can be shared remotely. In particular, the Libre (as sold, without NotWaiting hardware) doesn’t wake anyone from an overnight hypo, or alert anyone while driving, and it doesn’t enable concerned parents to watch their childrens’ BG remotely. Supposedly the Libre is much less expensive, but given the fact that Dex users restart sensors and run them for close to 2 weeks on average, the sensor cost of the Dex is comparable with that of the Libre. (And this gives Dex a good reason to avoid putting a suicide timer on the sensor.)
So far Dexcom has shipped to 4000 systems paid by Medicare. There are another 20,000 people in the queue for Medicare approval, and Dexcom is working hard to handle them, hopefully by the end of 2017.
There was no mention of a touch-screen Dexcom receiver in this conference call. Maybe they’d rather have us just use our smartphones…