DexCom's FDA app nod is just in time for the Apple Watch

US approval of the first smartphone apps as medical devices is remarkable chiefly for the unassuming nature of the products. The Share Direct Secondary Displays system developed by the glucose monitor company DexCom does not do anything as potentially dangerous as controlling a monitor; the apps simply permit carers and doctors to see a constant feed of a patient’s blood sugar levels.

They are trailblazers purely for the reason that they have been approved via the FDA’s de novo route, as befits their innovative nature. They will now serve as predicates to similar apps that will now not have to undergo full FDA premarket review. And the timing is ideal: DexCom has clearly been aiming for the advent of the Apple Watch, expected in the next few months, as a crucial platform for its apps.

Cascade of products

The apps – the FDA approval covers two – work with a suite of DexCom’s products. First there is the subcutaneous glucose monitor itself, which adheres to the patient’s skin at the abdomen. A wireless transmitter is then connected, also sitting against the patient’s skin.

The sensor data are received by DexCom’s G4 Platinum glucose monitor, which in turn fits into a communications device called the DexCom Share – a docking system and charger that syncs with the monitor itself and transmits the data to an app on the patient’s phone.

The other approved app is to be used by “followers” – people the patient designates to receive continuous updates on their glucose levels. DexCom is seeing strong uptake of its technologies by paediatric type 1 diabetes patients, analysts say, perhaps helped by the range of colours the G4 Platinum comes in. These patients can now be monitored remotely by their parents and doctors. Adult patients may wish to share their data with their partners.

Software along the lines of the Share and its related apps was already available, but these were not sanctioned as medical devices by the FDA. This approval should give DexCom a marketing advantage.


So far the Share apps only work with Apple products, namely the iPhone and iPod Touch. But at the 2015 Consumer Electronics Show DexCom presented a simulation of an Apple Watch displaying live glucose readings from its monitors via an app.

It is believed that this is the first time a company has shown its determination to transmit continuous glucose monitor data to a smartwatch rather than a phone. DexCom is targeting a platform that has not even launched yet.

The Share sells for $299 in the US, and the apps are free. Analysts at Canaccord Genuity are modelling sales of $8.1m for the DexCom Share in 2015.

The approval also helps position DexCom for the artificial pancreas, the next technological revolution in diabetes. The company has agreements with two insulin pump makers, Tandem Diabetes Care and Insulet, both of which aim to create a device that can control blood sugar levels without any input from the patient at all.

This dream is still a long way off (Therapeutic focus – Artificial pancreas projects will deliver over time, October 4, 2013). But last year Insulet and DexCom agreed to allow data from each company’s device – Insulet’s OmniPod pump and DexCom’s G5 sensor, the next-generation monitor following the G4 Platinum – to be integrated into the other company’s apps. The newly approved Share apps could soon carry data from the OmniPod.

Moreover, in November DexCom received FDA approval for an artificial pancreas algorithm that works with the G4 Platinum. This software features the same advanced algorithm as used in artificial pancreas research around the world and will help improve the accuracy of DexCom’s devices.

Fast growth

The fact that the Share apps are not used to control any of DexCom’s devices makes a lot of sense when the ultimate aim is to allow an artificial pancreas to operate without requiring such control.

Michael Weinstein, an analyst from JP Morgan, estimated that the continuous glucose monitoring market could be worth $1.5bn in 2018.

Hitching an app to the hottest consumer electronics device to be launched this year could help DexCom add to its devices’ popularity among teenagers by gaining share among the much larger population of diabetic adults.

To contact the writer of this story email Elizabeth Cairns in London at [email protected] or follow @LizEPVantage on Twitter

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