Glucose sensing and continuous glucose monitoring (CGM) manufacturer for diabetes management, Dexcom, and pharmaceutical and medical devices organisation, Abbott, have been locked in a series of patent disputes over their continuous glucose monitoring (CGM) devices and systems, in a battle that spans multiple patents and several jurisdictions including the UK, US and Germany. In the UK alone, both parties have brough infringement proceedings, with a total of seventeen patents being at issue.

A recent decision issued by the Unified Patent Court (UPC) sees one of Dexcom’s patents revoked in its entirety, representing a significant win for Abbott. Notably, this patent had already been defended successfully during opposition proceedings at the European Patent Office (EPO).

In this article, we take a look at the two decisions and discuss the potential risks – and rewards – of opting into the UPC.

What are Continuous Glucose Monitors (CGMs)?

According to the World Health Organisation (WHO), it is estimated that 422 million people worldwide have diabetes, with the disease being directly attributable to about 1.5 million deaths each year. In the UK alone, around one in 14 people are living with the condition.

Traditionally, a patient’s glucose levels have been monitored by taking a small sample of blood via a ‘finger prick’ method. However, more recently (over the last 20 years or so), CGM systems have been developed. CGM devices are small sensors that can be inserted under a user’s skin, typically on the upper arm or torso. Once applied, they take regular measurements of glucose concentrations in the user’s interstitial fluid to determine blood glucose concentrations. Measurements are sent to a nominated smart device, which as well as displaying the recorded data, can send the user an alert when blood glucose levels are outside of a predetermined range.

Due to the high prevalence of diabetes, the market for CGM devices is already huge, and it is set to grow. A number of devices are already available on the market, including two from Dexcom (G6 and G7) and three from Abbott (Freestyle Libre, Freestyle Libre 2 and 3). In the UK, Abbott’s devices are supplied to patients on the NHS.

Against this backdrop, it is perhaps not surprising that Dexcom and Abbott have been locked in patent disputes over their CGM devices and systems. Capturing a larger, or exclusive, market share would be incredibly lucrative.

Dexcom’s patent at the EPO

Dexcom filed European patent EP3435866 (EP’866) to seek protection for systems and methods for communicating between a CGM and a smart device.

Claim one as granted relates to an analyte monitoring system comprising a sensor and a display device. The claims require that the sensor is able to i) transmit data continuously in a “broadcast-type” manner from the sensor to the display device via a first communication protocol that is Bluetooth or Bluetooth low energy (BLE) and is also able to ii) transmit data “on demand” upon receiving a data command from the display device via a second communication protocol that is nearfield communication (NFC) or radiofrequency identification (RFID).

Abbott opposed EP’866 on the grounds of added matter, and lack of novelty and inventive step over several documents including their own prior art, US2015/0205947 (US’947), which disclosed systems and methods of data exchange between a sensor and a display device. Arguments focussed on whether the prior art disclosed the specific combination of first and second communication protocols as claimed.

The Opposition Division (OD) was unconvinced by Abbot’s novelty arguments, stating that it is “not derivable [from US’947] that the known system is configured for exchanging data over two distinct communication protocols”. In particular, the OD noted that while continuous broadcast and on demand protocols, including Bluetooth, BLE and NFC, respectively, are each disclosed, they are presented as a series of alternatives. The OD went on to say that it cannot be derived that the two types of transmissions are using distinct communication protocols, “even less that one type of transfer is using Bluetooth or BLE while the second type is using NFC or RFID”. The OD therefore concluded that the claims were novel over US’947.

The finding is in line with the EPOs “two lists” principle. For example, it is well established that a combination – unsupported in the application as filed – of one item from each of two lists is such that although the application might conceptually comprise the claimed subject-matter, it does not disclose it in that particular individual form (T 727/00).

The OD also found the claims of EP’866 to be inventive because the skilled person, having reviewed US’947 in view of the common general knowledge, would not think to use two separate communication protocols when using the two transmission systems.

The claims were additionally found to be valid over the other prior art documents raised. Abbott’s bid to revoke EP ‘866 was therefore unsuccessful, and the patent was maintained as granted by the OD. Abbott did not appeal the decision.

Dexcom’s Patent at the Unitary Patent Court

Following the commencement of the UPC in June 2023, which for the first time offered the opportunity for parties to obtain a binding decision in all the European countries participating in the UPC system, Dexcom lodged an infringement action against Abbott at the Paris Local Division.

Abbott responded by counterclaiming for revocation. Once again, they asserted that EP’866 lacked novelty and inventive step over their own prior art, US’947. In other words, they attacked the validity of the patent on the same grounds, and on the same facts, as used during European opposition proceedings.

However, in contrast to the EPO, the UPC found Dexcom’s claims to be invalid.

On novelty, the UPC also found the claims to be novel over US’947 (as well as the other documents raised). However, whereas the EPO concluded that a single monitoring system using two different types of communication protocols is not disclosed, the UPC considered the use of two protocols to be “expressly envisaged”. It went on to say that the skilled person would not be deterred from implementing such a system. As to the specific combination of communication protocols, the UPC found that Bluetooth or BLE were “expressly listed” as alternatives for the first. However, it concluded that US’947 does not “expressly disclose” the use of NFC for the second protocol. Thus, the claims were found to be novel.

It is interesting that the UPC appears to differ from the EPO as to whether a selection from a single list is enough to establish novelty. It is well established in Europe that a selection of one or more elements from a single list of specifically disclosed elements does not confer novelty (see the EPO Guidelines, G-VI.7). In assessing EP’866, the EPO considered a three-fold selection to be necessary to arrive at the claimed subject matter: 1) using two different communication protocols, 2) using Bluetooth or BLE for the first protocol and 3) using NFC (or RFID) as the second protocol. In contrast, the UPC considered features 1) and 2) to be disclosed in the prior art. It nevertheless concluded that the claims were novel because feature 3) was not disclosed.

In assessing inventive step, the UPC took a different view to the EPO when determining the differences between the prior art and the claimed subject matter. As mentioned above, they considered that the disclosure of multiple transmission methods, alongside the disclosure of multiple possible communication protocols, had, in effect, disclosed the use of two different communication protocols. Therefore, they concluded that the only difference lay in the fact that US’947 does not expressly disclose the choice of second protocol used, i.e., NFC or RFID.

The UPC decided that the advantages and disadvantages of each communication protocol were part of the common general knowledge, and that Dexcom had not identified any surprising benefit to using NFC. On this, the UPC stated that the US’947 “expressly lists four candidates, namely NFC, Bluetooth, BLE and Wi-Fi. The advantages and disadvantages of each protocol are common general knowledge, such as considerations of energy efficiency and security. The patent in suit does not ascribe any particular or surprising effect to choosing NFC (or RFID), beyond the well-known advantages of low power consumption and security due to the low range”. They further noted that the prior art already disclosed the use of NFC to send an initial command for data. The UPC therefore concluded that it would be obvious to use NFC for the second communication protocol to achieve the effects commonly ascribed to this protocol.

The patent was therefore revoked in its entirety across all UPC contracting states.

Take home

This case highlights the need for patent proprietors to carefully consider the advantages and disadvantages of opting into the jurisdiction of the UPC.

Decisions covering multiple European countries can be sought, offering a cost effective and relatively quick option for users (the UPC aim to have a first instance decision within a year). However, the prospect of central revocation may be considered too much of a risk for some. In the present case, Dexcom may have held some level of comfort on the basis that the EPO had already found its claims to be valid. However, as seen, decisions on validity between the EPO and the UPC may differ.

It is worth noting that both Dexcom and Abbott have several patents relating to their CGM technology. Having multiple patents means that a party can adopt different strategies, if required. For example, some family members can be opted into the UPC whereas so some could be left outside of its jurisdiction. This flexibility may be of interest to some (perhaps those with the largest pockets, or those with the most to gain or, of course, lose).

In any case, it is very unlikely that this will be the last we hear on this already long-running patent dispute.