Regulatory News | 25 March 2025 | Ferdous Al-Faruque

Dexcom headquarters in San Diego, CA. (Source: iStock)

The US Food and Drug Administration (FDA) has cited Dexcom, a continuous glucose meter (CGM) manufacturer, for several current good manufacturing practices (cGMP) violations. The agency said the company failed to maintain the procedures necessary to ensure its products provide accurate readings, made a design change without proper procedures, and didn’t follow proper corrective and preventive actions (CAPA).

On 4 March, FDA inspectors sent Dexcom a warning letter stating it had found significant quality system regulation (QSR) violations at its San Diego, CA, and Mesa, AZ, facilities. The agency said the company failed to establish proper procedures to monitor and control process parameters for a validated process.

“Specifically, your firm conducts functional acceptance testing, [redacted], on your Dexcom G6 and G7 Continuous Glucose Monitoring Systems,” wrote FDA. “This testing accepts or rejects the glucose sensors based on values of glucose sensitivity slope, accuracy in the presence of acetaminophen (G6 only), and low oxygen response (G6 only); however, your firm has not established procedures to adequately monitor and control the glucose and acetaminophen concentrations used during the [redacted] process.”

FDA also cited Dexcom for failing to establish several other procedures to validate its manufacturing processes properly and to establish design input procedures adequately. For example, the agency said the company’s design inputs do not conform to special controls required for integrated CGMs by regulation.

“Your design inputs do not clearly define all of these requirements to ensure appropriate design control activities can be conducted,” the agency wrote. “Specifically, your firm has not defined appropriate design input requirements for manufacturing controls and acceptance criteria for your [redacted] system for slope and mean absolute relative distance (MARD).”

FDA cited Dexcom for failing to establish proper procedures for product design changes, adequately establish procedures for design output, and adequately establish procedures for design validation to ensure its products conform to user needs and intended uses.

The agency said the company made a design change to a component used in the resistance layer of the sensors used in its products, which was a significant change that should have been evaluated and validated. It said the company failed to establish adequate specifications for parts of the sensor coating used to make their CGMs and failed to institute risk analysis procedures for the devices.

Finally, FDA also cited Dexcom for failing to establish proper CAPA procedures. The agency noted that in April, the company initiated a CAPA procedure after discovering that the dissolved oxygen content requirements for part of its G6 CGM were outside the scope of the device’s specifications.

“This CAPA investigation determined your firm was not consistently monitoring or recording the values of dissolved oxygen, notifying management of out of specification results, or consistently scrapping affected sensors when identified,” according to the letter. “The CAPA also found this deficiency was consistent across both your San Diego, CA and Mesa, AZ facilities.”

The agency added, “In your CAPA investigation your firm limited your evaluation to [redacted] lots of G6 sensors potentially impacted by the deficiency, despite finding all lots may have been potentially impacted.”

While Dexcom has responded to many of the FDA’s concerns and listed steps it is taking to rectify the issues, the agency said those responses were inadequate and asked the company to respond to the warning letter within 15 business days