Dive Brief:

• A warning letter posted Tuesday by the Food and Drug Administration revealed quality control issues with Dexcom’s continuous glucose monitors. The FDA raised concerns with a design change to a component used in the resistance layer of Dexcom’s sensors.
• The sensors with the new component were less accurate than those with the original component, according to the warning letter. Dexcom has ceased distribution of G7 sensors with the component, but the company’s response did not address affected G6 sensors. 
• J.P. Morgan analyst Robbie Marcus wrote in a research note Tuesday that the letter concerns a chemical compound that the sensor wire is dipped in. Dexcom began producing the compound internally to add redundancy to its supply chain.

Dive Insight:

Dexcom Chief Operating Officer Jake Leach said in an interview with MedTech Dive last week that the company does not expect the warning letter to affect future product approvals, including a 15-day version of its G7 CGM, and there’s no need yet to recall products. Dexcom has submitted the device to the FDA and anticipates a launch in the second half of the year.

Marcus, after speaking to company leadership and a quality control expert, wrote that many of the issues outlined in the letter could be addressed quickly. He added that the warning letter could explain minor delays in approval to the 15-day sensor, but Dexcom is still within the 90-day window for a 510(k) submission. 

“While there’s always a risk this could impede future product approvals,” Marcus wrote, “we do not expect this to materially delay the 15 day G7 sensor approval.”

The warning letter followed an FDA inspection last year of Dexcom’s facilities in San Diego and Mesa, Arizona. Marcus wrote that after the FDA requested additional information and a separate 510(k), Dexcom stopped in-sourcing the compound and reverted back to the external supplier. 

Dexcom’s devices were misbranded because the company did not submit a premarket notification to the FDA before making major changes to the sensors, according to the warning letter. The sensors with the changed coating “cause higher risks for users who rely on the sensors to dose insulin or make other diabetes treatment decisions,” the letter said.   

The FDA raised other concerns in the warning letter, including procedures to monitor the glucose and acetaminophen concentrations used in testing of the G6 and G7 CGMs. The FDA also cited problems with Dexcom’s handling last year of a deficiency in its G6 sensors with dissolved oxygen content values, a key input for measuring blood glucose levels.