The Food and Drug Administration on Tuesday posted a warning letter sent to Beta Bionics in late January.
The letter raised concerns with how the diabetes tech company handled complaints of severe low and high blood sugar associated with its automated insulin delivery system. The FDA also flagged problems with the company making modifications to its device without notifying regulators.
In an annual report filed Tuesday, the company said it has already taken several corrective actions, including improvements to the processes identified in the warning letter. The company is also preparing a written response to the letter.
Beta Bionics did not immediately respond to MedTech Dive’s request for comment on the warning letter.
Beta Bionics received the warning letter on Jan. 28 and informed investors in early February. The letter followed an inspection of its Irvine, California, facility last June. The company does not expect the warning to affect its ability to produce, market, manufacture or distribute products.
The iLet Bionic Pancreas system automates insulin therapy for people with Type 1 diabetes when used with a continuous glucose monitor. Beta Bionics advertises the device as requiring no carbohydrate counting and no manual corrections.
The FDA uses warning letters to flag significant violations and bring manufacturers into compliance.
Unreported adverse events
Many of the FDA’s concerns focused on delayed reporting of adverse events. Typically, companies must report within 30 days if a device may have contributed to a death or a serious injury.
For example, the FDA listed five reports of hypoglycemia, three of which were reported after 30 days and two instances from 2024 which were never reported. The agency also listed three complaints suggesting the device’s pump malfunctioned, which could lead to serious injury. Beta Bionics still has not reported these malfunctions, according to the warning letter.
Delayed glucose readings
Beta Bionics made software modifications to its iLet system as it grappled with a problem with CGMs providing delayed readings. However, it did not report the changes to the FDA.
The company investigated an issue with its CGM supplier where it received five-minute delayed glucose readings instead of real-time data. The problem could lead to patients not receiving the right insulin dose as their CGM values trend up or down.
Beta Bionics issued a temporary software change in April 2024 to mitigate the risk to patients while the CGM supplier implemented a permanent solution. The FDA requires medical device manufacturers to report changes or corrections that could alter a device’s safety or effectiveness.
The FDA said that even though the issue involved a third-party CGM, Beta Bionics still should have reported the change since the correction was intended to reduce health risks posed by its device.
Separately, the warning letter also said Beta Bionics made changes to address a cybersecurity vulnerability without reporting them to the FDA.
Problems with cartridges, circuit boards
The warning letter also listed hardware problems with Beta Bionics’ devices. More than 500 complaints between June 2023 and June 2025 reported leaking insulin cartridges or cartridge connectors. Beta Bionics closed 31 of those complaints without an investigation, 18 of which mentioned patients experiencing hyperglycemic health effects.
In one instance, a user experienced a hyperglycemic event that required emergency room treatment and insulin administration. That person developed diabetic ketoacidosis, a life-threatening complication. The case was closed without proper evaluation, according to the warning letter.
Inspectors also found that 61 printed circuit board assembly mainboards failed testing due to faulty connections. Beta Bionics said it investigated the problem with its supplier, but the investigation was not documented and the supplier did not take any corrective action because it was a first-time issue. Later, the company received 19 complaints related to device failures caused by defective PCBA mainboards. It’s not clear whether Beta Bionics is still tracking and investigating non-conforming devices, according to the warning letter.
The letter also mentioned complaints of damaged pump displays and faulty motors, although it did not disclose how many complaints Beta Bionics had received related to the latter problem.
Hypoglycemic episodes from user error
Finally, the warning letter noted several complaints reporting hypoglycemic episodes that were attributed to user error. Although the total number of complaints was redacted, the FDA said it received 107 complaints submitted as serious injury reports for severe hypoglycemia or where medical intervention was required to prevent severe hypoglycemia.
Beta Bionics closed 56 related complaints without implementing corrective actions, according to the warning letter. The firm later took actions to reduce user errors, such as providing office hours for healthcare providers, better user training materials and creating materials for people transitioning from hybrid closed-loop systems or people new to pump therapy.
