Dive Brief:

• FDA has served Abaxis a warning letter over the company’s alleged failure to file a 510(k) premarket notification when it modified its potassium assay.

• Inspectors found changes Abaxis made to its Piccolo potassium assay could lead to serious adverse consequences and as such required regulatory clearance.

• The warning letter comes nine months after Zoetis paid $2 billion to acquire Abaxis and its portfolio of veterinary point-of-care diagnostics.

Dive Insight:

FDA inspectors visited Abaxis’ facility in California around this time last year, one month before Zoetis revealed its intent to buy the business. The inspectors found the potassium assay used with Abaxis’ Piccolo Xpress chemistry analyzer is adulterated under FDA rules, as it qualifies as a Class III device but lacks premarket approval.

The inspection also uncovered evidence that the assay is misbranded under a different set of rules. That allegation centers on evidence that Abaxis made significant changes to the assay without properly informing FDA.

“Your firm made changes that affected the potassium assay calibration specifications and ultimately changed the performance of the device, as demonstrated by customer complaints,” FDA wrote in its warning letter.

The inspectors ruled that the changes to calibration set points raised new safety and effectiveness issues, such as the potential for a falsely low potassium result to delay treatment of hyperkalemia. Changes with such potentially significant outcomes require premarket notification. Even discounting the potential harm, FDA thinks a 510(k) was needed as the performance specifications of the device changed.

Abaxis responded to FDA’s findings on five separate occasions last year but was unable to change the agency’s belief that a 510(k) was required. That led FDA to send a warning letter to Abaxis earlier this month. The letter gave Abaxis 15 business days to detail the steps it has taken to fix the violations and stop similar problems from occurring again.

FDA also used the warning letter to address problems with Abaxis’ quality system. Specifically, FDA criticized Abaxis for changing the calibration of its potassium assay in 2013 “without establishing pre-approved acceptance criteria or evidence of performance of risk evaluation.”

Abaxis responded to that criticism last year, too, but FDA found the five submissions “did not assess whether the modifications could have significantly affected the safety or effectiveness."