The manufacturer of Mylan’s emergency allergy treatment devices has been accused of failing to investigate hundreds of complaints over three years that the EpiPen and EpiPen Jr. failed to work properly, a failure that resulted in the deaths of several people.

That’s according to a U.S. Food & Drug Administration warning letter sent last week to Pfizer subsidiary Meridian Medical Technologies, the company that manufactured the emergency allergy treatment devices for Mylan.

What’s more, the FDA claims that Meridian actually detected issues with the auto-injectors but failed to adequately address the devices’ failures.

Related: The Cost Of A Life-Saving EpiPen Has Increased 400% Since 2007

Instead, it took the company three years to issue the recall of EpiPen and EpiPen Jr. devices that misfired during life-threatening emergencies. And even then, the company may not have recalled all affected devices.

A Lot Of Complaints

According to the FDA warning letter, Meridian received 171 complaints about EpiPens that failed to activate between 2014 and 2017.

The complaints involved a plethora of issues related to the devices, including that the auto-injectors failed to activate despite users following the device’s directions, as well as issues related to the device spontaneously dispensing epinephrine prior to use, leaving no medication available when an actual attempt to use the injector was made.

However, the letter alleges that Meridian failed to adequately investigate these complaints, some of which included “situations in which patients subsequently died.”

For example, Meridian received a customer complaint in April 2016 that an EpiPen failed to activate. Meridian opened an investigation into the complaint the following month, finding that the device in question contained a defect.

Instead of examining its entire reserve of samples to determine the extent of the defect within the same lot, Meridian concluded that the defect was infrequent and that “no market action would be taken.”

No Disassembly

The FDA claims that the April 2016 complaint was not the only time in which Meridian failed to properly investigate issues with the EpiPen. Of the 171 complaints the company received, it did not disassemble “the vast majority” of the units in question.

When FDA investigators visited Meridian, a site quality lead said that while disassembly is necessary to detect defects, the company’s policy was not to disassemble products unless approved by management.

Related: Public Outcry Hasn’t Actually Decreased The Price Of EpiPens

However, the company did not provide the agency with additional information for “failing to disassemble the vast majority of complaint samples you received over nearly three years,” even though Meridian “concurred that disassembly would have been necessary to determine” if a defect was present.

Alleged Inaction

The FDA claims that in Feb. 2016 Meridian discovered a failed component in some of its devices.

The component in question ensures that the auto-injector properly fires and delivers the intended dose of epinephrine.

While Meridian rejected the two lots of injectors because of the issue, it did not examine any units from the associated lot to determine if other products were affected by the defect.

“You instructed your supplier to undertake a full investigation and corrective actions regarding the firing defect, but continued to manufacture finished products using other lots of the same component while the supplier’s investigation remained open until October 2016,” the letter states.

Additionally, the company did not investigate whether or not the defect was related to component failures mentioned in the hundreds of complaints it had received from consumers.

Although Meridian eventually recalled the specific lot of injectors and told the FDA that it had worked with the supplier of the deformed part to address the root cause of the defect, it came too little, too late, according to the FDA.

“Your response is inadequate,” the letter states. “You did not explain why your own investigations failed to identify the scope and frequency of the component defect, or why you had previously concluded that this component defect occurred too infrequently to warrant a market action.”

Looking For Answers

With the letter, the FDA requires Meridian to provide a comprehensive review of invitations and create plans for patient safety and assessing the quality of EpiPens that might already be in the hands of customers.

“Correct the violations cited in this letter promptly,” the FDA letter states. “Failure to promptly correct these violations may result in legal action.”

The company has 15 days to a provide a response to the FDA.

Pfizer said in a statement to The Washington Post that it is “very confident in the safety and efficacy of EpiPen products being produced” by Meridian.

Additionally, the company said it has no information that links product complaints with any patient deaths.

Despite the letter and failure allegations, a rep for the FDA tells The Post that the agency “was not aware of defective EpiPens currently on the market.”

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