The FDA asked Endo Pharmaceuticals (NSDQ:ENDP) to pull its opioid pain med, Opana ER, from the market, saying that the benefits of the abuse-deterrent drug no longer outweigh the risks.

The move marks the 1st time the federal regulatory watchdog has urged a company to remove an opioid painkiller due to concerns of abuse.

“We are facing an opioid epidemic – a public health crisis, and we must take all necessary steps to reduce the scope of opioid misuse and abuse,” FDA Commissioner Dr. Scott Gottlieb said in prepared remarks. “We will continue to take regulatory steps when we see situations where an opioid product’s risks outweigh its benefits, not only for its intended patient population but also in regard to its potential for misuse and abuse.”

The decision by the recently-confirmed commish won praise from former FDA chief, Dr. Robert Califf, on Twitter.

“Good evidence based move. As ppl [sic] review this case, the importance of empirical evidence as opposed to theory–critical for abuse deterrence,” Califf wrote.

Endo’s Opana ER won FDA approval in 2006 for the management of moderate-to-severe pain. Six years later, the company reformulated Opana ER with the intent to make it harder for people to snort or inject it.

But a review of postmarketing data showed that the reformulation may have encouraged users to shift from snorting Opana to injecting the painkiller by mixing it with large volumes of solvent.

The painkiller was even linked to a 2015 HIV outbreak in Indiana after people addicted to opioids shared needles while injecting Opana.

In March, an advisory committee voted 18-8 that the benefits of the reformulated Opana ER no longer outweigh the risks.

“The abuse and manipulation of reformulated Opana ER by injection has resulted in a serious disease outbreak. When we determined that the product had dangerous unintended consequences, we made a decision to request its withdrawal from the market,” Dr. Janet Woodcock, director of the FDA’s center for drug evaluation and research, said. “This action will protect the public from further potential for misuse and abuse of this product.”

The FDA has asked Endo to voluntarily pull Opana ER from the market, but the agency said if Endo does not remove the drug, the FDA plans to take steps to withdraw Opana’s approval.

In the meantime, the FDA said will evaluate the risk-benefit profile of all approved opioid analgesic drugs.

The move is a strong step for the newly-confirmed commish, who said this month that tackling the opioid crisis is among his top priorities.

ENDP shares tumbled today to $11.73 apiece in mid-morning activity, down -15%.

The company said it is reviewing the FDA’s request.

“While the benefits of opioids in treating and managing pain are widely recognized, the misuse and abuse of these products have increased greatly in the U.S. As a pharmaceutical company with a demonstrated commitment to the improvement of pain management, Endo feels a strong sense of responsibility to improve the care of pain for patients while at the same time taking comprehensive steps to minimize the potential misuse of its products,” the company wrote in prepared remarks.

“Despite the FDA’s request to withdraw Opana ER from the market, this request does not indicate uncertainty with the product’s safety or efficacy when taken as prescribed. Endo remains confident in the body of evidence established through clinical research demonstrating that Opana ER has a favorable risk-benefit profile when used as intended in appropriate patients.”