FDA panel backs approval of Pfizer's opioid painkiller

[June 09, 2016]  By Toni Clarke

(Reuters) - A U.S. advisory panel on Wednesday recommended approval of Pfizer Inc's long-acting opioid painkiller Troxyca ER, saying it dulls pain and its design could deter abuse by addicts in search of a quick high.

The panel, however, had reservations about the drug's ability to curb all forms of abuse, voting against a claim that it deters oral abuse while endorsing claims of deterring injecting or snorting the drug.

Troxyca ER contains oxycodone and naltrexone, a drug designed to cancel the effect of oxycodone. When taken as directed, the naltrexone remains hidden and does not diminish the effect of the oxycodone, which is released over time.

The product is designed to deter addicts from crushing the pellets to release the oxycodone for a quick high. When crushed, the naltrexone is released along with the oxycodone.

The panel concluded that addicts could use certain solvents to extract oxycodone and only limited amounts of naltrexone, though they said it would be harder to take the additional steps needed to snort or inject it.

The FDA is not obliged to follow the advice of its panels, but typically does so.

On Tuesday the panel concluded that a different long-acting opioid made by Teva Pharmaceutical Industries Ltd was likely to deter abuse whether addicts sought to swallow, snort or inject it.

Panelists were more conflicted about Pfizer's drug, voting 9-6 to recommend approval of the product but voting 9-6 against the claim that it deters oral abuse. They voted 11-4 that the drug deterred nasal abuse and 9-6 that it deterred intravenous abuse.

"The committee is in a quandary about Troxyca ER," Dr. Raeford Brown, Jr., a professor of anesthesiology and pediatrics at the University of Kentucky, said, summarizing the views of the panel. "The data are not clear."

Panelists also wrestled with their role in recommending approval for any high-dose opioid at a time when opioid abuse has reached epidemic proportions. The Centers for Disease Control and Prevention estimates that 78 Americans die every day from opioid overdose. Music superstar Prince died from an accidental overdose of an opioid painkiller in April.

Dr. Jeanmarie Perrone, a professor of emergency medicine at the University of Pennsylvania, described the entire discussion as one of "whether we should approve another high-dose opioid with maybe a bit of abuse deterrence."

A number of panelists said Pfizer met current standards for approval, but said they would like to see those standards raised.

Companies that make abuse-resistant opioid painkillers are supposed to conduct subsequent studies to prove whether they reduce abuse in the real world. None of those results have come in so far.

(Reporting by Toni Clarke in Washington, Editing by G Crosse and Leslie Adler)

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