FDA advisers spurn KemPharm’s abuse-deterrent claim for opioid

A big group of outside advisers to the FDA waved through another opioid pain drug on Thursday evening, with a big majority voting to recommend marketing approval. But an even larger number slammed the door shut on labeling the KemPharm drug abuse-deterrent, threatening to scuttle the one big advantage it could have on the market.

Investors hated the implications, and KemPharm’s stock ($KMPH) collapsed in after-market trading, plunging more than 50%.

By 16 to 4, the panelists concluded that the opioid Apadaz, a prodrug of hydrocodone and benzoic acid combined with acetaminophen, should get a green light. But by 18 to 2 they shot down a question added at the 11th hour, concluding that the drug should not be labeled as abuse deterrent.

Coralville, IA-based KemPharm set out to make an opioid that could only be activated by enzymes in the intestinal tract, making it resistant to efforts to snort it, inject it or smoke it for a quick high--something millions of Americans have done with opioids like OxyContin in an epidemic of abuse. But the advisers were left deeply unimpressed by KemPharm's evidence and clearly reluctant to hand the biotech rights to a claim that would encourage physicians to prescribe Apadaz over other opioids.

“We would all like to see” an abuse-deterrent opioid on the market, said Tobias Gerhard, a panel member from Rutgers University's Ernest Mario School of Pharmacy, but “we have to remain critical. We haven’t seen the kind of evidence that this product makes a difference.”

Gerhard and a joint FDA panel had spent the previous two days reviewing the FDA’s risk evaluation and mitigation strategy (REMS) for opioids, and many seemed exhausted at the end of the third day of talks.

KemPharm is remaining resolute in the face of a clear setback.

“We continue to believe in the value of our prodrug technology as a platform for developing prescription opioids with abuse-deterrent properties,” said Travis Mickle, president and CEO of KemPharm, in a statement. “While it is inevitable that there will be different points of view when evaluating new molecular entities with abuse-deterrent properties, we will continue to work collaboratively with the FDA to complete the review process of Apadaz.”

The PDUFA date is June 9.

- read the release