A Food and Drug Administration (FDA) advisory panel will be reviewing formulations of the opioid oxymorphone with special emphasis on Endo International’s Opana ER version and whether the powerful painkiller is too dangerous to stay on the market.
Endo’s immediate-release (IR) version of oxymorphone, Opana, received FDA approval in 2006. The patent expired in 2011, and Endo responded with an extended-release version (ER) of the pill, which is protected by a patent until 2023. Opana ER was formulated to be “abuse deterrent,” with a special coating designed to make it more difficult to crush and be snorted or dissolve and be injected – both of which would give abusers a powerful high.
Endo had filed for specific abuse deterrent labeling from the FDA, but in 2013, took back its request. In January 2016, Endo resubmitted its request specifically for snorting deterrence along with studies to support its request. But the data only muddied the waters.
“While the evidence that Endo presents is multi-faceted, it is also quite complex,” the FDA said in a briefing document. “Each of these data sources and methodologies has its own set of assumptions and limitations that render the results more or less relevant in determining the effect of the reformulated product on abuse, route of abuse, and therefore the safety issues that result from the different routes of abuse.”
The agency noted that the data suggested that while there was a decrease in abuse through snorting, there was a spike in abuse of the drug through injection. The agency also clarified that it was difficult to interpret the data.
Another safety issue the FDA panel will weigh is regarding serious blood disorders associated with use of Opana ER when dissolved and injected. The condition, alled thrombotic thrombocytopenic purpura, occurs when blood clots form in the microvasculature.
The panel will also consider a Center for Disease Control and Prevention (CDC) report of 108 cases of HIV infection in patients who abused extended-release oxymorphone. While no specific brand was identified in this outbreak, it has been suggested that Opana ER’s abuse-deterrent coating may be contributing to these outbreaks. With the pill harder to crush and snort, addicts resort to dissolving the pill and injecting it, putting them at risk of needle-borne diseases.
While it is considered a remote possibility that the FDA will pull Opana ER from the market based on safety and abuse concerns, at the very least the agency may require more restrictive labeling, which would likely cut into sales of the drug. The drug generated $159 million in revenue for Endo last year.