WASHINGTON — The maker of OxyContin says it has completed testing of an abuse-resistant version of the painkiller hydrocodone, a surprise development that could derail sales of the recently launched Zohydro, a similar medication that has been criticized for lacking such safeguards.
Purdue Pharma says it plans to submit its extended-release hydrocodone drug to the Food and Drug Administration later this year. The company's tablets are designed to prevent users from crushing them for snorting or injection.
Shares of rival Zogenix Inc. plunged more than 20 percent after the announcement, which appears to jeopardize sales of the company's just-launched drug Zohydro. Physicians would presumably be more likely to prescribe a harder-to-abuse form of hydrocodone to try to protect their patients from addiction and abuse. And the Food and Drug Administration could potentially pull Zogenix's drug off the market if its regulators determine that a safer alternative is available.
Zogenix began shipping Zohydro to pharmacies last week.
Purdue Pharma said a study of its once-a-day hydrocodone pill showed positive results in a 588-patient study of low back pain. Sixty five percent of patients experienced a 30 percent reduction in their pain, while 48 percent of patients reported a 50 percent reduction in pain, according to the company. Purdue Pharma's formulation would last longer than Zohydro, which is designed to be taken twice a day, or every 12 hours. Pain experts said both durations are important for treating different types of conditions and patients.
"As a pain specialist, and specifically a cancer pain specialist, I think we are always interested in adding more tools to our toolbox," said Dr. Larry Driver, a professor at the MD Anderson Cancer Center in Houston. "It boils down to individualizing patient care to prescribe the safest and most effective regimen available."
Hydrocodone is used to treat pain from injuries, surgery, cancer, arthritis and a variety of other ailments. It is part of the family of drugs known as opiates that also includes morphine and heroin. Hydrocodone can unleash intense feelings of euphoria, especially when quickly absorbed via injection or inhalation.
Before Zohydro's approval, hydrocodone was available only in combinations with other non-addictive pain relievers, such as acetaminophen. These combination pills, such as Vicodin, were the most prescribed drugs in the U.S. in 2012, with more than 125 million prescriptions filled. But they are also the most abused medications in the U.S, according to the federal government.
As the first pure form of hydrocodone, Zohydro's approval by the FDA in December touched off a firestorm of criticism from some medical groups, lawmakers and state prosecutors who feared the drug would exacerbate the national epidemic of prescription drug abuse.
This month Sens. Charles Schumer, D-N.Y., and Joe Manchin, D-W. Va., separately called on the Obama administration to overturn the approval of Zohydro.
One of the chief criticisms leveled against the drug is that it does not have any design features to discourage abuse, something that has become an increasing focus for makers of extended-release opiates.
Purdue Pharma says its version of hydrocodone will be similar to the tamper-resistant version of OxyContin it launched in 2010, which is designed to be more difficult to crush, break or dissolve. After the Stamford, Conn.-based company launched its reformulated OxyContin, the FDA blocked all generic versions of the pill that did not have the abuse-deterrent features. The move effectively helped Purdue Pharma extend its exclusive marketing of the pill.
The first of the extended-release opiates, OxyContin's formula was hailed as a breakthrough when first approved in 1995, allowing patients to maintain 12 hours of continuous pain relief. But drug abusers quickly discovered they could get a heroin-like high by crushing the pills to get the entire dose all at once.
In 2007, Purdue Pharma and three of its executives paid $634 million and plead guilty to charges of misleading the public about the safety and addictiveness of OxyContin.
Zogenix previously announced plans for a tamper-resistant version of Zohydro, but that product is several years away from approval.
The company said in a statement Wednesday that "deterring opioid abuse requires solutions that go well beyond abuse deterrent formulations." The company highlighted other measures it is taking to try and prevent misuse of its drug, including a third party surveillance board that will monitor prescribing of Zohydro.
Shares of the San Diego-based drugmaker fell $1.03, or 22.7 percent, to $3.51 in afternoon trading. They had risen 32 percent so far this year through Tuesday's close.
