Regulators have rejected a Pfizer Inc. pain drug that is designed to discourage abuse.
The New York drugmaker said the Food and Drug Administration asked for more information about the drug, called Remoxy. In May it said approval of Remoxy could be delayed because of issues with the manufacturing part of its application. Pfizer did not say Friday if the FDA's decision was related to those problems. Its shares slipped 8 cents to $20.57 in premarket trading.
Shares of Pfizer's partners on Remoxy, Pain Therapeutics Inc. and Durect Corp., both plunged. Durect shares dropped 89 cents, or 29 percent, to $2.20. Pain Therapeutics stock gave up $4.83, or 52 percent, to $4.41.
Remoxy is similar to Purdue Pharma LP's pain drug OxyContin. Both drugs contain an extended-release version of the drug oxycodone and both are intended to treat severe pain. OxyContin is one of the most frequently abused prescription drugs, and Remoxy is designed to be more difficult to abuse. The oxycodone in Remoxy is in a thick liquid form, which is designed to make it hard to crush and snort, or be injected, or dissolved in alcohol. Remoxy is a key part of Pfizer's $3.6 billion acquisition of King Pharmaceuticals, which closed in March.
Purdue began selling a new tampering-resistant version of OxyContin last year. The time-release formula in the original version could be avoided if the drug was crushed or dissolved, which delivered the full dose quickly and created a high similar to heroin.
The FDA has long been concerned about abuse of prescription pain drugs, and in May, the agency called a meeting with drug companies who were studying extended-release opioid pain drugs. They discussed ways to train prescribers and reduce the risks of the drugs. Pfizer said those issues could also complicate approval for Remoxy.
The agency also delayed approval of Remoxy in December 2008, saying it needed more data.
Remoxy was developed by Durect, which licensed it to Pain Therapeutics in 2002. Pain Therapeutics later sublicensed the rights to King Pharmaceuticals, which was acquired by Pfizer.