NEW YORK (AP) -- Pfizer said Tuesday it will keep trying to win approval of Remoxy, an experimental pain drug that has been held up for years because of regulatory concerns.
Pfizer said it will run new clinical trials of Remoxy, a potential treatment for moderate to severe pain. The drug is designed to be harder to abuse than older medications. Pfizer said it will compare a new version of Remoxy to an older one and will conduct a study that evaluates the potential for abuse of the new version. The New York drugmaker said it doesn't expect to be able to file for approval again until the middle of 2015 or later.
The news boosted shares of Durect Corp., which developed Remoxy, and Pain Therapeutics Inc., which is set to receive payments and royalties if the drug is approved and goes on sale. Pain Therapeutics shares jumped 63 cents, or 19 percent, to $3.88 in morning trading and Durect stock rose 11 cents, or 8 percent, to $1.51.
Pfizer said it made its decision after consultations with the Food and Drug Administration, which refused to approve Remoxy in 2008 and 2011. In May Durect and Pain Therapeutics said Pfizer might end development of Remoxy.
Remoxy is an immediate-release drug designed to treat pain when patients need continuous treatment for a long period of time. Its main ingredient is oxycodone, the primary ingredient in OxyContin. Remoxy tablets include the drug in a thick liquid form, and the developers say that makes it harder to abuse.
Because of widespread abuse of the drug, Purdue Pharma has replaced the original formulation of OxyContin with a newer version that is also intended to be harder to abuse. The FDA has said it won't approve generic forms of the original version of the drug.
Pain Therapeutics will get a $15 million payment from Pfizer if the FDA approves Remoxy. It will get royalty payments of 15 percent on the first $1 billion in domestic sales and 20 percent after that, with lower royalty payments outside the U.S.
Pain Therapeutics also said it regained the rights to three other pain drug candidates from Pfizer and can now develop and commercialize those products on its own. The FDA has approved human testing of all three products. The experimental drugs and Remoxy are all based on Durect's Oradur technology, which is designed to discourage abuse.
Durect developed Remoxy and licensed it to Pain Therapeutics. Pfizer now holds a sublicense from Pain Therapeutics.
Pfizer Inc. shares rose 38 cents to $30.78 in morning trading.