NEW YORK ( TheStreet) -- Pfizer's ( PFE) $3.6 billion acquisition of King Pharmaceuticals ( KG) brings King's drug development partners Pain Therapeutics ( PTIE) and Acura Pharmaceuticals ( ACUR) into the Pfizer orbit. Pain Therapeutics and King are partners on Remoxy, an abuse-resistant, controlled-release formulation of the opioid pain reliever oxycontin intended for the treatment of moderate to severe chronic pain. The U.S. Food and Drug Administration rejected Remoxy in December 2008 and since then, efforts by King and Pain Therapeutics to respond to the agency's concerns have taken longer than expected. Most recently, King said it plans to resubmit Remoxy to the FDA in the fourth quarter. King and Pain Therapeutics are also co-developing two additional, early-stage pain drugs under their partnership agreement. Pain Therapeutics shares were up 16% to $7.28 in recent trading as investors respond favorably to the prospect that Pfizer will take over the Remoxy program. Acura Pharmaceuticals and King are co-developing Acurox, an abuse-resistant formulation of the pain drug oxycodone. An FDA advisory committee voted in April to recommend against Acurox's approval, in part because of concerns about the use of niacin as an integral part of the drug's abuse-resistant formulation. In July, King said it planned to meet with FDA before submitting data on a new, niacin-free formulation of Acurox in the first quarter 2011. Acura shares were up 15 cents to $2.42 in recent trading. --Written by Adam Feuerstein in Boston. >To contact the writer of this article, click here: Adam Feuerstein. >To follow the writer on Twitter, go to http://twitter.com/adamfeuerstein. >To submit a news tip, send an email to: firstname.lastname@example.org.