King Pharmaceuticals ( KG) signed an agreement to help develop and commercialize the Pain Therapeutics' ( PTIE) drug Remoxy, which has the same active ingredient as OxyContin, and other abuse-resistant opioid painkillers.

Shares of Pain Therapeutics took off following the news, and lately traded higher by $2.77, or 44%, at $9.11. Volume was extremely heavy. King lost 1 cent at $16.99.

Remoxy contains long-acting oral oxycodone. The drug is in late-stage clinical development for treating moderate-to-severe chronic pain.

Purdue Pharma's painkiller OxyContin, also containing oxycodone, has become widely known and covered by the media more for its illicit rather than its legitimate use. Remoxy has a sticky make-up that means its hard to inject or inhale, which Pain Therapeutics says may deter recreational abuse or accidental misuse.

Oxycodone abuse can be fatal, and its use carries the risk of addiction.

King will make an upfront payment of $150 million to Pain Therapeutics, and the company could get additional milestone payments of up to another $150 million. The Food and Drug Administration hasn't yet evaluated Remoxy.