PTI-202 is the second such drug to enter clinical development under the collaboration. The first drug to be developed was Remoxy, an abuse-resistant oxycodone which is currently in phase III trials.
Under the collaboration agreement, which was announced in November 2005, the companies agreed to co-develop and commercialize a total of four long-acting, abuse-resistant opioid painkillers.
Pain Therapeutics recently submitted an investigational new drug application (IND) to the FDA for PTI-202. FDA acceptance of this IND triggered the payment of a $5 million cash milestone from King to Pain Therapeutics.