Nektar NDA for Pain Drug with Reduced Euphoria

Nektar Therapeutics has submitted an NDA for NKTR-181, an analgesic opioid molecule that the company says exhibits a reduced incidence of specific side effects, such as euphoria, through the targeted alteration of brain-entry kinetics. The submission is supported by clinical data from 15 studies in 2,234 subjects, pharmacokinetic/pharmacodynamic studies in over 450 subjects, and two human abuse-potential studies evaluating both therapeutic and supratherapeutic doses of NKTR-181 versus an oxycodone control in recreational drug users.

The new molecular entity is described by Nektar as a selective full mu-opioid agonist designed to provide potent pain relief. It is designed to have “low permeability across the blood-brain barrier in order to slow its rate of entry into the brain and attenuate the dopamine release that underlies euphoria,” it says. “In addition, NKTR-181 has a 14-hour elimination half-life to enable twice-daily dosing for pain control.”