Nektar begins Phase 2 study of NKTR-181

The double-blind, placebo-controlled trial is designed to evaluate the efficacy, safety and tolerability of NKTR-181 in patients with moderate to severe chronic pain from osteoarthritis of the knee.

The study will randomise approximately 200 opioid-naive patients with osteoarthritis of the knee who are not getting adequate pain relief from their current non-opioid pain medication with either NKTR-181 or placebo.

The average change in a patient’s pain score from baseline to the end of the double-blind, randomised treatment period is the primary endpoint of the study, while the secondary endpoints include quality-of-life assessment, sleep and motor activity scoring, as well as tolerability endpoints.

Nektar senior vice president and chief medical officer Robert Medve said, "As a new mu-opioid analgesic molecule, NKTR-181 has the potential to transform the treatment of chronic pain by using a molecular approach to reduce the risk of traditional opioid therapy while preserving its analgesic benefit."

NKTR-181 has a slow rate of entry into the brain to reduce the attractiveness of the molecule as a target of abuse and to reduce other CNS-mediated side effects, such as sedation and respiratory depression.