Mar 20, 2017
Nektar Therapeutics has reported results from the first late-stage clinical trial showing its experimental, addiction-resistant opioid NKTR-181 reduces pain significantly more than a placebo in patients with chronic back problems.
NKTR-181 failed to beat placebo in a previous, randomized phase II pain study. Hence, this positive outcome of the phase III “SUMMIT-07” study comes as somewhat of a surprise.
NKTR-181 makes a unique change to the actual opioid molecule. This alteration creates an opioid that has low permeability across the blood-brain barrier. By design, NKTR-181 enters the brain slowly, resulting in less euphoria and not enough of a high to make the drug desirable for abuse. The challenge for Nektar was to demonstrate that a slower and less addictive opioid could still provide meaningful pain relief for patients suffering from chronic pain.
Stephen Doberstein, Chief Scientific Officer of Nektar, said: “This could be a kind of entry opioid for chronic pain patients for whom NSAIDS are not working. Patients could take this product without worrying about becoming addicted. They don’t have to worry about their kids stealing NKTR-181 out of their medicine cabinets.”
However, there are still outstanding questions about the overall risk-benefit profile of the drug against standard opioids in real world settings. As stated by David Juurlink, an expert on opioids and drug safety at the University of Toronto: “These findings are interesting but they’re also no home run. I’d be very interested to see how NKTR-181 compares in a more generalizable setting versus something other than a placebo. That should help clarify whether the compound is more of a meaningful advance or just another gimmick like tamper-resistant opioids.”