New mu-opioid receptor agonist offers pain relief with low withdrawal risk

  • Henningfield JE & al.
  • Pain Med
  • 9 Mar 2020

  • curated by Kelli Whitlock Burton
  • Clinical Essentials
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Takeaway

  • Patients with chronic low back pain (CLBP) who received a new molecular entity mu-opioid receptor agonist, NKTR-181, experienced opioid withdrawal symptoms less often and with less severity than patients who received a placebo.
  • Withdrawal symptoms were rare whether patients abruptly discontinued NKTR-181 or followed a 1-week drug taper.

Why this matters

  • These findings, along with earlier results from this phase 3 clinical trial showing significantly greater pain relief with NKTR-181 compared with placebo, suggest the drug may be an effective treatment for CLBP with less risk for opioid withdrawal.

Study design

  • Phase 3, enriched-enrollment, double-blind, randomized-withdrawal, 12-week study of 1190 patients with CLBP.
  • Funding: Nektar Therapeutics.

Key results

  • Patients who received NKTR-181 vs placebo had mild withdrawal at:
    • Day 8: 1.0% vs 2.4%.
    • Day 15: 1.4% vs 0.4%.
    • 1 week after the end of study: 2.3% vs 0.5%.
  • No significant withdrawal symptoms were observed in patients receiving NKTR-181 vs placebo (P=.0545).

Limitations

  • No comparison of NKTR-181 with conventional mu-opioid agonists.
  • Short duration of study.

Coauthored with Vijay Rathod, PhD.