Nektar Says Results from Phase 2 Trial of NKTR-181 Missed Primary Efficacy Endpoint

Nektar Therapeutics

announced the preliminary topline results from a Phase 2 study of NKTR-181 for the treatment of moderate-to-severe chronic pain in patients with osteoarthritis of the knee. The Phase 2 study utilized a double-blind, placebo-controlled, randomized withdrawal study design to assess the efficacy, safety and tolerability of NKTR-181. Of the 295 patients that entered the study, only 9 (3%) patients were unable to achieve meaningful pain relief with NKTR-181.  53 (18%) patients discontinued treatment during the titration period because of adverse events, most of which are those commonly associated with opioids.  A total of 213 patients achieved an average 40% reduction in pain and entered the randomized phase of the study.  Following the titration period, patients were randomized 1:1 to either continue to receive their analgesic dose of NKTR-181 or to receive placebo for 21 days.  NKTR-181 performed as expected as an opioid analgesic throughout the study with patients continuing to show a reduction in pain scores throughout the randomized phase of the study as well.  However, patients who were randomized to