Nektar's NKTR-181 misses in Phase II pain trial
Nektar Therapeutics (NASDAQ:NKTR) slid $3.46 (25%) to $10.39 in early after-hours trading after the company said late Thursday that twice-daily oral NKTR-181 for 21 days missed the primary endpoint of improving mean pain scores vs. placebo in a Phase II trial to treat chronic pain in patients with osteoarthritis (OA) of the knee. Nektar said the mu opioid receptor ( OPRM1; MOR) agonist "performed as expected" as an opioid analgesic, with patients showing a reduction in pain scores throughout the study. However, the company said patients who were randomized to placebo did not show the expected increase in pain scores that have been observed in similar randomized withdrawal studies. Nektar said it plans to evaluate the lack of post-randomization rebound in the placebo arm in order to design optimal pivotal trials with NKTR-181, but could not be reached for details. ...