This is an open-label safety and tolerability study in which approximately 600 subjects will receive NKTR-181 for up to 52 weeks. Subjects may include newly enrolled subjects and subjects who have recently completed SUMMIT-07 study.~This study will also investigate the pharmacokinetics of NKTR-181 in patients with chronic low back pain or chronic non-cancer pain.
The purpose of this 52-week open label study is to determine the long-term safety of a new opioid molecule, NKTR-181, in patients with moderate to severe chronic low back pain or chronic non-cancer pain.