Following last year's phase III win in the SUMMIT-07 study of NKTR-181 in more than 600 patients with moderate to severe chronic low back pain, Nektar Therapeutics Inc. took the next step toward commercialization by submitting the new drug application (NDA) to the FDA. The San Francisco-based company is seeking to advance the mu-opioid agonist, which has shown reduced incidence of central nervous system-mediated side effects such as euphoria, along the road less traveled to set itself apart in the controversial asset class. If approved, NKTR-181 could become the first analgesic opioid molecule to exhibit reduced incidence of such effects, through targeted alteration of brain-entry kinetics.