Nektar Therapeutics Submits NDA for NKTR-181 to Treat Chronic Low Back Pain

Nektar Therapeutics announced the submission of a new drug application (NDA) to the US Food and Drug Administration (FDA) for NKTR-181, a first-in-class investigational opioid to treat chronic low back pain in adults new to opioid therapy.

The new molecular entity is the first analgesic opioid molecule to exhibit a reduced incidence of specific CNS-mediated side effects like euphoria through the targeted alternation of brain-entry kinetics.

NKTR-181, an investigational novel structure, is designed to have low permeability across the blood-brain barrier to slow its rate of entry into the brain, attenuating the dopamine release that underlies euphoria.

“This innovative investigational medicine separates analgesic efficacy from the high levels of euphoria that too often lead to the abuse and addiction of traditional opioids,” Steve Doberstein, PhD, senior vice president of research and development, and chief development officer, Nektar Therapeutics, said in a statement.

The NDA submission is backed by an extensive clinical and nonclinical data package comprised of 15 studies.

The clinical data submitted in the NDA was conducted in 2234 subjects and includes a 600-patient efficacy study in patients with chronic low back pain new to opioid therapy; a 630-patient long-term 52-week safety study in those with noncancer pain who are new to opioid therapy, as well as those who have experience with opioid therapy; pharmacokinetic/pharmacodynamic studies in more than 450 subjects; and 2 human abuse potential studies that evaluated both NKTR-181 therapeutic and supratherapeutic doses versus an oxycodone control in recreational drug users.

NKTR-181 has a 14-hour elimination half-life to enable twice-daily dosing for pain control.