Nektar Therapeutics announced this week that the Food and Drug Administration (FDA) has designated the oral opioid analgesic NKTR-181 in a Fast Track development program for the treatment of moderate to severe chronic pain.
NKTR-181 crosses the blood-brain barrier at a rate about ten-times slower than oxycodone and other opioids. Because it has a slower rate of entry into the brain, the company says the drug has the potential to reduce the euphoria that leads to the abuse and addiction associated with other opioids. Side effects such as respiratory depression and sedation may also be reduced.
NKTR-181 has completed a Phase I clinical study involving more than 180 patients, which showed it controlled pain across all dose levels with an average half-life of approximately 12 hours and no evidence of drug tolerance after 8 days of twice-daily dosing.
“”We are very pleased that the NKTR-181 development program has been granted Fast Track designation and we look forward to working closely with the FDA on this program,” said Robert Medve, MD, Chief Medical Officer of Nektar Therapeutics.”NKTR-181 could have significant advantages over currently-available opioids, including reduced attractiveness for abuse and reduced CNS-mediated side effects, such as sedation and respiratory depression. As a new chemical entity with these properties, we believe NKTR-181 has the potential to transform the treatment of chronic pain.”
The company expects Phase II development tests to begin in July. The study will use a standard, randomized, placebo-controlled withdrawal design to evaluate the efficacy and safety of NKTR-181 in up to 200 patients with chronic pain from osteoarthritis of the knee. A human abuse liability study is also planned as part of Phase II development.
The FDA’s Fast Track program enables a company to file sections of a New Drug Application (NDA) on a rolling basis as data becomes available. This permits the FDA to review portions of the NDA as they are received, rather than waiting for the entire NDA filing before starting a review process. The Fast Track designation also creates an opportunity for more frequent interactions with the FDA and the possibility of a priority review, which could decrease the typical development time and review period.
Editor’s Note: An early version of this story incorrectly stated that Nektar has an exclusive worldwide license agreement with AstraZeneca for NKTR-181. The license agreement actually covers another investigational drug called NKTR-118. American News Report regrets the error.