Therapeutic Area Nektar
Indication Phase
NKTR-181 Chronic Pain
Phase 3

NKTR-181 is a first-in-class, mu-opioid analgesic investigational drug candidate with a novel molecular structure designed to provide potent pain relief with a slow rate of entry into the brain. This slow rate of entry is designed to reduce the euphoria that can lead to the abuse of current opioid analgesics.1

About Opioids and Pain Management
Pain is one of the most common reasons people seek medical treatment.2 A study published in the American Pain Society's The Journal of Pain in October 2014 estimated that 19 percent of the U.S. population, or 39 million people, suffer from persistent pain.3

Opioids are considered the most effective therapeutic option for pain with 270 million prescriptions written in the U.S. alone in 2013.4,5 The global opioid market for chronic pain, which includes chronic back pain, osteoarthritis, fibromyalgia and neuropathic pain, is estimated to be $12.6 billion. Opioids can cause serious side effects such as respiratory depression and sedation and have the potential for addiction, abuse and misuse. According to the Centers for Disease Control and Prevention (CDC), 420,040 emergency department visits in 2011 were related to opioid analgesics.6 In the United States, prescription opioid abuse costs were about $55.7 billion in 2007, of which 46 percent was attributable to workplace costs (e.g., lost productivity), 45 percent to healthcare costs (e.g., abuse treatment), and 9 percent to criminal justice costs.7

NKTR-181 is a new chemical entity (NCE) that was created using Nektar's proprietary small molecule polymer conjugate technology. NKTR-181 has several potential differentiating properties that are inherent to the structure of the molecule, including a slow rate of entry into the CNS as measured by pupillometry (contraction of the pupils) and a plasma pharmacokinetic profile that supports twice-daily oral dosing. NKTR-181 is not a reformulation of a marketed opioid, which is a commonly-used method to attempt to prevent the manipulation of existing long-acting opioid drugs into more abusable forms. NKTR-181 has been granted has been granted Fast Track designation for the treatment of moderate to severe chronic pain by the U.S. Food and Drug Administration.

SUMMIT Phase 3 Program
The SUMMIT Phase 3 program for NKTR-181 includes two enriched-enrollment, randomized withdrawal (EERW) efficacy and safety studies and a 52-week long-term safety study (SUMMIT-LTS). Enrollment has begun in the first Phase 3 efficacy study (SUMMIT-07) which will evaluate NKTR-181 versus placebo in opioid-naïve patients with chronic low back pain. The SUMMIT Phase 3 program will also include a Phase 3 efficacy and safety trial in patients who are opioid-experienced (SUMMIT-12). Information about the SUMMIT studies can be found on clinicaltrials.gov.

February 18-21, 2016 American Academy of Pain Medicine Annual Meeting Palm Springs, CA
May 11-14, 2016 American Pain Society 33rd Annual Scientific Meeting Austin, TX
May 23-24, 2016 16th Annual Pain Therapeutics Conference London, UK
June 5-7, 2016 International Conference on Opioids Boston, MA
September 6-10, 2016 PainWeek 2016 Las Vegas, NV

View our Scientific & Medical event calendar »

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  1. Hyman, Steven E., Harvard Review of Psychiatry. 2(1):43-46, May/June 1994.
  2. 2011 National Academy of Sciences. Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education and Research, 2010 Decision Resources, and Harstall, C. How prevalent is chronic pain? Pain Clinical Updates X, 1-4 (2003).
  3. http://americanpainsociety.org/about-us/press-room/persistent-pain-incidence-news-release.
  4. IMS, NSP, NPA and Defined Health 2013 Estimates.
  5. Melnikova, I, Pain Market, Nature Reviews Drug Discovery, Volume 9, 589-90 (August 2010).
  6. http://www.cdc.gov/homeandrecreationalsafety/overdose/facts.html.
  7. http://www.cdc.gov/homeandrecreationalsafety/overdose/facts.html.

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