A Phase 2, Double-Blind, Multiple-Dose Escalation Study to Evaluate NKTR-118 (Oral PEG-Naloxol) in Patients With Opioid-Induced Constipation (OIC)

This study has been completed.
Nektar Therapeutics
Information provided by (Responsible Party):
ClinicalTrials.gov Identifier:
First received: January 11, 2008
Last updated: January 28, 2013
Last verified: January 2013

Study (07-IN-NX003) is a Phase 2, multi-center, placebo-controlled, double-blind, randomized, dose-escalation trial. It is designed to investigate the safety, efficacy and tolerability of NKTR-118 (PEG-naloxol) in patients with opioid-induced constipation (OIC) and other clinical manifestations of opioid-induced bowel dysfunction (OBD). The objective of this study is to evaluate the safety, effectiveness and pharmacokinetics of NKTR-118 at 4 different doses. The study is currently active and plans to enroll approximately 224 patients at about 50 sites in the US, Canada and the EU.

Condition Intervention Phase
Opioid Induced Constipation (OIC)
Drug: placebo
Drug: NKTR-118
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
Official Title: A Phase 2, Double-Blind, Randomized, Placebo-Controlled, Multiple-Dose, Dose Escalation Study to Evaluate the Efficacy, Safety and Tolerability of NKTR-118 in Patients With Opioid-Induced Constipation (OIC)

Resource links provided by NLM:

Further study details as provided by AstraZeneca:

Primary Outcome Measures:
  • Increase in number of spontaneous bowel movements from baseline [ Time Frame: 5 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Dose-response, safety, tolerability, pharmacokinetics, other symptoms of OBD assessed using the Patient Assessment of Constipation Symptoms (PAC-SYM), QOL, measurements, and maintenance of opioid analgesic effect [ Time Frame: 5 weeks ] [ Designated as safety issue: No ]

Enrollment: 224
Study Start Date: December 2007
Study Completion Date: April 2009
Primary Completion Date: March 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: A
Drug: placebo
placebo, oral, once daily (QD)
Experimental: B
Drug: NKTR-118
5 mg, 25 mg, 50 mg or 100 mg, oral,once daily (QD)


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Main Inclusion Criteria:

  • 18 years of age or older, male or female
  • Receiving a stable opioid regimen
  • Documented opioid-induced constipation
  • Willingness to stop all laxatives and other bowel regimens. The use of constipation rescue medication will be allowed during the study.

Main Exclusion Criteria:

  • Life expectancy less than 6 months
  • Active substance abuse
  • Fecal incontinence, irritable bowel syndrome, inflammatory bowel disease, or other active medical disorders associated with diarrhea or intermittent loose stools or constipation
  • Pregnant or breast-feeding
  • Any receipt of an investigational medication within 30 days of screening
  • History or presence of specific cardiac, neurologic, endocrine and/or psychiatric conditions
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00600119

  Show 33 Study Locations
Sponsors and Collaborators
Nektar Therapeutics
Study Director: Mark Sostek AstraZeneca Pharmaceuticals, Wilm DE
  More Information

No publications provided

Responsible Party: AstraZeneca
ClinicalTrials.gov Identifier: NCT00600119     History of Changes
Other Study ID Numbers: 07-IN-NX003
Study First Received: January 11, 2008
Last Updated: January 28, 2013
Health Authority: United States: Food and Drug Administration
Canada: Health Canada
Germany: BfArM
Romania: Romanian MOH

Keywords provided by AstraZeneca:
NKTR, constipation, opioid, induced, bowel, dysfunction, Naloxol, Naloxone, Narcan, PEG naloxol, OIC, OBD, Nektar

Additional relevant MeSH terms:
Signs and Symptoms
Signs and Symptoms, Digestive

ClinicalTrials.gov processed this record on May 20, 2015