NCT00143286 is a Phase 3 clinical trial of varenicline (CP-526,555) in Smoking Cessation, sponsored by Pfizer.

Who is sponsoring NCT00143286?

NCT00143286 is sponsored by Pfizer.

What drugs are being tested in NCT00143286?

Interventions in NCT00143286: varenicline (CP-526,555).

What condition does NCT00143286 study?

NCT00143286 studies Smoking Cessation.

Is NCT00143286 still recruiting?

NCT00143286 is currently completed. Last updated 1 June 2007.

Last reviewed 2007-06-01 · How we verify

NCT00143286

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

A 52-Week Multicenter Study Evaluating the Safety and Efficacy of Varenicline ( CP-526,555) for the Maintenance of Smoking Cessation

Completed Phase 3 Last updated 1 June 2007

What this trial tests

Phase 3 trial testing varenicline (CP-526,555) in Smoking Cessation in 2,000 participants. Completed in 1 March 2005.

Timeline

1 April 2003

1 March 2005

Quick facts

Lead sponsor	Pfizer
Phase	Phase 3
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	double
Primary purpose	treatment
Enrollment	2,000
Start date	1 April 2003
Estimated completion	1 March 2005
Sites	24 locations across United States, Canada, Czechia, Denmark, Norway, Sweden, United Kingdom

Drugs / interventions tested

varenicline (CP-526,555) — full drug profile →

Conditions studied

Smoking Cessation — all drugs for Smoking Cessation →

Sponsor

Pfizer — full company profile →

Who can join

Adults 18 to 75, any sex, with Smoking Cessation. Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

Continuous abstinence Weeks 13 -24.

Sponsor's own description

The primary purpose of this study is a comparison of abstinence maintenance in subjects randomized to double-blind varenicline or placebo from Weeks 13 -24 in subjects who responded to an intial 12-week open label course of varenicline, with post-treatment follow-up of smoking status to Week 52.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

Effect of maintenance therapy with varenicline on smoking cessation: a randomized controlled trial.
Tonstad S, Tønnesen P, Hajek P, Williams KE, et al · · 2006 · cited 396× · PMID 16820548 · DOI 10.1001/jama.296.1.64
Maintenance pharmacotherapy normalizes the relapse curve in recently abstinent tobacco smokers with schizophrenia and bipolar disorder.
Evins AE, Hoeppner SS, Schoenfeld DA, Hoeppner BB, et al · · 2017 · cited 17× · PMID 27956009 · DOI 10.1016/j.schres.2016.11.018

Verify or expand the search:

Other recruiting trials for Smoking Cessation

Currently open trials in the same condition.

NCT07420621 — Preliminary Effectiveness of Enhanced Text Message + Incentives · NA · recruiting
NCT07224087 — Development of a MHBC Intervention for Weight Loss and Smoking Cessation for Pre-Bariatric Surgery Patients · Phase 1 · recruiting
NCT07331519 — Integrating Smoking Cessation With Low-dose CT-screening for Lung Cancer · NA · recruiting
NCT07210567 — Mindfulness-based Ecological Momentary Intervention for Smoking Cessation Among Cancer Survivors · NA · recruiting
NCT07129590 — Trauma-Informed Care for Smoking Cessation for Pregnancy · NA · recruiting

Other Pfizer trials

Trials by the same sponsor.

NCT04982848 — Korea Post Marketing Surveillance (PMS) Study of Talzenna® · not yet recruiting
NCT06873191 — A Study to Learn More About Tukysa Once it is Out in the Korean Market · not yet recruiting
NCT07497854 — A Study to Learn About the Study Medicine NURTEC® ODT 75 mg After it is Released Into the Markets in Korea · not yet recruiting
NCT06507904 — A Study to Learn How Different Preparations of Osivelotor Taste and Enter the Blood With Food or Liquids or With an Anta · Phase 1 · not yet recruiting
NCT06864585 — A Study to Learn About the Study Medicine - Zavicefta in Patients With Sepsis or Loss of Kidney Function in Japan · not yet recruiting

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT00143286 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Pfizer
Last refreshed: 1 June 2007

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT00143286.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing