Effect of Diltiazem Administration on CP-945,598 Pharmacokinetics

This study has been completed.
Information provided by:
ClinicalTrials.gov Identifier:
First received: March 21, 2008
Last updated: September 16, 2009
Last verified: March 2008

A recently completed clinical drug interaction study of CP-945,598 with ketoconazole, a potent CYP3A inhibitor, showed that coadministration of CP-945,598 with ketoconazole results in an approximately 5-fold increase in CP-945,598 total exposure (AUC) and 4-fold increase in Cmax. Therefore, the sensitivity of CP-945,598 pharmacokinetics (PK) to less potent CYP3A inhibitors needs to be characterized to support labeling and registration.

Diltiazem is a known substrate and moderate mechanism-based inhibitor of the CYP3A enzyme system and was chosen as the moderate CYP3A inhibitor for this study as it is a clinically relevant medication likely to be prescribed concomitantly with CP-945,598 given the increased risk of hypertension and cardiovascular disease in the obese patient population.

Condition Intervention Phase
Drug: CP-945,598
Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A Phase 1, Randomized, Fixed Sequence Study To Evaluate The Effect Of Multiple Dose Administration Of Modified Release Diltiazem On The Multiple Dose Pharmacokinetics Of CP-945,598 In Healthy Overweight And Obese Subjects

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Pharmacokinetic parameters of CP-945,598 and its metabolite, CE-156,706, (AUCtau, Cmax and Tmax) [ Time Frame: Days 7 and 28 ] [ Designated as safety issue: No ]
  • Safety endpoints including adverse event monitoring, physical examinations, vital signs, ECGs, and clinical laboratory tests. [ Time Frame: 28 days ] [ Designated as safety issue: No ]

Enrollment: 28
Study Start Date: March 2007
Study Completion Date: June 2007
Arms Assigned Interventions
Experimental: Group A Drug: CP-945,598
20 mg CP-945,598 + 240 mg MR Diltiazem
Experimental: Group B Drug: CP-945,598
20 mg CP-945,598 alone


Ages Eligible for Study:   18 Years to 55 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • No clinically relevant abnormalities based upon medical history, physical exam, 12-lead ECG, and clinical lab tests
  • Body Mass Index (BMI) ~ 27-40 kg/m2, inclusive
  • Personally signed inform consent document

Exclusion Criteria:

  • Evidence or history of significant acute or chronic disease
  • Pregnant or nursing females
  • Screening PR interval > 220 msec
  • Sitting blood pressure <= 90 mmHg systolic or <= 60 mmHg diastolic
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00645463

United States, Michigan
Pfizer Investigational Site
Ann Arbor, Michigan, United States, 48105
Sponsors and Collaborators
Study Director: Pfizer CT.gov Call Center Pfizer
  More Information

Additional Information:
Responsible Party: Director, Clinical Trial Disclosure Group, Pfizer, Inc.
ClinicalTrials.gov Identifier: NCT00645463     History of Changes
Other Study ID Numbers: A5351043 
Study First Received: March 21, 2008
Last Updated: September 16, 2009
Health Authority: United States: Food and Drug Administration

Additional relevant MeSH terms:
Antihypertensive Agents
Calcium Channel Blockers
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Vasodilator Agents

ClinicalTrials.gov processed this record on May 26, 2016