This study will test the effectiveness of warfarin in patients with IPF. Approximately 256 patients will be randomized 1:1 to either warfarin or placebo. Patients will return at week 1 for a safety review and every 16 weeks for 48 weeks. The primary endpoint in the study is the time to either death, non-bleeding/non-elective hospitalization, or a drop of greater than 10% in forced vital capacity (FVC) from baseline.
Study design: ACE-IPF was a double-blind, randomized, placebo-controlled trial of an oral warfarin dose adjusted to an international normalized ratio (INR) response of 2.0 to 3.0, compared with a sham dose-adjusted placebo. The trial was originally designed as an event-driven study with a treatment period of up to 144 weeks. Given the slow rate of recruitment and higher than anticipated event rates seen in another Idiopathic Pulmonary Fibrosis Clinical Research Network (IPFnet) trial, the protocol was modified to have a maximum treatment period of 48 weeks after eleven patients were enrolled in the study. Participants were to be seen at screening, baseline, and at 16, 32, and 48 weeks after enrollment. Outcome measures: The primary outcome was a composite endpoint based on the time to all-cause mortality; non-elective, non-bleeding hospitalization; or a decrease in the absolute FVC ≥10% from baseline value. Secondary outcome measures included rates of mortality, hospitalization, respiratory-related hospitalization, acute exacerbation, bleeding, cardiovascular events, and changes over time in FVC, six-minute walk test distance, diffusing capacity of lung for carbon monoxide (DLCO), plasma fibrin D-dimer levels, and quality of life (QOL) assessments. Data Analysis Continuous variables at baseline were expressed as means (standard deviations) and medians (25th and 75th percentiles). Categorical variables at baseline were expressed as counts and percentages. Unadjusted estimates of event rates for time-to-event variables were computed using the Kaplan-Meier estimator with comparisons based on the log-rank test statistic. The primary hypothesis was tested using a Cox proportional hazards regression model, comparing the treatment effect on the primary composite endpoint. Pre-specified covariates in this model included an indicator variable for the treatment group and the DLCO measurement from the baseline assessment. Randomization: Subjects were randomly assigned to study arms in a 1:1 ratio, using a permuted-block design with varying block sizes, to receive either warfarin or matched placebo. Subjects were stratified by clinical center and a DLCO threshold of 35% of predicted. Randomization lists were generated by the study data coordinating center (DCC) and provided to a phone- and web-enabled registration system (Almac Clinical Services, Inc.) that allowed sites to enroll subjects and receive study kits while keeping the study team and subjects blinded to treatment assignment. INR testing and monitoring: Study subjects were provided two strengths of warfarin tablets (1 mg and 2.5 mg) or matching placebos. Subjects measured their INR with encrypted meters (INRatio®, Alere, San Diego, CA) at least weekly. Home monitoring was validated by plasma INR measurement at the week 1 and 16 visits. Individual INR meters and test strips were replaced and subjects were reinstructed if meter INR readings varied by more than 30% from the laboratory INR. Efficacy of home INR measures were determined by time-in-target INR range of all patients, calculated on the basis of linear interpolation, 12 after excluding readings taken at baseline, during initial warfarin titration (until INR ≥ 2.0), study drug interruption, or following the discontinuation of study drug.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
145
University of Alabama - Birmingham
Birmingham, Alabama, United States
Death, Non-bleeding/Non-elective Hospitalization, or >10% Drop in Forced Vital Capacity
Death, non-bleeding/non-elective hospitalization, or \>10% drop in forced vital capacity.
Time frame: Events up to 48 weeks
All Cause Mortality
Time frame: maximum of 48 weeks
Change in Forced Vital Capacity (FVC) From Baseline to 16 Weeks
Week-16 change from Baseline
Time frame: 16 weeks
All-cause Hospitalizations
Time frame: maximum 48 weeks
Bleeding Events
Time frame: maximum of 48 weeks
Acute Exacerbations of Idiopathic Pulmonary Fibrosis (IPF)
Time frame: maximum of 48 weeks
Respiratory-related Hospitalizations
Time frame: maximum 48 weeks
Cardiovascular Mortality or Morbidity
Measured at 48 Weeks
Time frame: maximum of 48 weeks
Change in 6-minute Walk Distance (6MWD)
The 6MWD is a measure of exercise tolerance. Change in exercise tolerance is calculated at the latest time point (up to 48 weeks) minus the earliest time point (at baseline).
Time frame: Change from baseline to last visit (maximum of 48 weeks)
Total Score St. George's Respiratory Questionnaire (SGRQ)
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University of California - Los Angeles
Los Angeles, California, United States
University of California - San Francisco
San Francisco, California, United States
National Jewish Medical and Research Center
Denver, Colorado, United States
Yale University School of Medicine
New Haven, Connecticut, United States
University of Miami Miller School of Medicine
Miami, Florida, United States
University of Chicago
Chicago, Illinois, United States
University of Louisville
Louisville, Kentucky, United States
Tulane University
New Orleans, Louisiana, United States
University of Michigan
Ann Arbor, Michigan, United States
...and 12 more locations
The SGRQ is a quality of life measurement used to assess respiratory well being with a 0\*-100 range (\*indicates better health--lower is better).
Time frame: Week 16 Change from Baseline
Change in Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) From Baseline to 16 Weeks
The DLCO measures the partial pressure difference between inspired and expired carbon monoxide.
Time frame: Week 48 / Final Visit
Fibrin D-dimer Change From Baseline to 16 Weeks
Biomarker that measures biologic activities in patients as opposed to response.
Time frame: maximum of 48 weeks