Evaluating the Dose Timing (Morning vs Evening) of Endocrine Therapy and Its Effects on Tolerability and Compliance

December 17, 2025 updated by: Ottawa Hospital Research Institute

A Pragmatic Randomised, Multicentre Trial Evaluating the Dose Timing (Morning vs Evening) of Endocrine Therapy and Its Effects on Tolerability and Compliance (REaCT-CHRONO)

Endocrine therapy is an established treatment for hormone receptor-positive breast cancer, but can cause significant side effects with deterioration in quality of life. The side effects of all forms of endocrine therapy are well recognized and can lead to treatment non-persistence or non-compliance. Chronotherapy, also called chronotherapeutics, is defined as the administration of a medication in coordination with circadian rhythm in order to minimize side effects and yield a greater efficacy. The investigators propose to perform a pragmatic, multi-centre, open-label, randomized clinical trial to establish the optimal timing (morning vs. evening) of administering endocrine therapy based on side effects and benefits in early stage breast cancer patients.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Endocrine therapy is an established treatment for hormone receptor-positive breast cancer, but can cause significant side effects with deterioration in quality of life. The side effects of all forms of endocrine therapy are well recognized and can lead to treatment non-persistence or non-compliance. Compliance is defined as the degree or extent of conformity to the recommended administration by the provider, whereas persistence refers to the act of continuing treatment for a certain prescribed duration. Treatment adherence is especially important in breast cancer, as early cessation or reduced compliance to hormonal therapy are associated with reduced disease-free survival and increased mortality. Chronotherapy, also called chronotherapeutics, is defined as the administration of a medication in coordination with circadian rhythm in order to minimize side effects and yield a greater efficacy. The investigators propose to perform a pragmatic, multi-centre, open-label, randomized clinical trial to establish the optimal timing (morning vs. evening) of administering endocrine therapy based on side effects and benefits in early stage breast cancer patients.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
245

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Ottawa, Ontario, Canada
        • The Ottawa Hospital Cancer Centre
      • Thunder Bay, Ontario, Canada, P7B 6V4
        • Thunder Bay Regional Health Sciences Centre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with an early stage or locally advanced hormonal receptor positive breast cancer
  • Plan to receive endocrine therapy
  • 18 years of age or older
  • Able to provide oral consent
  • Willing and able to complete questionnaires as per study protocol

Exclusion Criteria:

  • Metastatic cancer
  • Previous endocrine therapy for breast cancer
  • Plan to receive adjuvant abemaciclib

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Morning administration of endocrine therapy
Administration of endocrine therapy defined as, within one hour of the patient wake up time
Other: Morning administration of endocrine therapy
Endocrine therapy administered within one hour of patient wake up time
Active Comparator: Evening administration of endocrine therapy
Administration of endocrine therapy defined as, within one hour of the patient bed time
Other: Evening administration of endocrine therapy
Endocrine therapy administered within one hour of the patient bed time

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Endocrine Toxicity and Tolerability at 12 Weeks
Time Frame: Baseline to 12 weeks after treatment initiation
Measured by the change in total Functional Assessment of Cancer Therapy - Endocrine Symptoms (FACT-ES) questionnaire from baseline to 12 weeks following the beginning of endocrine therapy. FACT-ES is a validated sub scale of the Functional Assessment of Chronic Illness Therapy (FACIT) measurement system. FACT-ES consists of 46 items on a 5 point Likert type scale ranging from 0 (not at all) to 4 (very much), with a total range of 0 to 184. Higher FACT-ES scores indicate better outcomes. The current outcome is a change in FACT-ES scores.
Baseline to 12 weeks after treatment initiation

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Cost-effectiveness
Time Frame: 52 weeks after treatment initiation
Incremental cost-effectiveness rations (cost per one quality-adjusted life year (QALY) gained).
52 weeks after treatment initiation
Change in Endocrine Toxicity and Tolerability
Time Frame: Baseline, 4, 8, 12 and 52 weeks after treatment initiation
Measured by the change in total score and individual Functional Assessment of Cancer Therapy - Endocrine Symptoms (FACT-ES) questionnaires from baseline to 4, 8, 12 and 52 weeks following the beginning of endocrine therapy. FACT-ES consists of 46 items on a 5 point Likert type scale ranging from 0 (not at all) to 4 (very much), with a total score range of 0 to 184. Higher scores indicate better quality of life. The current outcome is a change in FACT-ES scores over time.
Baseline, 4, 8, 12 and 52 weeks after treatment initiation
Change in Health Related Quality of Life Scores
Time Frame: Baseline, 4, 8, 12 and 52 weeks after treatment initiation
Measured by the change in the total score and individual sub scales of the validated Functional Assessment of Cancer Therapy for patients with Breast cancer (FACT-B) questionnaire from baseline to 4, 8, 12 and 52 weeks following the beginning of endocrine therapy. The FACT-B consists of 37 items on a 5 point Likert type scale ranging from 0 (not at all) to 4 (very much), with a total score range of 0 to 148. Higher FACT-B scores indicate better quality of life. The current outcome is a change in FACT-B scores over time.
Baseline, 4, 8, 12 and 52 weeks after treatment initiation
Number of Participants Who Were Compliant With ET
Time Frame: 52 weeks after treatment initiation
Rates of non-persistence or non-compliance with initially prescribed endocrine therapy (ET)
52 weeks after treatment initiation

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Rates of Non-compliance to Endocrine Therapy
Time Frame: 52 weeks after treatment initiation
Comparing rates of non-compliance and non-persistence to endocrine therapy with patient age, turmour stage, chemotherapy use and type of endocrine therapy. The rates of non-compliance and rates of non-persistence will be tracked throughout the duration of the study and then compared to patient age, tumour stage, chemotherapy use and the type of endocrine therapy used.
52 weeks after treatment initiation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ottawa Hospital Research Institute

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Marie-France Savard, MD, Ottawa Hospital Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 30, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 5, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 29, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 9, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 27, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 28, 2021

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 17, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • REaCT-CHRONO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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