Recruiting

Endocrine Therapy

Sponsor:

Ottawa Hospital Research Institute

Code:

NCT07252726

Conditions

Metastatic Breast Cancer

Metastatic Prostate Cancer

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Morning administration of CDK4/6 inhibitor

Evening administration of CDK4/6 inhibitor

Morning administration of ARPI

Evening administration of ARPI

Study Details

Brief summary:

The REaCT-CHRONO-MetBP Pilot study will compare morning and evening administration of endocrine-based therapy in metastatic breast and prostate cancers.

Participants with metastatic breast or prostate cancer will be randomly placed in one of two groups: a morning group and an evening group. The group assignment will determine whether they take their endocrine therapy in the morning or the evening. The primary outcome of this pilot study is to evaluate the feasibility of study procedures in order to conduct a larger definitive trial in the future. The secondary outcomes include comparing quality of life, tolerability, and efficacy outcomes between the morning and evening groups for each of the two cancer cohorts (metastatic breast and prostate cancer).

Conditions

Metastatic Breast Cancer

Metastatic Prostate Cancer

Study ID

NCT07252726

Start date

Feb 2, 2026

Status verified date

Jul, 2026

Completion date

Mar, 2033

Anticipated

Primary completion date

Mar, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Cohort A (Breast Cohort) Inclusion Criteria

  • Patients with metastatic hormonal receptor positive breast cancer
  • Plan to receive endocrine therapy and a CDK4/6 inhibitor (either Ribociclib or Palbociclib) in the first-line metastatic setting
  • Age ≥18 years
  • Able to provide oral consent
  • Willing and able to complete questionnaires as per study protocol

Cohort A (Breast Cohort) Exclusion Criteria

  • Any contraindication in taking endocrine therapy and CDK4/6 inhibitor in the morning or evening
  • Plan to receive abemaciclib (as this requires twice a day dosing)

Cohort B (Prostate Cancer) Inclusion Criteria

  • Patients with metastatic castrate sensitive prostate cancer
  • Plan to receive androgen receptor pathway inhibitor (either enzalutamide, apalutamide or abiraterone acetate) in combination with androgen deprivation therapy
  • Age ≥18 years
  • Able to provide oral consent
  • Willing and able to complete questionnaires as per study protocol

Cohort B (Prostate Cancer) Exclusion Criteria

  • Any contraindication in taking androgen receptor pathway inhibitor in the morning or evening
  • Plan to receive darolutamide (as this requires twice a day dosing)
  • Plan to receive docetaxel in combination with androgen receptor pathway inhibitor

Study Design

Enrollment

50 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: Cohort A, Arm A: Breast Cancer Cohort, Morning Group

Participants with metastatic breast cancer in this arm are assigned morning administration of CDK4/6 inhibitor.

active comparator: Cohort A, Arm B: Breast Cancer Cohort, Evening Group

Participants with metastatic breast cancer in this arm are assigned evening administration of CDK4/6 inhibitor.

active comparator: Cohort B, Arm A: Prostate Cancer Cohort, Morning Group

Participants with metastatic prostate cancer in this arm are assigned morning administration of ARPI.

active comparator: Cohort B, Arm B: Prostate Cancer Cohort, Evening Group

Participants with metastatic prostate cancer in this arm are assigned evening administration of ARPI.

Interventions

Morning administration of CDK4/6 inhibitor

Morning administration of cyclin-dependent kinase (CDK) 4/6 inhibitor defined as, within one hour of the participant wake up time.

Evening administration of CDK4/6 inhibitor

Evening administration of cyclin-dependent kinase (CDK) 4/6 inhibitor defined as, within one hour of the participant bedtime.

Morning administration of ARPI

Morning administration of androgen receptor pathway inhibitors (ARPI) defined as, within one hour of the patient wake up time.

Evening administration of ARPI

Evening administration of androgen receptor pathway inhibitors (ARPI) defined as, within one hour of the patient bedtime.

Primary outcome measure

  • Feasibility: accrual per site [ Time Frame: 1 year ]
  • Feasibility: participation rate [ Time Frame: The accrual period, approximately 1 year ]
  • Feasibility: number of participants who received allocated intervention [ Time Frame: 4 weeks ]

Central Contacts and Locations

Central contacts

Lisa Vandermeer, MSc

613-737-7700lvandermeer@ohri.ca

Deanna Saunders, MSc

613-737-7700dsaunders@ohri.ca

Locations

Waterloo Regional Health Network

Recruiting

Kitchener, Ontario, Canada

The Ottawa Hospital Cancer Centre

Recruiting

Ottawa, Ontario, Canada, K1H 8L6

Contacts

Lauren Butterfield, MSc

613-737-7700lbutterfield@ohri.ca

More Information

Sponsor

Ottawa Hospital Research Institute

Last update posted

Jul 17, 2026

Last verified

Jul, 2026

Keywords

  • Chronotherapy
  • breast cancer
  • prostate cancer
  • endocrine therapy
  • metastatic cancer

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Ottawa Hospital Research Institute on 2026-07-17.