A Study of Extending Relugolix Dosing Intervals Through Addition of Itraconazole or Ritonavir in Prostate Cancer Patients

October 5, 2023 updated by: University of Chicago

A Phase Ib Study of Extending Relugolix Dosing Intervals Through Addition of the CYP3A4 and Pg-P Inhibitor Itraconazole or Ritonavir in Prostate Cancer Patients

Researchers leading this study hope to learn about the safety of combining the study drug relugolix with another study drug called itraconazole or ritonavir in prostate cancer. This study is for individuals who have advanced prostate cancer and plans to have medical castration (the use of medications or chemicals to lower hormone production in the testicles). Your participation in this research will last up to 1 month.

The purpose of this research is to gather information on the safety and effectiveness of relugolix in combination with ritonavir or itraconazole. The goal of this research is to find out if combining two medications (relugolix and itraconazole or relugolix and ritonavir) could possibly lead to using less relugolix, which is an expensive drug.

Study Overview

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Phase 1

Contacts and Locations

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

Study Contact

Study Locations

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

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Must have histologically or cytologically confirmed prostate cancer with plans to start medical castration therapy.
  • Age 18 or older. Because no dosing or adverse event data are currently available on the use of relugolix in combination with itraconazole or ritonavir in patients <18 years of age, children are excluded from this study.
  • Eastern Cooperative Oncology Group performance status ≤2 (Karnofsky ≥60%)
  • Participants must satisfy the following laboratory criteria:
  • Testosterone > 200 ng/dl
  • QTc within normal limits
  • Aspartate Transferase (AST)/alanine transaminase (ALT) < 3x upper limit of normal
  • Ability to take oral medication and be willing to adhere to the medication regimen.
  • Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

  • Need for combination systemic therapy for prostate cancer including docetaxel and/or second-generation androgen receptor pathway targeted agents (i.e. abiraterone, enzalutamide, apalutamide, darolutamide, etc).
  • Concurrent therapy with strong interacting drugs with CYP3A4 and P-gp (See Appendix list of strong inhibitors or inducers) due to concerning possible drug-drug interactions with itraconazole, ritonavir and relugolix. Potential drug-drug interactions will also be reviewed by study investigators prior to enrollment.
  • History of allergic reactions attributed to compounds of similar chemical or biologic composition to relugolix, itraconazole or ritonavir.
  • Patients receiving treatment with another investigational drug or other intervention within 3 expected half-lives of the agent.
  • Serious or uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, unstable angina pectoris, or psychiatric illness/social situations that would limit compliance with study requirements.
  • New York Heart Association Class III of IV congestive heart failure
  • Known gastrointestinal malabsorption.
  • Active psychiatric illness/social situations that would limit compliance with protocol requirements.

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Study Group 1

All study participants will receive a starting dose of relugolix (360 mg in the form of three 120 mg tablets) on Day 1 of the 29-day drug administration period. After Day 1, you will receive relugolix on its own or relugolix combined with another medication called itraconazole or ritonavir. The combination of medications you receive, the dosage for each medication, and when you take each medication will be based on the study group you are enrolled in.

Study Group 1 will receive:

  • Relugolix (360 mg) on Day 1
  • Relugolix (120 mg) on Days 2-7
A medication used to treat prostate cancer. Relugolix comes as a tablet to take by mouth. It is usually taken with or without food once daily.
Experimental: Study Group 2a

All study participants will receive a starting dose of relugolix (360 mg in the form of three 120 mg tablets) on Day 1 of the 29-day drug administration period. After Day 1, you will receive relugolix on its own or relugolix combined with another medication called itraconazole or ritonavir. The combination of medications you receive, the dosage for each medication, and when you take each medication will be based on the study group you are enrolled in.

Study Group 2a will receive:

  • Relugolix (360 mg) on Day 1
  • Relugolix (120 mg) on Days 2-7
  • Itraconazole (200 mg) on Days 1-14
A medication used to treat prostate cancer. Relugolix comes as a tablet to take by mouth. It is usually taken with or without food once daily.
A drug used to treat fungal infections.
Other Names:
  • Sporanox
Experimental: Study Group 2b

All study participants will receive a starting dose of relugolix (360 mg in the form of three 120 mg tablets) on Day 1 of the 29-day drug administration period. After Day 1, you will receive relugolix on its own or relugolix combined with another medication called itraconazole or ritonavir. The combination of medications you receive, the dosage for each medication, and when you take each medication will be based on the study group you are enrolled in.

Study Group 2b will receive:

  • Relugolix (360 mg) on Day 1
  • Relugolix (120 mg) on Days 2-7
  • Ritonavir (100 mg tablets taken by mouth) on Days 1-14
A medication used to treat prostate cancer. Relugolix comes as a tablet to take by mouth. It is usually taken with or without food once daily.
HIV antiviral It can treat HIV infection, which causes AIDS. It does not cure HIV or AIDS, but combinations of drugs may slow the progress of the disease and prolong life.
Experimental: Study Group 3a

All study participants will receive a starting dose of relugolix (360 mg in the form of three 120 mg tablets) on Day 1 of the 29-day drug administration period. After Day 1, you will receive relugolix on its own or relugolix combined with another medication called itraconazole or ritonavir. The combination of medications you receive, the dosage for each medication, and when you take each medication will be based on the study group you are enrolled in.

Study Group 3a will receive:

  • Relugolix (360 mg) on Day 1
  • Relugolix (120 mg) on Days 2-4
  • Itraconazole (200 mg tablets taken by mouth) on Days 1-14
A medication used to treat prostate cancer. Relugolix comes as a tablet to take by mouth. It is usually taken with or without food once daily.
A drug used to treat fungal infections.
Other Names:
  • Sporanox
Experimental: Study Group 3b

All study participants will receive a starting dose of relugolix (360 mg in the form of three 120 mg tablets) on Day 1 of the 29-day drug administration period. After Day 1, you will receive relugolix on its own or relugolix combined with another medication called itraconazole or ritonavir. The combination of medications you receive, the dosage for each medication, and when you take each medication will be based on the study group you are enrolled in.

Study Group 3b will receive:

  • Relugolix (360 mg) on Day 1
  • Relugolix (120 mg) on Days 2-4
  • Ritonavir (100 mg) on Days 1-14
A medication used to treat prostate cancer. Relugolix comes as a tablet to take by mouth. It is usually taken with or without food once daily.
HIV antiviral It can treat HIV infection, which causes AIDS. It does not cure HIV or AIDS, but combinations of drugs may slow the progress of the disease and prolong life.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Testosterone Suppression of Participants as Assessed by Testosterone Levels
Time Frame: 1 month post start of treatment
To determine whether the addition of itraconazole and ritonavir to relugolix sustains testosterone suppression as assessed by participant testosterone levels.
1 month post start of treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Decrease in Relugolix Levels
Time Frame: 1 month post start of treatment
To evaluate whether itraconazole or ritonavir significantly decreases relugolix clearance in participants with prostate cancer as assessed by relugolix serum levels on days 8 and 15.
1 month post start of treatment
Reduction in Prostate-Specific Antigens Levels of Participants After Study Treatment
Time Frame: 1 month post start of treatment
To evaluate the efficacy of itraconazole or ritonavir combined with relugolix in patients with prostate cancer as assessed by a reduction in Prostate-Specific Antigen (PSA) levels of patients after study treatment.
1 month post start of treatment
Rate of Reported Adverse Events Among Participants
Time Frame: 1 month post start of treatment
To evaluate the safety of itraconazole or ritonavir combined with longer interval relugolix dosing regimens in patients with prostate cancer as assessed by the rate of reported adverse events according to Common Terminology Criteria for Adverse Events (CTCAE) V5.
1 month post start of treatment

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Walter Stadler, University of Chicago

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)

February 13, 2023

Primary Completion (Estimated)

April 1, 2025

Study Completion (Estimated)

April 1, 2025

Study Registration Dates

First Submitted

December 23, 2022

First Submitted That Met QC Criteria

December 23, 2022

First Posted (Actual)

January 11, 2023

Study Record Updates

Last Update Posted (Actual)

October 6, 2023

Last Update Submitted That Met QC Criteria

October 5, 2023

Last Verified

October 1, 2023

More Information

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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