Duration of Androgen Receptor Pathway Inhibitor and ADT With Metastasis Directed Therapy in Oligometastatic Cancer of the Prostate (DIRECT)

Phase 2

Recruiting

• Conditions: Metastatic Prostate Cancer
• Interventions: Other: Standard of Care SBRT and ADT; Drug: Enzalutamide

• Registration Number: NCT05404139
• Lead Sponsor: University Health Network, Toronto

Brief Summary

This is a multi-centre, investigator-initiated, two-arm, randomized trial to investigate the addition on androgen receptor pathway inhibitor to standard of care radiation and hormone therapy improve quality of life.

Participants will either receive standard of care radiation and hormone (ADT) therapy (Arm 1) or standard of care radiation and hormone (ADT) therapy plus oral abiraterone for 8-9 months (Arm 3). Participants will be routinely follow-up in clinic or remotely for up to 5 years.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2022-05-19
• Study First Submitted QC: 2022-05-30
• Study First Posted: 2022-06-03
• Study Start: 2023-05-24
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-21
• Last Update Posted: 2024-11-25
• Primary Completion: 2026-03
• Study Completion: 2026-03

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Male
• Target Recruitment: 132

Inclusion Criteria

1. Age > 18 years

2. Able to provide informed consent

3. Histologic diagnosis of prostate adenocarcinoma

4. ECOG performance status 0-2

5. Stage IV castrate sensitive metachronous metastatic prostate cancer. diagnosed within 6 months of study enrollment with 1-10 metastases

   1. Maximum one metastatic deposit on conventional imaging (CT or bone scan or MR)
   2. Additional metastases can be detectable by PSMA PET only

6. All sites of disease are amenable to and can be safely treated with radiotherapy

7. Patients decline continuous use of ADT

Exclusion Criteria

1. Significant comorbidities rendering patient not suitable for ADT, enzalutamide and SBRT
2. History of malignancy within the past 5 years, excluding non-melanoma skin cancer and in-situ cancer, managed non-curatively
3. Prior use of salvage systemic therapy
4. Evidence of spinal cord compression

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Arm 1 - Standard of Care	Standard of Care SBRT and ADT	Participants in this group will receive standard of care radiation treatment and ADT. Participants will start ADT first. Androgen deprivation therapy will be delivered via injection every 4 months as per standard of care (for 8 months total). At the same time, or within 3 months of starting ADT, participants will begin radiation treatment. The radiation treatment course will consist of 2-5 sessions of radiation daily or every other day (the number of sessions will be determined by the physician depending on the location of cancer, number of cancer spots, etc.).
Arm 3 - Study Treatment	Enzalutamide	Participants in this group will receive standard of care radiation treatment and ADT, plus abiraterone. Participants will start ADT first. Androgen deprivation therapy will be delivered via injection every 4 months as per standard of care (for 8 months total). At the same time, or within 3 months of starting ADT, participants will begin radiation treatment. The radiation treatment course will consist of 2-5 sessions of radiation daily or every other day (the number of sessions will be determined by the physician depending on the location of cancer, number of cancer spots, etc.). In addition, participants will take abiraterone orally (by mouth) daily for 8-9 months. Participants will start the first pill within a month of enrollment. This pill can be taken around the same time of day with or without food.
Arm 3 - Study Treatment	Standard of Care SBRT and ADT	Participants in this group will receive standard of care radiation treatment and ADT, plus abiraterone. Participants will start ADT first. Androgen deprivation therapy will be delivered via injection every 4 months as per standard of care (for 8 months total). At the same time, or within 3 months of starting ADT, participants will begin radiation treatment. The radiation treatment course will consist of 2-5 sessions of radiation daily or every other day (the number of sessions will be determined by the physician depending on the location of cancer, number of cancer spots, etc.). In addition, participants will take abiraterone orally (by mouth) daily for 8-9 months. Participants will start the first pill within a month of enrollment. This pill can be taken around the same time of day with or without food.

Primary Outcome Measures

Name	Time	Method
Progression free survival	5 years	Determine if progression free survival improves with the addition of intermittent enzalutamide to standard of care treatment.

Secondary Outcome Measures

Name	Time	Method
Patient-reported quality of life	5 years	Determine if the addition of intermittent enzalutamide to standard of care treatment results in a patient-reported quality of life difference compared to standard of care treatment alone using quality of life questionnaires (FACT-Fatigue).
Physician-reported toxicity	5 years	Determine if the addition of intermittent enzalutamide to standard of care treatment results in a physician-reported difference in acute and late toxicities compared to standard of care treatment alone assessed by CTCAE Toxicity 5.0.

Trial Locations

Locations (2)

Princess Margaret Cancer Center; 🇨🇦 Toronto, Ontario, Canada

Sunnybrook Research Institute; 🇨🇦 Toronto, Ontartio, Canada