Phase II Randomised Controlled Trial of Patient-specific Adaptive vs. Continuous Abiraterone or eNZalutamide in mCRPC

Summary

Hormone tablets, abiraterone (Zytiga®) and enzalutamide (Xtandi®) are approved to treat advanced prostate cancer. However, even if these drugs are helpful, their effectiveness usually diminishes over time. Small pilot studies have indicated that using hormone tablets sparingly, for just long enough to control the cancer, followed by a break in treatment and restarting them later, seems to improve how long hormone tablets can control the cancer. This study aims to find out if this pause/restart strategy is better than taking hormone tablets every day continuously. The study will include 168 people with metastatic castrate resistant prostate cancer in the Netherlands and Australia. Patients will be randomly 1:1 assigned between the control group and the experimental group. In the control group, patients will take the treatment with AA/ENZ every day until the prostate cancer doesn't respond anymore to the treatment. In the experimental group, patients will start with daily AA/ENZ until the PSA has declined for \>50%. The treatment will then be paused and monthly PSA measurements will be performed. The treatment will be re-initiated when the PSA has increased to the level of before starting treatment. The treatment will be continued daily until the PSA has again dropped for \>50%. This pause/restart cycle will be repeated until the prostate cancer doesn't respond anymore to the treatment.

Conditions

• Prostatic Neoplasms, Castration-Resistant

Interventions

OTHER

Patient-specific adaptive therapy

Patients will start taking abiraterone or enzalutamide (AA/ENZ) daily. PSA will be measured every month as well as radiological evaluation by CT-scan and bone scan. Treatment will be continued until PSA has dropped \>50%. The treatment will then be paused. Once the PSA has risen again above the pretreatment baseline, treatment will be re-initiated. AA/ENZ will be stopped again after the PSA declines \>50% from the baseline. This will be continued until criteria for treatment failure are met (death by any cause or at least 2 out of 3 of the following events while on treatment: radiographic progression on CT-scan and/or bone scan, PSA progression or clinical progression).

DRUG

Abiraterone acetate

Use of abiraterone or enzalutamide

DRUG

Enzalutamide

Use of abiraterone or enzalutamide

Sponsors & Collaborators

• Australian and New Zealand Urogenital and Prostate Cancer Trials Group

  collaborator OTHER

• Anticancer Fund, Belgium

  collaborator OTHER

• Leiden University Medical Center

  lead OTHER

Principal Investigators

• Tom van der Hulle, MD · Leiden University Medical Center

• A/Prof. Craig Gedye, MBChB,FRACP · Australian and New Zealand Urogenital and Prostate Cancer Trials Group

• Dr. Laurence Krieger, MBChB,FRACP · Australian and New Zealand Urogenital and Prostate Cancer Trials Group

• Dr. Amy Rieborn · Leiden University Medical Center

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

MALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-11-10

Primary Completion

2027-11-10

Completion

2027-11-10

Countries

• Australia
• Netherlands

Study Locations