Prostate cancer study includes a tumor test to personalize treatment

September 27, 2024

A phase III clinical trial for patients with prostate cancer is currently open at several Providence Cancer Institute sites. The study, known as PREDICT-RT, evaluates different treatment approaches for men with high-risk prostate cancer based on their Decipher genomic risk scores.

The Decipher test is used to help physicians understand how aggressive a patient’s prostate cancer might be. It analyzes the activity of 22 specific genes in a tumor sample to determine the likelihood that the cancer will spread or progress after initial treatment.

Decipher scores help put patients into different risk categories. The information can guide decisions on the best treatment approaches.

Study design

This clinical trial compares less intense hormone therapy and radiation therapy to standard hormone therapy and radiation therapy in treating patients with high-risk prostate cancer and low gene risk score. In addition, the trial compares more intense hormone therapy and radiation therapy to standard hormone therapy and radiation therapy in patients with high-risk prostate cancer and high gene risk score.

In one of the randomized study arms, the androgen deprivation therapy apalutamide is given with the standard treatment.

What is apalutamide and how does it work?

Apalutamide is an oral medication to treat prostate cancer. As a type of androgen deprivation therapy (ADT) it is used to reduce male hormones levels and inhibit prostate cancer cell growth.

In 2018, the Food and Drug Administration approved apalutamide for men with prostate cancer that has not spread and is resistant to standard hormone therapy. Currently, apalutamide is used to treat prostate cancer that has spread to other parts of the body and still responds to a medical or surgical treatment that lowers testosterone. It also is used to treat prostate cancer that has not spread to other parts of the body after other treatments or surgery did not work or stopped working.

In PREDICT-RT, researchers will evaluate whether adding apalutamide to standard hormone treatment can help prevent prostate cancer from spreading for a longer period of time, offering hope for better outcomes.

Two studies, four arms

There are two studies within PREDICT-RT, where patients are randomly assigned to one of four arms. Patients receive a combination of radiation therapy and ADT for varied amounts of time. Here’s what that means:

De-intensification study for patients with a Decipher score less than 0.85

ARM I: Patients receive radiation therapy (RT) over 2-11 weeks and ADT (consisting of either leuprolide, goserelin, triptorelin, degarelix, buserelin or histrelin and bicalutamide or flutamide) for 24 months (about 2 years) if the disease doesn’t progress or side effects are intolerable.
ARM II: Patients receive RT over 2-11 weeks and ADT (consisting of either leuprolide, goserelin, triptorelin, degarelix, buserelin or histrelin and bicalutamide or flutamide) for 12 months if the disease doesn’t progress or side effects are intolerable.

Intensification study for patients with a Decipher score more than 0.85 or node positive (cancer has spread to lymph nodes)

ARM III: Patients receive RT over 2-11 weeks (about two and a half months) and ADT (consisting of either leuprolide, goserelin, triptorelin, degarelix, buserelin or histrelin and bicalutamide or flutamide) for 24 months (about two years) if the disease doesn’t progress or side effects are intolerable.
ARM IV: Patients receive RT over 2-11 weeks and ADT (consisting of either leuprolide, goserelin, triptorelin, degarelix, buserelin or histrelin) for 24 months in the absence of disease progression or unacceptable toxicity. Patients in this arm also receive apalutamide orally once daily.

After completing the study treatment, patients will receive annual follow-ups.

Learn more about PREDICT-RT

Parallel Phase III Randomized Trials for High-Risk Prostate Cancer Evaluating De-Intensification for Lower Genomic Risk and Intensification of Concurrent Therapy for Higher Genomic Risk with Radiation

PREDICT-RT is open within the Pacific Cancer Research Consortium (PCRC), an NCI Community Oncology Research Program site. As part of the PCRC collective, Providence Cancer Institute is currently enrolling patients at the following sites: