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Study of Niraparib, Abiraterone Acetate, and Prednisone for Patients with Gene-Mutated Metastatic Castration-Sensitive Prostate Cancer

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a type of prostate cancer known as metastatic castration-sensitive prostate cancer (mCSPC) that has specific genetic changes called homologous recombination repair (HRR) gene mutations. The study is testing a combination of medications to see if they can improve outcomes for patients with this type of cancer. The medications being tested include niraparib, abiraterone acetate, and prednisone. Niraparib is a medication that may help prevent cancer cells from repairing themselves, while abiraterone acetate and prednisone are used to manage prostate cancer by reducing the levels of male hormones that can promote cancer growth.

The purpose of the study is to determine if the combination of niraparib with abiraterone acetate and prednisone is more effective than using abiraterone acetate and prednisone alone. Participants in the study will be randomly assigned to receive either the combination of all three medications or just abiraterone acetate and prednisone. Some participants may receive a placebo instead of niraparib. The study will be conducted over a period of time, and participants will take the medications orally in the form of tablets or capsules. The study aims to observe the effects of these treatments on the progression of the cancer.

Throughout the study, participants will undergo regular monitoring, which may include imaging tests like computed tomography (CT) or magnetic resonance imaging (MRI) to track the cancer's response to the treatment. The study will help researchers understand if the new combination of medications can provide better outcomes for patients with HRR gene-mutated mCSPC. The study is expected to continue until 2027, with the goal of improving treatment options for this specific type of prostate cancer.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes verifying a diagnosis of prostate adenocarcinoma and the presence of specific gene mutations related to homologous recombination repair (HRR).

    Imaging tests such as CT, MRI, or a bone scan may be performed to document metastatic disease.

  2. Step 2

    Treatment initiation

    Participants begin treatment with abiraterone acetate and prednisone. Abiraterone acetate is administered orally in tablet form at a dosage of 250 mg.

    Prednisone is also taken orally in tablet form at a dosage of 5 mg.

  3. Step 3

    Combination therapy

    Participants are randomly assigned to receive either a combination of niraparib with abiraterone acetate and prednisone or a placebo with abiraterone acetate and prednisone.

    Niraparib is administered orally in capsule form at a dosage of 100 mg.

  4. Step 4

    Ongoing treatment

    The treatment continues with regular monitoring to assess the effectiveness and safety of the medication. This includes periodic imaging tests to evaluate disease progression.

    Participants are required to continue androgen deprivation therapy (ADT) throughout the treatment phase.

  5. Step 5

    End of study

    The study is estimated to conclude by May 7, 2027. At the end of the study, final assessments are conducted to determine the overall effectiveness of the treatment in improving radiographic progression-free survival (rPFS).

Who can join the trial?

5 criteria

  • Must have a confirmed diagnosis of prostate adenocarcinoma, which is a type of prostate cancer.
  • Must have a specific change in genes related to homologous recombination repair (HRR). This means there is a change in the genes that help fix DNA damage.
  • Must have cancer that has spread to other parts of the body, as shown by imaging tests like a CT scan (a detailed X-ray) or an MRI (a scan that uses magnets and radio waves). If the cancer has spread to the bones, it must be confirmed by a bone scan or other imaging tests. If the cancer is only in the lymph nodes, the patient cannot participate.
  • Must have started androgen deprivation therapy (ADT) at least 14 days before joining the study. ADT is a treatment that lowers male hormones to slow the growth of cancer. The patient must agree to continue this therapy during the study.
  • Only male participants are eligible for this study.

Who cannot join the trial?

4 criteria

  • Patients who do not have a mutation in the **HRR gene**. This gene is involved in repairing DNA, which is the genetic material in our cells.
  • Patients who do not have **metastatic castration-sensitive prostate cancer (mCSPC)**. This is a type of prostate cancer that has spread to other parts of the body but still responds to treatments that lower testosterone.
  • Patients who are female, as the study is only for male participants.
  • Patients who are considered part of a vulnerable population, which means they might need special protection or care.
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Investigated drugs

  • Niraparib

    is a medication used in this trial to see if it can help treat prostate cancer that has specific genetic mutations. It is being tested to find out if it can improve the condition of patients when used together with other medications.

  • Abiraterone Acetate

    is a medication that helps lower the levels of certain hormones in the body. It is used in this trial to see if it can help control prostate cancer when combined with other treatments.

  • Prednisone

    is a type of steroid that is used to reduce inflammation and help manage symptoms. In this trial, it is used alongside other medications to see if it can improve the treatment of prostate cancer.

What is already known about the treatment

  • Niraparib

    This medication is administered orally and is currently being studied in clinical trials for its effectiveness in treating metastatic castration-sensitive prostate cancer with specific genetic mutations. It is primarily indicated for patients with mutations in homologous recombination repair genes. Niraparib works by inhibiting an enzyme called PARP, which helps repair damaged DNA in cells. By blocking this enzyme, niraparib prevents cancer cells from repairing themselves, leading to their death. It is classified as a PARP inhibitor.

  • Abiraterone Acetate

    This medication is taken orally and is widely used in the treatment of prostate cancer. It is indicated for patients with metastatic castration-sensitive prostate cancer, often in combination with other medications like prednisone. Abiraterone works by blocking the production of androgens, which are hormones that can promote the growth of prostate cancer cells. It is classified as an androgen biosynthesis inhibitor.

  • Prednisone

    This medication is administered orally and is commonly used in combination with other cancer treatments. It is indicated for reducing inflammation and suppressing the immune system in various conditions, including prostate cancer. Prednisone works by mimicking the effects of cortisol, a natural hormone, to reduce inflammation and alter the immune response. It is classified as a corticosteroid.

Investigated diseases

Metastatic Castration-Sensitive Prostate Cancer (mCSPC) – This is a type of prostate cancer that has spread to other parts of the body but still responds to treatments that lower testosterone levels. It is characterized by the presence of cancer cells in distant organs or bones, beyond the prostate gland. The disease progresses as cancer cells continue to grow and spread, despite initial responses to hormone therapy. Over time, the cancer may become resistant to treatments that lower testosterone, leading to further progression. The presence of mutations in homologous recombination repair (HRR) genes can influence the behavior and progression of the disease.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-506365-64-00Protocol code67652000PCR3002Estimated enrolment698 patientsSponsorJanssen Cilag International

sourced from the EU Clinical Trials Register and site verification

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