A Phase III Study of Rucaparib versus Physician's Choice of Therapy for Patients with Metastatic Castration-Resistant Prostate Cancer and Certain Genetic Mutations


Full Title

TRITON3: A Multicenter, Randomized, Open-label Phase 3 Study of Rucaparib versus Physician’s Choice of Therapy for Patients with Metastatic Castration-resistant Prostate Cancer Associated with Homologous Recombination Deficiency (WIRB)


PARP is a protein that helps cells, including cancer cells, repair their DNA. Some cancer cells, especially those that have mutations in DNA repair genes like BRCA and ATM, may rely on the PARP protein to repair their DNA and survive. If the PARP protein is blocked, these cells may die.

BRCA and ATM mutations are known biomarkers for prostate cancer. Research has shown that prostate cancer patients with these mutations may benefit from treatment with a PARP inhibitor. Rucaparib is a PARP inhibitor used to treat ovarian cancer. In this study, researchers are comparing rucaparib with standard therapy in men with metastatic prostate cancer that has continued to grow despite hormonal therapy (“castration-resistant prostate cancer” or CRPC) and contains BRCA or ATM mutations.

Two-thirds of the patients in this study will be randomly assigned to receive rucaparib, and one-third will receive their physician’s choice of standard therapy (abiraterone acetate, enzalutamide, or docetaxel). Rucaparib is taken orally (by mouth).


To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have CRPC that persists despite prior treatment with an androgen receptor (AR)-targeted therapy, such as abiraterone acetate or enzalutamide.
  • Patients’ tumors must contain a BRCA1, BRCA2, or ATM mutation.
  • At least 2 weeks must pass between the completion of prior therapies and entry into the study (1 week since the last dose of hormonal therapy). Prior PARP inhibitor treatment is not permitted.
  • Patients must be physically well enough that they are fully ambulatory, capable of all self care, and are capable of all but physically strenuous activities. As an example, patients must be well enough that they would be able to carry out office work or light housework.
  • This study is for men age 18 and older.

For more information about this study and to inquire about eligibility, please contact Dr. Wassim Abida at 646-422-4633.