Joaquin Mateo, MD, PhD

FORMAL DISCUSSANT Joaquin Mateo, MD, PhD, of the Prostate Cancer Translational Research Group, Vall d’Hebron Institute of Oncology, Barcelona, said that the TRITON2 findings were encouraging, although still preliminary. “We should interpret these results with caution, because this interim analysis was not preplanned, and the trial is expected to recruit over 150 patients,” he said.

The percentage of men with prostate cancer harboring BRCA1/2 mutations is estimated at about 12%. Because prostate cancer is so common, that group represents “a lot of patients who may benefit from a different therapeutic approach,” Dr. Mateo noted.

He said that the confirmed radiographic and PSA responses observed thus far with rucaparib (Rubraca) in a biomarker-defined population is in the range of what was described in the trials that led to registration of abiraterone (Yonsa, Zytiga), and enzalutamide (Xtandi) a few years ago. Hence, this is a promising drug for some prostate cancer patients.

“If phase III trials confirm the data, we might have poly (ADP-ribose) polymerase inhibitors coming soon into the prostate cancer clinic for patients with mutations in BRCA1/2,” he stated. ■

DISCLOSURE: Dr. Mateo is on the advisory boards of AstraZeneca and Janssen and is a speaker (with travel support to conference) for AstraZeneca, Astellas, Ipsen, and Sanofi.