ESMO 2018: Responses to Rucaparib in Men With HRR-Deficient Prostate Cancer
Posted: Tuesday, November 20, 2018
Results from the TRITON2 trial reported anticancer activity with the PARP inhibitor rucaparib in patients with metastatic castration-resistant prostate cancer and homologous recombination repair (HRR) gene alterations. According to the study, presented at the European Society for Medical Oncology (ESMO) 2018 Congress in Munich (Abstract 793PD), nearly half of the evaluable men with BRCA1 and BRCA2 alterations had a confirmed prostate-specific antigen (PSA) response to the treatment.
“[Rucaparib] has previously demonstrated antitumor activity in its approved indications for women with advanced ovarian cancer,” Wassim Abida, MD, PhD, of Memorial Sloan Kettering Cancer Center, New York, stated in a press release. “These new data show that [rucaparib] may also offer a new approach for the treatment of [metastatic castration-resistant prostate cancer] associated with BRCA1 and BRCA2 alterations….”
The phase II, multicenter study included 85 men with metastatic castration-resistant prostate cancer and deleterious alteration in BRCA1, BRCA2, or 1 of 13 other prespecified HRR genes. Patients showed disease progression on androgen-receptor–directed therapy and had received one prior taxane-based chemotherapy. In patients with BRCA1/2 alteration, the median duration of treatment was 4.4 months, and 80.8% remain on study.
Of the evaluable patients with a BRCA mutation, the overall response rate was 44% and the PSA response rate was 51%. As for toxicity, dose reductions in rucaparib were needed for about one-third (29.4%) of the 85 patients. Common treatment-emergent adverse events of any grade included fatigue, nausea, anemia, and constipation. Five patients discontinued therapy because of adverse events.
