Rubraca Approved for Metastatic Castration-Resistant Prostate Cancer With BRCA Mutations

The Food and Drug Administration has granted accelerated approval to Rubraca® (rucaparib; Clovis Oncology) for the treatment of adult patients with a deleterious BRCA mutation (germline and/or somatic)-associated metastatic castration-resistant prostate cancer (mCRPC) who have been treated with androgen receptor-directed therapy and a taxane-based chemotherapy.

The approval was based on data from the ongoing multicenter, single-arm phase 2 TRITON2 study that assessed the efficacy of rucaparib in 115 adults with BRCA-mutated (germline and/or somatic) mCRPC who had been treated with androgen receptor-directed therapy and taxane-based chemotherapy, of whom 62 patients had measurable disease. Patients received rucaparib 600mg orally twice daily until disease progression or unacceptable toxicity; they also received concomitant gonadotropin-releasing hormone analog or had prior bilateral orchiectomy.

The major efficacy end points were objective response rate (ORR) and duration of response (DoR) according to modified RECIST v1.1/Prostate Cancer Working Group 3 criteria assessed by blinded independent radiologic review.

Findings showed that among the 62 patients with measurable disease, the ORR was 44% (95% CI, 31-57). At data cut-off, the median DoR was not evaluable; however, 56% (n=15/27) of patients with a confirmed objective response had a DoR of ≥6 months. The range for the DoR was 1.7-24+ months. Additionally, an analysis of all 115 patients demonstrated a confirmed prostate specific antigen (PSA) response rate of 55% (95% CI, 45-64).

Regarding safety, the most common adverse reactions (≥20%) among all 115 patients were fatigue, nausea, anemia, increased ALT/AST, decreased appetite, rash, constipation, thrombocytopenia, vomiting, and diarrhea.

Rubraca, a poly (ADP-ribose) polymerase (PARP) inhibitor, is currently approved for the maintenance treatment of recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer in adults with complete or partial response to platinum-based chemotherapy. It is also indicated for the treatment of deleterious BRCA mutation (germline and/or somatic)-associated epithelial ovarian, fallopian tube, or primary peritoneal cancer in adults who have been treated with ≥2 chemotherapies (based on an FDA-approved companion diagnostic test).

Continued approval for Rubraca in the treatment of prostate cancer may be contingent upon verification of clinical benefit in confirmatory trials. According to Clovis Oncology, the TRITON3 study is expected to serve as the confirmatory trial.

Rubraca is supplied as 200mg, 250mg, and 300mg strength tablets in 60-count bottles.

For more information visit clovisoncology.com.

This article originally appeared on MPR