Clovis Oncology Shows off Positive Rubraca Data at ESMO for Prostate Cancer
3D Illustration of Prostate Cancer Cells
Shares of Clovis Oncology are up more than 7 percent in premarket trading after the company announced positive results from a mid-stage clinical trial that showed patients treated with Rubraca achieved a 44 percent objective response rate in some patients with metastatic castration-resistant prostate cancer (mCRPC).
The latest data from the Phase II TRITON 2 trial will be presented at the European Society for Medical Oncology. The ORR was shown in 25 patients with a BRCA1/2 alteration. Clovis noted that the median duration of response has yet to be seen. In addition to the ORR, Clovis noted that a 51 percent confirmed prostate-specific antigen (PSA) response rate was observed in 45 PSA response-evaluable patients with a BRCA1/2 alteration.
Patients who participated in the TRITON 2 study had received prior treatment with at least one androgen receptor (AR)-directed therapy and taxane-based chemotherapy. They had also been screened for deleterious germline or somatic alteration in BRCA1, BRCA2 or one of 13 other pre-specified homologous recombination (HR) genes, Clovis said.
As a result from the data, the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy Designation for Rubraca as a monotherapy treatment in mCRPC patients who have the BRCA1/2 mutation and have received at least one prior androgen receptor (AR)-directed therapy and taxane-based chemotherapy.
According to the American Cancer Society, more than 164,000 men in the United States will be diagnosed with prostate cancer in 2018. Castration-resistant prostate cancer has a high likelihood of developing metastases. Metastatic castration-resistant prostate cancer, or mCRPC, is an incurable disease, usually associated with poor prognosis,” Clovis said. The five-year survival rate for mCRPC is approximately 29 percent. Approximately 12 percent of mCRPC patients have a deleterious mutation in BRCA1 or BRCA2, Clovis added.
Wassim Abida, an oncologist with Memorial Sloan Kettering who will present the data at ESMO, said the data from TRITON 2 indicates that Rubraca may provide a new treatment approach for mCRPC associated with BRCA1 and BRCA2 alterations.
Rubraca is an inhibitor of PARP1, PARP2 and PARP3 that has been approved for multiple indications in the United States, including the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic) associated epithelial ovarian, fallopian tube, or primary peritoneal cancer. The company is investigating its efficacy in other tumor types, including ovarian, metastatic castration-resistant prostate, and bladder cancers.
Patrick J. Mahaffy, president and chief executive officer of Clovis, said the company is encouraged by the TRITON 2 findings. He said the medicine shows the potential to treat men with advanced prostate cancer whose disease has progressed after receiving multiple prior lines of therapy.
PARP inhibitors are now a validated therapeutic class in oncology in multiple tumor types, and these new data underscore the benefit that Rubraca may provide for men with advanced, BRCA-mutant castration-resistant prostate cancer. Having recently received Breakthrough Therapy designation based on these data, we are committed to the rapid development of Rubraca for men with this very difficult-to-treat disease,” Mahaffy said in a statement.