Clovis Oncology Inc. (NASDAQ: CLVS) shares dropped on Friday after the company announced initial data from its Phase 2 TRITON2 clinical trial of Rubraca at the ESMO 2018 Congress of the European Society for Medical Oncology.
According to the study, the data show a 44% confirmed objective response rate by investigator assessment. The median duration of response in these patients has not yet been reached. Additionally, a 51% confirmed prostate specific antigen (PSA) response rate was observed in 45 PSA response-evaluable patients with a BRCA1/2 alteration.
The TRITON2 results were the basis for Breakthrough Therapy designation for Rubraca, which was granted on October 2, 2018, by the U.S. Food and Drug Administration (FDA).
While most of these results were positive, there was a downside. The most common treatment-emergent adverse events of any in all patients regardless of causality included asthenia/fatigue (44.7), nausea (42.4%), anemia/decreased hemoglobin (22.4%) and constipation (28.2%). Five patients (5.9%) discontinued therapy due to a non-progression treatment-emergent adverse event. One patient died due to disease progression.
Dr. Wassim Abida, medical oncologist, Memorial Sloan Kettering Cancer Center, and principal investigator for the TRITON2 study, commented:
Rubraca has previously demonstrated antitumor activity in its approved indications for women with advanced ovarian cancer. These new data show that Rubraca may also offer a new approach for the treatment of mCRPC associated with BRCA1 and BRCA2 alterations, with the potential to achieve a clinical response in patients with few remaining therapy options.
Shares of Clovis were last seen down about 4% at $28.86 Friday morning, with a consensus analyst price target of $62.40 and a 52-week trading range of $26.21 to $79.60.