Rucaparib has leapfrogged over olaparib to become the first PARP inhibitor approved for prostate cancer patients with either a germline (inherited) or somatic (tumor) BRCA1/2 mutation after analysis of the TRITON2, Phase 2 clinical trial for metastatic castrate resistant (mCRPC) patients who were previously treated with Androgen Receptor-Directed Therapy and a Taxane-Based Chemotherapy (docetaxel or cabazitaxel). Continued FDA-approval will be dependent upon successful completion of the ongoing Phase 3 TRITON3 clinical trial. This is an unusual development since most drugs are not approved until completion of Phase 3 data.
Rubraca’s accelerated approval was based on an overall response rate of 44% and duration of response exceeding 6 months, but not yet evaluable because the endpoint had not yet been met.
Adverse Effects
The most common adverse reactions (greater than or equal to 20% of patients Grade 1-4) occurring in the BRCA mutant population (n=115) were asthenia/fatigue, nausea, anemia, ALT/AST increased, decreased appetite, constipation, rash, thrombocytopenia, vomiting, and diarrhea. The most common laboratory abnormalities (greater than or equal to 35% of patients Grade 1-4) were increase in ALT, decrease in leukocytes, decrease in phosphate, decrease in absolute neutrophil count, decrease in hemoglobin, increase in alkaline phosphatase, increase in creatinine, increase in triglycerides, decrease in lymphocytes, decrease in platelets, and decrease in sodium.
The full BusinessWire press release can be found here: https://www.businesswire.com/news/home/20200515005527/en/Rubraca%C2%AE-Rucaparib-Approved-U.S.-Monotherapy-Treatment-Patients