Precision Medicine in Metastatic Prostate Cancer: FDA Approves PARP Inhibitors for Men with Genetic Mutations
In May, the U.S. Food and Drug Administration (FDA) approved two PARP inhibitors for men with certain genetic mutations and metastatic castration-resistant prostate cancer (mCRPC).
The two drugs are olaparib (brand name Lynparza) and rucaparib (brand name Rubraca). Both of these PARP inhibitors have been the focus of scientific research in recent years and the approvals are advancements in precision medicine treatments for prostate cancer.
Lynparza is approved for men with HRR genetic-mutated mCRPC who were previously treated with enzalutamide or abiraterone, but their disease still progressed. The Phase III PROfound trial found that olaparib reduced the risk of disease progression or death by 51%. For a subset of men with BRCA or ATM gene mutations, the results were even better, with a 66% reduced risk of disease progression or death.
Rucaparib is approved for men with BRCA-mutated mCRPC who were previously treated for androgen- deprivation therapy and chemotherapy, but still had disease progression. The drug’s efficacy was investigated in the clinical trial TRITON2. The study found that an objective response rate of 44% with rucaparib, indicating the tumor size shrank.
The availability of these treatments for men with certain types of genetic mutations are further support for continued investigations into the genetic and genomic links to prostate cancer.
PARP inhibitor stands for poly (ADP-ribose) polymerase inhibitor. These drugs are used to treat adults with certain types of cancers. They work by blocking an enzyme that is involved in many cell functions, including repair of DNA damage. Blocking this enzyme may kill cancer cells by blocking their ability to repair damaged DNA.