Targeted therapies are currently a significant research focus for the treatment of prostate cancer, as well as other cancers.
For cancer treatment, targeted therapies use drugs that block the function of specific molecules within cells. Genetic alterations within these molecules are associated with the progression of cancer. The drugs interact with the molecules in order slow or stop the spread of the cancer cells.
This interaction is different from standard chemotherapy, which works by killing cells. Another difference from standard chemotherapy is that targeted therapy pinpoints certain kinds of cells, whereas chemotherapy affects both healthy and cancerous cells.
Drugs for targeted therapy in prostate cancer are in various stages of development. Last fall, the FDA granted a Breakthrough Therapy designation to Rubraca (rucaparib), a PARP inhibitor, for use in prostate cancer patients who have BRCA1 or BRCA2 genetic mutations and metastatic castration-resistant prostate cancer. The designation is meant to speed up the development and review of the drug. The new designation was based on the results of a Phase 2 study of men with advanced prostate cancer and BRCA1/2 genetic mutations.
Rubraca (rucaparib) is already approved for patients with recurrent ovarian cancer and BRCA genetic mutations. Another PARP inhibitor, olaparib, was recently approved by the U.S. FDA to treat breast cancer patients who have BRCA genetic mutations. BRCA genetic mutations are common in men with prostate cancer, which is why the drugs are being explored as potential treatment for men with the disease.
The field has potential to offer new personalized treatments for many prostate cancer patients in the future. For example, a new study completed genomic profiling of more than 3,400 prostate tumor samples and found that the majority of the tumors had genomic alterations that were being investigated as candidates for targeted therapies. Nearly 60% of the tumors had genomic alterations that could be the focus of targeted therapies in the future.
JCO Precis Oncol. 2019;3. doi: 10.1200/PO.18.00283. Epub 2019 May 10.