HIGHLY RECOMMENDED: The Prostate Cancer Foundation (PCF) recently published (November 2017) an electronic patient guide which can be downloaded to your computer or obtained as a hard copy. Main topics include: 1) You and Prostate Cancer – General Information -Medical Basics; 2) For the Newly Diagnosed; 3) Treatment Options for Localized or Locally Advanced Prostate Cancer; 4) Living With and After Prostate Cancer; 5) What to Do if Your PSA Starts to Rise; 6) Cutting Edge Developments in Prostate Cancer Research; and, 7) For Our Sons and Daughters (genetics). One can receive the guide from the PCF electronically or by mail.
Adding Xtandi® (enzalutamide) to hormone therapy reduces the risk of cancer spreading in patients with non-metastatic, hormone-resistant prostate cancer (CRPC), new Phase 3 trial data shows. Additional results were announced by Pfizer and Astellas Pharma, the drug developers. “Many prostate cancer patients who initiate hormone therapy will experience disease progression illustrated by a rising PSA level, and currently, there are no FDA-approved treatment options for patients with non-metastatic CRPC until they develop confirmed radiographic metastatic disease,” according to Dr. Neal Shore, MD, director, Carolina Urologic Research Center.
Pfizer and Astellas initiated the multinational PROSPER trial to determine the effects of Xtandi® in men with non-metastatic CRPC. The trial enrolled approximately 1,400 patients with prostate cancer that had progressed, based on rising PSA levels, despite androgen deprivation (hormone) therapy (ADT) but with no symptoms or other evidence of metastasis. Participants were randomly assigned Xtandi® plus hormone therapy or a placebo plus hormone therapy. The study’s primary endpoint was metastasis-free survival, which is the amount of time passed until the cancer spread.
Results seen in the PROSPER study showed that Xtandi® plus ADT delayed clinically detectable metastases compared to ADT alone in patients with non-metastatic CRPC whose only sign of underlying disease was a rapidly rising prostate-specific antigen (PSA) level. Xtandi® is already established as a standard of care for men with metastatic CRPC based on the results of prior studies, such as AFFIRM and PREVAIL, which demonstrated that Xtandi® delayed disease progression and improved overall survival in men with clinically detectable metastatic disease. For additional information, see the following link.
It seems that Xtandi® (enzalutamide) and ARN-509 (apalutamide) share similar biological properties and mechanisms of action. Perhaps there differences in pharmacologic properties due to their differing chemical structures but they seem similar. (See the Nov. 10th post for comparison.)
Janssen-Biotech has submitted a new drug application to the Food and Drug Administration (FDA) for apalutamide (ARN-509) to treat non-metastatic hormone-resistant prostate cancer. Apalutamide is an oral androgen receptor inhibitor that blocks the action of testosterone in prostate cancer cells. (Whether ARN-509 differs in its mechanism of action from enzalutamide [Xtandi] is not known to this website at this point.) The drug had been tested in the Phase 3 SPARTAN clinical trial in men with non-metastatic hormone-resistant cancer who have a rapidly rising prostate specific antigen (PSA), despite receiving continuous androgen deprivation (hormone) therapy (ADT). The primary objective of the trial was to assess metastasis-free survival, or the time from randomization to first evidence of confirmed metastasis (the spread of cancer cells to another part of the body). Janssen revealed that patients receiving ADT plus apalutamide lived significantly longer without metastasis, compared to those receiving ADT plus a placebo. But the company did not disclose any further details. The hope is to treat men with prostate cancer earlier in the disease course before the cancer has metastasized.
Studies have estimated that between 10 and 20 percent of patients diagnosed with prostate cancer might develop the hormone-resistant form within about five years. Moreover, metastatic hormone-resistant prostate cancer is associated with deterioration in quality of life and few therapeutic options. For details about the FDA approval process, see the following link.