Apalutamide is an oral drug in a class of medications called androgen receptor inhibitors. Androgens are male reproductive hormones that can fuel the growth of prostate cancer cells. Apalutamide works by blocking androgens from binding with androgen receptors in prostate cells. Without the androgens, it is harder for the cancer cells to grow.
The new FDA approval came after phase 3 results from the TITAN clinical trial, which were published in the New England Journal of Medicine and presented at the 2019 American Society of Clinical Oncology (ASCO) meeting this summer.
The trial compared results of adding apalutamide to androgen-deprivation therapy (ADT, or hormone therapy) in men with metastatic hormone-sensitive prostate cancer. The 1,052 men in the study were randomized to either a group that took apalutamide or a control group that did not. Men in both groups continued to be on ADT.
After two years of follow up, the researchers compared outcomes for men in the control group and men who took apalutamide. Men who took apalutamide had a 33% reduced risk of death and a 52% reduced risk of disease progression. Men in the apalutamide group also saw longer times before their PSA scores began to rise, they had to use chemotherapy to control the disease, or their pain progressed.
The rates of adverse events were about the same between the two groups, although rashes were more common in the apalutamide group. In October, the research team presented quality of life data from TITAN, as reported by patients in the study. The report, published in Lancet Oncology, included information on patient pain levels and fatigue. The team found that in these categories, patients experiences were comparable between the two groups in the study or favored apalutamide.
However, an accompanying editorial discussed the need for data on additional quality of life considerations that were not assessed as part of the TITAN study. These include changes in mood, insomnia, and cognitive effects.
Apalutamide is also sold under the brand name Erleada. The drug was previously approved by the FDA for the treatment of non-metastatic castrationresistant prostate cancer.
Metastatic hormone-sensitive prostate cancer has spread out of the prostate yet is still responding to ADT. The goal of treatment for this type of prostate cancer is to slow or stop the spread of the disease before it metastasizes further.
Non-metastatic castration-resistant prostate cancer has not yet spread out of the prostate, yet the cancer has developed resistance to ADT, and the disease is at high risk for metastasizing out of the prostate.