FDA Approves Xtandi to Treat Metastatic Castration-Sensitive Prostate Cancer

The Food and Drug Administration approved Xtandi (enzalutamide) for the treatment of patients with metastatic castration-sensitive prostate cancer.

"Men with metastatic castration-sensitive prostate cancer face complex treatment decisions and it is critical for physicians and patients to have as much information as possible when deciding on all of the options available," Dr. Andrew Armstrong, professor of medicine, surgery, pharmacology and cancer biology, and director of research in the Duke Cancer Institute's Center for Prostate and Urologic Cancers, stated in a press release. Armstrong was the lead study author of the phase 3 ARCHES trial that the approval was based on.

"The research supporting the FDA approval and updated treatment guidelines provide physicians and patients with compelling evidence to consider enzalutamide as a treatment option for men with this disease,” he added.

The international, double-blind trial of 1,150 patients with histologically verified metastatic castration-sensitive prostate cancer across North America, Europe and the Asia-Pacific region evaluated the agent, compared with placebo, to determine radiographic progression-free survival (the length of time during and after the treatment that cancer does not progress or worsen).

Radiographic progression-free survival was not reached in the Xtandi plus androgen deprivation therapy (ADT) group, compared with 19.45 months with placebo and ADT, translating to a 61% reduction in the risk of radiographic progression or death.

Moreover, Xtandi was associated with a reduction in the risk of time to progression of prostate-specific antigen, also known as PSA (a protein made by the prostate gland, whose high levels can be a sign of prostate cancer), by 81% and the time to initiation of a new antineoplastic therapy by 72%, compared with placebo.

In the trial, the most common side effects that were reported more frequently in patients treated with Xtandi plus ADT, compared with placebo and ADT, included hot flashes (27% vs 22%, respectively), asthenic conditions (24% vs 20%), hypertension (8% vs 5.6%), fractures (6.5% vs 4.2%) and musculoskeletal pain (6.3% vs 4%).

"This approval in metastatic castration-sensitive prostate cancer means physicians can now offer Xtandi to men earlier in their advanced prostate cancer treatment journey,” Dr. Andrew Krivoshik, senior vice president and oncology therapeutic area head at Astellas, which co-develops Xtandi with Pfizer, said in the release.