Janssen Biotech has announced that the US Food and Drug Administration (FDA) has granted Priority Review designation for the New Drug Application (NDA) for apalutamide, an investigational, next-generation oral androgen receptor (AR) inhibitor for the treatment of men with non-metastatic castration-resistant prostate cancer (CRPC). Currently, there are no FDA-approved treatments for patients with non-metastatic CRPC.

The FDA grants Priority Review designation to investigational therapies that, if approved, may offer significant improvements in the safety and effectiveness of the treatment, diagnosis or prevention of serious conditions when compared to standard applications. This designation means the FDA's goal is to take action on an application within six months of receipt, compared to 10 months for Standard Review. The FDA has assigned a Prescription Drug User Fee Act (PDUFA) target date of April 2018 to render a decision on the apalutamide application.

"The prognosis for men with prostate cancer is significantly worse once the cancer has spread to other parts of the body. Accordingly, men with non-metastatic castration-resistant prostate cancer need treatment options that can delay disease progression and improve long-term outcomes," said Craig Tendler, M.D., vice president, Late Development and Global Medical Affairs, Oncology, Janssen Research & Development, LLC. "We are encouraged by the FDA's recognition, via the priority review designation, of the potential for apalutamide to provide such an option for these men."

The NDA submission for apalutamide, which was completed on October 10, 2017, was based on phase 3 data from the pivotal ARN-509-003 (SPARTAN) clinical trial, which assessed the safety and efficacy of apalutamide versus placebo in men with non-metastatic CRPC who have a rapidly rising prostate specific antigen (PSA) despite receiving continuous androgen deprivation therapy (ADT). These men with a rapidly rising PSA are at high risk for developing metastatic disease. The primary endpoint of this study was metastasis-free survival (MFS). MFS is the time from randomization to first evidence of confirmed metastasis, or time to death. The SPARTAN study results have been accepted for oral presentation at the ASCO Genitourinary Cancers Symposium on Thursday, February 8, 2018, in San Francisco.

According to the American Cancer Society, prostate cancer is the most common cancer among American men, other than skin cancer.6 More than 161,000 men are estimated to be diagnosed with prostate cancer in 2017.

Non-metastatic castration-resistant prostate cancer refers to patients with CRPC who lack detectable distant metastatic disease. These individuals have a rising PSA, serum testosterone level below 50 ng/dL and bone scan and computed tomography (CT) scans that show no evidence of spread to bones or visceral organs. Men with rapidly rising PSA have a high unmet medical need, as these patients are at high risk for developing metastatic disease.

Patients with non-metastatic prostate cancer receiving ADT will eventually become resistant to ADT, developing CRPC. It is estimated 10 to 20 percent of patients diagnosed with prostate cancer may develop CRPC within approximately five years of follow-up.