Apalutamide has become the first FDA-approved treatment for non-metastatic, castration-resistant prostate cancer.
"This approval is the first to use the endpoint of metastasis-free survival, measuring the length of time that tumors did not spread to other parts of the body or that death occurred after starting treatment," said Richard Pazdur, MD, Director of the FDA's Oncology Center of Excellence and Acting Director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research. "In the trial supporting approval, apalutamide had a robust effect on this endpoint. This demonstrates the agency's commitment to using novel endpoints to expedite important therapies to the American public."
According to the NCI, prostate cancer is the second most common form of cancer in men in the U.S. The NCI estimates approximately 161,360 men were diagnosed with prostate cancer in 2017, and 26,730 were expected to die of the disease. Approximately 10-20 percent of prostate cancer cases are castration-resistant, and up to 16 percent of these patients show no evidence that the cancer has spread at the time of the castration-resistant diagnosis.
Apalutamide works by blocking the effect of androgens on the tumor. These androgens, such as testosterone, can promote tumor growth.
The safety and efficacy of apalutamide was based on a randomized clinical trial of 1,207 patients with non-metastatic, castration-resistant prostate cancer. Patients in the trial either received apalutamide or a placebo. All patients were also treated with hormone therapy, either with gonadotropin-releasing hormone analog therapy or with surgery to lower the amount of testosterone in their body (surgical castration). The median metastasis-free survival for patients taking apalutamide was 40.5 months compared to 16.2 months for patients taking a placebo.
"The SPARTAN trial results demonstrated impressive clinical benefits in patients with non-metastatic castration-resistant prostate cancer," said Matthew Smith, MD, PhD, Director of the Genitourinary Malignancies Program at Massachusetts General Hospital Cancer Center, Boston, and a co-principal investigator of the SPARTAN study. "As an oncologist and clinical investigator, I know how devastating it can be for patients and their families to hear that the cancer has spread. With this approval, doctors now have the chance to offer hope for delaying metastases in patients with castration-resistant prostate cancer."
"As the impact of prostate cancer continues to grow, we are reminded every day of the critical need for therapeutic options that offer patients with prostate cancer more time with their loved ones," noted Mark Scholz, MD, Executive Director of the Prostate Cancer Research Institute. "[This] approval is significant, as it means that patients with non-metastatic castration-resistant prostate cancer now have a treatment option that offers renewed hope."
Common side effects of apalutamide include fatigue, hypertension, rash, diarrhea, nausea, weight loss, arthralgia, falls, hot flush, decreased appetite, fractures, and peripheral edema. Severe side effects include falls, fractures, and seizures.
This application was granted Priority Review, under which the FDA's goal is to take action on an application within 6 months where the agency determines that the drug, if approved, would significantly improve the safety or effectiveness of treating, diagnosing, or preventing a serious condition.