Erleada (Apalutamide) Significantly Extends Overall Survival in nmCRPC Patients: Final SPARTAN Phase 3 Trial Results

Compiled by S.Li

Recently, Janssen Pharmaceuticals, a subsidiary of Johnson & Johnson, announced Erleada^®Final Analysis Results of the Key Phase 3 SPARTAN Clinical Trial (Apalutamide): In patients with non-metastatic castration-resistant prostate cancer (nmCRPC) at high risk of metastasis, Erleada combined with androgen deprivation therapy (ADT) significantly improved overall survival (OS) compared to ADT alone. Detailed results will be presented at the American Society of Clinical Oncology (ASCO) Annual Meeting at the end of the month.

Specifically, the median overall survival (OS) in the Erleada plus androgen deprivation therapy (ADT) group was 73.9 months, compared with 59.9 months in the control group, demonstrating a statistically significant prolongation of median OS (hazard ratio [HR]=0.78; p=0.0161) and a 22% reduction in the risk of death. After the study met its primary endpoint of metastasis-free survival (MFS), it was unblinded, and patients in the placebo arm were permitted to cross over to receive Erleada treatment.

Compared with the control group, the median duration of treatment in the Erleada plus ADT group was nearly three times longer (12 months in the control group vs. 33 months in the Erleada group). The statistical results for safety and tolerability in this trial were consistent with those from previous trials. Grade 3–4 treatment-emergent adverse events of special interest included rash (5.2%), fracture (4.9%), falls (2.7%), and ischemic heart disease (2.6%).

Eric Small, Professor of Medicine at the University of California, San Francisco, and Principal Investigator of the SPARTAN study, stated: “In the treatment of non-metastatic castration-resistant prostate cancer, the primary focus is on delaying metastasis and prolonging overall survival. The final analysis of the SPARTAN study includes long-term data for each treatment parameter, supporting the early addition of apalutamide to androgen deprivation therapy (ADT).”

SPARTAN (NCT01946204) is a randomized, double-blind, multicenter Phase 3 clinical study designed to evaluate Erleada in combination with androgen deprivation therapy (ADT) for the treatment of patients with non-metastatic castration-resistant prostate cancer (nmCRPC) exhibiting rapid PSA elevation (PSA doubling time ≤10 months). The study enrolled a total of 1,207 patients. The results were initially presented at the 2018 ASCO GU Symposium and published simultaneously in The New England Journal of Medicine. Updated trial results were presented at the 2019 ESMO Congress.

Based on the integrated analysis of the primary data, the SPARTAN study met all primary, secondary, and exploratory endpoints, including: the primary endpoint was metastasis-free survival (MFS); secondary endpoints were time to metastasis, progression-free survival (PFS), time to symptom progression, overall survival (OS), and time to initiation of cytotoxic chemotherapy; exploratory endpoints were second progression-free survival (PFS2), prostate-specific antigen (PSA) response, and risk of PSA progression.

Erleada is a next-generation androgen receptor (AR) inhibitor that helps block the activity of male hormones, such as testosterone, thereby delaying disease progression. In the United States, Erleada was first approved by the FDA in February 2018 for the treatment of adult patients with non-metastatic castration-resistant prostate cancer (nmCRPC) at high risk of metastasis, becoming the first drug globally approved for nmCRPC. In September 2019, based on the Phase III TITAN clinical study, the FDA approved Erleada for the treatment of metastatic hormone-sensitive prostate cancer (mCSPC). In China, Erleada (Ansenke^®) was approved for marketing in 2019 for the treatment of adult patients with nmCRPC at high risk of metastasis.

Reference Source: ERLEADA® (apalutamide) Significantly Improved Overall Survival in Patients with Non-Metastatic Castration-Resistant Prostate Cancer