New findings released from SPARTAN
SAN FRANCISCO & RARITAN, N.J.—Just a matter of days ago, the American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU) in San Francisco and The New England Journal of Medicine became the avenues for the Janssen Pharmaceutical Companies of Johnson & Johnson to share new data about Erleada (apalutamide), Janssen’s investigational, next-generation oral androgen receptor (AR) inhibitor that blocks the androgen signaling pathway in prostate cancer cells. Erleada inhibits the growth of cancer cells in three ways: by preventing the binding of androgen to the AR; by stopping the AR from entering the cancer cells; and by preventing the AR from binding to the DNA of the cancer cell.
Data came from the Phase 3 SPARTAN clinical trial, which indicated that treatment with Erleada—compared to placebo—decreased risk of metastasis or death by 72 percent and improved median metastasis-free survival (MFS) by more than two years (difference of 24.3 months) in patients with non-metastatic castration-resistant prostate cancer (CRPC) whose prostate specific antigen (PSA) is rapidly rising. Non-metastatic CRPC refers to a disease stage when the cancer no longer responds to medical or surgical treatments that lower testosterone, but has not yet been discovered in other parts of the body using a total body bone scan or CT scan.
SPARTAN was a randomized, double-blind, placebo-controlled, multicenter study that enrolled 1,207 patients with non-metastatic CRPC. It was conducted at 332 sites in 26 countries in North America, Europe, Australia and at various locations in the Asia-Pacific region.
“While there have been advances in the treatment of prostate cancer over the years, metastatic castration-resistant prostate cancer is still a lethal disease. These compelling results are the first to show that metastases can be delayed in these patients,” said Dr. Eric Small, the chief of the Division of Hematology and Oncology at the University of California, San Francisco, who serves as lead investigator for SPARTAN. “These data suggest that apalutamide could potentially be a new standard of care for patients with non-metastatic castration-resistant prostate cancer.”
Erleada in combination with andogren-deprivation therapy (ADT) decreased the risk of metastasis or death by 72 percent compared to placebo in combination with ADT. The median MFS was 40.5 months for Erleada in combination with ADT, compared to 16.2 months for placebo in combination with ADT, prolonging MFS by more than two years. According to Janssen, MFS benefit was consistent across all subgroups of patients.
“Delaying the metastasis of prostate cancer is critical. Once the cancer starts to spread, the patient’s overall health, well-being and prognosis change drastically,” said Dr. Peter Lebowitz, global therapeutic area head of oncology at Janssen Research & Development LLC. “The Erleada data presented at ASCO GU demonstrate the important impact this medicine can have for patients with prostate cancer. Janssen is committed to addressing unmet needs for treatment across all stages of disease progression with novel combinations and novel therapeutics.”
Secondary endpoints were also promising, with statistically significant improvements in time to metastasis, with a median of 40.5 months in the Erleada arm compared to median of 16.6 months in the placebo arm, and progression-free survival (PFS), with a median of 40.5 months in the Erleada arm compared to median of 14.7 months in the placebo arm. Symptomatic progression also decreased with Erleada treatment, by 55 percent compared to placebo.
Furthermore, Erleada was associated with a 30-percent risk reduction of death compared to placebo in terms of overall survival—though it’s worth noting of this finding that the SPARTAN results thus far are from an early interim analysis. Also notable was a 94-percent risk reduction in time to PSA progression and a 51-percent risk reduction in second PFS.
Reportedly, patients were able to maintain overall health-related quality of life, and Janssen described the combination of Erleada and ADT as “tolerable.” The most common Grade 3/4 treatment-emergent adverse events for this treatment regimen vs. placebo and ADT were rash (5.2 percent vs. 0.3 percent), fall (1.7 percent vs. 0.8 percent) and fracture (2.7 percent vs. 0.8 percent). Treatment discontinuation due to adverse events were 11 percent in the Erleada arm compared to 7 percent in the placebo arm. Rates of serious adverse events were similar in both arms.