Adding Erleada (apalutamide) to androgen deprivation therapy (ADT) significantly extends the lives of men with non-metastatic castration-resistant prostate cancer (CRPC) by more than one year, a final analysis of the SPARTAN Phase 3 clinical trial shows.
Representing a 22% reduction in the risk of death in men at high risk of developing metastasis, the findings add up to positive results across all other SPARTAN’s primary, secondary, and exploratory goals. That includes a significant extension by more than two years in the time lived without metastasis — a result that granted Erleada its approval in the the U.S. and European Union for this patient population.
“Treatment for patients with non-metastatic castration-resistant prostate cancer is primarily focused on delay of metastases and improvement of overall survival,” Eric Small, MD, lead SPARTAN investigator, said in a press release.
“The final analysis of SPARTAN includes long-term data for each of these treatment parameters and helps to support the earlier use of apalutamide [Erleada] versus ADT alone,” added Small, who also is chief scientific officer at the Helen Diller Family Comprehensive Cancer Center at the University of California, San Francisco.
Results will be presented at the American Society of Clinical Oncology (ASCO) Virtual Scientific Programme, which starts May 29, in the poster, “Final survival results from SPARTAN, a phase III study of apalutamide (APA) versus placebo (PBO) in patients (pts) with nonmetastatic castration-resistant prostate cancer (nmCRPC).”
Erleada, developed by Janssen, is a form of hormone therapy that blocks the androgen receptor, preventing male hormones, or androgens, from sending chemical signals that stimulate cancer growth. ADT, a standard prostate cancer treatment, also is a hormone therapy, but works by lowering the amount of androgens in the body.
The SPARTAN trial (NCT01946204) included 1,207 patients with non-metastatic CRPC whose prostate-specific antigen (PSA) levels were rising rapidly despite ADT treatment. In the trial, participants kept receiving ADT and were assigned randomly to either Erleada (806 patients) or a placebo (401 patients), both taken once-daily by mouth.
In a prior analysis, results showed that men receiving Erleada lived more than two years without metastasis than those on a placebo — 40.5 months versus 16.2 months – representing a 72% reduction in the risk of cancer spreading or death, the trial’s main goal.
Erleada also extended the time a patient lived without disease worsening, the time to symptomatic progression, and the time to metastasis, all without affecting quality of life.
At that time, survival results were not mature enough to assess Erleada’s superiority, but a later analysis demonstrated that more patients on Erleada were alive at the four-year mark (72%) compared to those on ADT (65%).
Now, final results from SPARTAN collected after a median follow-up of 52 months (for four years) show that men receiving Erleada lived 14 more months than those on ADT, representing a 22% lower risk of death — despite the transition of 76 patients from the control group to the Erleada group after no evidence of disease progression.
After adjusting the placebo group for the crossover of these patients, Erleada demonstrated even greater benefits, extending survival from a median of 52.8 months (4.4 years) to 73.9 months (6.2 years), a difference of nearly 21 months.
“Our driving commitment to delay the onset of metastases and add years to life for prostate cancer patients has taken a significant step forward with today’s data,” said Joaquín Casariego, MD, Janssen’s therapeutic area lead for oncology in Europe, Middle East and Africa, Janssen-Cilag.
“The SPARTAN trial has successfully demonstrated that apalutamide [Erleada] improved overall survival by an average of 14 months, reinforcing the need to treat earlier in prostate cancer for the benefit of patients and their families,” Casariego added. “At Janssen, our vision is to pioneer new approaches to treating cancer by thinking differently about diagnosis and looking towards intercepting the disease before it can even take a hold.”
Also, the recent findings demonstrated that add-on Erleada significantly delayed the need for chemotherapy, and that men on Erleada remained on treatment for nearly three times as long as those on ADT only — 33 months vs. 12 months.
Erleada’s safety and tolerability were consistent with those reported in earlier trials. Serious treatment-related side effects of special interest included rash, fractures, falls, and heart disease. About 15.2% of patients on Erleada and 8.4% on ADT stopped treatment only due to adverse side effects. One patient died due to a heart attack possibly related to Erleada.