GU Symposium 2021: Final ACIS Results on Apalutamide-Based Therapy for Metastatic Prostate Cancer
Posted: Thursday, February 18, 2021
Combination therapy utilizing apalutamide plus abiraterone acetate and prednisone led to a reduction in the risk of radiographic disease progression and death in patients with chemotherapy-naive, metastatic castration-resistant prostate cancer. Dana E. Rathkopf, MD, of the Memorial Sloan Kettering Cancer Center in New York, presented the final results of the ACIS study on behalf of her colleagues during the virtual edition of the 2021 Genitourinary (GU) Cancers Symposium (Abstract 9).
This phase III, double-blind study enrolled 982 patients with metastatic castration-resistant prostate cancer treated with ongoing androgen-deprivation therapy. These patients were on no other life-prolonging treatment since the time of their diagnosis. Patients were randomly assigned 1:1 to receive either 240 mg of daily oral apalutamide, 100 mg of daily oral abiraterone acetate, and 5 mg of daily oral prednisone or placebo plus abiraterone acetate and prednisone.
The median radiographic progression-free survival rate was lengthened by 6 months when apalutamide was added to abiraterone acetate and prednisone (22.6 months) compared with abiraterone acetate and prednisone alone (16.6 months, hazard ratio = 0.69). Additionally, this triplet therapy showed a significantly higher rate of reducing prostate-specific antigen (PSA) value by 50% or more. There was also a longer median overall survival when apalutamide was used, although it was not statistically significant. There was no statistically significant difference between the triplet and doublet arms in time to PSA progression, chronic opioid use, initiation of cytotoxic chemotherapy, and pain regression. No new safety concerns emerged during this study.
“Insights from the ACIS study regarding differences in benefit for specific patient subgroups treated with the combination warrant additional evaluation,” said Dr. Rathkopf in a press release.
Disclosure: For a full list of author disclosures, visit coi.asco.org.